C++ SDL2中SDL_Renderer使用
配置请参照前面的笔记https://www.cnblogs.com/zzr-stdio/p/14514043.html
主要介绍SDL_Renderer。
示例程序:
#include <iostream>
#include<SDL.h>
#include<SDL_image.h>
using namespace std;
const int WIDTH = 800;
const int HEIGHT = 600;
int main(int argc, char* argv[])
{
::SDL_Init(SDL_INIT_VIDEO);//初始化SDL
::SDL_Window* window = ::SDL_CreateWindow("SDL test", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
WIDTH, HEIGHT, SDL_WINDOW_SHOWN);//创建窗体
::SDL_Renderer* rend = ::SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);//创建renderer
::SDL_RenderClear(rend);//清空
::SDL_Surface* imagesurface = ::SDL_LoadBMP("r.bmp");
//创建纹理,转为可以贴在rend上的纹理
::SDL_Texture* image = ::SDL_CreateTextureFromSurface(rend, imagesurface);
::SDL_Rect rect;
rect.x = 0;//显示位置
rect.y = 0;
rect.w = imagesurface->w;
rect.h = imagesurface->h;
bool quit = false;
::SDL_Event event;
while (quit == false)
{
while (::SDL_PollEvent(&event))
{
if (event.type == ::SDL_QUIT)//退出事件
{
quit = true;
}
else if (event.type == SDL_MOUSEMOTION)
{
rect.x = event.motion.x - rect.w / 2;
rect.y = event.motion.y - rect.h / 2;
::SDL_RenderClear(rend);//清空
::SDL_RenderCopy(rend, image, nullptr, &rect);//让图片跟随鼠标移动
}
}
::SDL_RenderPresent(rend);//显示
::SDL_Delay(10);
}
::SDL_DestroyWindow(window);//销毁窗体
::SDL_Quit();//退出SDL
return 0;
}
透明设置:
- 设置支持透明模式:SDL_SetTextureBlendMode(image, SDL_BLENDMODE_BLEND);//设置支持透明度
- 设置透明量:SDL_SetTextureAlphaMod(image, alpha);//设置透明度