MFC 使用Opengl贴图

用opengl库在mfc 对话框程序中创建简单的opengl程序。

步骤：

1.用vs2010创建mfc dialog对话框程序

直接点击完成，创建工程结束。

2.删掉对话框上面的lable，及button按钮

3.打开对话框页，并选择“”项目“中的 ”添加类向导“ 打开添加类向导对话框，添加WM_CLOSE .

4.打开Dlg_OpenGLDlg.h文件，修改如下代码：

public:
	afx_msg void OnTimer(UINT_PTR nIDEvent);
	afx_msg void OnClose();


	HDC m_dc;
	void DrawFunc();

在OnInitDialog()函数里面添加

{
		m_dc = ::GetDC(m_hWnd);
		PIXELFORMATDESCRIPTOR pfd;
		pfd.nVersion = 1;
		pfd.nSize = sizeof(PIXELFORMATDESCRIPTOR);
		pfd.cColorBits = 32;
		pfd.cDepthBits = 24;
		pfd.cStencilBits = 8;
		pfd.iPixelType = PFD_TYPE_RGBA;
		pfd.iLayerType = PFD_MAIN_PLANE;
		pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;

		int nPixelFormat = ChoosePixelFormat(m_dc, &pfd);
		SetPixelFormat(m_dc, nPixelFormat, &pfd);

		HGLRC rc = wglCreateContext(m_dc);
		wglMakeCurrent(m_dc, rc);

		glMatrixMode(GL_PROJECTION);
		gluPerspective(50, 800/600, 0.1f, 1000.0f);
		glMatrixMode(GL_MODELVIEW);
		glLoadIdentity();
	}

	Texture texture;
	texture.Init("test.bmp");//init opengl texture
	glBindTexture(GL_TEXTURE_2D, texture.mTextureID);
	SetTimer(0, 50, NULL);

其他实现函数：

void COpenGLDlg::DrawFunc()
{
	glLoadIdentity();
	glClear(GL_COLOR_BUFFER_BIT);
	glEnable(GL_TEXTURE_2D);

	{
		glBegin(GL_TRIANGLES);//start to draw something
		//glNormal3f(0.0f,1.0f,0.0f);
		glTexCoord2f(0.0f, 0.0f);
		glVertex3f(-1.0f, -0.5f, -2.0f);

		//glNormal3f(0.0f, 1.0f, 0.0f);
		glTexCoord2f(2.0f, 0.0f);
		glVertex3f(1.0f, -0.5f, -2.0f);

		//glNormal3f(0.0f, 1.0f, 0.0f);
		glTexCoord2f(0.0, 2.0f);
		glVertex3f(-1.0f, -0.5f, -3.0f);


		//glNormal3f(0.0f, 1.0f, 0.0f);
		glTexCoord2f(2.0f, 0.0f);
		glVertex3f(1.0f, -0.5f, -2.0f);

		//glNormal3f(0.0f, 1.0f, 0.0f);
		glTexCoord2f(2.0f, 2.0f);
		glVertex3f(1.0f, -0.5f, -3.0f);

		//glNormal3f(0.0f, 1.0f, 0.0f);
		glTexCoord2f(0.0, 2.0f);
		glVertex3f(-1.0f, -0.5f, -3.0f);

		glEnd();//end
	}
	SwapBuffers(m_dc);
}
void COpenGLDlg::OnTimer(UINT_PTR nIDEvent)
{
	DrawFunc();
	CDialogEx::OnTimer(nIDEvent);
}


void COpenGLDlg::OnClose()
{
	KillTimer(0);
	::ReleaseDC(m_hWnd, m_dc);
	CDialogEx::OnClose();
}

读取bmp并去掉bmp头：utils.h

#pragma once
#include 

unsigned char* LoadFileContent(const char*filePath);

utils.cpp

#include "utils.h"

unsigned char* LoadFileContent(const char*filePath)
{
	unsigned char* fileContent = nullptr;
	FILE*pFile = fopen(filePath, "rb");
	if (pFile)
	{
		//read
		fseek(pFile,0,SEEK_END);
		int nLen = ftell(pFile);
		if (nLen>0)
		{
			rewind(pFile);
			fileContent = new unsigned char[nLen+1];
			fread(fileContent,sizeof(unsigned char),nLen,pFile); 
			fileContent[nLen]='\0';
		}
		fclose(pFile);
	}
	return fileContent;
}

texture.h

#pragma once
#include 
#include 

class Texture
{
public:
	GLuint mTextureID;//gpu
	void Init(const char*imagePath);
};

texture.cpp

#include "texture.h"
#include "utils.h"

unsigned char* DecodeBMP(unsigned char*bmpFileData, int&width, int&height)
{
	if (0x4D42==*((unsigned short*)bmpFileData))
	{
		int pixelDataOffset = *((int*)(bmpFileData + 10));
		width = *((int*)(bmpFileData+18));
		height = *((int*)(bmpFileData + 22));
		unsigned char*pixelData = bmpFileData + pixelDataOffset;
		//bgr bgr bgr ....
		//rgb rgb rgb
		for (int i=0;i

OpenGL——纹理过滤函数glTexParameteri()

图象从纹理图象空间映射到帧缓冲图象空间(映射需要重新构造纹理图像,这样就会造成应用到多边形上的图像失真),这时就可用glTexParmeteri()函数来确定如何把纹理象素映射成像素.
　　部分参数功能说明如下:
　　glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
　　GL_TEXTURE_2D: 操作2D纹理.
　　GL_TEXTURE_WRAP_S: S方向上的贴图模式.
　　GL_CLAMP: 将纹理坐标限制在0.0,1.0的范围之内.如果超出了会如何呢.不会错误,只是会边缘拉伸填充.
　　glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
　　这里同上,只是它是T方向
　　glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
　　这是纹理过滤
　　GL_TEXTURE_MAG_FILTER: 放大过滤
　　GL_LINEAR: 线性过滤, 使用距离当前渲染像素中心最近的4个纹素加权平均值.
　　glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
　　GL_TEXTURE_MIN_FILTER: 缩小过滤
　　GL_LINEAR_MIPMAP_NEAREST: 使用GL_NEAREST对最接近当前多边形的解析度的两个层级贴图进行采样,然后用这两个值进行线性插值.

demo下载地址：http://download.csdn.net/detail/sz76211822/9761124