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：