diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt index 4403626c45..a2a2441bb8 100644 --- a/examples/CMakeLists.txt +++ b/examples/CMakeLists.txt @@ -177,6 +177,7 @@ macro(add_sdl_example_executable TARGET) endmacro() add_sdl_example_executable(renderer-clear SOURCES renderer/01-clear/renderer-clear.c) +add_sdl_example_executable(renderer-primitives SOURCES renderer/02-primitives/renderer-primitives.c) if(PSP) diff --git a/examples/renderer/02-primitives/renderer-primitives.c b/examples/renderer/02-primitives/renderer-primitives.c new file mode 100644 index 0000000000..d2263a88b7 --- /dev/null +++ b/examples/renderer/02-primitives/renderer-primitives.c @@ -0,0 +1,89 @@ +/* + * This example code creates an SDL window and renderer, and then draws a few + * lines and rectangles to it every frame. + * + * This code is public domain. Feel free to use it for any purpose! + */ + +#define SDL_MAIN_USE_CALLBACKS 1 /* use the callbacks instead of main() */ +#include +#include + +/* We will use this renderer to draw into this window every frame. */ +static SDL_Window *window = NULL; +static SDL_Renderer *renderer = NULL; +static SDL_FPoint points[500]; + +/* This function runs once at startup. */ +int SDL_AppInit(void **appstate, int argc, char *argv[]) +{ + int i; + + if (SDL_CreateWindowAndRenderer("examples/renderer/clear", 640, 480, 0, &window, &renderer) == -1) { + SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "Couldn't create window/renderer!", SDL_GetError(), NULL); + return SDL_APP_FAILURE; + } + + /* set up some random points */ + SDL_srand(0); /* seed the random number generator with current time */ + for (i = 0; i < SDL_arraysize(points); i++) { + points[i].x = (SDL_randf() * 440.0f) + 100.0f; + points[i].y = (SDL_randf() * 280.0f) + 100.0f; + } + + return SDL_APP_CONTINUE; /* carry on with the program! */ +} + +/* This function runs when a new event (mouse input, keypresses, etc) occurs. */ +int SDL_AppEvent(void *appstate, const SDL_Event *event) +{ + if (event->type == SDL_EVENT_QUIT) { + return SDL_APP_SUCCESS; /* end the program, reporting success to the OS. */ + } + return SDL_APP_CONTINUE; /* carry on with the program! */ +} + +/* This function runs once per frame, and is the heart of the program. */ +int SDL_AppIterate(void *appstate) +{ + SDL_FRect rect; + + /* as you can see from this, rendering draws over whatever was drawn before it. */ + SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255); /* black, full alpha */ + SDL_RenderClear(renderer); /* start with a blank canvas. */ + + /* draw a filled rectangle in the middle of the canvas. */ + SDL_SetRenderDrawColor(renderer, 0, 0, 255, 255); /* blue, full alpha */ + rect.x = rect.y = 100; + rect.w = 440; + rect.h = 280; + SDL_RenderFillRect(renderer, &rect); + + /* draw a unfilled rectangle in-set a little bit. */ + SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255); /* green, full alpha */ + rect.x += 30; + rect.y += 30; + rect.w -= 60; + rect.h -= 60; + SDL_RenderRect(renderer, &rect); + + /* draw two lines in an X across the whole canvas. */ + SDL_SetRenderDrawColor(renderer, 255, 255, 0, 255); /* yellow, full alpha */ + SDL_RenderLine(renderer, 0, 0, 640, 480); + SDL_RenderLine(renderer, 0, 480, 640, 0); + + /* draw some points across the canvas. */ + SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255); /* red, full alpha */ + SDL_RenderPoints(renderer, points, SDL_arraysize(points)); + + SDL_RenderPresent(renderer); /* put it all on the screen! */ + + return SDL_APP_CONTINUE; /* carry on with the program! */ +} + +/* This function runs once at shutdown. */ +void SDL_AppQuit(void *appstate) +{ + /* SDL will clean up the window/renderer for us. */ +} + diff --git a/examples/template.c b/examples/template.c index 6add816545..caff36210c 100644 --- a/examples/template.c +++ b/examples/template.c @@ -35,6 +35,7 @@ int SDL_AppEvent(void *appstate, const SDL_Event *event) /* This function runs once per frame, and is the heart of the program. */ int SDL_AppIterate(void *appstate) { + return SDL_APP_CONTINUE; /* carry on with the program! */ } /* This function runs once at shutdown. */