SDL支持视频双窗口或者创建多个视频窗口

出处：/article/3731240.html

笔者这段时间在研究SDL，发现很多人在问如何让SDL支持视频双窗口或者创建多个视频窗口，而baidu和google上居然没有详细介绍的相关文档，故在此作一个简单介绍。

根据笔者的理解，在SDL1.2中是不支持多窗口的，而还没有正式发布的、非稳定状态下的SDL1.3是完全支持多窗口的。

下面是笔者写的一个简单的程序，其中创建2个视频窗口并在每一个窗口中显示不同位图：

#include <stdlib.h>

#include <math.h>

#include <stdio.h>

#include <tchar.h>

#include "SDL.h"

#include "SDL_shape.h"

void renderBlue(SDL_Renderer *renderer,SDL_Texture *texture,SDL_Rect texture_dimensions)

{

//Clear render-target to blue.

SDL_SetRenderDrawColor(renderer,0x00,0x00,0xff,0xff);

SDL_RenderClear(renderer);

//Render the texture.

SDL_RenderCopy(renderer,texture,&texture_dimensions,&texture_dimensions);

SDL_RenderPresent(renderer);

}

void renderRed(SDL_Renderer *renderer,SDL_Texture *texture,SDL_Rect texture_dimensions)

{

//Clear render-target to red.

SDL_SetRenderDrawColor(renderer,0xff,0x00,0x00,0xff);

SDL_RenderClear(renderer);

//Render the texture.

SDL_RenderCopy(renderer,texture,&texture_dimensions,&texture_dimensions);

SDL_RenderPresent(renderer);

}

int _tmain(int argc,TCHAR** argv)

{

SDL_Color black = {0,0,0,0xff};

Uint32 pixelFormat = 0;

int access = 0;

SDL_Rect texture_dimensions;;

char *szAnsiFile="e://hello.bmp";

char *szAnsiFile2="e://hello2.bmp";

if(SDL_VideoInit(NULL) == -1) {

printf("Could not initialize SDL video./n");

exit(-2);

}

SDL_PixelFormat* pixformat = NULL;

SDL_Window * win1 = SDL_CreateWindow("TEST1", 10, 10, 640,480, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);

SDL_Renderer *render1 = SDL_CreateRenderer(win1,-1,0);

SDL_Surface *imgSurface1 = SDL_LoadBMP(szAnsiFile);

SDL_Texture *texture1 = SDL_CreateTextureFromSurface(render1,imgSurface1);

SDL_QueryTexture(texture1,(Uint32 *)&pixelFormat,(int *)&access,&texture_dimensions.w,&texture_dimensions.h);

SDL_SetWindowSize(win1,texture_dimensions.w,texture_dimensions.h);

SDL_WindowShapeMode shapeMode1;

pixformat = imgSurface1->format;

if(pixformat->Amask != 0) {

shapeMode1.mode = ShapeModeBinarizeAlpha;

shapeMode1.parameters.binarizationCutoff = 255;

}

else {

shapeMode1.mode = ShapeModeColorKey;

shapeMode1.parameters.colorKey = black;

}

SDL_SetWindowShape(win1,imgSurface1,&shapeMode1);

texture_dimensions.x = 0;

texture_dimensions.y = 0;

texture_dimensions.w = 640;

texture_dimensions.h = 480;

renderBlue(render1,texture1,texture_dimensions);

SDL_Window * win2 = SDL_CreateWindow("TEST2", 650, 10, 640,480, SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);

SDL_Renderer *render2 = SDL_CreateRenderer(win2,-1,0);

SDL_Surface *imgSurface2 = SDL_LoadBMP(szAnsiFile2);

SDL_Texture *texture2 = SDL_CreateTextureFromSurface(render2,imgSurface2);

SDL_QueryTexture(texture2,(Uint32 *)&pixelFormat,(int *)&access,&texture_dimensions.w,&texture_dimensions.h);

SDL_SetWindowSize(win2,texture_dimensions.w,texture_dimensions.h);

SDL_WindowShapeMode shapeMode2;

pixformat = imgSurface2->format;

if(pixformat->Amask != 0) {

shapeMode2.mode = ShapeModeBinarizeAlpha;

shapeMode2.parameters.binarizationCutoff = 255;

}

else {

shapeMode2.mode = ShapeModeColorKey;

shapeMode2.parameters.colorKey = black;

}

SDL_SetWindowShape(win2,imgSurface2,&shapeMode2);

texture_dimensions.x = 0;

texture_dimensions.y = 0;

texture_dimensions.w = 640;

texture_dimensions.h = 480;

renderRed(render2,texture2,texture_dimensions);

SDL_Delay(5000);

SDL_DestroyTexture(texture1);

SDL_DestroyRenderer(render1);

SDL_DestroyWindow(win1);

SDL_FreeSurface(imgSurface1);

SDL_DestroyTexture(texture2);

SDL_DestroyRenderer(render2);

SDL_DestroyWindow(win2);

SDL_FreeSurface(imgSurface2);

//Call SDL_VideoQuit() before quitting.

SDL_VideoQuit();

return 0;

}

要编译上面这段代码，需要下载最新的SDL1.3源码，然后编译生成SDL.lib和SDL.dll，然后将SDL.lib导入库加入到VS2005的工程中即可。