SDL2.0的几何图行绘画

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）：

 #include <stdio.h>
 #include <string.h>
 #include <time.h>
 #include <SDL2\SDL.h>
 #include <SDL2\SDL_image.h>
 #include <SDL2\ex\SDLex.h>

 SDL_Window *sdlWindow = NULL;
 SDL_Renderer *sdlRender = NULL;
 SDL_Texture *sdlTexture = NULL;
 SDL srcRect;
 int w = ;
 int h = ;

 void DrawCircle(SDL_Renderer *ren,int radius){
     int st=clock(),tx=,ty=radius,d=-(radius<<),x=radius,y=radius;
     while(tx<ty){
         for (int i=x-ty;i<=x+ty;++i){
             SDL_RenderDrawPoint(ren,i,y-tx);
             if (tx)
                 SDL_RenderDrawPoint(ren,i,y+tx);
         }
         if (d<)
             d+=(tx<<)+;
         else{
             for (int i=x-tx;i<=x+tx;++i){
                 SDL_RenderDrawPoint(ren,i,y-ty);
                 SDL_RenderDrawPoint(ren,i,y+ty);
             }
             d+=((tx - ty)<<)+,ty--;
         }
         tx++;
     }
     if (tx==ty)
         for (int i=x-ty;i<=x+ty;++i){
                 SDL_RenderDrawPoint(ren,i,y-tx);
                 SDL_RenderDrawPoint(ren,i,y+tx);
         }
     int en=clock();
 }

 bool InitView(int width, int height, const char *iconName)
 {
     //初始化窗体
     SDL_Init(SDL_INIT_VIDEO);

     sdlWindow = SDL_CreateWindow(
         "The First SDL Program",
         SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, width, height,
         SDL_WINDOW_RESIZABLE);
     if (sdlWindow == NULL) return false;

     //加载窗体图标
     SDL_Surface *iconSurface = IMG_Load(iconName);
     if (iconSurface == NULL) return false;

     SDL_SetWindowIcon(sdlWindow, iconSurface);

     return true;
 }

 bool InitDraw()
 {
     //加载渲染器
     sdlRender = SDL_CreateRenderer(sdlWindow, -, );
     if (sdlRender == NULL) return false;

     sdlTexture = SDL_CreateTexture(sdlRender, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_TARGET, w, h);
     if (sdlTexture == NULL) return false;
     //SDL_SetTextureBlendMode(sdlTexture, SDL_BLENDMODE_BLEND);
     //SDL_SetRenderTarget(sdlRender, sdlTexture);

     return true;
 }

 void UpdateDraw()
 {
     //设置背景颜色
     SDL_SetRenderDrawColor(sdlRender, , , , 0xFF);
     SDL_RenderClear(sdlRender);

     //左眼
     SDL_SetRenderDrawColor(sdlRender, 0x00, 0xFF, 0xFF, 0xFF);
     srcRect = SDLMake(w/*, h/, w/, h/);
     SDL_RenderFillRect(sdlRender, &srcRect);

     //左眉毛
     SDL_SetRenderDrawColor(sdlRender, 0x00, 0x00, 0x00, 0xFF);
     SDL_RenderDrawLine(sdlRender, srcRect.x, srcRect.y - , SDLMaxX(srcRect), srcRect.y - );

     //右眼
     SDL_SetRenderDrawColor(sdlRender, 0xFF, 0x00, 0xFF, 0xFF);
     srcRect = SDLMake(w/*, srcRect.y, srcRect.w, srcRect.h);
     SDL_RenderDrawRect(sdlRender, &srcRect);

     //右眉毛
     SDL_SetRenderDrawColor(sdlRender, 0x00, 0x00, 0x00, 0xFF);
     SDL_RenderDrawLine(sdlRender, srcRect.x, srcRect.y - , SDLMaxX(srcRect), srcRect.y - );

     //嘴巴
     SDL_SetRenderDrawColor(sdlRender, 0xFF, 0xFF, 0x00, 0xFF);
     srcRect = SDLMake(w/*, h/*, w/*, h/);
     SDL_RenderFillRect(sdlRender, &srcRect);

     SDL_SetRenderDrawColor(sdlRender, 0xFF, 0x00, 0x00, 0xFF);
     DrawCircle(sdlRender, );

     SDL_RenderPresent(sdlRender);
 }

 void Quit(int code)
 {
     const char *errMsg = SDL_GetError();
     if (errMsg && strlen(errMsg)) {
         SDL_Log("Error : %s\n", errMsg);
     }

     //销毁窗口、渲染器、纹理
     if (sdlWindow) SDL_DestroyWindow(sdlWindow);
     if (sdlRender) SDL_DestroyRenderer(sdlRender);
     if (sdlTexture) SDL_DestroyTexture(sdlTexture);
     SDL_Quit();
     exit(code);
 }

 void HandleKeyEvent(const SDL_Keysym* keysym)
 {
     int key = keysym->sym;
     switch(key)
     {
     case SDLK_ESCAPE:
         Quit();
         break;
     case SDLK_SPACE:
         break;
     case SDLK_UP:
     case SDLK_DOWN:
     case SDLK_LEFT:
     case SDLK_RIGHT:
         int x, y;
         SDL_GetWindowPosition(sdlWindow, &x, &y);
         x = (key == SDLK_LEFT ? x- : (key == SDLK_RIGHT ? x+ : x));
         y = (key == SDLK_UP ? y- : (key == SDLK_DOWN ? y+ : y));
         SDL_SetWindowPosition(sdlWindow, x, y);
         SDL_Log("x=%d, y=%d\n", x, y);
         break;
     case SDLK_KP_PLUS:
     case SDLK_KP_MINUS:
         w = (key == SDLK_KP_PLUS ? w+ : w-);
         h = (key == SDLK_KP_PLUS ? h+ : h-);
         SDL_SetWindowSize(sdlWindow, w, h);
         SDL_Log("w=%d, h=%d\n", w, h);
         break;
     default:
         break;
     }
 }

 void HandleEvents()
 {
     //Our SDL event placeholder.
     SDL_Event event;
     //Grab all the events off the queue.
     while(SDL_PollEvent(&event)) {
         switch(event.type) {
         case SDL_KEYDOWN:
             //Handle key Event
             HandleKeyEvent(&event.key.keysym);
             break;
         case SDL_QUIT:
             //Handle quit requests (like Ctrl-c).
             Quit();
             break;
         }
     }
 }

 int main(int argc, char* argv[])
 {
     printf("可以通过↑↓←→+ -按键控制移动和大小\n");
     if (InitView(w, h, "yp.ico") == false) {
         SDL_Log("sdlWindow is null @_@\n");
         Quit();
         return -;
     }

     if (InitDraw() == false) {
         SDL_Log("Init Fail @_@\n");
         Quit();
         return -;
     }

     //配置客户区大小
     SDL_QueryTexture(sdlTexture,NULL, NULL, &w, &h);
     SDL_SetWindowSize(sdlWindow, w + , h);
     SDL_Log("w=%d, h=%d\n", w, h);

     while () {
         HandleEvents();
         UpdateDraw();
     }

     SDL_DestroyWindow(sdlWindow);
     SDL_Quit();
     return ;
 }

效果图：