diff options
Diffstat (limited to 'contrib/SDL-3.2.8/examples/renderer/07-streaming-textures/streaming-textures.c')
| -rw-r--r-- | contrib/SDL-3.2.8/examples/renderer/07-streaming-textures/streaming-textures.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/contrib/SDL-3.2.8/examples/renderer/07-streaming-textures/streaming-textures.c b/contrib/SDL-3.2.8/examples/renderer/07-streaming-textures/streaming-textures.c new file mode 100644 index 0000000..bf309bc --- /dev/null +++ b/contrib/SDL-3.2.8/examples/renderer/07-streaming-textures/streaming-textures.c | |||
| @@ -0,0 +1,109 @@ | |||
| 1 | /* | ||
| 2 | * This example creates an SDL window and renderer, and then draws a streaming | ||
| 3 | * texture to it every frame. | ||
| 4 | * | ||
| 5 | * This code is public domain. Feel free to use it for any purpose! | ||
| 6 | */ | ||
| 7 | |||
| 8 | #define SDL_MAIN_USE_CALLBACKS 1 /* use the callbacks instead of main() */ | ||
| 9 | #include <SDL3/SDL.h> | ||
| 10 | #include <SDL3/SDL_main.h> | ||
| 11 | |||
| 12 | /* We will use this renderer to draw into this window every frame. */ | ||
| 13 | static SDL_Window *window = NULL; | ||
| 14 | static SDL_Renderer *renderer = NULL; | ||
| 15 | static SDL_Texture *texture = NULL; | ||
| 16 | |||
| 17 | #define TEXTURE_SIZE 150 | ||
| 18 | |||
| 19 | #define WINDOW_WIDTH 640 | ||
| 20 | #define WINDOW_HEIGHT 480 | ||
| 21 | |||
| 22 | /* This function runs once at startup. */ | ||
| 23 | SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[]) | ||
| 24 | { | ||
| 25 | SDL_SetAppMetadata("Example Renderer Streaming Textures", "1.0", "com.example.renderer-streaming-textures"); | ||
| 26 | |||
| 27 | if (!SDL_Init(SDL_INIT_VIDEO)) { | ||
| 28 | SDL_Log("Couldn't initialize SDL: %s", SDL_GetError()); | ||
| 29 | return SDL_APP_FAILURE; | ||
| 30 | } | ||
| 31 | |||
| 32 | if (!SDL_CreateWindowAndRenderer("examples/renderer/streaming-textures", WINDOW_WIDTH, WINDOW_HEIGHT, 0, &window, &renderer)) { | ||
| 33 | SDL_Log("Couldn't create window/renderer: %s", SDL_GetError()); | ||
| 34 | return SDL_APP_FAILURE; | ||
| 35 | } | ||
| 36 | |||
| 37 | texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_STREAMING, TEXTURE_SIZE, TEXTURE_SIZE); | ||
| 38 | if (!texture) { | ||
| 39 | SDL_Log("Couldn't create streaming texture: %s", SDL_GetError()); | ||
| 40 | return SDL_APP_FAILURE; | ||
| 41 | } | ||
| 42 | |||
| 43 | return SDL_APP_CONTINUE; /* carry on with the program! */ | ||
| 44 | } | ||
| 45 | |||
| 46 | /* This function runs when a new event (mouse input, keypresses, etc) occurs. */ | ||
| 47 | SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event) | ||
| 48 | { | ||
| 49 | if (event->type == SDL_EVENT_QUIT) { | ||
| 50 | return SDL_APP_SUCCESS; /* end the program, reporting success to the OS. */ | ||
| 51 | } | ||
| 52 | return SDL_APP_CONTINUE; /* carry on with the program! */ | ||
| 53 | } | ||
| 54 | |||
| 55 | /* This function runs once per frame, and is the heart of the program. */ | ||
| 56 | SDL_AppResult SDL_AppIterate(void *appstate) | ||
| 57 | { | ||
| 58 | SDL_FRect dst_rect; | ||
| 59 | const Uint64 now = SDL_GetTicks(); | ||
| 60 | SDL_Surface *surface = NULL; | ||
| 61 | |||
| 62 | /* we'll have some color move around over a few seconds. */ | ||
| 63 | const float direction = ((now % 2000) >= 1000) ? 1.0f : -1.0f; | ||
| 64 | const float scale = ((float) (((int) (now % 1000)) - 500) / 500.0f) * direction; | ||
| 65 | |||
| 66 | /* To update a streaming texture, you need to lock it first. This gets you access to the pixels. | ||
| 67 | Note that this is considered a _write-only_ operation: the buffer you get from locking | ||
| 68 | might not acutally have the existing contents of the texture, and you have to write to every | ||
| 69 | locked pixel! */ | ||
| 70 | |||
| 71 | /* You can use SDL_LockTexture() to get an array of raw pixels, but we're going to use | ||
| 72 | SDL_LockTextureToSurface() here, because it wraps that array in a temporary SDL_Surface, | ||
| 73 | letting us use the surface drawing functions instead of lighting up individual pixels. */ | ||
| 74 | if (SDL_LockTextureToSurface(texture, NULL, &surface)) { | ||
| 75 | SDL_Rect r; | ||
| 76 | SDL_FillSurfaceRect(surface, NULL, SDL_MapRGB(SDL_GetPixelFormatDetails(surface->format), NULL, 0, 0, 0)); /* make the whole surface black */ | ||
| 77 | r.w = TEXTURE_SIZE; | ||
| 78 | r.h = TEXTURE_SIZE / 10; | ||
| 79 | r.x = 0; | ||
| 80 | r.y = (int) (((float) (TEXTURE_SIZE - r.h)) * ((scale + 1.0f) / 2.0f)); | ||
| 81 | SDL_FillSurfaceRect(surface, &r, SDL_MapRGB(SDL_GetPixelFormatDetails(surface->format), NULL, 0, 255, 0)); /* make a strip of the surface green */ | ||
| 82 | SDL_UnlockTexture(texture); /* upload the changes (and frees the temporary surface)! */ | ||
| 83 | } | ||
| 84 | |||
| 85 | /* as you can see from this, rendering draws over whatever was drawn before it. */ | ||
| 86 | SDL_SetRenderDrawColor(renderer, 66, 66, 66, SDL_ALPHA_OPAQUE); /* grey, full alpha */ | ||
| 87 | SDL_RenderClear(renderer); /* start with a blank canvas. */ | ||
| 88 | |||
| 89 | /* Just draw the static texture a few times. You can think of it like a | ||
| 90 | stamp, there isn't a limit to the number of times you can draw with it. */ | ||
| 91 | |||
| 92 | /* Center this one. It'll draw the latest version of the texture we drew while it was locked. */ | ||
| 93 | dst_rect.x = ((float) (WINDOW_WIDTH - TEXTURE_SIZE)) / 2.0f; | ||
| 94 | dst_rect.y = ((float) (WINDOW_HEIGHT - TEXTURE_SIZE)) / 2.0f; | ||
| 95 | dst_rect.w = dst_rect.h = (float) TEXTURE_SIZE; | ||
| 96 | SDL_RenderTexture(renderer, texture, NULL, &dst_rect); | ||
| 97 | |||
| 98 | SDL_RenderPresent(renderer); /* put it all on the screen! */ | ||
| 99 | |||
| 100 | return SDL_APP_CONTINUE; /* carry on with the program! */ | ||
| 101 | } | ||
| 102 | |||
| 103 | /* This function runs once at shutdown. */ | ||
| 104 | void SDL_AppQuit(void *appstate, SDL_AppResult result) | ||
| 105 | { | ||
| 106 | SDL_DestroyTexture(texture); | ||
| 107 | /* SDL will clean up the window/renderer for us. */ | ||
| 108 | } | ||
| 109 | |||
