OpenGL_ES加载TGA/BMP纹理

typedef struct TGAImage											{
	GLubyte	*imageData;											// 	图像数据
	GLuint	bpp;												// 	像素颜色深度
	GLuint	width;												//      图像宽度
	GLuint	height;												// 	图像高度
	GLuint	texID;																	//	纹理ID
} TGAImage;	
bool LoadTGA(TGAImage *texture, char *filename)
{
	GLubyte		TGAheader[12]={0,0,2,0,0,0,0,0,0,0,0,0};		// Uncompressed TGA Header			不压缩的TGA头
	GLubyte		TGAcompare[12];									// Used To Compare TGA Header		压缩的
	GLubyte		header[6];										// First 6 Useful Bytes From The Header		TGA头的前6个有用的字节
	GLuint		bytesPerPixel;									// Holds Number Of Bytes Per Pixel Used In The TGA File		TGA文件每个像素使用的字节
	GLuint		imageSize;										// Used To Store The Image Size When Setting Aside Ram
	GLuint		temp;											// Temporary Variable		临时变量
	GLuint		type=GL_RGBA;									// Set The Default GL Mode To RBGA (32 BPP)	默认的GL模式
	FILE *file = fopen(filename, "rb");							// Open The TGA File
	printf("TGA_file=%d/n",file);
	if(	file==NULL ||											// Does File Even Exist?
		fread(TGAcompare,1,sizeof(TGAcompare),file)!=sizeof(TGAcompare) ||	// Are There 12 Bytes To Read?		是否读到12字节数据
		memcmp(TGAheader,TGAcompare,sizeof(TGAheader))!=0				||	// Does The Header Match What We Want?	是否是压缩的，压缩的就读取失败，关闭file
		fread(header,1,sizeof(header),file)!=sizeof(header))				// If So Read Next 6 Header Bytes		再读6个字节
	{
		if (file == NULL)										// Did The File Even Exist? *Added Jim Strong*
			return false;										// Return False
		else													// Otherwise
		{
			fclose(file);										// If Anything Failed, Close The File
			return false;										// Return False
		}
	}
	
	//12到17字节前四字节是图像宽高，第五字节是图像位深度
	texture->width  = header[1] * 256 + header[0];				// Determine The TGA Width	(highbyte*256+lowbyte)//低字节，高字节
	texture->height = header[3] * 256 + header[2];				// Determine The TGA Height	(highbyte*256+lowbyte)
	if(	texture->width	<=0	||									// Is The Width Less Than Or Equal To Zero
		texture->height	<=0	||									// Is The Height Less Than Or Equal To Zero
		(header[4]!=24 && header[4]!=32))						// Is The TGA 24 or 32 Bit?		
	{
		fclose(file);											// If Anything Failed, Close The File
		return false;											// Return False
	}
	texture->bpp	= header[4];								// Grab The TGA's Bits Per Pixel (24 or 32)
	bytesPerPixel	= texture->bpp/8;							// Divide By 8 To Get The Bytes Per Pixel	每个像素使用的字节数
	imageSize		= texture->width*texture->height*bytesPerPixel;	// Calculate The Memory Required For The TGA Data
	texture->imageData=(GLubyte *)malloc(imageSize);			// Reserve Memory To Hold The TGA Data	申请内存
	if(	texture->imageData==NULL ||								// Does The Storage Memory Exist?
		fread(texture->imageData, 1, imageSize, file)!=imageSize)	// Does The Image Size Match The Memory Reserved?	图像数据保存到纹理结构数据缓存imageData中
	{//失败情况下释放资源
		if(texture->imageData!=NULL)							// Was Image Data Loaded
			free(texture->imageData);							// If So, Release The Image Data
		fclose(file);											// Close The File
		return false;											// Return False
	}
	for(GLuint i=0; i<int(imageSize); i+=bytesPerPixel)			// Loop Through The Image Data
	{															// Swaps The 1st And 3rd Bytes ('R'ed and 'B'lue)
		temp=texture->imageData[i];								// Temporarily Store The Value At Image Data 'i'
		texture->imageData[i] = texture->imageData[i + 2];		// Set The 1st Byte To The Value Of The 3rd Byte
		texture->imageData[i + 2] = temp;						// Set The 3rd Byte To The Value In 'temp' (1st Byte Value)
	}
	fclose (file);												// Close The File
	glGenTextures(1, &texture->texID);							// Generate生产，产生 OpenGL texture IDs
	printf("纹理ID=%d/n",texture->texID );
	glBindTexture(GL_TEXTURE_2D, texture->texID);						// Bind 绑定Our Texture
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);	// Linear Filtered
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);	// Linear Filtered
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
	if (texture[0].bpp==24)										// Was The TGA 24 Bits
	{
		type=GL_RGB;											// If So Set The 'type' To GL_RGB
	}
	//创建纹理
	glTexImage2D(GL_TEXTURE_2D, 0, type, texture->width, texture->height, 0, type, GL_UNSIGNED_BYTE, texture->imageData);
	return true;
}
bool LoadBMP(TGAImage *texture, char *filename)
{
	
	BITMAPFILEHEADER	bmpFileHeader;		//bmp文件头 
	BITMAPINFOHEADER	bmpInfoHeader;			 //bmp格式头   
	GLuint		imageSize;										//纹理数据大小
	GLuint		temp;											// 		临时变量
	GLuint		type=GL_RGB;									
	FILE *file = fopen(filename, "rb");						
	printf("BMP_file=%d/n",file);	
	if(	file==NULL)											// Does File Even Exist?
		return	false;
	fread(&bmpFileHeader,1,sizeof(BITMAPFILEHEADER),file);	//读取文件头 
	if(bmpFileHeader.bfType!=0x4d42)						//判断是否是BM 
		return	false;
	else
		printf("是bmp图像/n");
	
	fread(&bmpInfoHeader,1,sizeof(BITMAPINFOHEADER),file);		//	读取信息头
	texture->width	=	bmpInfoHeader.biWidth;				//图片宽度
	texture->height	=	bmpInfoHeader.biHeight;				//图片高度
	texture->bpp	=	bmpInfoHeader.biBitCount;			//位深度
	imageSize		=	bmpInfoHeader.biSizeImage ;			//图像数据的大小，用作申请纹理缓存
	if(	texture->width	<=0	||									
		texture->height	<=0	||									
		texture->bpp!=24)									// bmp不是24位图	
	{
		fclose(file);										
		return false;										
	}
	//BITMAPFILEHEADER.bfOffBits从文件头开始到颜色数据的偏移量
	fseek(file,bmpFileHeader.bfOffBits,SEEK_SET);	//移动指针到图像数据
	texture->imageData=(GLubyte *)malloc(imageSize);
	if(	texture->imageData==NULL ||								// Does The Storage Memory Exist?
		fread(texture->imageData, 1, imageSize, file)!=imageSize)	// Does The Image Size Match The Memory Reserved?	图像数据保存到纹理结构数据缓存imageData中
	{
		//失败情况下释放资源
		if(texture->imageData!=NULL)							// Was Image Data Loaded
			free(texture->imageData);							// If So, Release The Image Data
		fclose(file);											// Close The File
		return false;											// Return False
	}
	for(GLuint i=0; i<int(imageSize); i+=texture->bpp/8)		// Loop Through The Image Data
	{															// Swaps The 1st And 3rd Bytes ('R'ed and 'B'lue)
		temp=texture->imageData[i];								// Temporarily Store The Value At Image Data 'i'
		texture->imageData[i] = texture->imageData[i + 2];		// Set The 1st Byte To The Value Of The 3rd Byte
		texture->imageData[i + 2] = temp;						// Set The 3rd Byte To The Value In 'temp' (1st Byte Value)
	}
	fclose (file);												// Close The File
	glGenTextures(1, &texture->texID);							// Generate生产，产生 OpenGL texture IDs
	printf("纹理ID=%d/n",texture->texID );
	glBindTexture(GL_TEXTURE_2D, texture->texID);						// Bind 绑定Our Texture
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);	// Linear Filtered
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);	// Linear Filtered
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
	//创建纹理
	glTexImage2D(GL_TEXTURE_2D, 0, type, texture->width, texture->height, 0, type, GL_UNSIGNED_BYTE, texture->imageData);
	return true;
}
使用：
	/*LoadTGA(&MainImage,"//NAND//skyworth//tga//main.tga/0");
	LoadTGA(&MovieImage,"//NAND//skyworth//tga//movie.tga");*/
	LoadBMP(&MainImage,"//USER//tv.bmp/0");
	LoadBMP(&MovieImage,"//USER//music.bmp/0");