《SDL Game Development》中有這樣一個遊戲的流程圖 html
這個game loop 在遊戲開發裏面用到的每每是下面一種ios
《Game Programming Patterns》 http://gameprogrammingpatterns.com/game-loop.html
app
下面是一個game loop實現的示例代碼oop
void init(){} void render(){} void update(){} void handleEvents(){} void clean(){} bool g_bRunning = true; int main() { init(); while(g_bRunning) { handleEvents(); update(); render(); } clean(); }
一般遊戲循環會按照幀率刷新,因此實現代碼以下:code
double lastTime = getCurrentTime(); while (true) { double current = getCurrentTime(); double elapsed = current - lastTime; processInput(); update(elapsed); render(); lastTime = current; }``` 如下實現一個簡單的game class **GameApp.h**
#pragma once #include <SDL.h> class GameApp { public: GameApp(); ~GameApp();htm
bool Init( ); void OnEvent(SDL_Event* event); void GameLoop(); void Render(); void Cleanup(); int OnExecute();
private: bool m_bRunning; SDL_Window* m_pWindow; SDL_Renderer* m_pRenderer; };遊戲
**GameApp.cpp**
#include "GameApp.h" #include <iostream> GameApp::GameApp() { if (!Init()) throw std::runtime_error("Init SDL error"); }圖片
GameApp::~GameApp() { } bool GameApp::Init( ) { m_bRunning = true; if (SDL_Init(SDL_INIT_EVERYTHING) < 0) { std::cerr << "can not init SDL" << std::endl; return false; } if (SDL_CreateWindowAndRenderer(640, 480, SDL_WINDOW_SHOWN, &m_pWindow, &m_pRenderer) < 0) { std::cerr << "can not create render" << std::endl; return false; } SDL_SetWindowTitle(m_pWindow, "Game App");ip
return true;
} void GameApp::OnEvent(SDL_Event* event) { if (event->type == SDL_QUIT) { m_bRunning = false; } } void GameApp::GameLoop() {遊戲開發
} void GameApp::Render() { SDL_RenderClear(m_pRenderer); SDL_RenderPresent(m_pRenderer);
} void GameApp::Cleanup() { SDL_DestroyRenderer(m_pRenderer); SDL_DestroyWindow(m_pWindow); } int GameApp::OnExecute() {
SDL_Event event; while (m_bRunning) { while (SDL_PollEvent(&event)) { OnEvent(&event); } Render(); } Cleanup(); return 0;
}
**main.cpp**
#include "GameApp.h"
int main(int argc, char** argv) { GameApp app; return app.OnExecute(); }
代碼放在如下路徑了 SDL game class.zip > http://pan.baidu.com/s/1nvwjmm1