//
//	BMP version 3.x header
//
 
#pragma	pack(1)
typedef struct Bmp3XHead_Type
{
	unsigned short	ImageFileType;			// File Identifier (always 0)
 
	unsigned int	FileSize;				// Size of files in bytes
	unsigned short	Reserved[2];
	unsigned int	ImageDataOffset;			// Start of image data offset
} Bmp3XHead;
#pragma pack()
 
 
 
//
//	BMP version 3.x informational header
//
 
#pragma	pack(1)
typedef struct Bmp3XInfo_Type
{
	unsigned int	HeaderSize;		// Size of this header
	unsigned int	Width;			// Width of image
	unsigned int	Height;			// Height of bitmap in scanlines
	unsigned short	Planes;			// # of color planes
	unsigned short	Depth;			// # of bits per pixel
	unsigned int	Compression;		// Type of compression
	unsigned int	ImageSize;		// Size of bitmap in bytes
	unsigned int	HRes;			// Horizontal Resolution in pixels/meter
	unsigned int	VRes;			// Vertical Resolution in pixels/meter
	unsigned int	nColor;			// # of colors in image
	unsigned int	nColorCnt;		// Number of important colors in palette
} Bmp3XInfo;
#pragma pack()
 
 
 
 
 
void load_texture ( char *filename, int width, int height, int depth, GLenum colour_type, GLenum filter_type )
{
   GLubyte *texture ;
   FILE *file;
 
	file = fopen( filename, "rb" );
    if ( file == NULL ) 
		printf("File not found: \n", filename);
 
	Bmp3XHead head;
 
	fread( &head, sizeof(head), 1, file );
	if ( 0x4d42 != head.ImageFileType )
	{
		fclose(file);
		return;
	}
 
	Bmp3XInfo info;
 
	fread( &info, sizeof(info), 1, file );
 
	width = info.Width;
	height = info.Height;
	depth = info.Depth;
 
	if (depth != 24)
	{
		fclose( file );
		return;
	}
 
	depth >>= 3;
 
	fseek( file, head.ImageDataOffset, SEEK_SET );	// Start of pixels!
 
   texture = (GLubyte *) malloc ( width * height * depth * ( sizeof(GLubyte)) );
 
   if (texture == NULL)
   {
      printf ( "Cannot allocate memory for texture\n" );
      fclose ( file);
      exit   ( 1 );
   }
 
   fread  ( texture , width * height * depth, 1 , file );
   fclose ( file);
 
	// Swap blue & red
   GLubyte *pix, *pixEnd, col;
	pix = texture;
	pixEnd = texture + width * height * depth;
 
	while( pix < pixEnd )
	{
		col = *pix;
		*pix = *(pix+2);
		*(pix+2) = col;
		pix += 3;
	}
 
   //  Set Filtering type
   glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter_type );
   glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, filter_type );
 
   //  Set Texture Evironment
   glTexEnvf ( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
 
   //  Build Mipmaps
   gluBuild2DMipmaps ( GL_TEXTURE_2D, colour_type, width, height,
                       colour_type, GL_UNSIGNED_BYTE, texture );
 
   //  Free up the array
   free ( texture );
}