basic TGA question

	if(tgaheader[0])	{		if(fread(&tgaID, tgaheader[0], 1, fTGA) == 0)					// Read TGA ID		{													if(fTGA != NULL)													// if file is still open			{				fclose(fTGA);													// Close it			}			return false;														// Return failular		}		}

	if((texture->width <= 0) || (texture->height <= 0) || ((texture->bpp != 24) && (texture->bpp !=32)))	// Make sure all information is valid	{		if(fTGA != NULL)													// Check if file is still open		{			fclose(fTGA);													// If so, close it		}		return false;														// Return failed	}

#ifndef __TGA_H__#define __TGA_H__#pragma comment(lib, "Opengl32.lib")					//Link to OpenGL32.lib so we can use OpenGL stuff#include <windows.h>									// Standard windows header#include <stdio.h>										// Standard I/O header #include <gl\gl.h>										// Header for OpenGL32 library#include "texture.h"typedef struct{	GLubyte		header[6];								// First 6 Useful Bytes From The Header	GLuint		bytesPerPixel;							// Holds Number Of Bytes Per Pixel Used In The TGA File	GLuint		imageSize;								// Used To Store The Image Size When Setting Aside Ram	GLuint		temp;									// Temporary Variable	GLuint		type;		GLuint		Height;									//Height of Image	GLuint		Width;									//Width ofImage	GLuint		Bpp;									// Bits Per Pixel} TGA;char tgaheader[12];									// TGA headerchar tgaID[256];									// TGA headerTGA tga;												// TGA image databool LoadUncompressedTGA(Texture *, char *, FILE *);	// Load an Uncompressed filebool LoadCompressedTGA(Texture *, char *, FILE *);		// Load a Compressed file#endif

/********************************************************************************/Name:		TGA.cpp																*/Header:	tga.h																*/Purpose:	Load Compressed and Uncompressed TGA files							*/Functions:	LoadTGA(Texture * texture, char * filename)							*/			LoadCompressedTGA(Texture * texture, char * filename, FILE * fTGA)	*/			LoadUncompressedTGA(Texture * texture, char * filename, FILE * fTGA)*	/*******************************************************************************/#include "tga.h"/********************************************************************************/name :		LoadTGA(Texture * texture, char * filename)							*/function:  Open and test the file to make sure it is a valid TGA file			*	/parems:	texture, pointer to a Texture structure								*/			filename, string pointing to file to open							*/********************************************************************************/bool LoadTGA(Texture * texture, char * filename)				// Load a TGA file{	FILE * fTGA;												// File pointer to texture file	fTGA = fopen(filename, "rb");								// Open file for reading	if(fTGA == NULL)											// If it didn't open....	{		MessageBox(NULL, "Could not open texture file", "ERROR", MB_OK);	// Display an error message		return false;														// Exit function	}	if(fread(&tgaheader, 12, 1, fTGA) == 0)					// Attempt to read 12 byte header from file	{		MessageBox(NULL, "Could not read file header", "ERROR", MB_OK);		// If it fails, display an error message 		if(fTGA != NULL)													// Check to seeiffile is still open		{			fclose(fTGA);													// If it is, close it		}		return false;														// Exit function	}	if(tgaheader[2]==2)				// See if header matches the predefined header of 	{	// an Uncompressed TGA image		LoadUncompressedTGA(texture, filename, fTGA);						// If so, jump to Uncompressed TGA loading code	}	else if(tgaheader[2]==10)		// See if header matches the predefined header of	{																		// an RLE compressed TGA image		LoadCompressedTGA(texture, filename, fTGA);							// If so, jump to Compressed TGA loading code	}	else																	// If header matches neither type	{		MessageBox(NULL, "TGA file be type 2 or type 10 ", "Invalid Image", MB_OK);	// Display an error		fclose(fTGA);		return false;																// Exit function	}	return true;															// All went well, continue on}bool LoadUncompressedTGA(Texture * texture, char * filename, FILE * fTGA)	// Load an uncompressed TGA (note, much of this code is based on NeHe's {																			// TGA Loading code nehe.gamedev.net)	if(fread(tga.header, sizeof(tga.header), 1, fTGA) == 0)					// Read TGA header	{												MessageBox(NULL, "Could not read info header", "ERROR", MB_OK);		// Display error		if(fTGA != NULL)													// if file is still open		{			fclose(fTGA);													// Close it		}		return false;														// Return failular	}		texture->width  = tga.header[1] * 256 + tga.header[0];					// Determine The TGA Width	(highbyte*256+lowbyte)	texture->height = tga.header[3] * 256 + tga.header[2];					// Determine The TGA Height	(highbyte*256+lowbyte)	texture->bpp	= tga.header[4];										// Determine the bits per pixel	tga.Width		= texture->width;										// Copy width into local structure							tga.Height		= texture->height;										// Copy height into local structure	tga.Bpp			= texture->bpp;											// Copy BPP into local structure	if((texture->width <= 0) || (texture->height <= 0) || ((texture->bpp != 24) && (texture->bpp !=32)))	// Make sure all information is valid	{		MessageBox(NULL, "Invalid texture information", "ERROR", MB_OK);	// Display Error		if(fTGA != NULL)													// Check if file is still open		{			fclose(fTGA);													// If so, close it		}		return false;														// Return failed	}	if(tgaheader[0]!=0)	{		if(fread(&tgaID, tgaheader[0], 1, fTGA) == 0)						// Read TGA Id tag		{				MessageBox(NULL, "Could not read tga ID", "ERROR", MB_OK);				// Display Error			if(fTGA != NULL)												// if file is still open			{				fclose(fTGA);												// Close it			}			return false;													// Return fail		}	}	if(texture->bpp == 24)													//If the BPP of the image is 24...	{		texture->type	= GL_RGB;											// Set Image type to GL_RGB	}	else																	// Else if its 32 BPP	{		texture->type	= GL_RGBA;											// Set image type to GL_RGBA	}	tga.bytesPerPixel	= (tga.Bpp / 8);									// Compute the number of BYTES per pixel	tga.imageSize		= (tga.bytesPerPixel * tga.Width * tga.Height);		// Compute the total amout ofmemory needed to store data	texture->imageData	= (GLubyte *)malloc(tga.imageSize);					// Allocate that much memory	if(texture->imageData == NULL)											// If no space was allocated	{		MessageBox(NULL, "Could not allocate memory for image", "ERROR", MB_OK);	// Display Error		fclose(fTGA);														// Close the file		return false;														// Return failed	}	if(fread(texture->imageData, 1, tga.imageSize, fTGA) != tga.imageSize)	// Attempt to read image data	{		MessageBox(NULL, "Could not read image data", "ERROR", MB_OK);		// Display Error		if(texture->imageData != NULL)										// If imagedata has data in it		{			free(texture->imageData);										// Delete data from memory		}		fclose(fTGA);														// Close file		return false;														// Return failed	}	// Byte Swapping Optimized By Steve Thomas	for(GLuint cswap = 0; cswap < (int)tga.imageSize; cswap += tga.bytesPerPixel)	{		texture->imageData[cswap] ^= texture->imageData[cswap+2] ^=		texture->imageData[cswap] ^= texture->imageData[cswap+2];	}	fclose(fTGA);															// Close file	return true;															// Return success}bool LoadCompressedTGA(Texture * texture, char * filename, FILE * fTGA)		// Load COMPRESSED TGAs{ 	if(fread(tga.header, sizeof(tga.header), 1, fTGA) == 0)					// Attempt to read header	{		MessageBox(NULL, "Could not read info header", "ERROR", MB_OK);		// Display Error		if(fTGA != NULL)													// If file is open		{			fclose(fTGA);													// Close it		}		return false;														// Return failed	}	texture->width  = tga.header[1] * 256 + tga.header[0];					// Determine The TGA Width	(highbyte*256+lowbyte)	texture->height = tga.header[3] * 256 + tga.header[2];					// Determine The TGA Height	(highbyte*256+lowbyte)	texture->bpp	= tga.header[4];										// Determine Bits Per Pixel	tga.Width		= texture->width;										// Copy width to local structure	tga.Height		= texture->height;										// Copy width to local structure	tga.Bpp			= texture->bpp;											// Copy width to local structure	if((texture->width <= 0) || (texture->height <= 0) || ((texture->bpp != 24) && (texture->bpp !=32)))	//Make sure all texture info is ok	{		MessageBox(NULL, "Invalid texture information", "ERROR", MB_OK);	// If it isnt...Display error		if(fTGA != NULL)													// Check if file is open		{			fclose(fTGA);													// Ifit is, close it		}		return false;														// Return failed	}		if(tgaheader[0]!=0)	{		if(fread(&tgaID, tgaheader[0], 1, fTGA) == 0)						// Read TGA Id tag		{				MessageBox(NULL, "Could not read tga ID", "ERROR", MB_OK);				// Display Error			if(fTGA != NULL)												// if file is still open			{				fclose(fTGA);												// Close it			}			return false;													// Return fail		}	}	tga.bytesPerPixel	= (tga.Bpp / 8);									// Compute BYTES per pixel	tga.imageSize		= (tga.bytesPerPixel * tga.Width * tga.Height);		// Compute amout of memory needed to store image	texture->imageData	= (GLubyte *)malloc(tga.imageSize);					// Allocate that much memory	if(texture->imageData == NULL)											// If it wasnt allocated correctly..	{		MessageBox(NULL, "Could not allocate memory for image", "ERROR", MB_OK);	// Display Error		fclose(fTGA);														// Close file		return false;														// Return failed	}	GLuint pixelcount	= tga.Height * tga.Width;							// Nuber of pixels in the image	GLuint currentpixel	= 0;												// Current pixel being read	GLuint currentbyte	= 0;												// Current byte 	GLubyte * colorbuffer = (GLubyte *)malloc(tga.bytesPerPixel);			// Storage for 1 pixel	do	{		GLubyte chunkheader = 0;											// Storage for "chunk" header		if(fread(&chunkheader, sizeof(GLubyte), 1, fTGA) == 0)				// Read in the 1 byte header		{			MessageBox(NULL, "Could not read RLE header", "ERROR", MB_OK);	// Display Error			if(fTGA != NULL)												// If file is open			{				fclose(fTGA);												// Close file			}			if(texture->imageData != NULL)									// If there is stored image data			{				free(texture->imageData);									// Delete image data			}			return false;													// Return failed		}		if(chunkheader < 128)												// If the ehader is < 128, it means the that is the number of RAW color packets minus 1		{																	// that follow the header			chunkheader++;													// add 1 to get number of following color values			for(short counter = 0; counter < chunkheader; counter++)		// Read RAW color values			{				if(fread(colorbuffer, 1, tga.bytesPerPixel, fTGA) != tga.bytesPerPixel) // Try to read 1 pixel				{					MessageBox(NULL, "Could not read image data", "ERROR", MB_OK);		// IF we cant, display an error					if(fTGA != NULL)													// See if file is open					{						fclose(fTGA);													// If so, close file					}					if(colorbuffer != NULL)												// See if colorbuffer has data in it					{						free(colorbuffer);												// If so, delete it					}					if(texture->imageData != NULL)										// See if there is stored Image data					{						free(texture->imageData);										// If so, delete it too					}					return false;														// Return failed				}																						// write to memory				texture->imageData[currentbyte		] = colorbuffer[2];				    // Flip R and B vcolor values around in the process 				texture->imageData[currentbyte + 1	] = colorbuffer[1];				texture->imageData[currentbyte + 2	] = colorbuffer[0];				if(tga.bytesPerPixel == 4)												// if its a 32 bpp image				{					texture->imageData[currentbyte + 3] = colorbuffer[3];				// copy the 4th byte				}				currentbyte += tga.bytesPerPixel;										// Increase thecurrent byte by the number of bytes per pixel				currentpixel++;															// Increase current pixel by 1				if(currentpixel > pixelcount)											// Make sure we havent read too many pixels				{					MessageBox(NULL, "Too many pixels read", "ERROR", NULL);			// if there is too many... Display an error!					if(fTGA != NULL)													// If there is a file open					{						fclose(fTGA);													// Close file					}						if(colorbuffer != NULL)												// If there is data in colorbuffer					{						free(colorbuffer);												// Delete it					}					if(texture->imageData != NULL)										// If there is Image data					{						free(texture->imageData);										// delete it					}					return false;														// Return failed				}			}		}		else																			// chunkheader > 128 RLE data, next color reapeated chunkheader - 127 times		{			chunkheader -= 127;															// Subteact 127 to get rid of the ID bit			if(fread(colorbuffer, 1, tga.bytesPerPixel, fTGA) != tga.bytesPerPixel)		// Attempt to read following color values			{					MessageBox(NULL, "Could not read from file", "ERROR", MB_OK);			// If attempt fails.. Display error (again)				if(fTGA != NULL)														// If thereis a file open				{					fclose(fTGA);														// Close it				}				if(colorbuffer != NULL)													// If there is data in the colorbuffer				{					free(colorbuffer);													// delete it				}				if(texture->imageData != NULL)											// If thereis image data				{					free(texture->imageData);											// delete it				}				return false;															// return failed			}			for(short counter = 0; counter < chunkheader; counter++)					// copy the color into the image data as many times as dictated 			{																			// by the header				texture->imageData[currentbyte		] = colorbuffer[2];					// switch R and B bytes areound while copying				texture->imageData[currentbyte + 1	] = colorbuffer[1];				texture->imageData[currentbyte + 2	] = colorbuffer[0];				if(tga.bytesPerPixel == 4)												// If TGA images is 32 bpp				{					texture->imageData[currentbyte + 3] = colorbuffer[3];				// Copy 4th byte				}				currentbyte += tga.bytesPerPixel;										// Increase current byte by the number of bytes per pixel				currentpixel++;															// Increase pixel count by 1				if(currentpixel > pixelcount)											// Make sure we havent written too many pixels				{					MessageBox(NULL, "Too many pixels read", "ERROR", NULL);			// if there is too many... Display an error!					if(fTGA != NULL)													// If there is a file open					{						fclose(fTGA);													// Close file					}						if(colorbuffer != NULL)												// If there is data in colorbuffer					{						free(colorbuffer);												// Delete it					}					if(texture->imageData != NULL)										// If there is Image data					{						free(texture->imageData);										// delete it					}					return false;														// Return failed				}			}		}	}	while(currentpixel < pixelcount);													// Loop while there are still pixels left	fclose(fTGA);																		// Close the file	return true;																		// return success}

int LoadGLTextures()											// Load Bitmaps And Convert To Textures{	int Status=FALSE;											// Status Indicator	// Load The Bitmap, Check For Errors.	if (LoadTGA(&texture[0], "Data/Uncompressed.tga") &&		LoadTGA(&texture[1], "Data/Compressed.tga"))	{		Status=TRUE;											// Set The Status To TRUE			glGenTextures(1, &texture[0].texID);				// Create The Texture ( CHANGE )			glBindTexture(GL_TEXTURE_2D, texture[0].texID);			glTexImage2D(GL_TEXTURE_2D, 0, 4, texture[0].width, texture[0].height, 0, GL_RGBA, GL_UNSIGNED_BYTE, texture[0].imageData);			glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);			glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);			if (texture[0].imageData)						// If Texture Image Exists ( CHANGE )			{				free(texture[0].imageData);					// Free The Texture Image Memory ( CHANGE )			}			// Typical Texture Generation Using Data From The TGA ( CHANGE )			glGenTextures(1, &texture[1].texID);				// Create The Texture ( CHANGE )			glBindTexture(GL_TEXTURE_2D, texture[1].texID);			glTexImage2D(GL_TEXTURE_2D, 0, 3, texture[1].width, texture[1].height, 0, GL_RGB, GL_UNSIGNED_BYTE, texture[1].imageData);			glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);			glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);			if (texture[1].imageData)						// If Texture Image Exists ( CHANGE )			{				free(texture[1].imageData);					// Free The Texture Image Memory ( CHANGE )			}			}	return Status;												// Return The Status}