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OpenGL Texture Binding with Material Class

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Im having a problem binding textures that I am loading from an .obj Material library. My texture loading code works if I load each texture individually, then all textures work great. But if a load the textures while parsing the Material Library file only the last texture loaded can be rendered. I have written a smaller program to try to get to the root of the problem. Basically, an instance of my Material class will load a texture and store the texture ID so that it can be bound when rendering. Any suggestions? Can anyone tell what I am doing wrong? Thanks for any help. Main.cpp:
#include <windows.h>		// Header File For Windows
#include <stdio.h>			// Header File For Standard Input/Output
#include <gl\gl.h>			// Header File For The OpenGL32 Library
#include <gl\glu.h>			// Header File For The GLu32 Library
#include <gl\glaux.h>		// Header File For The Glaux Library

#include <ios>
#include <iostream>
#include <string>
#include <tchar.h>
#include <windowsx.h>
#include <fstream>

#include <vector>

#include "Material.h"

using namespace std;

HDC			hDC=NULL;		// Private GDI Device Context
HGLRC		hRC=NULL;		// Permanent Rendering Context
HWND		hWnd=NULL;		// Holds Our Window Handle
HINSTANCE	hInstance;		// Holds The Instance Of The Application

bool	active=TRUE;		// Window Active Flag Set To TRUE By Default

// Log file
ofstream logFile("C:\\Documents and Settings\\Dave\\My Documents\\Visual Studio Projects\\TextureManager\\Debug\\log.txt", ios::out);

// Materials Container
std::vector<Material> materials;


// Number of textures loaded
int numTexture = 0;

void checkGlErrors() {
	int glError = 1;
	while (glError != 0) {
		glError = glGetError();
		if (glError != 0) {
			logFile << "[ERROR] glGetError = " << glError << endl;

// Call to load a Bitmap
int loadBitmap(const char *filename) 
	logFile << "	loadBitmap called: file name = " << filename << endl;
    FILE *file;				// File pointer
    unsigned char *texture; // The pointer to the memory in which we will load the texture
    // windows.h gives us these types to work with the Bitmap files
    BITMAPFILEHEADER fileheader; 
    BITMAPINFOHEADER infoheader;
    RGBTRIPLE rgb;

	// Increment the texture count
	logFile << "		numTexture = " << numTexture << endl;

	// Open the file for reading
	if ( (file = fopen(filename, "rb")) == NULL) {
		logFile << "		COULDN'T OPEN FILE" << endl;
		return (-1); 
	} else {
		logFile << "		The file has been opened for reading." << endl;
	// Read the fileheader
    fread(&fileheader, sizeof(fileheader), 1, file); 
	// Jump the fileheader
    fseek(file, sizeof(fileheader), SEEK_SET); 
	// and read the infoheader
    fread(&infoheader, sizeof(infoheader), 1, file); 

    // Allocate the memory for our image (width * height * color deep)
    texture = (byte *) malloc(infoheader.biWidth * infoheader.biHeight * 4);
    // And fill it with zeros
    memset(texture, 0, infoheader.biWidth * infoheader.biHeight * 4);
    // Read in the image
	int j = 0;
    for (int i = 0; i < infoheader.biWidth*infoheader.biHeight; ++i) {            
        // We load an RGB value from the file
        fread(&rgb, sizeof(rgb), 1, file); 

        // And store it
        texture[j+0] = rgb.rgbtRed;		// Red component
        texture[j+1] = rgb.rgbtGreen;	// Green component
        texture[j+2] = rgb.rgbtBlue;	// Blue component
        texture[j+3] = 255;				// Alpha value
        j += 4;							// Go to the next position

	// Close the file stream
	// Bind the ID texture
    glBindTexture(GL_TEXTURE_2D, numTexture); 

	// Define the 2d texture
    glTexImage2D(GL_TEXTURE_2D, 0, 4, infoheader.biWidth, infoheader.biHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, texture);

    // Sets the texture parameters

	// Use only the texture map

    // And create 2d mipmaps for the minifying function
    gluBuild2DMipmaps(GL_TEXTURE_2D, 4, infoheader.biWidth, infoheader.biHeight, GL_RGBA, GL_UNSIGNED_BYTE, texture);

	// Free the memory used to load the texture


	// Returns texture ID for the new texture
	int isTexture = glIsTexture(numTexture);
	logFile << "		is a texture ? = " << isTexture << endl;
    return (numTexture); 

// Load an Alias Wavefront .obj Material Library
bool loadMaterialFile(const char filename[]) {

	std::ifstream ifs(filename);

	if (ifs) {
		Material *pmat = 0;

		while (!ifs.eof()) {

			std::string s;
			ifs >> s;

			if (s == "newmtl") {
				Material mat;
				ifs >> mat.name;
				pmat = &(materials[materials.size()-1]);

			} else if (s == "map_Kd") {

				char buffer[512];
				char* ptr = buffer;
				while (*ptr == ' ' || *ptr == '\t') {
				pmat->diffuseTextureName = ptr;
		return true;
	logFile << "File not Found!!!" << endl;

	return false;

// Resize the GL Scene
GLvoid ReSizeGLScene(GLsizei width, GLsizei height)		
	// Prevent A Divide By Zero By
	if (height==0)										

	// Reset The Current Viewport

	// Select and Reset The Projection Matrix

	// Calculate The Aspect Ratio Of The Window

	// Select and Reset The Modelview Matrix

// All Setup For OpenGL Goes Here
int InitGL(GLvoid)										
	glEnable(GL_TEXTURE_2D);							// Enable Texture Mapping ( NEW )
	glShadeModel(GL_SMOOTH);							// Enable Smooth Shading
	glClearColor(0.0f, 0.0f, 0.0f, 0.5f);				// Black Background
	glClearDepth(1.0f);									// Depth Buffer Setup
	glEnable(GL_DEPTH_TEST);							// Enables Depth Testing
	glDepthFunc(GL_LEQUAL);								// The Type Of Depth Testing To Do
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);	// Really Nice Perspective Calculations

	// load material file
	if (!loadMaterialFile("squares2.mtl")) {
		logFile << "Materials NOT loaded." << endl;
	} else {
    	logFile << "Materials loaded - materials.size() = " << materials.size() << endl;

	// Print out the loaded materials props of interest
	for (int i = 0; i < materials.size(); ++i) {
		logFile << "Material " << i << ":" << endl;
		logFile << "    name = " << materials.name << endl;
		logFile << "    diffuseTextureName = " << materials.diffuseTextureName << endl;
		logFile << "    diffuseTextureId = " << materials.diffuseTextureId << endl;
		int isTexture = glIsTexture(materials.diffuseTextureId);
		logFile << "    isTexture? = " << isTexture << endl;

	// Check for errors

	// Initialization completed OK
	return TRUE;	

// Draw the scene
// Render 4 quads - each with a different Material
int DrawGLScene(GLvoid)	

	// Clear The Screen And The Depth Buffer and Reset The View

	// move the camera a little

	int isTexture = glIsTexture(materials[0].diffuseTextureId);
	logFile << "  glIsTexture? materials[0] = " << isTexture << endl;
		glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  0.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f( 0.0f, -1.0f,  0.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f( 0.0f,  0.0f,  0.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  0.0f,  0.0f);

	isTexture = glIsTexture(materials[1].diffuseTextureId);
	logFile << "  glIsTexture? materials[1] = " << isTexture << endl;
		glTexCoord2f(0.0f, 0.0f); glVertex3f(0.0f, 0.0f,  1.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 0.0f,  1.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(0.0f,  1.0f,  1.0f);		

	return TRUE;

// Properly Kill The Window
GLvoid KillGLWindow(GLvoid)								
	// Do We Have A Rendering Context?
	if (hRC)											
		// Are We Able To Release The DC And RC Contexts?
		if (!wglMakeCurrent(NULL,NULL))					

		// Are We Able To Delete The RC?
		if (!wglDeleteContext(hRC))						
			MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hRC = NULL;
	// Are We Able To Release The DC
	if (hDC && !ReleaseDC(hWnd,hDC))					
		MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hDC = NULL;
	// Are We Able To Destroy The Window?
	if (hWnd && !DestroyWindow(hWnd))					
		MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hWnd = NULL;
	// Are We Able To Unregister Class
	if (!UnregisterClass("OpenGL",hInstance))			
		MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
		hInstance = NULL;

// Create an OpenGL Window 
BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag)

	logFile << "CreateGLWindow called." << endl;

	GLuint		PixelFormat;			// Holds The Results After Searching For A Match
	WNDCLASS	wc;						// Windows Class Structure
	DWORD		dwExstyle;				// Window Extended style
	DWORD		dwstyle;				// Window style
	RECT		WindowRect;				// Grabs Rectangle Upper Left / Lower Right Values
	WindowRect.left=(long)0;			// Set Left Value To 0
	WindowRect.right=(long)width;		// Set Right Value To Requested Width
	WindowRect.top=(long)0;				// Set Top Value To 0
	WindowRect.bottom=(long)height;		// Set Bottom Value To Requested Height

	hInstance			= GetModuleHandle(NULL);				// Grab An Instance For Our Window
	wc.style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;	// Redraw On Size, And Own DC For Window.
	wc.lpfnWndProc		= (WNDPROC) WndProc;					// WndProc Handles Messages
	wc.cbClsExtra		= 0;									// No Extra Window Data
	wc.cbWndExtra		= 0;									// No Extra Window Data
	wc.hInstance		= hInstance;							// Set The Instance
	wc.hIcon			= LoadIcon(NULL, IDI_WINLOGO);			// Load The Default Icon
	wc.hCursor			= LoadCursor(NULL, IDC_ARROW);			// Load The Arrow Pointer
	wc.hbrBackground	= NULL;									// No Background Required For GL
	wc.lpszMenuName		= NULL;									// We Don't Want A Menu
	wc.lpszClassName	= "OpenGL";								// Set The Class Name

	if (!RegisterClass(&wc))									// Attempt To Register The Window Class
		MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;											// Return FALSE

	dwExstyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;			// Window Extended style
	dwstyle=WS_OVERLAPPEDWINDOW;							// Windows style

	AdjustWindowRectEx(&WindowRect, dwstyle, FALSE, dwExstyle);		// Adjust Window To True Requested Size

	// Create The Window
	if (!(hWnd=CreateWindowEx(	dwExstyle,							// Extended style For The Window
								"OpenGL",							// Class Name
								title,								// Window Title
								dwstyle |							// Defined Window style
								WS_CLIPSIBLINGS |					// Required Window style
								WS_CLIPCHILDREN,					// Required Window style
								0, 0,								// Window Position
								WindowRect.right-WindowRect.left,	// Calculate Window Width
								WindowRect.bottom-WindowRect.top,	// Calculate Window Height
								NULL,								// No Parent Window
								NULL,								// No Menu
								hInstance,							// Instance
								NULL)))								// Dont Pass Anything To WM_CREATE
		KillGLWindow();								// Reset The Display
		MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE

	static	PIXELFORMATDESCRIPTOR pfd=				// pfd Tells Windows How We Want Things To Be
		sizeof(PIXELFORMATDESCRIPTOR),				// Size Of This Pixel Format Descriptor
		1,											// Version Number
		PFD_DRAW_TO_WINDOW |						// Format Must Support Window
		PFD_SUPPORT_OPENGL |						// Format Must Support OpenGL
		PFD_DOUBLEBUFFER,							// Must Support Double Buffering
		PFD_TYPE_RGBA,								// Request An RGBA Format
		bits,										// Select Our Color Depth
		0, 0, 0, 0, 0, 0,							// Color Bits Ignored
		0,											// No Alpha Buffer
		0,											// Shift Bit Ignored
		0,											// No Accumulation Buffer
		0, 0, 0, 0,									// Accumulation Bits Ignored
		16,											// 16Bit Z-Buffer (Depth Buffer)  
		0,											// No Stencil Buffer
		0,											// No Auxiliary Buffer
		PFD_MAIN_PLANE,								// Main Drawing Layer
		0,											// Reserved
		0, 0, 0										// Layer Masks Ignored
	if (!(hDC=GetDC(hWnd)))							// Did We Get A Device Context?
		KillGLWindow();								// Reset The Display
		MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE

	if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd)))	// Did Windows Find A Matching Pixel Format?
		KillGLWindow();								// Reset The Display
		MessageBox(NULL,"Can't Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE

	if(!SetPixelFormat(hDC,PixelFormat,&pfd))		// Are We Able To Set The Pixel Format?
		KillGLWindow();								// Reset The Display
		MessageBox(NULL,"Can't Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE

	if (!(hRC=wglCreateContext(hDC)))				// Are We Able To Get A Rendering Context?
		KillGLWindow();								// Reset The Display
		MessageBox(NULL,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE

	if(!wglMakeCurrent(hDC,hRC))					// Try To Activate The Rendering Context
		KillGLWindow();								// Reset The Display
		MessageBox(NULL,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE

	ShowWindow(hWnd,SW_SHOW);						// Show The Window
	SetForegroundWindow(hWnd);						// Slightly Higher Priority
	SetFocus(hWnd);									// Sets Keyboard Focus To The Window
	ReSizeGLScene(width, height);					// Set Up Our Perspective GL Screen

	if (!InitGL())									// Initialize Our Newly Created GL Window
		KillGLWindow();								// Reset The Display
		MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);
		return FALSE;								// Return FALSE

	return TRUE;									// Success

LRESULT CALLBACK WndProc(	HWND	hWnd,			// Handle For This Window
							UINT	uMsg,			// Message For This Window
							WPARAM	wParam,			// Additional Message Information
							LPARAM	lParam)			// Additional Message Information
	switch (uMsg)									// Check For Windows Messages
		case WM_ACTIVATE:							// Watch For Window Activate Message
			if (!HIWORD(wParam))					// Check Minimization State
				active=TRUE;						// Program Is Active
				active=FALSE;						// Program Is No Longer Active

			return 0;								// Return To The Message Loop

		case WM_SYSCOMMAND:							// Intercept System Commands
			switch (wParam)							// Check System Calls
				case SC_SCREENSAVE:					// Screensaver Trying To Start?
				case SC_MONITORPOWER:				// Monitor Trying To Enter Powersave?
				return 0;							// Prevent From Happening
			break;									// Exit

		case WM_CLOSE:								// Did We Receive A Close Message?
			PostQuitMessage(0);						// Send A Quit Message
			return 0;								// Jump Back

		case WM_SIZE:								// Resize The OpenGL Window
			ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));  // LoWord=Width, HiWord=Height
			return 0;								// Jump Back

	// Pass All Unhandled Messages To DefWindowProc
	return DefWindowProc(hWnd,uMsg,wParam,lParam);

int WINAPI WinMain(	HINSTANCE	hInstance,			// Instance
					HINSTANCE	hPrevInstance,		// Previous Instance
					LPSTR		lpCmdLine,			// Command Line Parameters
					int			nCmdShow)			// Window Show State
	MSG		msg;									// Windows Message Structure
	BOOL	done=FALSE;								// Bool Variable To Exit Loop

	// Create Our OpenGL Window
	if (!CreateGLWindow("Materials", 640, 480, 16, false))
		// Quit If Window Was Not Created
		return 0;									

	// main loop
	while (!done)									
		// Is There A Message Waiting?
		if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))	
			// Have We Received A Quit Message?
			if (msg.message==WM_QUIT)				
				// If So done=TRUE
				// Translate and Dispatch the message
			// Draw The Scene.
			if ((active && !DrawGLScene()))
				// Quit signaled
				done = TRUE;
				// Swap Buffers (Double Buffering)

	// Shutdown
	KillGLWindow();									// Kill The Window
	return (msg.wParam);							// Exit The Program

End Main.cpp Material.h:
#ifndef MATERIAL_H
#define MATERIAL_H

#include <stdio.h>
#include <fstream>
#include <ios>
#include <iostream>
#include <string>

//#include "Engine.h"
#include <windows.h>		// Header File For Windows
#include <stdio.h>			// Header File For Standard Input/Output
#include <gl\gl.h>			// Header File For The OpenGL32 Library
#include <gl\glu.h>			// Header File For The GLu32 Library
#include <gl\glaux.h>		// Header File For The Glaux Library

using namespace std;

class Material
	Material(const char *name);
	Material(const Material &mat);

	virtual ~Material();

	void loadDiffuseTexture();

	/** apply the material */
	void apply() const;

	std::string name;		//< material name

	int illum;				//< don't know :| Seems to always be 4
	float transparency[3];	//< transparency
	float intensity;		//< intensity
	float specularPower;	//< specular power
	float bumpDepth;		//< bump map depth. Only used if bump is relevent.

	mutable float ambientColor[4];	//< ambient
	mutable float diffuseColor[4];	//< diffuse
	mutable float specularColor[4];	//< specular

	std::string ambientTextureName;		//< ambient texture map name
	std::string diffuseTextureName;		//< diffuse texture map name
	std::string specularTextureName;	//< specular texture map name
	std::string bumpTextureName;		//< bump texture map name

	// OpenGL texture IDs
	unsigned int ambientTextureId;		//< ambient texture object ID
	unsigned int diffuseTextureId;		//< diffuse texture object ID
	unsigned int specularTextureId;		//< specular texture object ID
	unsigned int bumpTextureId;			//< bump map texture object ID



End Material.h Material.cpp:
#include "Material.h"

#include "TextureManager.h"
#include "Globals.h"

//#include "lesson6.h"

 * Material constructor
Material::Material() : name(), illum(4), intensity(1), specularPower(10), bumpDepth(1),
		ambientTextureName(), diffuseTextureName(), specularTextureName(), bumpTextureName() {

	ambientColor[0] = ambientColor[1] = ambientColor[2] = 
	diffuseColor[0] = diffuseColor[1] = diffuseColor[2] = 
	specularColor[0] = specularColor[1] = specularColor[2] = 0;
	ambientColor[3] = diffuseColor[3] = specularColor[3] = 1;
	transparency[0] = transparency[1] = transparency[2] = 1;
	ambientTextureId = diffuseTextureId = specularTextureId = bumpTextureId = 0;

 * Material Copy Constructor
Material::Material(const Material& mat) {
	ambientColor[0] = mat.ambientColor[0]; 
	ambientColor[1] = mat.ambientColor[1]; 
	ambientColor[2] = mat.ambientColor[2]; 
	ambientColor[3] = mat.ambientColor[3];

	diffuseColor[0] = mat.diffuseColor[0]; 
	diffuseColor[1] = mat.diffuseColor[1]; 
	diffuseColor[2] = mat.diffuseColor[2]; 
	diffuseColor[3] = mat.diffuseColor[3];

	specularColor[0] = mat.specularColor[0];
	specularColor[1] = mat.specularColor[1];
	specularColor[2] = mat.specularColor[2];
	specularColor[3] = mat.specularColor[3];

	transparency[0] = mat.transparency[0];
	transparency[1] = mat.transparency[1];
	transparency[2] = mat.transparency[2];

	intensity = mat.intensity;
	specularPower = mat.specularPower;
	name = mat.name;
	ambientTextureName = mat.ambientTextureName;
	diffuseTextureName = mat.diffuseTextureName;
	specularTextureName = mat.specularTextureName;
	bumpTextureName = mat.bumpTextureName;
	illum = mat.illum;
	bumpDepth = mat.bumpDepth;

	ambientTextureId = mat.ambientTextureId;
	diffuseTextureId = mat.diffuseTextureId;
	specularTextureId = mat.specularTextureId;
	bumpTextureId = mat.bumpTextureId;

 * The material class destructor.
Material::~Material() {
	if (ambientTextureId) glDeleteTextures(1, &ambientTextureId);
	if (diffuseTextureId) glDeleteTextures(1, &diffuseTextureId);
	if (specularTextureId) glDeleteTextures(1, &specularTextureId);
	if (bumpTextureId) glDeleteTextures(1, &bumpTextureId);

void Material::apply() const {

	// HACK !?!??
	glColor3f(1.0f, 1.0f, 1.0f);

	float average_transp = (transparency[0]+transparency[1]+transparency[2])/3.0f;
	ambientColor[3] = diffuseColor[3] = specularColor[3] = average_transp;
	glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, ambientColor);
	glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, diffuseColor);
	glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specularColor);
	glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, specularPower);

	if (diffuseTextureId) {
		// maya always sets the diffuse color to black when a texture is applied.
		float color[4] = {0.8f, 0.8f, 0.8f, average_transp};
		glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, color);

		// apply texture
		glBindTexture(GL_TEXTURE_2D, diffuseTextureId);

		// Enable texturing
	} else {

 * Loads a bitmap and converts it to a texture.
 * @return The new texture's ID.
void Material::loadDiffuseTexture() {
	diffuseTextureId = loadBitmap(diffuseTextureName.c_str());

End Material.cpp Material Library file: newmtl grass illum 4 Kd 0.00 0.00 0.00 Ka 0.00 0.00 0.00 Tf 1.00 1.00 1.00 map_Kd grass.bmp Ni 1.00 Ks 0.33 0.33 0.33 Ns 0.06 newmtl Brick_dark_grout illum 4 Kd 0.00 0.00 0.00 Ka 0.00 0.00 0.00 Tf 1.00 1.00 1.00 map_Kd Brick_dark_grout.bmp Ni 1.00 Ks 0.33 0.33 0.33 Ns 0.06 end Material Library file [edit: added source tags -SiCrane]

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You need to call glGenTextures. You can't just assume gl will allow you to use sequential texture IDs. If you replace your numTexture stuff with glGenTextures it should work OK, I think.

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Here is the log file:

CreateGLWindow called.
loadBitmap called: file name = grass.bmp
numTexture = 1
The file has been opened for reading.
is a texture ? = 1
loadBitmap called: file name = Brick_dark_grout.bmp
numTexture = 2
The file has been opened for reading.
is a texture ? = 1
Materials loaded - materials.size() = 2
Material 0:
name = grass
diffuseTextureName = grass.bmp
diffuseTextureId = 1
isTexture? = 0
Material 1:
name = Brick_dark_grout
diffuseTextureName = Brick_dark_grout.bmp
diffuseTextureId = 2
isTexture? = 1
glIsTexture? materials[0] = 0
glIsTexture? materials[1] = 1
glIsTexture? materials[0] = 0
glIsTexture? materials[1] = 1
. . .

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I don't think that that is the problem. If I change the code that loads the textures (init) to the following, all the textures work:
int InitGL(GLvoid)
glEnable(GL_TEXTURE_2D); // Enable Texture Mapping ( NEW )
glShadeModel(GL_SMOOTH); // Enable Smooth Shading
glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background
glClearDepth(1.0f); // Depth Buffer Setup
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Really Nice Perspective Calculations

//// load material file
//if (!loadMaterialFile("squares2.mtl")) {
// logFile << "Materials NOT loaded." << endl;
//} else {
// logFile << "Materials loaded - materials.size() = " << materials.size() << endl;

Material mat1;
Material mat2;
materials[0].diffuseTextureId = loadBitmap("Grass.bmp");
materials[1].diffuseTextureId = loadBitmap("Brick_dark_grout.bmp");

// Print out the loaded materials props of interest
for (int i = 0; i < materials.size(); ++i) {
logFile << "Material " << i << ":" << endl;
logFile << " name = " << materials.name << endl;
logFile << " diffuseTextureName = " << materials.diffuseTextureName << endl;
logFile << " diffuseTextureId = " << materials.diffuseTextureId << endl;
int isTexture = glIsTexture(materials.diffuseTextureId);
logFile << " isTexture? = " << isTexture << endl;

// Check for errors

// Initialization completed OK
return TRUE;

The difference is that I am explicitly calling the loadBitmap method for each texture instead of loading the Material library. I don't know why the texture IDs would be valid when I call loadBitmap() directly and not when I call it from loadMaterialFile() ???

I tried to use glGenTextures() to give me valid texture IDs like so:

GLunit name[1];
glGenTexture(1, name);

But, with this, each call to loadBitmap() returns the same ID! The Texture doesn't really get bound to it for some reason.

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Well, I can't see exactly why it's happening, unless the vector is resizing itself after a single push_back, but I'm almost certain your problem is the destructor for Material. When you push_back an element into a vector the vector stores a copy, which means the following sequence of operations occurs:
Material::Material(); // your default constructed material object
Material::Material(Material const &); // the vector copy constructs your object into storage
Material::~Material(); // your material object leaves scope and is destructed

The last of those calls will result in you calling glDeleteTextures for any set textures ids. None of your texture ids should be set in your object, but if the vector has to further copy them then glDeleteTextures will be called and your texture object will be deleted. To solve this you'll probably need to store a reference count in your Material object or work with (smart) pointers to Materials or any other equivalent technique.

By the way, this code:
char buffer[512];
char* ptr = buffer;
while (*ptr == ' ' || *ptr == '\t') {
pmat->diffuseTextureName = ptr;

would be better implemented as:
std::getline(ifs, pmat->diffuseTextureName);
std::string::size_type whitespace = pmat->diffuseTextureName.find_first_not_of(" \t");
if (whitespace != std::string::npos)
pmat->diffuseTextureName = pmat->diffuseTextureName.substr(whitespace);


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You are right - I will have to re-write the Material class to handle this, or use a different container. Thanks for your help.

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