diff --git a/examples/renderer/19-affine-textures/affine-textures.c b/examples/renderer/19-affine-textures/affine-textures.c index 6cde3bae8a..05e314ba8d 100644 --- a/examples/renderer/19-affine-textures/affine-textures.c +++ b/examples/renderer/19-affine-textures/affine-textures.c @@ -1,142 +1,143 @@ /* affine-textures.c ... */ /* - * This example creates an SDL window and renderer, and then draws a cube - * using affine-transformed textures every frame. - * - * This code is public domain. Feel free to use it for any purpose! - */ +* This example creates an SDL window and renderer, and then draws a cube +* using affine-transformed textures 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_Texture *texture = NULL; +static int texture_width = 0; +static int texture_height = 0; + +#define WINDOW_WIDTH 640 +#define WINDOW_HEIGHT 480 + +/* This function runs once at startup. */ +SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[]) +{ + SDL_Surface *surface = NULL; + char *bmp_path = NULL; + + SDL_SetAppMetadata("Example Renderer Affine Textures", "1.0", "com.example.renderer-affine-textures"); + + if (!SDL_Init(SDL_INIT_VIDEO)) { + SDL_Log("Couldn't initialize SDL: %s", SDL_GetError()); + return SDL_APP_FAILURE; + } + + if (!SDL_CreateWindowAndRenderer("examples/renderer/affine-textures", WINDOW_WIDTH, WINDOW_HEIGHT, 0, &window, &renderer)) { + SDL_Log("Couldn't create window/renderer: %s", SDL_GetError()); + return SDL_APP_FAILURE; + } + + /* Textures are pixel data that we upload to the video hardware for fast drawing. Lots of 2D + engines refer to these as "sprites." We'll do a static texture (upload once, draw many + times) with data from a bitmap file. */ + + /* SDL_Surface is pixel data the CPU can access. SDL_Texture is pixel data the GPU can access. + Load a .bmp into a surface, move it to a texture from there. */ + SDL_asprintf(&bmp_path, "%ssample.bmp", SDL_GetBasePath()); /* allocate a string of the full file path */ + surface = SDL_LoadBMP(bmp_path); + if (!surface) { + SDL_Log("Couldn't load bitmap: %s", SDL_GetError()); + return SDL_APP_FAILURE; + } + + SDL_free(bmp_path); /* done with this, the file is loaded. */ + + texture_width = surface->w; + texture_height = surface->h; + + texture = SDL_CreateTextureFromSurface(renderer, surface); + if (!texture) { + SDL_Log("Couldn't create static texture: %s", SDL_GetError()); + return SDL_APP_FAILURE; + } + + SDL_DestroySurface(surface); /* done with this, the texture has a copy of the pixels now. */ + + return SDL_APP_CONTINUE; /* carry on with the program! */ +} + +/* This function runs when a new event (mouse input, keypresses, etc) occurs. */ +SDL_AppResult SDL_AppEvent(void *appstate, 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. */ +SDL_AppResult SDL_AppIterate(void *appstate) +{ + const float x0 = 0.5f * WINDOW_WIDTH; + const float y0 = 0.5f * WINDOW_HEIGHT; + const float px = SDL_min(WINDOW_WIDTH, WINDOW_HEIGHT) / SDL_sqrtf(3.0f); + + const Uint64 now = SDL_GetTicks(); + const float rad = (((float) ((int) (now % 4000))) / 4000.0f) * SDL_PI_F * 2; + const float cos = SDL_cosf(rad); + const float sin = SDL_sinf(rad); + const float k[3] = { 3.0f / SDL_sqrtf(50.0f), 4.0f / SDL_sqrtf(50.0f), 5.0f / SDL_sqrtf(50.0f)}; + float mat[9] = { + cos + (1.0f-cos)*k[0]*k[0], -sin*k[2] + (1.0f-cos)*k[0]*k[1], sin*k[1] + (1.0f-cos)*k[0]*k[2], + sin*k[2] + (1.0f-cos)*k[0]*k[1], cos + (1.0f-cos)*k[1]*k[1], -sin*k[0] + (1.0f-cos)*k[1]*k[2], + -sin*k[1] + (1.0f-cos)*k[0]*k[2], sin*k[0] + (1.0f-cos)*k[1]*k[2], cos + (1.0f-cos)*k[2]*k[2], + }; + + float corners[16]; + for (int i = 0; i < 8; i++) { + const float x = (i & 1) ? 0.5f : -0.5f; + const float y = (i & 2) ? 0.5f : -0.5f; + const float z = (i & 4) ? 0.5f : -0.5f; + corners[0 + 2*i] = mat[0]*x + mat[1]*y + mat[2]*z; + corners[1 + 2*i] = mat[3]*x + mat[4]*y + mat[5]*z; + } + + SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE); + SDL_RenderClear(renderer); + + for (int i = 1; i < 7; i++) { + const int dir = 3 & ((i & 4) ? ~i : i); + const int odd = (i & 1) ^ ((i & 2) >> 1) ^ ((i & 4) >> 2); + if (0 < (odd ? 1.0f : -1.0f) * mat[5 + dir]) continue; + int origin_index = (1 << ((dir - 1) % 3)); + int right_index = (1 << ((dir + odd) % 3)) | origin_index; + int down_index = (1 << ((dir + (odd^1)) % 3)) | origin_index; + if (!odd) { + origin_index ^= 7; + right_index ^= 7; + down_index ^= 7; + } + SDL_FPoint origin, right, down; + origin.x = x0 + px*corners[0 + 2*origin_index]; + origin.y = y0 + px*corners[1 + 2*origin_index]; + right.x = x0 + px*corners[0 + 2*right_index]; + right.y = y0 + px*corners[1 + 2*right_index]; + down.x = x0 + px*corners[0 + 2*down_index]; + down.y = y0 + px*corners[1 + 2*down_index]; + SDL_RenderTextureAffine(renderer, texture, NULL, &origin, &right, &down); + } + + SDL_RenderPresent(renderer); + + return SDL_APP_CONTINUE; +} + +/* This function runs once at shutdown. */ +void SDL_AppQuit(void *appstate, SDL_AppResult result) +{ + SDL_DestroyTexture(texture); + /* SDL will clean up the window/renderer for us. */ +} - #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_Texture *texture = NULL; - static int texture_width = 0; - static int texture_height = 0; - - #define WINDOW_WIDTH 640 - #define WINDOW_HEIGHT 480 - - /* This function runs once at startup. */ - SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[]) - { - SDL_Surface *surface = NULL; - char *bmp_path = NULL; - - SDL_SetAppMetadata("Example Renderer Affine Textures", "1.0", "com.example.renderer-affine-textures"); - - if (!SDL_Init(SDL_INIT_VIDEO)) { - SDL_Log("Couldn't initialize SDL: %s", SDL_GetError()); - return SDL_APP_FAILURE; - } - - if (!SDL_CreateWindowAndRenderer("examples/renderer/affine-textures", WINDOW_WIDTH, WINDOW_HEIGHT, 0, &window, &renderer)) { - SDL_Log("Couldn't create window/renderer: %s", SDL_GetError()); - return SDL_APP_FAILURE; - } - - /* Textures are pixel data that we upload to the video hardware for fast drawing. Lots of 2D - engines refer to these as "sprites." We'll do a static texture (upload once, draw many - times) with data from a bitmap file. */ - - /* SDL_Surface is pixel data the CPU can access. SDL_Texture is pixel data the GPU can access. - Load a .bmp into a surface, move it to a texture from there. */ - SDL_asprintf(&bmp_path, "%ssample.bmp", SDL_GetBasePath()); /* allocate a string of the full file path */ - surface = SDL_LoadBMP(bmp_path); - if (!surface) { - SDL_Log("Couldn't load bitmap: %s", SDL_GetError()); - return SDL_APP_FAILURE; - } - - SDL_free(bmp_path); /* done with this, the file is loaded. */ - - texture_width = surface->w; - texture_height = surface->h; - - texture = SDL_CreateTextureFromSurface(renderer, surface); - if (!texture) { - SDL_Log("Couldn't create static texture: %s", SDL_GetError()); - return SDL_APP_FAILURE; - } - - SDL_DestroySurface(surface); /* done with this, the texture has a copy of the pixels now. */ - - return SDL_APP_CONTINUE; /* carry on with the program! */ - } - - /* This function runs when a new event (mouse input, keypresses, etc) occurs. */ - SDL_AppResult SDL_AppEvent(void *appstate, 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. */ - SDL_AppResult SDL_AppIterate(void *appstate) { - const float x0 = 0.5f * WINDOW_WIDTH; - const float y0 = 0.5f * WINDOW_HEIGHT; - const float px = SDL_min(WINDOW_WIDTH, WINDOW_HEIGHT) / SDL_sqrtf(3.0f); - - const Uint64 now = SDL_GetTicks(); - const float rad = (((float) ((int) (now % 4000))) / 4000.0f) * SDL_PI_F * 2; - const float cos = SDL_cosf(rad); - const float sin = SDL_sinf(rad); - const float k[3] = { 3.0f / SDL_sqrtf(50.0f), 4.0f / SDL_sqrtf(50.0f), 5.0f / SDL_sqrtf(50.0f)}; - float mat[9] = { - cos + (1.0f-cos)*k[0]*k[0], -sin*k[2] + (1.0f-cos)*k[0]*k[1], sin*k[1] + (1.0f-cos)*k[0]*k[2], - sin*k[2] + (1.0f-cos)*k[0]*k[1], cos + (1.0f-cos)*k[1]*k[1], -sin*k[0] + (1.0f-cos)*k[1]*k[2], - -sin*k[1] + (1.0f-cos)*k[0]*k[2], sin*k[0] + (1.0f-cos)*k[1]*k[2], cos + (1.0f-cos)*k[2]*k[2], - }; - - float corners[16]; - for (int i = 0; i < 8; i++) { - const float x = (i & 1) ? 0.5f : -0.5f; - const float y = (i & 2) ? 0.5f : -0.5f; - const float z = (i & 4) ? 0.5f : -0.5f; - corners[0 + 2*i] = mat[0]*x + mat[1]*y + mat[2]*z; - corners[1 + 2*i] = mat[3]*x + mat[4]*y + mat[5]*z; - } - - SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE); - SDL_RenderClear(renderer); - - for (int i = 1; i < 7; i++) { - const int dir = 3 & ((i & 4) ? ~i : i); - const int odd = (i & 1) ^ ((i & 2) >> 1) ^ ((i & 4) >> 2); - if (0 < (odd ? 1.0f : -1.0f) * mat[5 + dir]) continue; - int origin_index = (1 << ((dir - 1) % 3)); - int right_index = (1 << ((dir + odd) % 3)) | origin_index; - int down_index = (1 << ((dir + (odd^1)) % 3)) | origin_index; - if (!odd) { - origin_index ^= 7; - right_index ^= 7; - down_index ^= 7; - } - SDL_FPoint origin, right, down; - origin.x = x0 + px*corners[0 + 2*origin_index]; - origin.y = y0 + px*corners[1 + 2*origin_index]; - right.x = x0 + px*corners[0 + 2*right_index]; - right.y = y0 + px*corners[1 + 2*right_index]; - down.x = x0 + px*corners[0 + 2*down_index]; - down.y = y0 + px*corners[1 + 2*down_index]; - SDL_RenderTextureAffine(renderer, texture, NULL, &origin, &right, &down); - } - - SDL_RenderPresent(renderer); - - return SDL_APP_CONTINUE; - } - - /* This function runs once at shutdown. */ - void SDL_AppQuit(void *appstate, SDL_AppResult result) - { - SDL_DestroyTexture(texture); - /* SDL will clean up the window/renderer for us. */ - } - \ No newline at end of file