OpenGL中用bmp图片做纹理贴图的三种方法

1、OpenGL中用bmp图片做纹理贴图的三种方法方法一：首先获取位图句柄HBITMAP hBmp = (HBITMAP) :LoadImage (AfxGetResourceHandle(), MAKEINTRESOURCE(IDB_BITMAP1), IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION);然后根据位图句柄得到位图信息BITMAP BM; :GetObject (hBmp, sizeof (BM), &BM);最后根据位图信息中的RGB值建立纹理 gluBuild2DMipmaps( GL_TEXTURE_2D, 3, BM.bmWidth, BM.b

2、mHeight, GL_BGR_EXT, GL_UNSIGNED_BYTE, BM.bmBits );方法二：首先用OpenGL辅助库获得位图信息 AUX_RGBImageRec* TextureImage1; TextureImage0=auxDIBImageLoad(1.bmp);然后建立纹理 gluBuild2DMipmaps(GL_TEXTURE_2D, 3, TextureImage0-sizeX, TextureImage0-sizeY, GL_RGB, GL_UNSIGNED_BYTE, TextureImage0-data);方法三：从底层做，需要了解bmp文件的结构，首先读取

3、bmp文件结构，包括文件头、信息头和数据，数据用于后面定义纹理long ImageWidth=256;long ImageHeight=256; GLubyte Image2562563;void ReadHeader(FILE *fp , BITMAPFH * p_bitmapheader , BITMAPIH *p_bitmapinfo) fseek(fp, 0, SEEK_SET) ; fread( &p_bitmapheader-bfType,sizeof(unsigned short), 1, fp ); fseek(fp, 2, SEEK_SET) ; fread( &p_bitm

4、apheader-bfSize,sizeof(unsigned long), 1, fp ); fseek(fp, 6, SEEK_SET) ; fread( &p_bitmapheader-bfReserved1,sizeof(unsigned short), 1, fp ); fseek(fp, 8, SEEK_SET) ; fread( &p_bitmapheader-bfReserved2,sizeof(unsigned short), 1, fp ); fseek(fp, 10, SEEK_SET) ; fread( &p_bitmapheader-bfOffBits,sizeof(

5、unsigned long), 1, fp ); fseek(fp, 14, SEEK_SET) ; fread( &p_bitmapinfo-biSize, sizeof(unsigned long), 1, fp ); fseek(fp, 18, SEEK_SET) ; fread( &p_bitmapinfo-biWidth, sizeof(unsigned long), 1, fp ); fseek(fp, 22, SEEK_SET) ; fread( &p_bitmapinfo-biHeight, sizeof(unsigned long), 1, fp ); fseek(fp, 2

6、6, SEEK_SET) ; fread( &p_bitmapinfo-biPlanes, sizeof(unsigned short), 1, fp ); fseek(fp, 28, SEEK_SET) ; fread( &p_bitmapinfo-biBitCount, sizeof(unsigned short), 1, fp ); fseek(fp, 30, SEEK_SET) ; fread( &p_bitmapinfo-biCompression, sizeof(unsigned long), 1, fp ); fseek(fp, 34, SEEK_SET) ; fread( &p

7、_bitmapinfo-biSizeImage, sizeof(unsigned long), 1, fp ); fseek(fp, 38, SEEK_SET) ; fread( &p_bitmapinfo-biXPelsPerMeter, sizeof(unsigned long), 1, fp ); fseek(fp, 42, SEEK_SET) ; fread( &p_bitmapinfo-biYPelsPerMeter, sizeof(unsigned long), 1, fp ); fseek(fp, 46, SEEK_SET) ; fread( &p_bitmapinfo-biCl

8、rUsed, sizeof(unsigned long), 1, fp ); fseek(fp, 50, SEEK_SET) ; fread( &p_bitmapinfo-biClrImportant, sizeof(unsigned long), 1, fp ); void ReadBitmapFile() BITMAPFH bitmapheader ; BITMAPIH bitmapinfo ; FILE *fp; fp = fopen(6.bmp , r) ; if(!fp) puts(Read file failed.) ; return; ReadHeader(fp, &bitmap

9、header , &bitmapinfo) ; if(bitmapinfo.biBitCount != 24) puts(UNSUPPORT) ; return; ImageWidth = bitmapinfo.biWidth; ImageHeight = bitmapinfo.biHeight; int i=bitmapheader.bfOffBits; while(ibitmapheader.bfSize) for(int j=0;jImageWidth;j+) for(int k=0;kImageHeight;k+) fseek(fp, i, SEEK_SET) ; fread(Imag

10、ejk+2, 1, 1, fp) ; fseek(fp, i+1, SEEK_SET) ; fread(Imagejk+1, 1, 1, fp) ; fseek(fp, i+2, SEEK_SET) ; fread(Imagejk, 1, 1, fp) ; i=i+3; fclose(fp) ;glTexImage2D(GL_TEXTURE_2D, 0, 3, ImageWidth,ImageHeight, 0, GL_RGB, GL_UNSIGNED_BYTE,&Image000);OpenGL中不用AUX库来加载BMP图片作为纹理转载(2007-02-11 21:22:15)大家在Open

11、GL中一般是用aux库的auxDIBImageLoad()函数来加载BMP格式的图片来作为纹理，这个确实是比较简单易用，但aux库的性能不佳，经常会出问题，稳定性较差。所以一般最好不要用aux库，可以用glut库，但glut库没有纹理加载函数。而有些程序是直接读取BMP格式来获得图像数据，从而生成纹理的，这种方法虽然很强大，但比较复杂，需要了解BMP的格式，对初学者比较困难。而下面的一段程序是用windows的API函数LoadImage()来实现这个功能，这种实现方法很简单，可以说比auxDIBImageLoad()函数复杂不了多少。 首先，加上头文件： #include 这是因为后面的GL

12、_BGR_EXT是定义在这个头文件里的，因为BMP格式是按Blue,Green,Red顺序储存图像数据的，这与OpenGL中正好相反。GL_BGR_EXT就是完成两者之间的转换的。 下面就是不用AUX库来加载BMP图片作为纹理的函数：bool LoadTexture(LPTSTR szFileName, GLuint &texid)/ Creates Texture From A Bitmap FileHBITMAP hBMP;/ Handle Of The BitmapBITMAPBMP;/ Bitmap StructureglGenTextures(1, &texid);/ Create

13、The TexturehBMP=(HBITMAP)LoadImage(GetModuleHandle(NULL), szFileName, IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION | LR_LOADFROMFILE );if (!hBMP)/ Does The Bitmap Exist?return FALSE;/ If Not Return FalseGetObject(hBMP, sizeof(BMP), &BMP);/ Get The Object/ hBMP: Handle To Graphics Object/ sizeof(BMP): Siz

14、e Of Buffer For Object Information/ &BMP: Buffer For Object InformationglPixelStorei(GL_UNPACK_ALIGNMENT, 4);/ Pixel Storage Mode (Word Alignment / 4 Bytes)/ Typical Texture Generation Using Data From The BitmapglBindTexture(GL_TEXTURE_2D, texid);/ Bind To The Texture IDglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);/ Linear Min FilterglTexParameteri(GL_TEXTURE_2D, GL_TEXTU