Thread: OpenGL Again, Loading Textures onto Quads

Code:

AUX_RGBImageRec *LoadBMP(char *Filename)				// Loads A Bitmap Image
{
	FILE *File=NULL;									// File Handle

	if (!Filename)										// Make Sure A Filename Was Given
	{
		return NULL;									// If Not Return NULL
	}

	File=fopen(Filename,"r");							// Check To See If The File Exists

	if (File)											// Does The File Exist?
	{
		fclose(File);									// Close The Handle
		return auxDIBImageLoad(Filename);				// Load The Bitmap And Return A Pointer
	}

	return NULL;										// If Load Failed Return NULL
}

int LoadGLTextures()									// Load Bitmaps And Convert To Textures
{
	int Status=FALSE;									// Status Indicator

	AUX_RGBImageRec *TextureImage[2];					// Create Storage Space For The Texture

	memset(TextureImage,0,sizeof(void *)*1);           	// Set The Pointer To NULL

	// Load The Bitmap, Check For Errors, If Bitmap's Not Found Quit
	if (TextureImage[0]=LoadBMP("Data/NeHe1.bmp"))
	{
		Status=TRUE;									// Set The Status To TRUE

		glGenTextures(1, &texture[0]);					// Create The Texture

		// Typical Texture Generation Using Data From The Bitmap
		glBindTexture(GL_TEXTURE_2D, texture[0]);
		glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage[0]->sizeX, TextureImage[0]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[0]->data);
		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
	}
	if (TextureImage[1]=LoadBMP("Data/NeHe.bmp"))
	{
		Status=TRUE;

		glGenTextures(2, &texture[1]);

		glBindTexture(GL_TEXTURE_2D, texture[1]);
		glTexImage2D(GL_TEXTURE_2D, 0, 3, TextureImage[1]->sizeX, TextureImage[1]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[1]->data);
		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);	
	}

	if (TextureImage[0])									// If Texture Exists
	{
		if (TextureImage[0]->data)							// If Texture Image Exists
		{
			free(TextureImage[0]->data);					// Free The Texture Image Memory
		}

		free(TextureImage[0]);								// Free The Image Structure
	}

	return Status;										// Return The Status
}

GLvoid ReSizeGLScene(GLsizei width, GLsizei height)		// Resize And Initialize The GL Window
{
	if (height==0)										// Prevent A Divide By Zero By
	{
		height=1;										// Making Height Equal One
	}

	glViewport(0,0,width,height);						// Reset The Current Viewport

	glMatrixMode(GL_PROJECTION);						// Select The Projection Matrix
	glLoadIdentity();									// Reset The Projection Matrix

	// Calculate The Aspect Ratio Of The Window
	gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);

	glMatrixMode(GL_MODELVIEW);							// Select The Modelview Matrix
	glLoadIdentity();									// Reset The Modelview Matrix
}

int InitGL(GLvoid)										// All Setup For OpenGL Goes Here
{
	if (!LoadGLTextures())								// Jump To Texture Loading Routine ( NEW )
	{
		return FALSE;									// If Texture Didn't Load Return FALSE
	}

	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
	return TRUE;										// Initialization Went OK
}

int DrawGLScene(GLvoid)									// Here's Where We Do All The Drawing
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	// Clear The Screen And The Depth Buffer
	glLoadIdentity();									// Reset The View
	glTranslatef(0.0f,0.0f,-5.0f);

	glRotatef(xrot,1.0f,0.0f,0.0f);
	glRotatef(yrot,0.0f,1.0f,0.0f);
	glRotatef(zrot,0.0f,0.0f,1.0f);

	glBindTexture(GL_TEXTURE_2D, texture[0]);

	glBegin(GL_QUADS);
		// Front Face
		glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
		// Back Face
	glBindTexture(GL_TEXTURE_2D, texture[1]);
		glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
		glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
		// Top Face
	glBindTexture(GL_TEXTURE_2D, texture[0]);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
		glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
		// Bottom Face
	glBindTexture(GL_TEXTURE_2D, texture[1]);
		glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
		glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
		// Right face
	glBindTexture(GL_TEXTURE_2D, texture[0]);
		glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
		glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);
		// Left Face
	glBindTexture(GL_TEXTURE_2D, texture[1]);
		glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
		glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);
		glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);
		glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
	glEnd();

	xrot+=0.3f;
	yrot+=0.2f;
	zrot+=0.4f;
	return TRUE;										// Keep Going
}

I took lesson 6 of NeHe's tutorials, thought I understood the code finally, so I tried to add another texture to the equation and place it on different faces of the quad here and there, All it Shows is NeHe1.bmp..... I Probably am not Loading it correctly, All the other coding for the window is there, I just didn't put it in the post due to how long it is, Any help on this one?

Hmm, Is that all that is wrong, iff so, could I start and end every single face of the quad with a glBindTexture?

OMG, I MADE IT WORK!!!!!!!

SCOREEEEE, !!!!! sweeeeet!!!!!!

it took me 5 days but now I understand the code and can now implement it and bend it to my WILLLLL!!!!!

Note to all: That code up there is trash, sorry to kill your brain cells with it

Yeah texture mapping can be difficult to get a grasp on but its just like riding a bike

Now that you've got it working, I suggest you write down some notes somewhere and keep it in a safe place.

Because if you don't use OpenGL regularly, in 3 months, you'll forget how texture mapping works.

Speaking from my own experience.