Code/Await Abstractions¶

SDL_Init¶

Initializes Céu-SDL, creates a SDL window, and provides a renderer to the application.

SDL_Init terminates once SDL_QUIT occurs.

code/await SDL_Init (var _char&& title, var int width, var int height, var SDL_Color? bg)
                        -> (var& _SDL_Renderer ren)
                            -> void

• Parameters
  • title: title of the window
  • width: width of the window in pixels
  • height: height of the window in pixels
  • bg: background color of the window (optional)
• Initialization
  • ren: created renderer
• Return
  • terminates on SDL_QUIT and returns no value

SDL_Init performs a number of initializations on Céu-SDL:

• initializes SDL
• creates a window
• creates a renderer
• initializes the text and audio subsystems

If a bg is provided, SDL_Init fills the window background with the provided color on every SDL_REDRAW.

Example:

#include "sdl/sdl.ceu"

var& _SDL_Renderer ren; ;
watching SDL_Init("Rectangle", 300,300, SDL_Color(0xFF,0xFF,0x00,0xFF)) -> (&ren) do
    var SDL_Rect rect = val SDL_Rect(100,100 , 100,100);
    every SDL_REDRAW do
        _SDL_SetRenderDrawColor(&&ren, 0xFF,0x00,0x00,0xFF);
        _SDL_RenderFillRect(&&ren, (&&rect as _SDL_Rect&&));
    end
end

escape 0;

Draws a 100x100 red rectangle centered in a 300x300 yellow window.

SDL References: SDL_Init, SDL_Quit, SDL_CreateWindow, SDL_DestroyWindow, SDL_CreateRenderer, SDL_DestroyRenderer, TTF_Init, TTF_Quit, Mix_OpenAudio, Mix_CloseAudio, SDL_SetRenderDrawColor, SDL_RenderClear.

Note: all allocated SDL resources are automatically released on termination.

SDL_Open_Image¶

Opens an image file into a new texture.

code/await SDL_Open_Image (var& _SDL_Renderer ren, var _char&& path)
                            -> (var& SDL_Texture tex)
                                -> FOREVER

• Parameters
  • ren: rendering context
  • path: path to the image
• Initialization
  • tex: created texture
• Return
  • never terminates naturally

Example:

#include "sdl/sdl.ceu"

var& _SDL_Renderer ren; ;
watching SDL_Init("Image", 68,68, SDL_Color(0xFF,0xFF,0x00,0xFF)) -> (&ren) do
    var& SDL_Texture img;
    spawn SDL_Open_Image(&ren, "img.png") -> (&img);
    var SDL_Rect rect = val SDL_Rect(10,10 , img.width,img.height);
    every SDL_REDRAW do
        _SDL_RenderCopy(&&ren, &&img.tex, null, &&rect as _SDL_Rect&&);
    end
end

escape 0;

Draws img.png in a 68x68 yellow window.

SDL References: IMG_LoadTexture, SDL_DestroyTexture, SDL_QueryTexture.

Note: all allocated SDL resources are automatically released on termination.

SDL_Open_Font¶

Opens a TTF font file.

code/await SDL_Open_Font (var _char&& path, var int size)
                            -> (var& _TTF_Font font)
                                -> FOREVER

• Parameters
  • path: path to the font
  • size: size of the font
• Initialization
  • font: created font
• Return
  • never terminates naturally

Example:

#include "sdl/sdl.ceu"

var& _SDL_Renderer ren; ;
watching SDL_Init("Font 1", 220,60, SDL_Color(0xFF,0xFF,0x00,0xFF)) -> (&ren) do
    var& _TTF_Font font;
    spawn SDL_Open_Font("samples/Deutsch.ttf", 40) -> (&font);

    var& SDL_Texture txt;
    spawn SDL_New_Text(&ren, &font, "Hello World!", SDL_Color(0x00,0x00,0x00,0xFF))
            -> (&txt);
    var SDL_Rect rect = val SDL_Rect(10, 10, txt.width, txt.height);

    every SDL_REDRAW do
        _SDL_RenderCopy(&&ren, &&txt.tex, null, &&rect as _SDL_Rect&&);
    end
end

escape 0;

Draws a black Hello World! text in yellow window.

SDL References: _TTF_OpenFont, _TTF_WasInit, _TTF_CloseFont.

Note: all allocated SDL resources are automatically released on termination.

SDL_New_Text¶

Writes a text into a new texture.

code/await SDL_New_Text (var& _SDL_Renderer ren, var& _TTF_Font font, var _char&& text, var SDL_Color color)
                            -> (var& SDL_Texture tex)
                                -> FOREVER

• Parameters
  • ren: rendering context
  • font: text font
  • text: text to write
  • color: text color
• Initialization
  • tex: created texture
• Return
  • never terminates naturally

Example:

#include "sdl/sdl.ceu"

var& _SDL_Renderer ren; ;
watching SDL_Init("Font 1", 220,60, SDL_Color(0xFF,0xFF,0x00,0xFF)) -> (&ren) do
    var& _TTF_Font font;
    spawn SDL_Open_Font("font.ttf", 40) -> (&font);

    var& SDL_Texture txt;
    spawn SDL_New_Text(&ren, &font, "Hello World!", SDL_Color(0x00,0x00,0x00,0xFF))
            -> (&txt);
    var SDL_Rect rect = val SDL_Rect(10, 10, txt.width, txt.height);

    every SDL_REDRAW do
        _SDL_RenderCopy(&&ren, &&txt.tex, null, &&rect as _SDL_Rect&&);
    end
end

escape 0;

Draws a black Hello World! text in yellow window.

SDL References: [_TTF_RenderText_Blended], [_SDL_FreeSurface], [_SDL_CreateTextureFromSurface], [_SDL_DestroyTexture], [_SDL_QueryTexture].

Note: all allocated SDL resources are automatically released on termination.

SDL_Open_Sound¶

Opens a sound file.

code/await SDL_Open_Sound (var _char&& path)
                            -> (var& _Mix_Chunk sound)
                                -> FOREVER

• Parameters
  • path: path to the sound
• Initialization
  • sound: created sound
• Return
  • never terminates naturally

Example:

#include "sdl/sdl.ceu"

var SDL_Color bg = val SDL_Color(0x00,0x00,0x00,0xFF);

var& _SDL_Renderer ren;
watching SDL_Init("Sound 1", 10,10, bg) -> (&ren)
do
    var& _Mix_Chunk sound;
    spawn SDL_Open_Sound("sound.wav") -> (&sound);
    every 1s do
        _Mix_PlayChannel(-1, &&sound, 0);
    end
end

escape 0;

Plays sound.wav every second.

SDL References: _Mix_LoadWAV, _Mix_FreeChunk.

Note: all allocated SDL resources are automatically released on termination.