diff options
Diffstat (limited to 'contrib/SDL-3.2.8/examples/renderer/10-geometry/geometry.c')
| -rw-r--r-- | contrib/SDL-3.2.8/examples/renderer/10-geometry/geometry.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/contrib/SDL-3.2.8/examples/renderer/10-geometry/geometry.c b/contrib/SDL-3.2.8/examples/renderer/10-geometry/geometry.c new file mode 100644 index 0000000..77ff863 --- /dev/null +++ b/contrib/SDL-3.2.8/examples/renderer/10-geometry/geometry.c | |||
| @@ -0,0 +1,166 @@ | |||
| 1 | /* | ||
| 2 | * This example creates an SDL window and renderer, and then draws some | ||
| 3 | * geometry (arbitrary polygons) 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 | static int texture_width = 0; | ||
| 17 | static int texture_height = 0; | ||
| 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_Surface *surface = NULL; | ||
| 26 | char *bmp_path = NULL; | ||
| 27 | |||
| 28 | SDL_SetAppMetadata("Example Renderer Geometry", "1.0", "com.example.renderer-geometry"); | ||
| 29 | |||
| 30 | if (!SDL_Init(SDL_INIT_VIDEO)) { | ||
| 31 | SDL_Log("Couldn't initialize SDL: %s", SDL_GetError()); | ||
| 32 | return SDL_APP_FAILURE; | ||
| 33 | } | ||
| 34 | |||
| 35 | if (!SDL_CreateWindowAndRenderer("examples/renderer/geometry", WINDOW_WIDTH, WINDOW_HEIGHT, 0, &window, &renderer)) { | ||
| 36 | SDL_Log("Couldn't create window/renderer: %s", SDL_GetError()); | ||
| 37 | return SDL_APP_FAILURE; | ||
| 38 | } | ||
| 39 | |||
| 40 | /* Textures are pixel data that we upload to the video hardware for fast drawing. Lots of 2D | ||
| 41 | engines refer to these as "sprites." We'll do a static texture (upload once, draw many | ||
| 42 | times) with data from a bitmap file. */ | ||
| 43 | |||
| 44 | /* SDL_Surface is pixel data the CPU can access. SDL_Texture is pixel data the GPU can access. | ||
| 45 | Load a .bmp into a surface, move it to a texture from there. */ | ||
| 46 | SDL_asprintf(&bmp_path, "%ssample.bmp", SDL_GetBasePath()); /* allocate a string of the full file path */ | ||
| 47 | surface = SDL_LoadBMP(bmp_path); | ||
| 48 | if (!surface) { | ||
| 49 | SDL_Log("Couldn't load bitmap: %s", SDL_GetError()); | ||
| 50 | return SDL_APP_FAILURE; | ||
| 51 | } | ||
| 52 | |||
| 53 | SDL_free(bmp_path); /* done with this, the file is loaded. */ | ||
| 54 | |||
| 55 | texture_width = surface->w; | ||
| 56 | texture_height = surface->h; | ||
| 57 | |||
| 58 | texture = SDL_CreateTextureFromSurface(renderer, surface); | ||
| 59 | if (!texture) { | ||
| 60 | SDL_Log("Couldn't create static texture: %s", SDL_GetError()); | ||
| 61 | return SDL_APP_FAILURE; | ||
| 62 | } | ||
| 63 | |||
| 64 | SDL_DestroySurface(surface); /* done with this, the texture has a copy of the pixels now. */ | ||
| 65 | |||
| 66 | return SDL_APP_CONTINUE; /* carry on with the program! */ | ||
| 67 | } | ||
| 68 | |||
| 69 | /* This function runs when a new event (mouse input, keypresses, etc) occurs. */ | ||
| 70 | SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event) | ||
| 71 | { | ||
| 72 | if (event->type == SDL_EVENT_QUIT) { | ||
| 73 | return SDL_APP_SUCCESS; /* end the program, reporting success to the OS. */ | ||
| 74 | } | ||
| 75 | return SDL_APP_CONTINUE; /* carry on with the program! */ | ||
| 76 | } | ||
| 77 | |||
| 78 | /* This function runs once per frame, and is the heart of the program. */ | ||
| 79 | SDL_AppResult SDL_AppIterate(void *appstate) | ||
| 80 | { | ||
| 81 | const Uint64 now = SDL_GetTicks(); | ||
| 82 | |||
| 83 | /* we'll have the triangle grow and shrink over a few seconds. */ | ||
| 84 | const float direction = ((now % 2000) >= 1000) ? 1.0f : -1.0f; | ||
| 85 | const float scale = ((float) (((int) (now % 1000)) - 500) / 500.0f) * direction; | ||
| 86 | const float size = 200.0f + (200.0f * scale); | ||
| 87 | |||
| 88 | SDL_Vertex vertices[4]; | ||
| 89 | int i; | ||
| 90 | |||
| 91 | /* as you can see from this, rendering draws over whatever was drawn before it. */ | ||
| 92 | SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE); /* black, full alpha */ | ||
| 93 | SDL_RenderClear(renderer); /* start with a blank canvas. */ | ||
| 94 | |||
| 95 | /* Draw a single triangle with a different color at each vertex. Center this one and make it grow and shrink. */ | ||
| 96 | /* You always draw triangles with this, but you can string triangles together to form polygons. */ | ||
| 97 | SDL_zeroa(vertices); | ||
| 98 | vertices[0].position.x = ((float) WINDOW_WIDTH) / 2.0f; | ||
| 99 | vertices[0].position.y = (((float) WINDOW_HEIGHT) - size) / 2.0f; | ||
| 100 | vertices[0].color.r = 1.0f; | ||
| 101 | vertices[0].color.a = 1.0f; | ||
| 102 | vertices[1].position.x = (((float) WINDOW_WIDTH) + size) / 2.0f; | ||
| 103 | vertices[1].position.y = (((float) WINDOW_HEIGHT) + size) / 2.0f; | ||
| 104 | vertices[1].color.g = 1.0f; | ||
| 105 | vertices[1].color.a = 1.0f; | ||
| 106 | vertices[2].position.x = (((float) WINDOW_WIDTH) - size) / 2.0f; | ||
| 107 | vertices[2].position.y = (((float) WINDOW_HEIGHT) + size) / 2.0f; | ||
| 108 | vertices[2].color.b = 1.0f; | ||
| 109 | vertices[2].color.a = 1.0f; | ||
| 110 | |||
| 111 | SDL_RenderGeometry(renderer, NULL, vertices, 3, NULL, 0); | ||
| 112 | |||
| 113 | /* you can also map a texture to the geometry! Texture coordinates go from 0.0f to 1.0f. That will be the location | ||
| 114 | in the texture bound to this vertex. */ | ||
| 115 | SDL_zeroa(vertices); | ||
| 116 | vertices[0].position.x = 10.0f; | ||
| 117 | vertices[0].position.y = 10.0f; | ||
| 118 | vertices[0].color.r = vertices[0].color.g = vertices[0].color.b = vertices[0].color.a = 1.0f; | ||
| 119 | vertices[0].tex_coord.x = 0.0f; | ||
| 120 | vertices[0].tex_coord.y = 0.0f; | ||
| 121 | vertices[1].position.x = 150.0f; | ||
| 122 | vertices[1].position.y = 10.0f; | ||
| 123 | vertices[1].color.r = vertices[1].color.g = vertices[1].color.b = vertices[1].color.a = 1.0f; | ||
| 124 | vertices[1].tex_coord.x = 1.0f; | ||
| 125 | vertices[1].tex_coord.y = 0.0f; | ||
| 126 | vertices[2].position.x = 10.0f; | ||
| 127 | vertices[2].position.y = 150.0f; | ||
| 128 | vertices[2].color.r = vertices[2].color.g = vertices[2].color.b = vertices[2].color.a = 1.0f; | ||
| 129 | vertices[2].tex_coord.x = 0.0f; | ||
| 130 | vertices[2].tex_coord.y = 1.0f; | ||
| 131 | SDL_RenderGeometry(renderer, texture, vertices, 3, NULL, 0); | ||
| 132 | |||
| 133 | /* Did that only draw half of the texture? You can do multiple triangles sharing some vertices, | ||
| 134 | using indices, to get the whole thing on the screen: */ | ||
| 135 | |||
| 136 | /* Let's just move this over so it doesn't overlap... */ | ||
| 137 | for (i = 0; i < 3; i++) { | ||
| 138 | vertices[i].position.x += 450; | ||
| 139 | } | ||
| 140 | |||
| 141 | /* we need one more vertex, since the two triangles can share two of them. */ | ||
| 142 | vertices[3].position.x = 600.0f; | ||
| 143 | vertices[3].position.y = 150.0f; | ||
| 144 | vertices[3].color.r = vertices[3].color.g = vertices[3].color.b = vertices[3].color.a = 1.0f; | ||
| 145 | vertices[3].tex_coord.x = 1.0f; | ||
| 146 | vertices[3].tex_coord.y = 1.0f; | ||
| 147 | |||
| 148 | /* And an index to tell it to reuse some of the vertices between triangles... */ | ||
| 149 | { | ||
| 150 | /* 4 vertices, but 6 actual places they used. Indices need less bandwidth to transfer and can reorder vertices easily! */ | ||
| 151 | const int indices[] = { 0, 1, 2, 1, 2, 3 }; | ||
| 152 | SDL_RenderGeometry(renderer, texture, vertices, 4, indices, SDL_arraysize(indices)); | ||
| 153 | } | ||
| 154 | |||
| 155 | SDL_RenderPresent(renderer); /* put it all on the screen! */ | ||
| 156 | |||
| 157 | return SDL_APP_CONTINUE; /* carry on with the program! */ | ||
| 158 | } | ||
| 159 | |||
| 160 | /* This function runs once at shutdown. */ | ||
| 161 | void SDL_AppQuit(void *appstate, SDL_AppResult result) | ||
| 162 | { | ||
| 163 | SDL_DestroyTexture(texture); | ||
| 164 | /* SDL will clean up the window/renderer for us. */ | ||
| 165 | } | ||
| 166 | |||
