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");