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  • SDL2.0的加载图片贴图

    加载图片贴图，采用了SDL_Window、SDL_Renderer、SDL_Texture和SDL_Image库 

    实例：

      1 #include <stdio.h>
  2 #include <math.h>
  3 #include <string.h>
  4 #include <SDL2SDL.h>
  5 #include <SDL2SDL_image.h>
  6 #include <SDL2exSDL_rectex.h>
  7 
  8 SDL_Window *sdlWindow = NULL;
  9 SDL_Renderer *sdlRender = NULL;
 10 SDL_Texture *sdlTexture = NULL;
 11 SDL_Rect srcRect;
 12 SDL_Rect dstRect;
 13 int w = 500;
 14 int h = 500;
 15 
 16 bool InitView(int width, int height, const char *iconName)
 17 {
 18     //初始化窗体
 19     SDL_Init(SDL_INIT_VIDEO);
 20 
 21     sdlWindow = SDL_CreateWindow(
 22         "The First SDL Program", 
 23         SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, width, height, 
 24         SDL_WINDOW_RESIZABLE);
 25     if (sdlWindow == NULL) return false;
 26 
 27     //加载窗体图标
 28     SDL_Surface *iconSurface = IMG_Load(iconName);
 29     if (iconSurface == NULL) return false;
 30 
 31     SDL_SetWindowIcon(sdlWindow, iconSurface);
 32 
 33     return true;
 34 }
 35 
 36 bool InitDraw(const char *imgName)
 37 {
 38     //加载渲染器
 39     sdlRender = SDL_CreateRenderer(sdlWindow, -1, 0);
 40     if (sdlRender == NULL) return false;
 41     SDL_SetRenderDrawColor(sdlRender, 255, 255, 255, 255);
 42 
 43     //加载绘画图片
 44     SDL_Surface *sdlSurface = IMG_Load(imgName);
 45     if (sdlSurface == NULL) return false;
 46 
 47     //加载绘画纹理
 48     sdlTexture = SDL_CreateTextureFromSurface(sdlRender, sdlSurface);
 49     if (sdlTexture == NULL) return false;
 50     
 51     SDL_FreeSurface(sdlSurface);
 52     return true;
 53 }
 54 
 55 void UpdateDraw()
 56 {
 57     SDL_RenderClear(sdlRender);
 58     
 59     //分X宫格
 60     const int count = 9;
 61     const int sqrtCount = (int)sqrt((double)count);
 62     for (int i = 0; i < sqrtCount; i++)    {
 63         srcRect = SDL_RectMake(0, 0, (w-sqrtCount)/sqrtCount, (h-sqrtCount)/sqrtCount);
 64         for (int j = 0; j < sqrtCount; j++) {
 65             srcRect.x = srcRect.w*j+(j?1*j:0);
 66             srcRect.y = srcRect.h*i+(i?1*i:0);
 67         
 68             //SDL_RectPrint("srcRect", srcRect);
 69             SDL_RectCopy(&srcRect, &dstRect);
 70             //SDL_RectPrint("dstRect", dstRect);
 71             SDL_RenderCopy(sdlRender, sdlTexture, &srcRect, &dstRect);
 72         }
 73     }
 74     
 75     SDL_RenderPresent(sdlRender);
 76 }
 77 
 78 void Quit(int code)
 79 {
 80     const char *errMsg = SDL_GetError();
 81     if (errMsg && strlen(errMsg)) {
 82         SDL_Log("Error : %s
", errMsg);
 83     }
 84 
 85     //销毁窗口、渲染器、纹理
 86     if (sdlWindow) SDL_DestroyWindow(sdlWindow);
 87     if (sdlRender) SDL_DestroyRenderer(sdlRender);
 88     if (sdlTexture) SDL_DestroyTexture(sdlTexture);
 89     SDL_Quit();
 90     exit(code);
 91 }
 92 
 93 void HandleKeyEvent(const SDL_Keysym* keysym)
 94 {
 95     int key = keysym->sym;
 96     switch(key)
 97     {
 98     case SDLK_ESCAPE:
 99         Quit(0);
100         break;
101     case SDLK_SPACE:
102         break;
103     case SDLK_UP:
104     case SDLK_DOWN:
105     case SDLK_LEFT:
106     case SDLK_RIGHT:
107         int x, y;
108         SDL_GetWindowPosition(sdlWindow, &x, &y);
109         x = (key == SDLK_LEFT ? x-2 : (key == SDLK_RIGHT ? x+2 : x));
110         y = (key == SDLK_UP ? y-2 : (key == SDLK_DOWN ? y+2 : y));
111         SDL_SetWindowPosition(sdlWindow, x, y);
112         SDL_Log("x=%d, y=%d
", x, y);
113         break;
114     case SDLK_KP_PLUS:
115     case SDLK_KP_MINUS:
116         w = (key == SDLK_KP_PLUS ? w+2 : w-2);
117         h = (key == SDLK_KP_PLUS ? h+2 : h-2);
118         SDL_SetWindowSize(sdlWindow, w, h);
119         SDL_Log("w=%d, h=%d
", w, h);
120         break;
121     default:
122         break;
123     }
124 }
125 
126 void HandleEvents()
127 {
128     //Our SDL event placeholder.
129     SDL_Event event;
130     //Grab all the events off the queue.
131     while(SDL_PollEvent(&event)) {
132         switch(event.type) {
133         case SDL_KEYDOWN:
134             //Handle key Event
135             HandleKeyEvent(&event.key.keysym);
136             break;
137         case SDL_QUIT:
138             //Handle quit requests (like Ctrl-c).
139             Quit(0);
140             break;
141         }
142     }
143 }
144 
145 int main(int argc, char* argv[])
146 {
147     printf("可以通过↑↓←→+ -按键控制移动和大小
");
148     if (InitView(w, h, "yp.ico") == false) {
149         SDL_Log("sdlWindow is null @_@
");
150         Quit(0);
151         return -1;
152     }
153 
154     char *imgName = "gril.jpg";
155     if (InitDraw(imgName) == false) {
156         SDL_Log("Init Fail @_@
");
157         Quit(0);
158         return -1;
159     }
160     
161     //配置客户区大小
162     SDL_QueryTexture(sdlTexture,NULL, NULL, &w, &h);
163     SDL_SetWindowSize(sdlWindow, w, h);
164     SDL_Log("w=%d, h=%d
", w, h);
165     
166     while (1) {
167         HandleEvents();
168         UpdateDraw();
169     }
170     
171     SDL_DestroyWindow(sdlWindow);
172     SDL_Quit();
173     return 0;
174 }

    结果：
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  • 原文地址：https://www.cnblogs.com/1024Planet/p/5752648.html
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