// GDISaveAsBMP.cpp : 定义控制台应用程序的入口点。

//

#include "stdafx.h"

#include <GL/glut.h>

#include <afx.h>

#include <afxwin.h>

#include <atlimage.h>

#include <iostream>

using namespace ATL;

using namespace std;

#define BMPWidth 640

#define BMPHeight 640

HBITMAP hBitmap,hOldBitmap;

HDC hScrDC, hMemDC,olddc;

HGLRC oldrc,newrc;

int _tmain(int argc, _TCHAR* argv[])

{

void InitializeDC();

void InitializeGL();

void DrawPolygon();

void SaveBMP(char*);

InitializeDC();

InitializeGL();

DrawPolygon();

SaveBMP("D://SaveAsBmp.bmp");

return 0;

}

void InitializeDC()

{

// 创建绘图DC及内存DC

hScrDC = CreateDC(_T("BITMAP"), NULL, NULL, NULL);

hMemDC = CreateCompatibleDC(hScrDC);

//设置位图信息

int iPixel = 32;

LPBITMAPINFO lpbmih = new BITMAPINFO;

lpbmih->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);

lpbmih->bmiHeader.biWidth = BMPWidth;

lpbmih->bmiHeader.biHeight = BMPHeight;

lpbmih->bmiHeader.biPlanes= 1;

lpbmih->bmiHeader.biBitCount = iPixel;

lpbmih->bmiHeader.biCompression = BI_RGB;

lpbmih->bmiHeader.biSizeImage = 0;

lpbmih->bmiHeader.biXPelsPerMeter = 0;

lpbmih->bmiHeader.biYPelsPerMeter = 0;

lpbmih->bmiHeader.biClrUsed= 0;

lpbmih->bmiHeader.biClrImportant= 0;

//创建HBITMAP

BYTE *pBits;

hBitmap = CreateDIBSection(hMemDC,lpbmih,DIB_PAL_COLORS,(void **)&pBits,NULL,0);

hOldBitmap = (HBITMAP)SelectObject(hMemDC, hBitmap);

CRect rc(0,0,BMPWidth,BMPHeight);

// 由内存DC创建新的RC，将图形绘制到该内存DC中

// 创建新的像素格式，用来将图形绘制到位图

PIXELFORMATDESCRIPTOR pfd= {

sizeof(PIXELFORMATDESCRIPTOR), // size of this pfd

1,

// version number

PFD_DRAW_TO_WINDOW | // support window

PFD_SUPPORT_OPENGL | // support OpenGL

PFD_DRAW_TO_BITMAP | // *** ***此处与绘制到窗口的rc设置不同，无double buffered *** ***

PFD_SUPPORT_GDI,

PFD_TYPE_RGBA, // RGBA type

24,// 24-bit color depth

0, 0, 0, 0, 0, 0,// color bits ignored

0,// no alpha buffer

0,// shift bit ignored

0,// no accumulation buffer

0, 0, 0, 0,// accum bits ignored

32,// 32-bit z-buffer

0,// no stencil buffer

0,// no auxiliary buffer

PFD_MAIN_PLANE, // main layer

0,// reserved

0, 0, 0// layer masks ignored

};

int pixelFormat=ChoosePixelFormat(hMemDC,&pfd);

SetPixelFormat(hMemDC,pixelFormat,&pfd);

// 保存之前绘图的RC及DC

oldrc = wglGetCurrentContext();

olddc = wglGetCurrentDC();

// 创建新的RC

newrc = wglCreateContext(hMemDC);

// 设置新的RC及DC

wglMakeCurrent(hMemDC,newrc);

}

void InitializeGL()

{

glViewport(0,0,BMPWidth,BMPHeight);

glClearDepth(1.0f);

glEnable(GL_DEPTH_TEST);

glClearColor(0.0f,0.0f,0.0f,1.0f);

// 设置投影矩阵，模型视图矩阵，视口

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

//glOrtho(-1.0,1.0,-1.0,1.0,-1.0,1.0);

gluPerspective(45.0,BMPWidth/BMPHeight,0.1f,100.0f);

glMatrixMode(GL_MODELVIEW);

glLoadIdentity();

gluLookAt(0.0,0.0,0.0, 0.0,0.0,-1.0, 0.0,1.0,0.0);

}

void DrawPolygon()

{

glTranslatef(0.0f,0.0f,-20.0f);

// 清除深度及颜色缓存

glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

// 开始绘制

glShadeModel(GL_SMOOTH);

glBegin(GL_POLYGON);

glColor3f(1.0,0.0,0.0);

glVertex3f(-1.0,1.0,0.0);

glColor3f(0.0,1.0,0.0);

glVertex3f(1.0,1.0,0.0);

glColor3f(0.0,0.0,1.0);

glVertex3f(1.0,-1.0,0.0);

glColor3f(1.0,1.0,0.0);

glVertex3f(-1.0,-1.0,0.0);

glEnd();

//结束绘制

glFinish();

SwapBuffers(wglGetCurrentDC());

//恢复之前的RC及DC，释放新创建的RC

wglMakeCurrent(olddc,oldrc);

wglDeleteContext(newrc);

// 完成OPENGL绘制

hBitmap = (HBITMAP)SelectObject(hMemDC, hOldBitmap);

// 释放DC

DeleteDC(hScrDC);

DeleteDC(hMemDC);

}

//保存HBITMAP为文件

void SaveBMP(char* fileName)

{

CImage image;

image.Attach(hBitmap);

HRESULT hResult = image.Save(fileName);

DeleteObject(hBitmap);

}