LISPBUILDER-SDL - a cool library


 

As of 2008-12-05 00:00, this project has moved to http://code.google.com/p/lispbuilder/.


 

Abstract

LISPBUILDER-SDL comprises several of packages that allow game development using Common Lisp. LISPBUILDER-SDL provides a set of bindings and Lispy abstractions for SDL and other graphics, sound, physics, character animation and 3D libraries. LISPBUILDER-SDL core functionality includes window and event management, 2D graphics, 3D graphics using OpenGL and sound support. The goal for the LISPBUILDER-SDL project is to become a useful resource for the development of games in Lisp.

SDL provides the low-level 2D rendering support. LISPBUILDER-SDL adds 2D graphical effects such as rotation, rendering circles, polygons, squares, Bezier and Cuttmull-Rom curves as well as bitmap font support. Additional packages provide native C drawing functions, True Type font rendering, loading of multiple image formats, a sound mixer and networking support. The lispbuilder packages are meant to work together with each package providing a specific core set of functionality. For example, an image that is loaded by lispbuilder-sdl-image may be rotated using lispbuilder-sdl-gfx. Text may be rendered to a surface using lispbuilder-sdl-ttf and finally blitted to the display using lispbuilder-sdl.

The code comes with a MIT-style license so you can basically do with it whatever you want.

Download shortcut: http://www.balooga.com/lispbuilder/lispbuilder-sdl.tgz.


 

Simple Example

	Alien Technology
(sdl:with-init ()
  (sdl:window 320 240)
  (sdl:draw-surface (load-image "lisp.bmp"))
  (sdl:update-display)
    (sdl:with-events ()
      (:quit-event () t)
      (:video-expose-event (sdl:update-display))))

 

Contents

  1. LISPBUILDER-SDL
    1. Abstract
    2. Compatibility
    3. Dependencies
    4. Download
    5. Installation
    6. Usage
    7. Included Examples
    8. Support
    9. License
    10. Package Overview
      1. Package Exports
      2. Package Structure
    11. Introduction
      1. Initialisation
      2. Creation of the SDL Window
      3. Events and the Game Loop
      4. Primitives
        1. Rectangle
        2. Color
      5. Drawing
      6. Fonts
        1. Initialisation
        2. Rendering Text
      7. Surfaces
        1. Overview
        2. Creation
        3. Loading Images
        4. Positioning
        5. Drawing & Blitting
      8. The SDL Display
      9. The Cursor
      10. Simple Example
      11. Garbage Collection
    12. The LISPBUILDER-SDL dictionary
    13. Acknowledgements

     

    Compatibility

    The following table describes the status of LISPBUILDER-SDL on the major Common Lisp implementations:

    Lisp Implementation LISPBUILDER-SDL Status Comments
    Win32 Linux MacOS
    CLISP v2.38 Working Working Working
    Lispworks v4.4.6 Personal Working Working Working
    Allegro Express 8.0 Unknown Working Unknown
    OpenMCL NA NA Unknown
    SBCL Working Working Unknown
    CMUCL Not Working Not Working Not Working

     

    Dependencies


     

    Download

    Current Version: The latest stable version of LISPBUILDER-SDL, together with this documentation can be downloaded from http://www.balooga.com/lispbuilder/lispbuilder-sdl.tgz. The current version is 0.9.5.


     

    Installation

    See the LISPBUILDER documentation for installation instructions for Windows, Mac OS-X and Linux.
     

    Using LISPBUILDER-SDL

    Enter the following at the REPL to compile and load the LISPBUILDER-SDL package: 

    (asdf:operate 'asdf:load-op :lispbuilder-sdl)
    ASDF will take care of loading the CFFI and :LISPBUILDER-SDL dependencies. The SDL.dll library will also be loaded into the Lisp image at this time.


     

    Running the Included Examples

    Enter the following at the REPL to compile and load the examples included in the LISPBUILDER-SDL-EXAMPLES package:

    	      (asdf:operate 'asdf:load-op :lispbuilder-sdl-examples)

    Run the examples by entering any of the following at the REPL: 

    	  (SDL-EXAMPLES:BEZIER)
	  (SDL-EXAMPLES:BMP-SAMPLE)
	  (SDL-EXAMPLES:CIRCLE-1)
	  (SDL-EXAMPLES:CIRCLE-2)
	  (SDL-EXAMPLES:CIRCLE-3)
	  (SDL-EXAMPLES:CIRCLE-4)
	  (SDL-EXAMPLES:CIRCLE-5)
	  (SDL-EXAMPLES:DISTANCE-2D)
	  (SDL-EXAMPLES:FLOOD-FILL)
	  (SDL-EXAMPLES:INBUILT-FONTS)
	  (SDL-EXAMPLES:LINE-DRAWING)
	  (SDL-EXAMPLES:MANDELBROT)
	  (SDL-EXAMPLES:METABALLS)
	  (SDL-EXAMPLES:MOUSE-2D)
	  (SDL-EXAMPLES:MOUSE-PAINTER)
	  (SDL-EXAMPLES:PIXELS-1)
	  (SDL-EXAMPLES:PIXELS-2)
	  (SDL-EXAMPLES:PIXELS-3)
	  (SDL-EXAMPLES:PIXELS-4)
	  (SDL-EXAMPLES:POINTS-AND-LINES)
	  (SDL-EXAMPLES:RANDOM-RECTS)
	  (SDL-EXAMPLES:RANDOM-BOX-1)
	  (SDL-EXAMPLES:RANDOM-BOX-2)
	  (SDL-EXAMPLES:RANDOM-BOX-3)
	  (SDL-EXAMPLES:RANDOM-BOX-4)
	  (SDL-EXAMPLES:RECURSIVE-RECTS)
	  (SDL-EXAMPLES:SETUP-AND-DRAW)
	  (SDL-EXAMPLES:SIMPLE-FONT-DEMO)
	  (SDL-EXAMPLES:STROKE)
	  (SDL-EXAMPLES:VERTICES)
	  (SDL-EXAMPLES:WIDTH-HEIGHT)

     

    Documentation, Support & Mailing Lists

    Questions answered and help given on the lispbuilder discussion list. Documentation for LISPBUILDER-SDL and related packages is available on the LISPBUILDER project page on Sourceforge. For additional information, look at the Lisp Gardeners page, and Application Builder page on the ALU's (Association of Lisp Users) wiki.
     

    License

    LISPBUILDER-SDL is distributed under the MIT-style license.


     

    Package Overview

    Package Exports

    Functions and symbols exported from the LISPBUILDER-SDL package are accessible from the LISPBUILDER-SDL: prefix or the shorter form SDL: nickname.

    Package Structure

    The cffi/ directory contains the raw CFFI bindings. These bindings may be automatically generated by SWIG or created by hand. CFFI translation functions perform simple low-level conversions for example, converting Lisp strings to C strings and back (see cffi-translate.lisp). All functions in cffi/ accept and return foreign objects only.

    The base/ directory defines wrappers over the functions in cffi/ . The functions in base/ accept keyword arguments and accept NIL instead of CFFI:NULL-POINTER where appropriate. Generally functions in base/ accept and return foreign objects. base/ may perform some type checks (IS-VALID-PTR SURFACE) but this layer is meant to be lean. Someone who implements a graphics engine might use this layer instead of sdl/ if speed is a concern. There are no fancy drawing primitives in this layer.

    The sdl/ directory defines the abstractions over cffi/ and base/. Foreign objects are passed around sdl/ neatly wrapped in CLOS objects, using TRIVIAL-GARBAGE for automatic garbage collection (minimize foreign objects being left on the heap). There are no functions in sdl/ that accept or return foreign objects (with the exception of the functions that create the CLOS wrapper objects) Functions in sdl/ call down into cffi/ and base/ as appropriate. All LISPBUILDER-SDL symbols available in SDL: are exported from sdl/, with symbols imported into sdl/ from cffi/ and base/ as appropriate (e.g. WITH-EVENTS). All drawing primitives are defined in this layer; circles, rectangles, lines, triangles, with-bezier etc. Functions in sdl/ implement a lot of type checking.

    An example of the difference between base/ and sdl/ is WITH-RECTANGLE. The WITH-RECTANGLE macro in base/ creates and destroys a foreign SDL_Rect. The WITH-RECTANGLE macro in sdl/ will create and destroy a RECTANGLE object.


     

    Introduction

    Initialisation of SDL

    The SDL library and SDL subsystems must be initialized prior to use. This is handled automatically when using the macro WITH-INIT. WITH-INIT also uninitialises the SDL library upon exit. More detailed information on the LISPBUILDER-SDL initialisation process can be found in the documentation for WITH-INIT. 

    (WITH-INIT (SDL-INIT-VIDEO)
  ...)

    Creation of the SDL Window

    A window must be created to display any kind of output. A window of a specific pixel width and height is created using the function WINDOW. WINDOW takes additional keyword parameters to set the requested video mode, color bit depth, the window title and the icon title. More detailed information can be found in in the documentation for WINDOW. 

    (WITH-INIT (SDL-INIT-VIDEO)
  (WINDOW 320 240))

    Handling Events and the Game Loop

    LISPBUILDER-SDL provides the WITH-EVENTS macro that simplifies the game loop and handling SDL events. Event handlers are defined by specifying the event type a well as an optional list of fields specific to that event.

    More detailed information on all SDL events (Keyboard events, Joystick events, User events etc.) can be found in in the documentation for WITH-EVENTS.

    For example, to process the current x and y mouse position when the mouse is moved: 

    (:MOUSE-MOTION-EVENT (:X X-POS :Y Y-POS)
  ...)

    Or to process the x and y relative mouse positions when the mouse is moved: 

    (:MOUSE-MOTION-EVENT (:X-REL relative-x :Y-REL relative-y)
  ...)

    The only event that must be handled with WITH-EVENTS is the :QUIT-EVENT. If :QUIT-EVENT is ignored then it is impossible for the user to close the SDL Window or exit the game loop. 

    (WITH-EVENTS ()
  (:QUIT-EVENT () T)
  (:MOUSE-MOTION-EVENT (:X mouse-x :Y mouse-y)
    ...))

    In addition to handling events, WITH-EVENTS also manages the game loop. Introducing the :IDLE event. :IDLE, although not technically an actual event, is executed once per game loop after all events have been processed in the SDL event queue. :IDLE is where the user can place code that needs to be executed once per game loop and that is not 'event' driven. This code may involve updating world physics, updating the state of game objects and rendering sprites to the display. 

    (WITH-EVENTS ()
  (:QUIT-EVENT () T)
  (:MOUSE-MOTION-EVENT (:X mouse-x :Y mouse-y)
    ...)
  (:IDLE ()
    (UPDATE-DISPLAY)))

    WITH-EVENTS can also limit execution of the the game loop to a specific number of iterations a second using FRAME-RATE. This effectively limits the number of frames displayed per second. To set the frame rate to 60 frames per second, (SETF (SDL:FRAME-RATE) 60). To unlock the frame rate effectively running the game loop as fast as the CPU will allow set the FRAME-RATE to NIL, (SETF (SDL:FRAME-RATE) NIL)

    The SDL display surface needs to be updated once per game loop, as described in the section SDL Display. 

    (SETF (FRAME-RATE) 30)
(WITH-EVENTS ()
  ...)

    Primitives

    LISPBUILDER-SDL supports the SDL RECTANGLE and COLOR primitives. These are described below.

    Rectangle

    A new rectangle is created by the function RECTANGLE. The function RECTANGLE-FROM-EDGES will create a new rectangle from the specified top left and bottom right coordinates. The function RECTANGLE-FROM-MIDPOINT-* will create a new rectangle from midpoint.

    The macros WITH-RECTANGLE and WITH-RECTANGLEs will create a new rectangle and free this rectangle when it goes out of scope.

    The rectangle position and width and height can be inspected and modified using the following functions: X, Y, WIDTH and HEIGHT. X2 and Y2 will return the (+ x width) and (+ y height) of the rectangle respectively.

    Additional functions that operate on rectangles are as follows:

    The section Drawing describes how to render a rectangle to a surface.

    Color

    A new SDL color is created by COLOR, returning either a new RGB or RGBA color.

    RGB/A color componets can be manipulated using the functions R, G, B, A, SET-COLOR and SET-COLOR-*. Two colors may be compared using COLOR=.

    Functions that accept a color parameter will most likely bind color to *DEFAULT-COLOR* when unspecified. The macro WITH-COLOR will bind a color to *DEFAULT-COLOR* within the scope of this macro. When *DEFAULT-COLOR* is bound to a color, all subsequent drawing functions will use this implied color while it remains in scope.

    Additional functions that operate on colors are as follows:

    LISPBULDER-SDL contains several predefined colors; *BLACK*, *WHITE*, *RED*, *GREEN*, *BLUE*, *YELLOW*, *CYAN*, *MAGENTA*.

    Drawing

    LISPBUILDER-SDL provides low-level drawing support for several primitives. Most primitives can be drawn with or without alpha transparency. In addition, the filled primitives can be drawn with a single pixel outline (or stroke) that is a different color to the fill color.

    Drawing functions require a target surface and color. LISPBUILDER-SDL uses defaults for both target surface (*DEFAULT-SURFACE*) and color (*DEFAULT-COLOR*) unless these are otherwise specified by the user. The macros with-surface, and with-surfaces will bind a surface to *DEFAULT-SURFACE* within the scope these macros. For example, instead of specifying a target surface for each draw-* function a user may bind *DEFAULT-SURFACE* to a surface once and subsequent draw-* functions will use this implied surface while it remains in scope. 

    (DRAW-POINT (sdl:point :x x1 :y y1) :surface a-surface :color *white*)
(DRAW-POINT (sdl:point :x x2 :y y2) :surface a-surface :color *white*)	    
(DRAW-POINT (sdl:point :x x3 :y y3) :surface a-surface :color *white*)
(DRAW-POINT (sdl:point :x x4 :y y4) :surface a-surface :color *white*)

    Now, we use WITH-SURFACE to bind a surface to *DEFAULT-SURFACE*.

    (WITH-SURFACE (a-surface)
  (DRAW-POINT (sdl:point :x x1 :y y1) :color *white*)
  (DRAW-POINT (sdl:point :x x2 :y y2) :color *white*)
  (DRAW-POINT (sdl:point :x x3 :y y3) :color *white*)
  (DRAW-POINT (sdl:point :x x4 :y y4) :color *white*))

    We can use WITH-COLOR to bind *DEFAULT-COLOR* to *WHITE*: 

    (WITH-SURFACE (a-surface)
  (WITH-COLOR (*white*)
    (DRAW-POINT (sdl:point :x x1 :y y1))
    (DRAW-POINT (sdl:point :x x2 :y y2))
    (DRAW-POINT (sdl:point :x x3 :y y3))
    (DRAW-POINT (sdl:point :x x4 :y y4)))

    Finally, if the target surface is the display then *WITH-SURFACE* is not required as :SURFACE when NIL will be bound to *DEFAULT-DISPLAY* as a default. So the above code can be shortened as follows: 

    (WITH-COLOR (*white*)
  (DRAW-POINT (sdl:point :x x1 :y y1))
  (DRAW-POINT (sdl:point :x x2 :y y2))
  (DRAW-POINT (sdl:point :x x3 :y y3))
  (DRAW-POINT (sdl:point :x x4 :y y4)))

    Fonts

    LISPBUILDER-SDL contains several bitmap fonts of different sizes and faces (italics/bolded). See INITIALISE-FONT for the complete list of built-in fonts.

    Initialisation

    Fonts are initialised using INITIALISE-DEFAULT-FONT, or INITIALISE-FONT. The resouces allocated to a font are freed by FREE-FONT. A font must be initialised prior to use.

    LISPBUILDER-SDL provides the macros WITH-DEFAULT-FONT and WITH-FONT for the above functions that bind *DEFAULT-FONT* to font within the scope of the macro.

    Rendering Text

    LISPBUILDER-SDL supports the rendering of colored text over a transparent background (Solid rendering), and the rendering of colored text over a solid colored background (Shaded rendering). Text may be left, right or center justified. Text can be drawn directly to a target surface using DRAW-STRING-SOLID and DRAW-STRING-SHADED. Text can be rendered to a new surface of character height and string width using RENDER-STRING-SOLID and RENDER-STRING-SHADED. This new surface may be optionally cached in the font object. A cached surface font can be accessed using CACHED-SURFACE) and can be blitted to a target surface using DRAW-FONT.

    The font rendering functions accept a font object. This font parameter is bound to *DEFAULT-FONT* when unspecified. The function INITIALISE-DEFAULT-FONT and the macros WITH-FONT and WITH-DEFAULT-FONT will bind a font to *DEFAULT-FONT* within the scope of these macros. When *DEFAULT-FONT* is bound to a font, all subsequent font drawing or font rendering functions will use this implied font while it remains in scope.

    The following methods also apply to fonts; X, Y, WIDTH, HEIGHT, Returns the width of the cached [SURFACE](#surface) when `OBJ` is a [FONT](#font). 

    (WITH-COLOR (*WHITE*)
  (WITH-FONT (*FONT-8x8*)
    (DRAW-STRING-SOLID-* "Font is 8x8." 10 10)

    (WITH-FONT (*FONT-10x20*)
      (DRAW-STRING-SOLID-* "Font is 10x20." 10 20))

    (DRAW-STRING-SOLID-* "Font is 8x8 again." 10 40)))

    Surfaces

    Overview of Surfaces

    An SDL surface, SURFACE, represents an area of graphical memory that can be drawn or rendered to, for example the video framebuffer or an image that is loaded from disk.

    Creating Surfaces

    A surface is created:

    Functions that accept a surface parameter will most likely bind surface to *DEFAULT-SURFACE* when unspecified. The macros WITH-SURFACE and WITH-SURFACES will bind a surface to *DEFAULT-SURFACE* within the scope of these macro. When *DEFAULT-SURFACE* is bound to a surface, all subsequent drawing functions will use this implied surface while it remains in scope.

    A surface can be explicitely freed by calling FREE-SURFACE.

    Images

    BMP images are loaded from disk using LOAD-IMAGE. Support for additional image formats is provided in the LISPBUILDER-SDL-IMAGE package. A surface is saved to disk as a BMP image using SAVE-IMAGE. 

    (DRAW-SURFACE (LOAD-IMAGE "sdl.bmp") 
              :surface *default-display*)

    Positioning Surfaces

    A SURFACE stores its own position X/Y coordinates. These coordinates can be inspected and modified using the following functions: X, Y, WIDTH and HEIGHT.

    Additional functions and macros that manage surface coordinates are as follows:

    Drawing & Blitting Surfaces

    The functions BLIT-SURFACE and DRAW-SURFACE will blit or draw a source surface onto a destination surface using the position coordinates stored in the source surface. DRAW-SURFACE-AT will draw the source surface at a specified position.

    The composition rules that determine how the source surface is composed over the destination surface are described in the description of BLIT-SURFACE. FILL-SURFACE fill will the target surface with a single color. Drawing Primitives describes how *DEFAULT-SURFACE* is used when calling blitting operations.

    Use SET-COLOR-KEY, CLEAR-COLOR-KEY and SET-ALPHA to modify the key color and alpha transparency properties of a surface after the surface has been created.

    Set a clipping rectangle to limit the draw area on a destination surface. The clipping rectangle for a surface is manipulated using GET-CLIP-RECT and SET-CLIP-RECT. When this surface is the destination of a blit, only the area within the clip rectangle will be drawn into.

    Set a cell rectangle to limit the surface area on the source surface. The cell rectangle for a surface is manipulated using CLEAR-CELL and SET-CELL. When this surface is the source of a blit, only the areas within the cell rectangle will be used. The cell is useful when only a small area of the source surface needs to be blitted to the destination surface. For example a sequence of images composed into a single sprite sheet and only the current frame of animation is to be drawn to the display at any one time.

    Sprite Sheet

    Updating SDL Surfaces and the SDL Display

    The functions UPDATE-DISPLAY and UPDATE-SURFACE update the SDL display surface (or OpenGL context) and general SDL surfaces respectively.

    The SDL Display

    The SDL display surface must be updated at least once each game loop using the function UPDATE-DISPLAY. This function will call SDL-GL-SWAP-BUFFERS to update the OpenGL display, or SDL-FLIP to update the SDL surface depending on the current *OPENGL-CONTEXT*. The display can be filled with a background color using CLEAR-DISPLAY.

    The properties of an SDL surface can be queried using SURFACE-INFO. The properties of the SDL display and video hardware can be queried using VIDEO-INFO. The screen resolutions supported by a particular set of video flags can be retrieved using LIST-MODES. A pointer to the native SDL window can be retrieved using GET-NATIVE-WINDOW. The name of the video driver can be retrieved as a STRING using VIDEO-DRIVER-NAME.

    The Cursor

    The the current state of the cursor is returned using QUERY-CURSOR, and is set using SHOW-CURSOR.

    Simple Example

    Putting this all together, we can write short example showing a white rectangle that follows the users mouse movements within an SDL Window. Exit the example by closing the window or pressing the Esc key on the keyboard. 

    ;; Initialise SDL and the Video subsystem
(WITH-INIT (SDL-INIT-VIDEO) 
  (WINDOW 320 240)          ; Open a window, 320 x 240

  (SETF (FRAME-RATE) 30)    ; Lock the frame rate to 30 fps
  (WITH-EVENTS ()
    (:QUIT-EVENT () T)      ; Absolutely have to handle the :QUIT-EVENT

    (:KEY-DOWN-EVENT (:KEY key) (WHEN (KEY= key :SDL-KEY-ESCAPE) (PUSH-QUIT-EVENT)))

    (:MOUSE-MOTION-EVENT (:X mouse-x :Y mouse-y)
      (CLEAR-DISPLAY *black*)
      ;; Draw the box with center at the mouse x/y coordinates.
      (DRAW-BOX-* (- mouse-x (/ 50 2)) (- mouse-y (/ 50 2)) 50 50 :color *white*))

    (:IDLE ()
      (UPDATE-DISPLAY))))

    Object Lifecycles and Garbage Collection

    ...


     

    The LISPBUILDER-SDL dictionary


    [Special variable]
    *black*


    RGBCOLOR black.


    [Special variable]
    *blue*


    RGBCOLOR blue.


    [Special variable]
    *cyan*


    RGBCOLOR cyan.


    [Special variable]
    *default-color*


    Functions that accept the KEYword parameter COLOR will most likely bind to the symbol *DEFAULT-COLOR* by default if COLOR is not specified.

    A color is bound to *DEFAULT-COLOR* by the following macro: WITH-COLOR.

    Example 
    (DRAW-BOX A-BOX :SURFACE SDL:DEFAULT-DISPLAY* :COLOR SDL:*BLACK*)
(DRAW-BOX B-BOX :SURFACE SDL:DEFAULT-DISPLAY* :COLOR SDL:*BLACK*)
(DRAW-BOX C-BOX :SURFACE SDL:DEFAULT-DISPLAY* :COLOR SDL:*BLACK*)

    The above can be shortened by setting *DEFAULT-COLOR* to *BLACK*. 

    (WITH-SURFACE (DISP SDL:*DEFAULT-DISPLAY*)
  (WITH-COLOR (COL SDL:*BLACK*)
    (DRAW-BOX A-BOX)
    (DRAW-BOX B-BOX)
    (DRAW-BOX C-BOX)))


    [Special variable]
    *default-display*


    The symbol *DEFAULT-DISPLAY* is bound to the current display surface DISPLAY-SURFACE) by the function WINDOW).


    [Special variable]
    *default-font*


    Functions that accept the KEYword parameter FONT will most likely bind to the symbol *DEFAULT-FONT* by default if FONT is not specified.

    A font is bound to *DEFAULT-FONT* by the following; WITH-DEFAULT-FONT, WITH-FONT and INITIALISE-DEFAULT-FONT.

    Example 
    (draw-string-solid-* "draw string centered" 100 100
                      :justify :center :color sdl:*white* :font a-font)
(draw-string-solid-* "draw string left" 100 100
                      :justify :left :color sdl:*white* :font a-font)
(draw-string-solid-* "draw string right" 100 100
                      :justify :right :color sdl:*white* :font a-font)

    The above can be shortened by setting *DEFAULT-FONT* to a-font. 

    (WITH-DEFAULT-FONT (a-font)
  (WITH-COLOR (COL SDL:*WHITE*)
    (DRAW-STRING-SOLID-* "draw string centered" 100 100 :JUSTIFY :CENTER)
    (DRAW-STRING-SOLID-* "draw string left" 100 100 :JUSTIFY :LEFT)
    (DRAW-STRING-SOLID-* "draw string right" 100 100 :JUSTIFY :RIGHT)))


    [Special variable]
    *default-font-path*


    The path to any fonts used in teh LISPBUILDER-SDL packages.


    [Special variable]
    *default-position*



    [Special variable]
    *default-rectangle*



    [Special variable]
    *default-surface*


    Functions that accept the KEYword parameter :SURFACE will most likely bind to the symbol *DEFAULT-SURFACE* by default if SURFACE is not specified.

    A surface is bound to *DEFAULT-SURFACE* by the following macros: WITH-SURFACE, and WITH-SURFACES.

    Example 
    (DRAW-SURFACE SURF-1 :SURFACE SDL:*DEFAULT-DISPLAY*)
(DRAW-SURFACE SURF-2 :SURFACE SDL:*DEFAULT-DISPLAY*)
(DRAW-SURFACE SURF-2 :SURFACE SDL:*DEFAULT-DISPLAY*)

    The above can be shortened using by setting the *DEFAULT-SURFACE* to the display surface. 

    (WITH-SURFACE (DISP SDL:*DEFAULT-DISPLAY*)
  (DRAW-SURFACE SURF-1)
  (DRAW-SURFACE SURF-2)
  (DRAW-SURFACE SURF-2))


    [Special variable]
    *external-init-on-startup*


    The list of functions that are called from INIT-SDL.


    [Special variable]
    *external-quit-on-exit*


    The list of functions that are called from QUIT-SDL.


    [Special variable]
    *font-10x20*


    Contains the font data for an 10x20 bitmap font.

    Packages


    [Special variable]
    *font-5x7*


    Contains the font data for an 5x7 bitmap font.

    Packages


    [Special variable]
    *font-5x8*


    Contains the font data for an 5x8 bitmap font.

    Packages


    [Special variable]
    *font-6x10*


    Contains the font data for an 6x10 bitmap font.

    Packages


    [Special variable]
    *font-6x12*


    Contains the font data for an 6x12 bitmap font.

    Packages


    [Special variable]
    *font-6x13*


    Contains the font data for an 6x13 bitmap font.

    Packages


    [Special variable]
    *font-6x13b*


    Contains the font data for an 6x13 bitmap font.

    Packages


    [Special variable]
    *font-6x13o*


    Contains the font data for an 6x13 bitmap font.

    Packages


    [Special variable]
    *font-6x9*


    Contains the font data for an 6x9 bitmap font.

    Packages


    [Special variable]
    *font-7x13*


    Contains the font data for an 7x13 bitmap font.

    Packages


    [Special variable]
    *font-7x13b*


    Contains the font data for an 7x13 bitmap font.

    Packages


    [Special variable]
    *font-7x13o*


    Contains the font data for an 7x13 bitmap font.

    Packages


    [Special variable]
    *font-7x14*


    Contains the font data for an 7x14 bitmap font.

    Packages


    [Special variable]
    *font-7x14b*


    Contains the font data for an 7x14 bitmap font.

    Packages


    [Special variable]
    *font-8x13*


    Contains the font data for an 8x13 bitmap font.

    Packages


    [Special variable]
    *font-8x13b*


    Contains the font data for an 8x13 bitmap font.

    Packages


    [Special variable]
    *font-8x13o*


    Contains the font data for an 8x13 bitmap font.

    Packages


    [Special variable]
    *font-8x8*


    Contains the font data for an 8x8 bitmap font.

    Packages


    [Special variable]
    *font-9x15*


    Contains the font data for an 9x15 bitmap font.

    Packages


    [Special variable]
    *font-9x15b*


    Contains the font data for an 9x15 bitmap font.

    Packages


    [Special variable]
    *font-9x18*


    Contains the font data for an 9x18 bitmap font.

    Packages


    [Special variable]
    *font-9x18b*


    Contains the font data for an 9x18 bitmap font.

    Packages


    [Special variable]
    *green*


    RGBCOLOR green.


    [Special variable]
    *magenta*


    RGBCOLOR magenta.


    [Special variable]
    *opengl-context*


    The symbol *OPENGL-CONTEXT* is T when an OpenGL display context is created, and NIL otherwise. UPDATE-SURFACE will swap the OPENGL buffers when *OPENGL-CONTEXT* is T, and swap the SDL video buffers otherwise.


    [Special variable]
    *red*


    RGBCOLOR red.


    [Special variable]
    *sdl-initialized*



    [Special variable]
    *white*


    RGBCOLOR white.


    [Special variable]
    *yellow*


    RGBCOLOR yellow.


    [Generic accessor]
    a color => result
    (setf (a color) value)


    Returns the alpha color component of the object.


    [Macro]
    all-integers? &rest values => result


    Returns T if all values are INTEGERS.


    [Generic accessor]
    alpha surface => result
    (setf (alpha surface) value)



    [Specialized accessor]
    alpha (surface sdl-surface) => result
    (setf (alpha (surface sdl-surface)) value)



    [Generic accessor]
    alpha-enabled-p surface => result
    (setf (alpha-enabled-p surface) value)



    [Specialized accessor]
    alpha-enabled-p (surface sdl-surface) => result
    (setf (alpha-enabled-p (surface sdl-surface)) value)



    [Generic function]
    any-color-but-this color => result


    Returns a new color that is different to COLOR.


    [Function]
    average-fps => result


    Returns the average frame rate of the event loop calculated over a sliding window of 100 frames.


    [Generic accessor]
    b color => result
    (setf (b color) value)


    Returns the blue color component of the object.


    [Function]
    bit-depth &optional surface => result


    Returns the number of bytes per pixel, or bpp, of SURFACE.


    [Standard class]
    bitmap-font


    The BITMAP-FONT object manages the resources for a bitmap font. Prior to the first call to a RENDER-STRING* function, the cached SURFACE is NIL.

    The cached surface is created by a call to any of the RENDER-STRING* functions. Use DRAW-FONT, DRAW-FONT-AT or DRAW-FONT-AT-* to draw the cached surface.

    Free using FREE


    [Function]
    blit-surface source &optional surface => result


    Performs a fast blit of the SOURCE surface to the destination SURFACE. The area defined by the SOURCE cell is blitted to the area defined by the destination clipping rectangle. The blit function should not be called on a locked surface. The results of blitting operations vary greatly depending on whether a surface ALPHA channel is set on the source surface or not. The priorty of how color key and alpha attributes interact with surface blitting is as follows:

    An ALPHA channel has the following effect on blitting operations:

    Note: RGBA to RGBA blits (with ALPHA-ENABLED-P set) keep the alpha of the destination surface. This means that you cannot compose two arbitrary RGBA surfaces this way and get the result you would expect from "overlaying" them; the destination alpha will work as a mask.


    [Generic accessor]
    cached-surface sdl-font => result
    (setf (cached-surface sdl-font) value)



    [Specialized accessor]
    cached-surface (sdl-font sdl-font) => result
    (setf (cached-surface (sdl-font sdl-font)) value)



    [Macro]
    cast type value => result


    Coerces the value VALUE to the type TYPE.


    [Macro]
    cast-all-to-int &rest values => result


    Casts the values in REST to FIXNUMs.


    [Macro]
    cast-to-int value => result


    Casts the value VALUE to a FIXNUM.


    [Function]
    catmull-rom-spline val v0 v1 v2 v3 => result



    [Generic function]
    char-height bitmap-font => result



    [Method]
    char-height (bitmap-font bitmap-font) => result



    [Generic function]
    char-width bitmap-font => result



    [Method]
    char-width (bitmap-font bitmap-font) => result



    [Macro]
    check-types type &rest rest => result


    Performs CHECK-TYPE on items in rest.


    [Function]
    clear-cell &key surface index => result


    Sets the CELL at INDEX to the bounds of SURFACE.


    [Function]
    clear-clip-rect &optional surface => result


    Removes the clipping RECTANGLE.


    [Function]
    clear-color-key &key surface => result


    Disables the color key.


    [Function]
    clear-display color &key surface update => result


    Fills the display SURFACE using color COLOR. SURFACE is bound to *DEFAULT-DISPLAY* if unspecified. The display is updated when UPDATE is T.


    [Generic accessor]
    clip-rect surface => result
    (setf (clip-rect surface) value)



    [Specialized accessor]
    clip-rect (surface sdl-surface) => result
    (setf (clip-rect (surface sdl-surface)) value)



    [Standard class]
    color


    A color containing INTEGER Red, Green and Blue components. Free using FREE.


    [Function]
    color &key r g b a => result


    Returns a new RGBCOLOR from the specified Red, Green, and Blue components. Returns a new RGBACOLOR-A from the specified Red, Green, Blue, and Alpha components.


    [Generic function]
    color-* color => result


    Returns the RGB/A color components as a spread. COLOR-A returns (VALUES R G B A). COLOR returns (VALUES R G B)


    [Standard class]
    color-a


    An color containing INTEGER Red, Green, Blue and Alpha components. Free using FREE.


    [Generic accessor]
    color-key surface => result
    (setf (color-key surface) value)



    [Specialized accessor]
    color-key (surface sdl-surface) => result
    (setf (color-key (surface sdl-surface)) value)



    [Generic accessor]
    color-key-enabled-p surface => result
    (setf (color-key-enabled-p surface) value)



    [Specialized accessor]
    color-key-enabled-p (surface sdl-surface) => result
    (setf (color-key-enabled-p (surface sdl-surface)) value)



    [Generic function]
    color= color1 color2 => result


    Returns T if the RGB<->RGB or RGBA<->RGBA color components in COLOR1 and COLOR2 match. Returns NIL otherwise.


    [Function]
    convert-surface &key surface to-surface enable-alpha enable-color-key free inherit type => result


    Converts :SURFACE and returns a new surface matching the pixel format and color of :TO-SURFACE. Calls CONVERT-TO-DISPLAY-FORMAT if converting to the display format.

    Use :ENABLE-COLOR-KEY or :ENABLE-ALPHA to take advantage of hardware colorkey or alpha blit acceleration. Enabling these flags once a surface is created will not necessarily utilize available harware acceleration if the surface was not initally created in video memory.

    Will create the new surface in system menory when TYPE is :SW. Will attempt to create the new surface in video menory when TYPE is :HW, otherwise the surface is created in system memory if the combination of color key and alpha do not allow hardware acceleration.

    The new surface will inherit the pixel, alpha and color key components of the source, unless:INHERIT is NIL.

    Use :FREE to delete the source SURFACE.


    [Function]
    convert-to-display-format &key surface enable-alpha enable-color-key pixel-alpha free inherit => result


    Returns a new surface matching the pixel format and color of the video frame buffer (*display surface*), that is suitable for fast blitting. The new surface will inherit the pixel, alpha and color key components of the source, *unless* :INHERIT is NIL`.

    Use :ENABLE-COLOR-KEY or :ENABLE-ALPHA to take advantage of hardware colorkey or alpha blit acceleration. Enabling these flags once a surface is created will not necessarily utilize available harware acceleration if the surface was not initally created in video memory.

    Use :PIXEL-ALPHA to enable the pixel alpha component (alpha mask of 0xFF) for the new surface.

    Use :FREE to delete the source SURFACE.

    Differences between CONVERT-TO-DISPLAY-FORMAT, CONVERT-SURFACE, COPY-SURFACE, and CREATE-SURFACE;


    [Function]
    copy-channel-to-alpha destination source &key channel => result



    [Function]
    copy-point point => result


    Returns a copy of the point POINT.


    [Function]
    copy-surface &key cell cell-index surface color-key alpha pixel-alpha rle-accel type free inherit fill color-key-fill pixel-format => result


    Returns a copy of :SURFACE.

    Use :COLOR-KEY or :ALPHA to set the key color and surface alpha transparency. Hardware colorkey and alpha blit acceleration will be used if supported.

    Will create the new surface in system menory when TYPE is :SW. Will attempt to create the new surface in video menory when TYPE is :HW, otherwise the surface is created in system memory if the combination of color key and alpha do not allow hardware acceleration.

    The new surface will be filled with the old surface unless :FILL is NIL. The new surface will be filled with the color key of the old surface (if available) unless :COLOR-KEY-FILL is NIL.

    The new surface will inherit the pixel, alpha and color key components of the source, unless:INHERIT is NIL.

    Use :FREE to delete the source SURFACE.


    [Function]
    create-list-if-not var => result


    If VAR is not already a list, then returns (LIST VAR).


    [Function]
    create-path filename &optional path => result


    Creates a new path from FILENAME and PATH.


    [Function]
    create-rwops-from-file filename => result


    Creates and returns a new RWOPS object from the file at location FILENAME.


    [Function]
    create-surface width height &key bpp type color-key color-key-at pixel-alpha alpha rle-accel x y => result


    Creates and returns a new SURFACE with the dimensions WIDTH and HEIGHT.

    :COLOR-KEY sets the color key of the surface and enables color-keying.

    :ALPHA sets the surface alpha transparency and enables alpha blending. This allows a pixel color of RGB with the surface A.

    :PIXEL-ALPHA enables a pixel alpha component (alpha mask of 0xFF) on the new surface. This allows a pixel color of RGBA.

    :RLE-ACCEL enables RLE blit acceleration.

    :BPP is the pixel depth of the surface, and my be 8, 16, 24 or 32.

    :TYPE attempts to create the SURFACE in video memory when :HW, and in system memory when :SW

    :X and :Y are the positions of the SURFACE in screen coordinates.


    [Function]
    disable-key-repeat => result


    Disables keyboard repeat.


    [Standard class]
    display-surface


    The current display surface. Can be accessed using SDL:*DEFAULT-DISPLAY*.


    [Function]
    distance p1 p2 => result


    Returns the distance between the POINTs P1 and P2.


    [Function]
    distance-* x1 y1 x2 y2 => result


    Returns the distance between the coordinates X1, Y1 and X2, Y2.


    [Function]
    draw-bezier vertices &key clipping surface color segments style => result


    Draw a bezier curve of COLOR to SURFACE. The shape of the Bezier curve is defined by several control points. A control point is a vertex containing an X and Y coordinate pair.

    Parameters
    Example 
    (DRAW-BEZIER (LIST (SDL:POINT :X 60  :Y 40)
                     (SDL:POINT :X 160 :Y 10)
                     (SDL:POINT :X 170 :Y 150)
                     (SDL:POINT :X 60 :Y 150))
               :style :SOLID)
    Packages


    [Function]
    draw-box rect &key clipping surface color stroke-color alpha => result


    See DRAW-BOX-*.

    Parameters
    Packages


    [Function]
    draw-box-* x y w h &key clipping surface color stroke-color alpha => result


    Draws a filled rectangle of COLOR to SURFACE.

    Parameters
    Packages


    [Function]
    draw-circle p1 r &key surface color alpha aa => result


    See DRAW-CIRCLE-*.

    Parameters
    Packages


    [Function]
    draw-circle-* x0 y0 r &key surface color alpha aa => result


    Draws a circle circumference of COLOR to SURFACE. Use DRAW-FILLED-CIRCLE-* to draw a filled circle.

    Parameters
    Packages


    [Function]
    draw-curve vertices &key clipping surface color segments style => result


    Draw a Cattmul-Rom spline of COLOR to SURFACE. The shape of the curve is defined by waypoints. A waypoint is a vertex containing an X and Y coordinate pair.

    Parameters
    Example 
    (DRAW-CURVE (LIST (SDL:POINT :X 60  :Y 40)
    	  (SDL:POINT :X 160 :Y 10)
	  (SDL:POINT :X 170 :Y 150)
	  (SDL:POINT :X 60  :Y 150)))
    Packages


    [Function]
    draw-ellipse p1 rx ry &key surface color aa => result


    See DRAW-ELLIPSE-*.

    Parameters
    Packages


    [Function]
    draw-ellipse-* x y rx ry &key surface color aa => result


    Draws an ellipse circumference of COLOR to the SURFACE. Use DRAW-FILLED-ELLIPSE-* to draw a filled ellipse.

    Parameters
    Packages


    [Function]
    draw-filled-circle p1 r &key surface color stroke-color alpha => result


    See DRAW-FILLED-CIRCLE-*.

    Parameters
    Packages


    [Function]
    draw-filled-circle-* x0 y0 r &key surface color stroke-color alpha => result


    Draws a filled circle of COLOR to SURFACE.

    Parameters
    Packages


    [Function]
    draw-filled-ellipse p1 rx ry &key surface color => result


    See DRAW-FILLED-ELLIPSE-*.

    Parameters
    Packages


    [Function]
    draw-filled-ellipse-* x y rx ry &key surface color => result


    Draws a filled ellipse of COLOR to the SURFACE.

    Parameters
    Packages


    [Function]
    draw-filled-pie p1 rad start end &key surface color => result


    See DRAW-FILLED-PIE-*.

    Parameters
    Packages


    [Function]
    draw-filled-pie-* x y rad start end &key surface color => result


    Draws a filled pie of COLOR to the SURFACE

    Parameters
    Packages


    [Function]
    draw-filled-polygon vertices &key surface color => result


    Draw a filled polygon of COLOR to the SURFACE

    Parameters
    Packages


    [Function]
    draw-filled-trigon p1 p2 p3 &key surface color => result


    Draw a filled trigon of COLOR to the SURFACE

    Parameters
    Packages


    [Generic function]
    draw-font &key font surface => result


    Blit the cached SURFACE in font to the destination SURFACE. The cached surface is created during a previous call to any of the DRAW-STRING* functions.

    Packages


    [Generic function]
    draw-font-at position &key font surface => result


    See DRAW-FONT. The cached surface is rendered at POSITIONPOINT.

    Packages


    [Generic function]
    draw-font-at-* x y &key font surface => result


    See DRAW-FONT. The cached surface is rendered at poisition X and Y.

    Packages


    [Function]
    draw-hline x0 x1 y &key surface color clipping template => result


    Draw a horizontal line of COLOR from X0 to X1 through Y onto onto SURFACE.

    Parameters
    Packages


    [Function]
    draw-line p1 p2 &key surface color clipping aa => result


    See DRAW-LINE-*.

    Parameters
    Packages


    [Function]
    draw-line-* x0 y0 x1 y1 &key surface color clipping aa => result


    Draws a line of COLOR to SURFACE.

    Parameters
    Packages


    [Function]
    draw-pie p1 rad start end &key surface color => result


    See DRAW-PIE-*.

    Parameters
    Packages


    [Function]
    draw-pie-* x y rad start end &key surface color => result


    Draws a pie of COLOR to the SURFACE. Use DRAW-FILLED-PIE-* to draw a filled pie.

    Parameters
    Packages


    [Function]
    draw-pixel point &key clipping surface color => result


    See DRAW-PIXEL-*.

    Parameters
    Packages


    [Function]
    draw-pixel-* x y &key clipping surface color => result


    Draw a single pixel of COLOR to the SURFACE at the specified X and Y coordiates.

    Parameters
    Packages


    [Function]
    draw-polygon vertices &key surface color clipping aa => result


    Draw the circumference of a polygon of COLOR to SURFACE using the vertices in POINTS. Use DRAW-FILLED-POLYGON-* to draw a filled polygon.

    Parameters
    Packages


    [Function]
    draw-rectangle rect &key clipping surface color alpha => result


    See DRAW-RECTANGLE-*.

    Parameters
    Packages


    [Function]
    draw-rectangle-* x y w h &key clipping surface color alpha => result


    Draw a rectangle outline of COLOR to SURFACE.

    Parameters
    Packages


    [Function]
    draw-shape vertices &key clipping surface color style => result


    Draw a polygon of COLOR to SURFACE using VERTICES.

    Parameters
    Example 
    (DRAW-SHAPE (LIST (SDL:POINT :X 60  :Y 40)
	    (SDL:POINT :X 160 :Y 10)
	    (SDL:POINT :X 170 :Y 150)
	    (SDL:POINT :X 60  :Y 150)))
    Packages


    [Function]
    draw-string-shaded string p1 fg-color bg-color &key justify surface font => result


    See DRAW-STRING-SHADED-*.

    Parameters
    Packages


    [Function]
    draw-string-shaded-* string x y fg-color bg-color &key justify surface font => result


    Draw text STRING at location XY using font FONT with text color FG-COLOR and background color BG-COLOR onto surface SURFACE. The surface background is filled with BG-COLOR so the surface cannot be keyed over other surfaces.

    Returns
    Example 
    (DRAW-STRING-SHADED-* &quot;Hello World!&quot; 0 0 F-COLOR B-COLOR :SURFACE A-SURFACE)
    Packages


    [Function]
    draw-string-solid string p1 &key justify surface font color => result


    See DRAW-STRING-SOLID-*.

    Parameters
    Packages


    [Function]
    draw-string-solid-* string x y &key justify surface font color => result


    Draw text STRING at location XY using font FONT with color COLOR onto surface SURFACE. The text is keyed onto SURFACE.

    Parameters
    Returns
    Example 
    (DRAW-STRING-SOLID-* &quot;Hello World!&quot; 0 0 :SURFACE A-SURFACE :COLOR A-COLOR)
    Packages


    [Function]
    draw-surface src &key surface => result


    See BLIT-SURFACE


    [Function]
    draw-surface-at src point &key surface => result


    Draws the source surface to the destination surface at position POINT. See BLIT-SURFACE.


    [Function]
    draw-surface-at-* src x y &key surface => result


    Draws the source surface to the destination surface at position X and Y. See BLIT-SURFACE


    [Function]
    draw-trigon p1 p2 p3 &key surface color clipping aa => result


    Draw the outline of a trigon or triangle, of COLOR to SURFACE. Use DRAW-FILLED-TRIGON-* to draw a filled trigon.

    Parameters
    Packages


    [Function]
    draw-vline x y0 y1 &key surface color clipping template => result


    Draw a vertical line of COLOR from Y0 to Y1 through X onto SURFACE.

    Parameters
    Packages


    [Function]
    enable-alpha value &key surface => result


    Enable surface alpha blending for when T. Disable surface alpha blending when NIL. A SURFACE need not have a pixel alpha component (RGBA) to use surface alpha blending.


    [Function]
    enable-color-key value &key surface => result


    Enables color keying when T. Disable color keying when NIL


    [Function]
    enable-key-repeat delay interval => result


    Enables the keyboard repeat rate. DELAY specifies how long the key must be pressed before it begins repeating, it then repeats at the speed specified by INTERVAL. Both DELAY and INTERVAL are expressed in milliseconds. Setting DELAY or INTERVAL to NIL will set the default values of SDL-DEFAULT-REPEAT-DELAY and SDL-DEFAULT-REPEAT-INTERVAL respectively.


    [Function]
    enable-key-repeat-p => result


    Returns the current keyboard DELAY and INTERVAL repeat rate in milliseconds as (VALUES DELAY INTERVAL).


    [Generic function]
    enable-rle-accel value &key => result



    [Method]
    enable-rle-accel value &key => result


    Enables RLE blit acceleration when T, disables RLE acceleration when NIL. RLE acceleration can substantially speed up blitting of images with large horizontal runs of transparent pixels (i.e., pixels that match the key color).


    [Function]
    enable-unicode state => result


    Unicode translation is enabled with STATE is T, and disabled when STATE is NIL. To obtain the character codes corresponding to received keyboard events, Unicode translation must first be turned on using this function. The translation incurs a slight overhead for each keyboard event and is therefore disabled by default. For each subsequently received key down event, the unicode member of the SDL_keysym structure will then contain the corresponding character code, or zero for keysyms that do not correspond to any character code. Note that only key press events will be translated, not release events. Returns the previous unicode translation state.


    [Function]
    enable-unicode-p => result


    Queries the current state of Unicode keyboard translation. Returns T if enabled, NIL if disabled.


    [Function]
    fill-surface color &key template surface update clipping => result


    Fills surface with the specified COLOR. :TEMPLATE accepts a RECTANGLE defining the fill bounds. The surface is updated when :UPDATE`


    [Function]
    fill-surface-* r g b &key a template surface update clipping => result


    Fill the surface with the specified color RGB:AA. See FILL-SURFACE.


    [Function]
    flood-fill point &key surface color => result


    See FLOOD-FILL-*.

    Parameters


    [Function]
    flood-fill-* x y &key surface color => result


    Performs a flood fill of surface SURFACE with color COLOR. The fill starts at the position specified by the X and Y coordinates. Uses a stack based flood fill that does a lot of consing because it uses PUSH/POP as the stack. This function is fast.

    Parameters


    [Function]
    flood-fill-stack point &key surface color => result


    See FLOOD-FILL-STACK-*.

    Parameters


    [Function]
    flood-fill-stack-* x y &key surface color => result


    See FLOOD-FILL-*.

    FLOOD-FILL-STACK-* is maintains an internal array-based stack.

    Note: More of an experiment to see if an array would be faster than a bunch of consing. The timing of both functions indicates they run at the same speed. With compiler declarations it may have better results. Another disadvantage to this is it preallocates the stack, chewing up quite a bit of ram.


    [Generic accessor]
    fp foreign-object => result
    (setf (fp rectangle-array) value)


    Returns the foreign pointer in FOREIGN-OBJECT


    [Accessor]
    frame-rate => result
    (setf (frame-rate ) rate)


    Manage the target frame rate for the game loop. RATE>0 will lock the game loop to the specified frame rate, and calculate the average frame rate over a number of frames. RATE = 0 will unlock the frame rate, and calculate the average frame rate over a number of frames. RATE<0 will unlock the frame rate. The average frane rate is not calculated.

    See WITH-EVENTS, and AVERAGE-FPS.


    [Generic function]
    free foreign-object => result


    The general explicit cleanup method for the FOREIGN-OBJECT wrapper class. Objects that subclass FOREIGN-OBJECT should specify an :AFTER method on FREE to clean up any additional fields, if necessary.


    [Generic function]
    free-cached-surface font => result



    [Method]
    free-cached-surface (font sdl-font) => result



    [Generic accessor]
    g color => result
    (setf (g color) value)


    Returns the green color component the object.


    [Function]
    get-clip-rect &key surface rectangle => result


    Returns the clipping RECTANGLE.


    [Function]
    get-key-state key => result


    Returns the current keypress state of the key KEY. Returns T if the SDL-KEY is pressed, returns NIL if SDL-KEY is not pressed. Note: Use SDL_PumpEvents to update the state array. Note: This function gives you the current state after all events have been processed, so if a key or button has been pressed and released before you process events, then the pressed state will never show up in the getstate calls. Note: This function doesn't take into account whether shift has been pressed or not. For example: (GET-KEY-STATE :SDL-KEY-F1)


    [Function]
    get-native-window => result


    Returns a foreign pointer to the native SDL display window.


    [Generic function]
    get-point object => result


    Returns the X and Y coordinates of object OBJ as a POINT.


    [Generic function]
    get-position object => result


    See GET-POINT


    [Generic function]
    get-rectangle obj => result


    Returns the rectangle RECTANGLE.


    [Function]
    get-surface-rect &key surface rectangle => result



    [Generic accessor]
    height obj => result
    (setf (height obj) value)


    Returns the height of the object, as an INTEGER. When OBJ is a FONT, use the cached SURFACE.


    [Generic function]
    image-p source image-type => result


    Returns T when the image type in SOURCE is of IMAGE-TYPE. Returns NIL otherwise. Attempts to detect the image type using the magic number contained in the image if one is available. NIL is always returned for images of type TGA as a TGA image does not contain a magic number. IMAGE-TYPE must be one of :BMP, :GIF, :JPG, :LBM, :PCX, :PNG, :PNM, :TIF, :XCF, :XPM or :XV.

    Example 
    (RWOPS-P SOURCE :IMAGE-TYPE :BMP)
(IMAGE-P &quot;image.bmp&quot; :IMAGE-TYPE :BMP)
    Packages


    [Generic function]
    image-type-of source => result


    Returns the type of image in source SOURCE. Attempts to detect the image type using the magic number contained in the image if one is available. Returns one of :BMP, :GIF, :JPG, :LBM, :PCX, :PNG, :PNM, :TIF, :XCF, :XPM or :XV, if the image type can be determined. Returns NIL if the image cannot be determined (The magic number is not supported or the magic number is not found). NIL is always returned for images of type TGA as a TGA image does not contain a magic number.

    Example 
    (IMAGE-TYPE-OF SOURCE)
(IMAGE-TYPE-OF &quot;image.bmp&quot;)
    Packages


    [Function]
    init-sdl &optional init => result


    Initalizes the SDL library when the OPTIONAL parameter INIT is T, or the value returned by SDL-INIT-ON-STARTUP is T.


    [Function]
    init-sub-systems &optional flags => result


    Initializes the SDL subsystems specified in FLAGS. FLAGS is an INTEGER bitmask containing the logior of zero or more of: SDL-INIT-EVERYTHING, SDL-INIT-VIDEO, SDL-INIT-CDROM, SDL-INIT-AUDIO, SDL-INIT-TIMER, SDL-INIT-JOYSTICK, SDL-INIT-EVENTTHREAD and SDL-INIT-NOPARACHUTE.

    INIT-SUB-SYSTEMS can be called only after SDL is succesfully initialized by INIT-SDL.


    [Function]
    initialise-default-font &optional font-definition => result


    Returns a new BITMAP-FONT initialized from FONT-DEFINITION data, or NIL if the font cannot be created. FONT-DEFINITION is set to *font-8x8* if unspecified. Binds the symbol *DEFAULT-FONT* to the new font to be used as the default for subsequent font rendering or drawing operations.

    Packages


    [Function]
    initialise-font font-definition => result


    Returns a new BITMAP-FONT initialized from FONT-DEFINITION data, or NIL if the font cannot be created. FONT-DEFINITION must be one of the following built-in fonts: *FONT-10X20*, *FONT-5X7*, *FONT-5X8*, *FONT-6X10*, *FONT-6X12*, *FONT-6X13*, *FONT-6X13B*, *FONT-6X13O*, *FONT-6X9*, *FONT-7X13*, *FONT-7X13B*, *FONT-7X13O*, *FONT-7X14*, *FONT-7X14B*, *FONT-8X13*, *FONT-8X13B*, *FONT-8X13O*, *FONT-8X8*, *FONT-9X15*, *FONT-9X15B*, *FONT-9X18* OR *FONT-9X18B*.

    Packages


    [Function]
    initialize-on-startup &rest flags => result


    Sets the SDL subsystems that must be initialized in subsequent calls to INIT-SUB-SYSTEMS.

    Parameters
    Returns
    Example 
    (INITIALIZE-ON-STARTUP SDL:SDL-INIT-VIDEO SDL:SDL-INIT-CDROM)


    [Function]
    initialized-sub-systems-p => result


    Returns a list of the initialized SDL subsystems.


    [Function]
    is-valid-ptr pointer => result


    Returns T if pointer is not NULL and is a valid CFFI pointer to a foreign object.


    [Function]
    key-repeat-delay => result


    Returns the current key repeat delay, in milliseconds.


    [Function]
    key-repeat-interval => result


    Returns the current key repeat interval, in milliseconds.


    [Function]
    key= key1 key2 => result



    [Function]
    list-modes flags &optional surface => result


    Returns a LIST of vectors sorted largest to smallest that contains the width and height dimensions of the screen that will support the pixel format of the specified surface SURFACE and video flags FLAGS. LIST-MODES must be called after SDL is initialised using INIT-SDL or WITH-INIT.

    Parameters
    Returns
    Example 
    (LIST-MODES &#039;(SDL-HW-SURFACE SDL-FULLSCREEN))


    [Function]
    list-sub-systems flag => result


    Returns a list of SDL subsystems that are specified in FLAGS.

    FLAGS is an INTEGER bitmask containing the logior of zero or more of: SDL-INIT-EVERYTHING, SDL-INIT-VIDEO, SDL-INIT-CDROM, SDL-INIT-AUDIO, SDL-INIT-TIMER, SDL-INIT-JOYSTICK, SDL-INIT-EVENTTHREAD and SDL-INIT-NOPARACHUTE.


    [Generic function]
    load-image source &key color-key alpha image-type force free-rwops color-key-at => result


    Creates and returns a new SURFACE from the image in SOURCE, or returns NIL if SOURCE does not contain a valid image or the image type cannot be determined.

    The magic number if present is be used to determine the image type. To load an image when the magic number is unavailable (image formats such as TGA do not contain a magic number), specify the image type using :IMAGE-TYPE. All non-magicable image formats, such as TGA, must be specified using IMAGE-TYPE. To load a TGA image use :IMAGE-TYPE :TGA

    Parameters
    Example
    Packages


    [Generic function]
    map-color color &optional surface => result


    Maps COLOR or COLOR-A to the pixel format of SURFACE and returns the pixel value that best approximates the color value of the surface. If the surface has a palette (8-bit) the index of the closest matching color in the palette will be returned. If the surface has an alpha component it will be returned as all 1 bits (fully opaque). If the surface color depth is less than 32-bpp then the unused upper bits of the return value can safely be ignored (e.g., with a 16-bpp format the return value can be assigned to a Uint16, and similarly a Uint8 for an 8-bpp format).


    [Generic function]
    map-color-* r g b a &optional surface => result


    Maps the color specified by the R, G, B, and A color components to the pixel format of SURFACE and returns the pixel value that best approximates the color value of the surface. If A is not NIL then the color is assumed to contain an alpha component. See MAP-COLOR for more details.


    [Function]
    num-joysticks => result



    [Generic function]
    pack-color color => result


    Packs COLOR or COLOR-A into a four byte INTEGER.


    [Generic function]
    pixel-alpha-enabled-p surface => result



    [Method]
    pixel-alpha-enabled-p (surface sdl-surface) => result


    Returns T if a pixel alpha component (RGBA) is available, or NIL if unavailable (RGB). Note: The pixel alpha component differs from the surface alpha component which is retrieved using ALPHA-ENABLED-P.


    [Function]
    point &key x y => result


    Creates a new POINT set to the specified horizontal X and vertical Y coordinate.


    [Generic function]
    point-* point => result


    Returns the X and Y coordinates of the object as a spread. The RESULT is (VALUES X Y)


    [Generic function]
    position-* obj => result


    See POINT-*


    [Function]
    push-quit-event => result


    Pushes a new SDL_Event of type :SDL-QUIT-EVENT onto the event queue.


    [Function]
    push-user-event &key code data1 data2 => result


    Pushes a new SDL_Event of type :SDL-USER-EVENT onto the event queue.


    [Function]
    query-cursor => result


    Queries the current state of the cursor. Returns T if the cursor is enabled and shown on the display. Returns NIL if the cursor is disabled and hidden.


    [Function]
    quit-on-exit &rest flags => result


    Sets one or more SDL subsystems that must be uninitialized in subsequent calls to QUIT-SUB-SYSTEMS.

    Parameters
    Returns
    Example 
    (QUIT-ON-EXIT SDL:SDL-INIT-VIDEO SDL:SDL-INIT-CDROM)


    [Function]
    quit-sdl &optional quit => result


    Uninitalizes the SDL library when the OPTIONAL parameter QUIT is T, or the value returned by SDL-QUIT-ON-EXIT is T.


    [Function]
    quit-sub-systems &optional flags => result


    Uninitializes the SDL subsystems specified in the INTEGER bitmask FLAGS. FLAGS contains the logior of zero or more of: SDL-INIT-EVERYTHING, SDL-INIT-VIDEO, SDL-INIT-CDROM, SDL-INIT-AUDIO, SDL-INIT-TIMER, SDL-INIT-JOYSTICK, SDL-INIT-EVENTTHREAD, SDL-INIT-NOPARACHUTE.

    QUIT-SUB-SYSTEMS can be called only after SDL is successfully intialized using INIT-SDL.


    [Generic accessor]
    r color => result
    (setf (r color) value)


    Returns the red color component of the object.


    [Function]
    random+1 rnd => result


    Returns a random number in the range 0 > num <= rnd.


    [Function]
    random-rectangle bound-w bound-h &optional rectangle => result


    Creates and return s a new RECTANGLE of random x, y width and height within the specified bounds of width BOUND-W and height BOUND-H. RECTANGLE if unset will force the creation of a new RECTANGLE object. RECTANGLE if set will be modified with the coordinates.


    [Function]
    read-pixel point &key clipping surface => result


    See READ-PIXEL-*.

    Parameters
    Packages


    [Function]
    read-pixel-* x y &key clipping surface => result


    Read the COLOR of the pixel at X and Y coordiates from SURFACE.

    Parameters
    Packages


    [Standard class]
    rectangle


    A RECTANGLE object manages the foreign SDL_Rect object. Free using FREE.


    [Function]
    rectangle &key x y w h fp => result


    Creates a new RECTANGLE from the specified X, Y, width W and height H. If FP&#039; is NIL then a foreign SDL_Rect is created. If FP is a pointer to a foreign SDL_Rect object then FP` is used.


    [Generic function]
    rectangle-* obj => result


    Returns the X, Y, WIDTH and HEIGHT coordinates of the object as a spread. The RESULT is (VALUES X Y WIDTH HEIGHT)


    [Function]
    rectangle-from-edges p1 p2 &optional rectangle => result


    See RECTANGLE-FROM-EDGES-*.


    [Function]
    rectangle-from-edges-* x1 y1 x2 y2 &optional rectangle => result


    Returns a new RECTANGLE using the bounds specified by the INTEGERSX1, X2, Y1 and Y2. The coordinates of the rectangle are X = X1, Y = Y1, WIDTH = (- X2 X1), HEIGHT = (- Y2 Y1)

    Parameters


    [Function]
    rectangle-from-midpoint-* x y w h &optional rectangle => result


    Returns a RECTANGLE of width W and height H with the rectangle mid-point at coordinates X and Y. RECTANGLE if unset will force the creation of a new RECTANGLE object. RECTANGLE if set will be modified with the coordinates.


    [Function]
    render-string-shaded string fg-color bg-color &key font free cache => result


    Render the string STRING using font FONT with text color FG-COLOR and background color BG-COLOR to a new SURFACE. The dimensions of the new surface are height == FONT height, and width == FONT width * STRING length. The surface background is filled with BG-COLOR so the surface cannot be keyed over other surfaces. Use :CACHE T to cache the new surface in the FONT object. When :FREE T any exisiting cached surface in FONT is automatically freed. When :FREE NIL the caller is responsible for freeing any existing cached surface in FONT.

    Parameters
    Returns
    Example 
    (RENDER-STRING-SHADED &quot;Hello World!&quot; F-COLOR B-COLOR)
    Packages


    [Function]
    render-string-solid string &key font color free cache => result


    Render the string STRING using font FONT with text color COLOR to a new SURFACE. The dimensions of the new surface are height == FONT height, and width == FONT width * STRING length. The surface background is transparent and therefore can be keyed over other surfaces. Use :CACHE T to cache the new surface in the FONT object. When :FREE T any exisiting cached surface in FONT is automatically freed. When :FREE NIL the caller is responsible for freeing any existing cached surface in FONT.

    Parameters
    Returns
    Example 
    (DRAW-STRING-SOLID &quot;Hello World!&quot; :COLOR A-COLOR)
    Packages


    [Function]
    return-sub-systems-of-status flags status => result


    Returns the status STATUS of the the specified SDL subsystems in FLAGS as an INTEGER bitmask.

    Parameters
    Returns


    [Generic accessor]
    rle-accel-enabled-p surface => result
    (setf (rle-accel-enabled-p surface) value)



    [Specialized accessor]
    rle-accel-enabled-p (surface sdl-surface) => result
    (setf (rle-accel-enabled-p (surface sdl-surface)) value)



    [Function]
    rotate-surface degrees &key surface free zoom smooth => result


    Returns a new SURFACE rotated to DEGREES.

    Parameters
    Packages


    [Function]
    rotate-surface-xy degrees &key surface free zoomx zoomy smooth => result


    Returns a new SURFACE rotated to DEGREES.

    Parameters
    Packages


    [Standard class]
    rwops


    A wrapper around a foreign SDL_RWops object. Free using FREE.


    [Function]
    save-image surface filename => result


    Saves the SURFACE as a BMP image to a file at location FILENAME.


    [Constant]
    sdl-any-format


    Applies to DISPLAY-SURFACE.

    Normally, if a DISPLAY-SURFACE of the requested bits-per-pixel (bpp) is not available, SDL will emulate one with a shadow surface. Passing SDL-ANY-FORMAT prevents this and causes SDL to use the DISPLAY-SURFACE surface, regardless of its pixel depth.


    [Constant]
    sdl-async-blit


    Applies to DISPLAY-SURFACE.

    Asynchronous blits usually slows down blitting on single CPU machines, but may provide a speed increase on SMP systems.


    [Constant]
    sdl-doublebuf


    Applies to DISPLAY-SURFACE.

    Calling SDL-FLIP will flip the buffers and update the screen. All drawing will take place on the surface that is not displayed at the moment. If double buffering could not be enabled then SDL-FLIP will just perform a SDL-UPDATE-RECT on the entire screen.


    [Constant]
    sdl-fullscreen


    Applies to DISPLAY-SURFACE.


    [Function]
    sdl-get-ticks => result



    [Constant]
    sdl-hw-accel


    Applies to SURFACE and DISPLAY-SURFACE.


    [Constant]
    sdl-hw-palette


    Applies to SURFACE and DISPLAY-SURFACE.

    Without this flag you may not always get the the colors you request with SDL-SET-COLORS or SDL-SET-PALETTE.


    [Constant]
    sdl-hw-surface


    Applies to SURFACE and DISPLAY-SURFACE.

    This will allow SDL to take advantage of Video->Video blits (which are often accelerated).


    [Constant]
    sdl-init-audio



    [Constant]
    sdl-init-cdrom



    [Constant]
    sdl-init-eventthread



    [Constant]
    sdl-init-everything



    [Constant]
    sdl-init-joystick



    [Constant]
    sdl-init-noparachute



    [Function]
    sdl-init-on-startup => result


    Returns T if the SDL library must be initialised in INIT-SDL, or WITH-INIT. Returns NIL otherwise.


    [Constant]
    sdl-init-timer



    [Constant]
    sdl-init-video



    [Constant]
    sdl-iyuv-overlay



    [Function]
    sdl-joystick-name device-index => result



    [Constant]
    sdl-no-frame


    Applies to DISPLAY-SURFACE.

    Fullscreen modes automatically have this flag set.


    [Constant]
    sdl-opengl


    Applies to DISPLAY-SURFACE.


    [Constant]
    sdl-pre-alloc


    Applies to SURFACE.


    [Function]
    sdl-quit-on-exit => result


    Returns T if the SDL library must be uninitialised in QUIT-SDL, or WITH-INIT. Returns NIL otherwise.


    [Constant]
    sdl-resizable


    Applies to DISPLAY-SURFACE.

    When the window is resized by the user a :VIDEO-RESIZE-EVENT event is generated and WINDOW can be called again with the new size.


    [Constant]
    sdl-rle-accel


    Applies to SURFACE

    RLE acceleration can substantially speed up blitting of images with large horizontal runs of transparent pixels (i.e., pixels that match the key color). The key must be of the same pixel format as the surface, MAP-COLOR is often useful for obtaining an acceptable value.


    [Constant]
    sdl-rle-accel-ok


    Applies to SURFACE.


    [Constant]
    sdl-src-alpha


    Applies to SURFACE.


    [Constant]
    sdl-src-color-key


    Applies to SURFACE.


    [Standard class]
    sdl-surface


    A wrapper for the foreign SDL_Surface object.


    [Constant]
    sdl-sw-surface


    Applies to SURFACE and DISPLAY-SURFACE.

    This improves the performance of pixel level access, however you may not be able to take advantage of some types of hardware blitting.


    [Constant]
    sdl-uyvy-overlay



    [Function]
    sdl-wm-grab-input mode => result



    [Constant]
    sdl-yuy2-overlay



    [Constant]
    sdl-yv12-overlay



    [Constant]
    sdl-yvyu-overlay



    [Function]
    set-cell rectangle &key surface index => result


    Sets the CELL at INDEX to the bounds of RECTANGLE. Note: When SURFACE is the source of a blit, only the area within the cell rectangle is drawn.


    [Function]
    set-cell-* x y w h &key surface index => result


    Sets the CELL at INDEX to a rectangle bounded by X, Y, W and H. Note: When SURFACE is the source of a blit, only the area within the cell rectangle is drawn.


    [Function]
    set-clip-rect rectangle &key surface => result


    See CLIP-RECT.


    [Generic function]
    set-color dst src => result


    Copies the RGB/A color components to the destination DST from the source SRC.


    [Generic function]
    set-color-* color &key r g b a => result


    Sets COLOR to the red R, green G, blue B and alpha A color components.


    [Function]
    set-gl-attribute attribute value => result



    [Generic function]
    set-point dst src => result


    Copies the X and Y coordinates to the destination DST from the source SRC.


    [Generic function]
    set-point-* obj &key x y => result


    Sets the X and Y coordinates of the object OBJ. X and Y are KEYword parameters.


    [Generic function]
    set-position dst src => result


    See SET-POINT


    [Generic function]
    set-position-* obj &key x y => result


    See SET-POINT-*


    [Generic function]
    set-rectangle dst src => result


    Copies the X, Y, WIDTH and HEIGHT coordinates to the destination rectangle DST from the source rectangle SRC.


    [Generic function]
    set-rectangle-* rectangle &key x y w h => result


    Sets the X, Y, WIDTH and HEIGHT coordinates of the rectangle RECTANGLE. X, Y, WIDTH and HEIGHT are KEYword parameters having default values of 0 if unspecified.


    [Generic function]
    set-surface surface position => result


    Sets the coordinates of the surface SURFACE to POSITION, where position is of type POINT.


    [Generic function]
    set-surface-* surface &key x y => result


    Sets the coordinates of the surface SURFACE. X and Y are KEYword parameters having default values of 0 if unspecified.


    [Function]
    show-cursor state => result


    Disables the cursor when state is NIL, otherwise enables the cursor.


    [Standard class]
    surface


    This object is garbage collected and the SDL_Surface object freed when out of scope. Free using FREE.


    [Function]
    surface-info surface &optional info => result


    Returns information about the SDL surface SURFACE.

    Parameters
    Returns

    INFO when NIL will return a list of all enabled surface flags. Otherwise will return INFO as T or NIL if supported by the surface.

    Example 
    (SURFACE-INFO A-SURFACE &#039;(SDL-HW-SURFACE SDL-HW-PALETTE SDL-HW-ACCELL))


    [Function]
    time-scale => result



    [Function]
    to-degree radian => result


    Converts radians to degrees.


    [Function]
    to-radian degree => result


    Converts degrees to radians.


    [Function]
    update-display &optional surface => result


    When OPENGL-CONTEXT is NIL; UPDATE-DISPLAY will flip the SDL video buffers and update the screen SURFACE if SDL-HW-SURFACE is set in WINDOW. If double buffering is not enabled then SDL will perform an SDL-UPDATE-RECT on the entire screen.

    When OPENGL-CONTEXT is T; UPDATE-DISPLAY will call SDL-GL-SWAP-BUFFERS to update the OpenGL display context.

    SURFACE is bound to *DEFAULT-DISPLAY* if unspecified.


    [Function]
    update-surface surface &optional template => result


    Updates the surface


    [Function]
    update-surface-* surface x y w h => result


    See UPDATE-SURFACE.


    [Function]
    video-dimensions => result


    Returns the best video dimensions if called before a window is created, using WINDOW. Returns the current video dimensions if called after a window is created. Must be called after SDL is initialized using INIT-SDL or WITH-INIT


    [Function]
    video-driver-name => result


    Returns the driver name of the initialised video driver. The driver name is a STRING containing a one-word identifier like "x11" or "windib". Returns 'NIL' if the video driver is not already initialised with INIT-SDL or WITH-INIT.

    Example 
    (sdl:with-init ()
  (sdl:video-driver-name))
&gt;&gt; &quot;windib&quot;


    [Function]
    video-info &optional info => result


    Returns information about the video hardware. GET-VIDEO-INFO must be called after SDL is initialised using INIT-SDL or WITH-INIT. If GET-VIDEO-INFO is called before WINDOW, the information returned is of the best video mode. If GET-VIDEO-INFO is called after WINDOW, the information returned is of the current video mode.

    Parameters
    Example 
    (video-info :HW-AVAILABLE)


    [Function]
    video-memory => result


    Returns the amount of video memory of the graphics hardware. Must be called after SDL is initialized using INIT-SDL or WITH-INIT.


    [Generic accessor]
    width obj => result
    (setf (width obj) value)


    Returns the width of the object, as an INTEGER. When OBJ is a FONT, use the cached SURFACE.


    [Function]
    window width height &key bpp flags title-caption icon-caption => result


    Creates a new SDL window of pixel width WIDTH and height HEIGHT using SDL_SetVideoMode.

    Use SDL-SW-SURFACE if you plan on doing per-pixel manipulations, or blit surfaces with alpha channels, and require a high framerate. When you use hardware surfaces like SDL-HW-SURFACE, SDL copies the surfaces from video memory to system memory when you lock them, and back when you unlock them. This can cause a major performance hit. (Be aware that you may request a hardware surface, but receive a software surface. Many platforms can only provide a hardware surface when using SDL-FULL-SCREEN.) SDL-HW-SURFACE` is best used when the surfaces you'll be blitting can also be stored in video memory.

    Note: To control the position on the screen when creating a windowed surface, set the environment variables SDL_VIDEO_CENTERED=center or SDL_VIDEO_WINDOW_POS=x,y. These may be set using SDL-PUT-ENV.

    Parameters
    Returns
    Example 
    (WINDOW 320 240 :TITLE-CAPTION &quot;Random-Rects&quot; :ICON-CAPTION &quot;Random-Rects&quot;
                 :FLAGS &#039;(SDL-DOUBLEBUF SDL-FULLSCREEN))


    [Macro]
    with-bezier (&optional style segments) declaration* statement* => result


    Draw a bezier curve of *DEFAULT-COLOR* to *DEFAULT-SURFACE*. The shape of the Bezier curve is defined by control points. A control point is a vertex containing an X and Y coordinate pair.

    The number of segments SEGENTS used to draw the Bezier curve defaults to 10. The greater the number of segments, the smoother the Bezier curve.

    Local Methods

    A vertex may be added using:

    ADD-VERTEX and ADD-VERTEX-* are valid only within the scop of WITH-BEZIER.

    Parameters
    Example 
    (SDL:WITH-COLOR (COL (SDL:COLOR))
   (WITH-BEZIER ()
     (ADD-VERTEX-* 60  40)
     (ADD-VERTEX-* 160 10)
     (ADD-VERTEX-* 170 150)
     (ADD-VERTEX-* 60  150)))
    Packages


    [Macro]
    with-color (var &optional color free) declaration* statement* => result


    A convience macro that binds *DEFAULT-COLOR* to VAR within the scope of WITH-COLOR. VAR is set to COLOR when COLOR is not NIL.VAR must be of type COLOR, or COLOR-A. VAR is freed using FREE when FREE is T.


    [Macro]
    with-curve (&optional style segments) declaration* statement* => result


    Draw a Cattmul-Rom spline of *DEFAULT-COLOR* to *DEFAULT-SURFACE*. The shape of the curve is defined by waypoints. A waypoint is a vertex containing an X and Y coordinate pair.

    Local Methods

    A vertex may be added using:

    ADD-VERTEX and ADD-VERTEX-* are valid only within the scope of WITH-CURVE.

    Parameters
    Example 
    (SDL:WITH-COLOR (COL (SDL:COLOR))
   (WITH-CURVE (:SOLID 30)
     (ADD-VERTEX-* 60  40)
     (ADD-VERTEX-* 160 10)
     (ADD-VERTEX-* 170 150)
     (ADD-VERTEX-* 60  150)))
    Packages


    [Macro]
    with-default-font (font) declaration* statement* => result


    Sets *DEFAULT-FONT* to FONT within the scope of WITH-DEFAULT-FONT.

    Example 
    (WITH-DEFAULT-FONT (new-font)
    (DRAW-CHARACTER-SHADED-* &quot;Hello World!&quot; 0 0 F-COLOR B-COLOR))
    Packages


    [Macro]
    with-events (&optional type) declaration* statement* => result


    WITH-EVENTS is a convenience macro for managing the main game loop. It processes incoming SDL events and limits the game loop to the specified number of frames per second.

    Both the SDL-POLL-EVENT and SDL-WAIT-EVENT event mechanisms are supported by specifying the TYPE as :POLL or :WAIT respectively.

    NOTE:WITH-EVENTS must be called in the same thread used to set the video mode.

    Example 
    (SDL:WITH-EVENTS (:POLL)
  (:QUIT-EVENT () T)
  (:KEY-DOWN-EVENT (:KEY KEY)
      (WHEN (SDL:KEY= KEY :SDL-KEY-ESCAPE)
        (SDL:PUSH-QUIT-EVENT)))
  (:VIDEO-EXPOSE-EVENT () (SDL:UPDATE-DISPLAY))))))
    Frame Rate Limiting

    The frame rate is specified using FRAME-RATE. For example to set the frame rate to 60 frames per second: 

    (SETF (SDL:FRAME-RATE) 60)
    Event Syntax

    Events are specified using the format (:EVENT-TYPE (&amp;KEYS KEYS))

    NOTE::QUIT-EVENT must return T to exit the WITH-EVENT macro.

    NOTE::IDLE is ignored when TYPE is :WAIT.

    Polling for Events

    When TYPE is :POLL, WITH-EVENTS will continually poll for currently pending events. If no events are available then the game loop is run and the forms in :IDLE are executed.

    Waiting for Events

    When TYPE is :WAIT, WITH-EVENTS will sleep indefinitely for the next available event. If no events are available then the game loop is paused.

    The :IDLE Event 
     (:IDLE ()
    &amp;BODY BODY)

    The :IDLE event is special in that it is not generated by SDL. Rather the forms in :IDLE are executed once each game loop after event queue is emptied. :IDLE is ignored when the event mechanism specified by TYPE is :WAIT.

    Active Event 
    (:ACTIVE-EVENT (:GAIN GAIN :STATE STATE) 
   &amp;BODY BODY)

    When the mouse leaves or enters the window area an SDL-APP-MOUSE-FOCUS type activation event is generated. If the mouse has entered the window then GAIN will be 1, otherwise GAIN will be 0. An SDL-APP-INPUT-FOCUS type activation event occurs when the application loses or gains keyboard focus, usually when a different application is made active. Finally, an SDL-APP-ACTIVE type event occurs when the application is either minimised/iconified, GAIN is 0, or restored. A single event can have multiple values set in STATE. Note: This event does not occur when an application window is first created.

    Keyboard Events 
    (:KEY-DOWN-EVENT (:STATE STATE :SCANCODE SCANCODE :KEY KEY :MOD MOD :UNICODE UNICODE)
   &amp;BODY BODY)
(:KEY-UP-EVENT (:STATE STATE :SCANCODE SCANCODE :KEY KEY :MOD MOD :UNICODE UNICODE)
   &amp;BODY BODY)

    A keyboard event generally occurs when a key is released or when a key is pressed. The information on the key that generated the event is stored in KEY and MOD.

    The SDL-CAPS-LOCK and SDL-NUM-LOCK keys are special cases and report an SDL-KEY-DOWN when first pressed, then an SDL-RELEASED when released and pressed again. These keys KEYUP and KEYDOWN events are therefore analogous to the state of the caps lock and num lock LEDs rather than the keys themselves. These special cases are required for compatibility with Sun workstations.

    Note: Repeating SDL-KEY-DOWN events will occur if key repeat is enabled using SDL-ENABLE-KEY-REPEAT.

    Mouse Motion Event 
    (:MOUSE-MOTION-EVENT (:STATE STATE :X X :Y Y :X-REL X-REL :Y-REL Y-REL)
   &amp;BODY BODY)

    A MOUSE-MOTION-EVENT event occurs when the mouse moves within the application window or when SDL-WARP-MOUSE is called. Both the absolute X and Y and relative X-REL and Y-REL coordinates are reported along with the current button state STATE. The button state can be interpreted using SDL-BUTTON, see SDL-GET-MOUSE-STATE.

    If the cursor is hidden using SDL-SHOW-CURSOR and the input is grabbed using SDL-WM-GRAB-INPUT, then the mouse will give relative motion events even when the cursor reaches the edge of the screen. This is currently only implemented on Windows and Linux/Unix-alikes.

    Mouse Button Events 
     (:MOUSE-BUTTON-DOWN-EVENT (:BUTTON BUTTON :STATE STATE :X X :Y Y)
   &amp;BODY BODY)
 (:MOUSE-BUTTON-UP-EVENT (:BUTTON BUTTON :STATE STATE :X X :Y Y)
   &amp;BODY BODY)

    When a mouse button press or release is detected the number of the button pressed (from 1 to 255, with 1 usually being the left button and 2 the right) is placed into BUTTON, the position of the mouse when this event occured is stored in the X and the Y fields.

    Mouse wheel events are reported as buttons 4 (up) and 5 (down). Two events are generated i.e. a SDL-MOUSE-BUTTON-DOWN followed by a SDL-MOUSE-BUTTON-UP event.

    Joystick Motion Event 
    (:JOY-AXIS-MOTION-EVENT (:WHICH WHICH :AXIS AXIS :VALUE VALUE)
   &amp;BODY BODY)

    A JOY-AXIS-MOTION-EVENT event occurs whenever a user moves an axis on the joystick.

    Joystick Button Events 
    (:JOY-BUTTON-DOWN-EVENT (:WHICH WHICH :BUTTON BUTTON :STATE STATE)
   &amp;BODY BODY)
(:JOY-BUTTON-UP-EVENT (:WHICH WHICH :BUTTON BUTTON :STATE STATE)
   &amp;BODY BODY)

    A JOY-BUTTON-DOWN-EVENT or JOY-BUTTON-DOWN-EVENT event occurs whenever a user presses or releases a button on a joystick.

    Joystick Hat Motion Event 
       (:JOY-HAT-MOTION-EVENT (:WHICH WHICH :HAT HAT :VALUE VALUE)
     &amp;BODY BODY)

    A JOY-HAT-MOTION-EVENT event occurs when ever a user moves a hat on the joystick.

    Joystick Ball Motion Event 
    (:JOY-BALL-MOTION-EVENT (:WHICH WHICH :BALL BALL :X-REL X-REL :Y-REL Y-REL)
  &amp;BODY BODY)

    A JOY-BALL-MOTION-EVENT event occurs when a user moves a trackball on the joystick. Trackballs only return relative motion.

    Quit Event 
    (:QUIT-EVENT () 
   &amp;BODY BODY)

    If QUIT-EVENT is filtered or ignored then it is impossible for the user to close the window. If QUIT-EVENT is accepted and returns T then the application window will be closed. Note: Screen updates will continue to report success even though the application is no longer visible. If QUIT-EVENT is accepted and returns NIL then the application window will not be closed. SDL_QUIT-REQUESTED will return non-zero if a QUIT-EVENT event is pending.

    SDL Window Resize Event 
    (:VIDEO-RESIZE-EVENT (:W W :H H)
   ...)

    When SDL-RESIZABLE is passed as a flag to WINDOW, the user is allowed to resize the application window. When the window is resized a VIDEO-RESIZE-EVENT event is reported, with the new window width and height values stored in W and H respectively. When an VIDEO-RESIZE-EVENT event is recieved the window should be resized to the new dimensions using WINDOW.

    SDL Window Expose Event 
    (:VIDEO-EXPOSE-EVENT ()
   ...)

    VIDEO-EXPOSE-EVENT is triggered when the screen has been modified outside of the application, usually by the window manager, and needs to be redrawn.

    System Window Events 
    (:SYS-WM-EVENT () 
   ...)

    The system window manager event contains a pointer to system-specific information about unknown window manager events. If this event is enabled using SDL-EVENT-STATE, it will be generated whenever unhandled events are received from the window manager. This can be used, for example, to implement cut-and-paste in your application. If you want to obtain system-specific information about the window manager, you can fill in the version member of a SDL-SYS-WM-INFO structure using SDL-VERSION, and pass it to the function: SDL-GET-WM-INFO

    User 
    (:USER-EVENT (:TYPE TYPE :CODE CODE :DATA1 DATA1 :DATA2 DATA2)
   ...)

    USER-EVENT is unique in that it is created by the user not SDL. USER-EVENT can be pushed onto the event queue using PUSH-USER-EVENT. The contents of the event are completely up to the programmer.

    Syntax 
    (WITH-EVENTS (TYPE)
 (:ACTIVE-EVENT (:GAIN GAIN :STATE STATE) 
    ... )
 (:KEY-DOWN-EVENT (:STATE STATE :SCANCODE SCANCODE :KEY KEY :MOD MOD :UNICODE UNICODE)
    ... )
 (:KEY-UP-EVENT (:STATE STATE :SCANCODE SCANCODE :KEY KEY :MOD MOD :UNICODE UNICODE)
    ...)
 (:MOUSE-MOTION-EVENT (:STATE STATE :X X :Y Y :X-REL X-REL :Y-REL Y-REL)
    ...)
 (:MOUSE-BUTTON-DOWN-EVENT (:BUTTON BUTTON :STATE STATE :X X :Y Y)
    ...)
 (:MOUSE-BUTTON-UP-EVENT (:BUTTON BUTTON :STATE STATE :X X :Y Y)
    ...)
 (:JOY-AXIS-MOTION-EVENT (:WHICH WHICH :AXIS AXIS :VALUE VALUE)
    ...)
 (:JOY-BUTTON-DOWN-EVENT (:WHICH WHICH :BUTTON BUTTON :STATE STATE)
    ...)
 (:JOY-BUTTON-UP-EVENT (:WHICH WHICH :BUTTON BUTTON :STATE STATE)
    ...)
 (:JOY-HAT-MOTION-EVENT (:WHICH WHICH :HAT HAT :VALUE VALUE)
    ...)
 (:JOY-BALL-MOTION-EVENT (:WHICH WHICH :BALL BALL :X-REL X-REL :Y-REL Y-REL)
    ...)
 (:VIDEO-RESIZE-EVENT (:W W :H H)
    ...)
 (:VIDEO-EXPOSE-EVENT ()
    ...)
 (:SYS-WM-EVENT () 
    ...)
 (:USER-EVENT (:TYPE TYPE :CODE CODE :DATA1 DATA1 :DATA2 DATA2)
    ...)
 (:QUIT-EVENT () 
    ... 
    T)
 (:IDLE ()
    ... ))


    [Macro]
    with-font (font font-definition) declaration* statement* => result


    Sets *DEFAULT-FONT* to a new BITMAP-FONT in FONT within the scope of WITH-FONT. Frees FONT when WITH-FONT goes out of scope.

    Example 
    (WITH-FONT (new-font *font-8x8*)
    (DRAW-CHARACTER-SHADED-* &quot;Hello World!&quot; 0 0 F-COLOR B-COLOR))
    Packages


    [Macro]
    with-foreign-color-copy (struct color) declaration* statement* => result


    Creates and assigns a new foreign SDL_Color to STRUCT. Then copies the color components from COLOR into STRUCT. STRUCT is free'd when out of scope.


    [Macro]
    with-init flags declaration* statement* => result


    WITH-INIT is a convenience macro that will attempt to initialise the SDL library and SDL subsystems prior to executing the forms in BODY. Upon exit WITH-INIT will uninitialize the SDL library and SDL subsystems.

    The lispbuilder-sdl initialization routines are somewhat complicated by the fact that a Lisp development environment will load a foreign library once but then initialise and uninitialise the library multiple times. A C/C++ development environment will open and then close a library after each execution, freeing all resources left hanging by incomplete or buggy uninitialise functions. C libraries may therefore frequently core dump in a Lisp environment when resources are not feed properly prior to the library being reinitialized.

    LISPBUILDER-SDL provides functionality affording the programmer a finer granularity of control of the initialisation/uninitialisation of foreign libraries. The fuctions that provide these capabilities are as follows:

    Defaults
    Initialisation/Uninitialisation of the SDL library

    The SDL library is initialised only:

    The SDL library is uninitialised only:

    Initialisation/Uninitialisation of external libraries

    Hooks are provided to allow external libraries to be initialized or uninitialised automatically following the initialisation or uninitialisation of the SDL library.

    To initialise an external library, push a function that initialises the external library onto *EXTERNAL-INIT-ON-STARTUP*. The function must take no arguments. For example: 

    (defun init-ttf ()
   (if (is-init)
     t
     (sdl-ttf-cffi::ttf-init)))
(pushnew &#039;init-ttf sdl:*external-init-on-startup*)

    To uninitialise an external library, push a function that uninitialises the external library onto *EXTERNAL-QUIT-ON-EXIT*. The function must take no arguments. For example: 

    (defun quit-ttf ()
   (if (is-init)
     (sdl-ttf-cffi::ttf-quit)))
(pushnew &#039;quit-ttf sdl:*external-quit-on-exit*)
    Parameters
    Example 
    (with-init (SDL-INIT-VIDEO SDL-INIT-CDROM SDL-INIT-AUDIO)
  ....)
(with-init ()
  (INITIALIZE-ON-STARTUP SDL-INIT-VIDEO SDL-INIT-CDROM SDL-INIT-AUDIO)
  (QUIT-ON-EXIT SDL-INIT-VIDEO SDL-INIT-CDROM SDL-INIT-AUDIO)
  ....)


    [Macro]
    with-locked-surface (var &optional surface) declaration* statement* => result



    [Macro]
    with-locked-surfaces bindings &rest body => result



    [Macro]
    with-point (var &optional point) declaration* statement* => result


    A convenience macro that binds *DEFAULT-POINT* to VAR within the scope of WITH-POINT. VAR must be of type POINT. If POINT is not NIL, then VAR is set to POINT`.


    [Macro]
    with-rectangle (var &optional rectangle free) declaration* statement* => result


    A convenience macro that binds *DEFAULT-RECTANGLE* to VAR within the scope of WITH-RECTANGLE. VAR must be of type RECTANGLE. VAR is set to RECTANGLE when RECTANGLE is not NIL. VAR is freed when FREE is T.

    Example 
    (WITH-RECTANGLE (a-rect (RECTANGLE :x 0 :y 0 :w 100 :h 100))
    ...)


    [Macro]
    with-rectangles bindings declaration* statement* => result


    A convenience macro that binds multiple rectangles as per WITH-RECTANGLE.

    Example 
    (WITH-RECTANGLES ((a-rect (RECTANGLE :x 0 :y 0 :w 100 :h 100))
                  ((b-rect (RECTANGLE :x 0 :y 100 :w 100 :h 100))
                  ((c-rect (RECTANGLE :x 0 :y 200 :w 100 :h 100)))
    ...)


    [Macro]
    with-shape (&optional style) declaration* statement* => result


    Draw a polygon of *DEFAULT-COLOR* to *DEFAULT-SURFACE*.

    Local Methods

    A vertex may be added using:

    ADD-VERTEX and ADD-VERTEX-* are valid only within the scop of WITH-SHAPE.

    Parameters
    Example 
    (SDL:WITH-COLOR (COL (SDL:COLOR))
   (WITH-SHAPE (:POINTS)
     (ADD-VERTEX-* 60  40)
     (ADD-VERTEX-* 160 10)
     (ADD-VERTEX-* 170 150)
     (ADD-VERTEX-* 60  150)))
    Packages


    [Macro]
    with-surface (var &optional surface free) declaration* statement* => result



    [Macro]
    with-surface-slots (var &optional surface) declaration* statement* => result



    [Macro]
    with-surfaces bindings &rest body => result



    [Function]
    within-range p1 p2 distance => result


    Returns true T, if the distance between the POINTs P1P2 is <= the distance DISTANCE.


    [Function]
    within-range-* x1 y1 x2 y2 distance => result


    Returns true T, if the distance between the coordinates X1, Y1 and X2, Y2 is <= the distance DISTANCE.


    [Generic accessor]
    x obj => result
    (setf (x obj) value)


    Returns the X coordinate of the object, as an INTEGER. When OBJ is a FONT, use the cached SURFACE.


    [Generic accessor]
    x2 obj => result
    (setf (x2 obj) value)


    Returns (+ X WIDTH) of the object, as an INTEGER.


    [Generic accessor]
    y obj => result
    (setf (y obj) value)


    Returns the Y coordinate of the object, as an INTEGER. When OBJ is a FONT, use the cached SURFACE.


    [Generic accessor]
    y2 obj => result
    (setf (y2 obj) value)


    Returns (+ Y HEIGHT) of the object, as an INTEGER.


    [Function]
    zoom-surface zoomx zoomy &key surface free smooth => result


    Returns a new SURFACE scaled to ZOOMX and ZOOMY.

    Parameters
    Packages


    [Method]
    (setf (fp (rectangle-array rectangle-array)) value)



    [Method]
    (setf (fp (rectangle-array color-a)) value)



    [Method]
    (setf (fp (rectangle-array color)) value)



     

    Acknowledgements

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