使用opengl渲染2D游戏的底层代码

// graphics.cpp: implementation of the graphics class. // ////////////////////////////////////////////////////////////////////// #include "StdAfx.h" #include "graphics.h" #include "texture.h" #include "quad.h" ////////////////////////////////////////////////////////////////////// // Construction/Destruction ////////////////////////////////////////////////////////////////////// Graphics::Graphics() { m_wglSwapIntervalEXT = NULL; m_wglGetSwapIntervalEXT = NULL; m_hRC = NULL; m_hdc = NULL; m_width = 320; m_height = 240; #ifdef FREEIMAGE_LIB FreeImage_Initialise(); #endif } Graphics::~Graphics() { #ifdef FREEIMAGE_LIB FreeImage_DeInitialise(); #endif release(); } void Graphics::release() { if (m_hRC) { if (!wglMakeCurrent(NULL, NULL)) TRACE("Release Of DC And RC Failed."); if (!wglDeleteContext(m_hRC)) TRACE("Release Rendering Context Failed."); m_hRC = NULL; } } // 设置HDC的像素格式 int Graphics::setPixelFormat(HDC hdc) { m_hdc = hdc; static PIXELFORMATDESCRIPTOR pfd=//pfd 告诉窗口我们所希望的东东 { sizeof(PIXELFORMATDESCRIPTOR),//上诉格式描述符的大小 1, // 版本号 PFD_DRAW_TO_WINDOW |// 格式必须支持窗口 PFD_SUPPORT_OPENGL |// 格式必须支持OpenGL PFD_DOUBLEBUFFER, // 必须支持双缓冲 PFD_TYPE_RGBA,// 申请 RGBA 格式 32, // 选定色彩深度 0, 0, 0, 0, 0, 0, // 忽略的色彩位 0,// 无Alpha缓存 0,// 忽略Shift Bit 0,// 无聚集缓存 0, 0, 0, 0, // 忽略聚集位 16, // 16位 Z-缓存 (深度缓存) 0,// 无模板缓存 0,// 无辅助缓存 PFD_MAIN_PLANE, // 主绘图层 0,// 保留 0, 0, 0 // 忽略层遮罩 }; int iPixelFormat; // 为设备描述表得到最匹配的像素格式 if((iPixelFormat = ChoosePixelFormat(hdc, &pfd)) == 0) { TRACE("ChoosePixelFormat Failed"); return 1; } // 设置最匹配的像素格式为当前的像素格式 if(SetPixelFormat(hdc, iPixelFormat, &pfd) == FALSE) { TRACE("SetPixelFormat Failed"); return 1; } if (!(m_hRC=wglCreateContext(hdc))) { TRACE("Can’t Create A GL Rendering Context."); return 1; } if (!wglMakeCurrent(hdc,m_hRC)) { TRACE("Can’t Activate The GL Rendering Context."); return 1; } return 0; } bool Graphics::initVSync() { char* extensions = (char*)glGetString(GL_EXTENSIONS); if (strstr(extensions,"WGL_EXT_swap_control")) { m_wglSwapIntervalEXT = (PFNWGLEXTSWAPCONTROLPROC)wglGetProcAddress("wglSwapIntervalEXT"); m_wglGetSwapIntervalEXT = (PFNWGLEXTGETSWAPINTERVALPROC)wglGetProcAddress("wglGetSwapIntervalEXT"); return true; } return false; } bool Graphics::isVSyncEnabled() { if (m_wglGetSwapIntervalEXT == NULL) return true; return (m_wglGetSwapIntervalEXT() > 0); } void Graphics::setVSyncState(bool enable) { if (m_wglSwapIntervalEXT == NULL) return; if (enable) m_wglSwapIntervalEXT(1); else m_wglSwapIntervalEXT(0); } bool Graphics::init() { bool isOk = initVSync(); if (isOk) { // 关闭垂直同步 setVSyncState(false); } glShadeModel(GL_SMOOTH); // GL_SMOOTH, GL_FLAT glClearColor(0.65f,0.65f,0.65f,1.0f); glClearDepth(1.0); glEnable(GL_DEPTH_TEST); glDepthFunc(GL_LEQUAL); //glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); //glPixelStorei (GL_UNPACK_ALIGNMENT, 1); // blend glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); // texture glEnable(GL_TEXTURE_2D); return true; } GLvoid Graphics::resizeScene(GLsizei width, GLsizei height) { glViewport(0, 0, width, height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glOrtho(0, width, height, 0, -1.0, 1.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); m_width = width; m_height = height; } void Graphics::setClearColor(float red, float green, float blue) { glClearColor(red, green, blue, 1.0f); } //int Graphics::renderScene() //{ // // return 0; //} void Graphics::beginScene() { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity(); } void Graphics::endScene() { if (m_hdc != NULL) { ::SwapBuffers(m_hdc); } } void Graphics::drawLine(float x1, float y1, float x2, float y2, const stColor& color) { glDisable(GL_BLEND); glLoadIdentity(); glColor4f(color.r, color.g, color.b, color.a); glBegin(GL_LINES); glVertex3f(x1, y1, 0); glVertex3f(x2, y2, 0); glEnd(); glEnable(GL_BLEND); } void Graphics::drawRectFrame(float x1, float y1, float x2, float y2, const stColor& color) { glDisable(GL_BLEND); glLoadIdentity(); glColor4f(color.r, color.g, color.b, color.a); glBegin(GL_LINE_LOOP); glVertex3f(x1, y1, 0); glVertex3f(x2, y1, 0); glVertex3f(x2, y2, 0); glVertex3f(x1, y2, 0); glEnd(); glEnable(GL_BLEND); }