SDL2.0的几何图形绘画
通过SDL_Window、SDL_Renderer、SDL_Texture三者实现了简单的几何图形绘画。
包括了SDL_RenderDrawPoint、SDL_RenderFillRect、SDL_RenderDrawLine、SDL_SetRenderDrawColor等。
具体看代码吧(VS2012运行):
1 #include <stdio.h> 2 #include <string.h> 3 #include <time.h> 4 #include <SDL2\SDL.h> 5 #include <SDL2\SDL_image.h> 6 #include <SDL2\ex\SDLex.h> 7 8 SDL_Window *sdlWindow = NULL; 9 SDL_Renderer *sdlRender = NULL; 10 SDL_Texture *sdlTexture = NULL; 11 SDL srcRect; 12 int w = 500; 13 int h = 500; 14 15 void DrawCircle(SDL_Renderer *ren,int radius){ 16 int st=clock(),tx=0,ty=radius,d=3-(radius<<1),x=radius,y=radius; 17 while(tx<ty){ 18 for (int i=x-ty;i<=x+ty;++i){ 19 SDL_RenderDrawPoint(ren,i,y-tx); 20 if (tx) 21 SDL_RenderDrawPoint(ren,i,y+tx); 22 } 23 if (d<0) 24 d+=(tx<<2)+6; 25 else{ 26 for (int i=x-tx;i<=x+tx;++i){ 27 SDL_RenderDrawPoint(ren,i,y-ty); 28 SDL_RenderDrawPoint(ren,i,y+ty); 29 } 30 d+=((tx - ty)<<2)+10,ty--; 31 } 32 tx++; 33 } 34 if (tx==ty) 35 for (int i=x-ty;i<=x+ty;++i){ 36 SDL_RenderDrawPoint(ren,i,y-tx); 37 SDL_RenderDrawPoint(ren,i,y+tx); 38 } 39 int en=clock(); 40 } 41 42 bool InitView(int width, int height, const char *iconName) 43 { 44 //初始化窗体 45 SDL_Init(SDL_INIT_VIDEO); 46 47 sdlWindow = SDL_CreateWindow( 48 "The First SDL Program", 49 SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, width, height, 50 SDL_WINDOW_RESIZABLE); 51 if (sdlWindow == NULL) return false; 52 53 //加载窗体图标 54 SDL_Surface *iconSurface = IMG_Load(iconName); 55 if (iconSurface == NULL) return false; 56 57 SDL_SetWindowIcon(sdlWindow, iconSurface); 58 59 return true; 60 } 61 62 bool InitDraw() 63 { 64 //加载渲染器 65 sdlRender = SDL_CreateRenderer(sdlWindow, -1, 0); 66 if (sdlRender == NULL) return false; 67 68 sdlTexture = SDL_CreateTexture(sdlRender, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_TARGET, w, h); 69 if (sdlTexture == NULL) return false; 70 //SDL_SetTextureBlendMode(sdlTexture, SDL_BLENDMODE_BLEND); 71 //SDL_SetRenderTarget(sdlRender, sdlTexture); 72 73 return true; 74 } 75 76 void UpdateDraw() 77 { 78 //设置背景颜色 79 SDL_SetRenderDrawColor(sdlRender, 255, 153, 153, 0xFF); 80 SDL_RenderClear(sdlRender); 81 82 //左眼 83 SDL_SetRenderDrawColor(sdlRender, 0x00, 0xFF, 0xFF, 0xFF); 84 srcRect = SDLMake(w/7*2, h/7, w/8, h/8); 85 SDL_RenderFillRect(sdlRender, &srcRect); 86 87 //左眉毛 88 SDL_SetRenderDrawColor(sdlRender, 0x00, 0x00, 0x00, 0xFF); 89 SDL_RenderDrawLine(sdlRender, srcRect.x, srcRect.y - 10, SDLMaxX(srcRect), srcRect.y - 10); 90 91 //右眼 92 SDL_SetRenderDrawColor(sdlRender, 0xFF, 0x00, 0xFF, 0xFF); 93 srcRect = SDLMake(w/7*4, srcRect.y, srcRect.w, srcRect.h); 94 SDL_RenderDrawRect(sdlRender, &srcRect); 95 96 //右眉毛 97 SDL_SetRenderDrawColor(sdlRender, 0x00, 0x00, 0x00, 0xFF); 98 SDL_RenderDrawLine(sdlRender, srcRect.x, srcRect.y - 10, SDLMaxX(srcRect), srcRect.y - 10); 99 100 //嘴巴 101 SDL_SetRenderDrawColor(sdlRender, 0xFF, 0xFF, 0x00, 0xFF); 102 srcRect = SDLMake(w/8*3, h/7*3, w/8*2, h/8); 103 SDL_RenderFillRect(sdlRender, &srcRect); 104 105 SDL_SetRenderDrawColor(sdlRender, 0xFF, 0x00, 0x00, 0xFF); 106 DrawCircle(sdlRender, 10); 107 108 SDL_RenderPresent(sdlRender); 109 } 110 111 void Quit(int code) 112 { 113 const char *errMsg = SDL_GetError(); 114 if (errMsg && strlen(errMsg)) { 115 SDL_Log("Error : %s\n", errMsg); 116 } 117 118 //销毁窗口、渲染器、纹理 119 if (sdlWindow) SDL_DestroyWindow(sdlWindow); 120 if (sdlRender) SDL_DestroyRenderer(sdlRender); 121 if (sdlTexture) SDL_DestroyTexture(sdlTexture); 122 SDL_Quit(); 123 exit(code); 124 } 125 126 void HandleKeyEvent(const SDL_Keysym* keysym) 127 { 128 int key = keysym->sym; 129 switch(key) 130 { 131 case SDLK_ESCAPE: 132 Quit(0); 133 break; 134 case SDLK_SPACE: 135 break; 136 case SDLK_UP: 137 case SDLK_DOWN: 138 case SDLK_LEFT: 139 case SDLK_RIGHT: 140 int x, y; 141 SDL_GetWindowPosition(sdlWindow, &x, &y); 142 x = (key == SDLK_LEFT ? x-2 : (key == SDLK_RIGHT ? x+2 : x)); 143 y = (key == SDLK_UP ? y-2 : (key == SDLK_DOWN ? y+2 : y)); 144 SDL_SetWindowPosition(sdlWindow, x, y); 145 SDL_Log("x=%d, y=%d\n", x, y); 146 break; 147 case SDLK_KP_PLUS: 148 case SDLK_KP_MINUS: 149 w = (key == SDLK_KP_PLUS ? w+2 : w-2); 150 h = (key == SDLK_KP_PLUS ? h+2 : h-2); 151 SDL_SetWindowSize(sdlWindow, w, h); 152 SDL_Log("w=%d, h=%d\n", w, h); 153 break; 154 default: 155 break; 156 } 157 } 158 159 void HandleEvents() 160 { 161 //Our SDL event placeholder. 162 SDL_Event event; 163 //Grab all the events off the queue. 164 while(SDL_PollEvent(&event)) { 165 switch(event.type) { 166 case SDL_KEYDOWN: 167 //Handle key Event 168 HandleKeyEvent(&event.key.keysym); 169 break; 170 case SDL_QUIT: 171 //Handle quit requests (like Ctrl-c). 172 Quit(0); 173 break; 174 } 175 } 176 } 177 178 int main(int argc, char* argv[]) 179 { 180 printf("可以通过↑↓←→+ -按键控制移动和大小\n"); 181 if (InitView(w, h, "yp.ico") == false) { 182 SDL_Log("sdlWindow is null @[email protected]\n"); 183 Quit(0); 184 return -1; 185 } 186 187 if (InitDraw() == false) { 188 SDL_Log("Init Fail @[email protected]\n"); 189 Quit(0); 190 return -1; 191 } 192 193 //配置客户区大小 194 SDL_QueryTexture(sdlTexture,NULL, NULL, &w, &h); 195 SDL_SetWindowSize(sdlWindow, w + 2, h); 196 SDL_Log("w=%d, h=%d\n", w, h); 197 198 while (1) { 199 HandleEvents(); 200 UpdateDraw(); 201 } 202 203 SDL_DestroyWindow(sdlWindow); 204 SDL_Quit(); 205 return 0; 206 }
效果图:
时间: 2024-10-15 19:41:45