happy.c (4607B)
1 /* 2 * happy.c 3 * written by Holmes Futrell 4 * use however you want 5 */ 6 7 #include "SDL.h" 8 #include "common.h" 9 10 #define NUM_HAPPY_FACES 100 /* number of faces to draw */ 11 #define HAPPY_FACE_SIZE 32 /* width and height of happyface */ 12 13 static SDL_Texture *texture = 0; /* reference to texture holding happyface */ 14 15 static struct 16 { 17 float x, y; /* position of happyface */ 18 float xvel, yvel; /* velocity of happyface */ 19 } faces[NUM_HAPPY_FACES]; 20 21 /* 22 Sets initial positions and velocities of happyfaces 23 units of velocity are pixels per millesecond 24 */ 25 void 26 initializeHappyFaces(SDL_Renderer *renderer) 27 { 28 int i; 29 int w; 30 int h; 31 SDL_RenderGetLogicalSize(renderer, &w, &h); 32 33 for (i = 0; i < NUM_HAPPY_FACES; i++) { 34 faces[i].x = randomFloat(0.0f, w - HAPPY_FACE_SIZE); 35 faces[i].y = randomFloat(0.0f, h - HAPPY_FACE_SIZE); 36 faces[i].xvel = randomFloat(-60.0f, 60.0f); 37 faces[i].yvel = randomFloat(-60.0f, 60.0f); 38 } 39 } 40 41 void 42 render(SDL_Renderer *renderer, double deltaTime) 43 { 44 int i; 45 SDL_Rect srcRect; 46 SDL_Rect dstRect; 47 int w; 48 int h; 49 50 SDL_RenderGetLogicalSize(renderer, &w, &h); 51 52 /* setup boundaries for happyface bouncing */ 53 int maxx = w - HAPPY_FACE_SIZE; 54 int maxy = h - HAPPY_FACE_SIZE; 55 int minx = 0; 56 int miny = 0; 57 58 /* setup rects for drawing */ 59 srcRect.x = 0; 60 srcRect.y = 0; 61 srcRect.w = HAPPY_FACE_SIZE; 62 srcRect.h = HAPPY_FACE_SIZE; 63 dstRect.w = HAPPY_FACE_SIZE; 64 dstRect.h = HAPPY_FACE_SIZE; 65 66 /* fill background in with black */ 67 SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255); 68 SDL_RenderClear(renderer); 69 70 /* 71 loop through all the happy faces: 72 - update position 73 - update velocity (if boundary is hit) 74 - draw 75 */ 76 for (i = 0; i < NUM_HAPPY_FACES; i++) { 77 faces[i].x += faces[i].xvel * deltaTime; 78 faces[i].y += faces[i].yvel * deltaTime; 79 if (faces[i].x > maxx) { 80 faces[i].x = maxx; 81 faces[i].xvel = -faces[i].xvel; 82 } else if (faces[i].y > maxy) { 83 faces[i].y = maxy; 84 faces[i].yvel = -faces[i].yvel; 85 } 86 if (faces[i].x < minx) { 87 faces[i].x = minx; 88 faces[i].xvel = -faces[i].xvel; 89 } else if (faces[i].y < miny) { 90 faces[i].y = miny; 91 faces[i].yvel = -faces[i].yvel; 92 } 93 dstRect.x = faces[i].x; 94 dstRect.y = faces[i].y; 95 SDL_RenderCopy(renderer, texture, &srcRect, &dstRect); 96 } 97 /* update screen */ 98 SDL_RenderPresent(renderer); 99 100 } 101 102 /* 103 loads the happyface graphic into a texture 104 */ 105 void 106 initializeTexture(SDL_Renderer *renderer) 107 { 108 SDL_Surface *bmp_surface; 109 /* load the bmp */ 110 bmp_surface = SDL_LoadBMP("icon.bmp"); 111 if (bmp_surface == NULL) { 112 fatalError("could not load bmp"); 113 } 114 /* set white to transparent on the happyface */ 115 SDL_SetColorKey(bmp_surface, 1, 116 SDL_MapRGB(bmp_surface->format, 255, 255, 255)); 117 118 /* convert RGBA surface to texture */ 119 texture = SDL_CreateTextureFromSurface(renderer, bmp_surface); 120 if (texture == 0) { 121 fatalError("could not create texture"); 122 } 123 SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND); 124 125 /* free up allocated memory */ 126 SDL_FreeSurface(bmp_surface); 127 } 128 129 int 130 main(int argc, char *argv[]) 131 { 132 SDL_Window *window; 133 SDL_Renderer *renderer; 134 int done; 135 int width; 136 int height; 137 138 /* initialize SDL */ 139 if (SDL_Init(SDL_INIT_VIDEO) < 0) { 140 fatalError("Could not initialize SDL"); 141 } 142 143 /* The specified window size doesn't matter - except for its aspect ratio, 144 * which determines whether the window is in portrait or landscape on iOS 145 * (if SDL_WINDOW_RESIZABLE isn't specified). */ 146 window = SDL_CreateWindow(NULL, 0, 0, 320, 480, SDL_WINDOW_FULLSCREEN | SDL_WINDOW_ALLOW_HIGHDPI); 147 148 renderer = SDL_CreateRenderer(window, -1, 0); 149 150 SDL_GetWindowSize(window, &width, &height); 151 SDL_RenderSetLogicalSize(renderer, width, height); 152 153 initializeTexture(renderer); 154 initializeHappyFaces(renderer); 155 156 157 /* main loop */ 158 done = 0; 159 while (!done) { 160 SDL_Event event; 161 double deltaTime = updateDeltaTime(); 162 163 while (SDL_PollEvent(&event)) { 164 if (event.type == SDL_QUIT) { 165 done = 1; 166 } 167 } 168 169 render(renderer, deltaTime); 170 SDL_Delay(1); 171 } 172 173 /* cleanup */ 174 SDL_DestroyTexture(texture); 175 /* shutdown SDL */ 176 SDL_Quit(); 177 178 return 0; 179 180 }