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OpenGL Textur Mapping problem

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Hi guys, I'm new in opengl programming and I have a question respectively a problem. At first same codesnippets:
#ifndef FIBS_H
#define FIBS_H

#include	<gl\glaux.h>	

class BMP{
private:
	GLuint	texture[1];
	AUX_RGBImageRec *LoadBMP(char *Filename);
public:
	BMP(void);
	int LoadGLTextures(void);
	GLuint getTextur(void);
	GLuint* getTexturPointer(void);
	~BMP(void);
};

#endif

#include	<windows.h>							// Header File For Windows
#include	<stdio.h>							// Header File For Standard Input/Output ( NEW )
#include	<gl\glaux.h>	

#include "BMP.h"

AUX_RGBImageRec *BMP::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
}

BMP::BMP(void){
}

int BMP::LoadGLTextures(void){									// Load Bitmaps And Convert To Textures
	int Status=FALSE;									// Status Indicator
	AUX_RGBImageRec *TextureImage[1];					// 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/NeHe.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[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
}

GLuint BMP::getTextur(void){
	return BMP::texture[0];
}

GLuint* BMP::getTexturPointer(void){
	return BMP::texture;
}

BMP::~BMP(void){
}

#ifndef FIBS_C
#define FIBS_C

#include "BMP.h"

class Aquarium{
private:
	BMP* bitmap;
	int init(GLvoid);
	void drawAquariumPart(float xCoord, float yCoord, float zCoord, float xSize, float ySize, float zSize);
	void drawWater(void);
	void drawQuad(void);
	void drawWasserPflanzen(void);

public:
	Aquarium(void);
	~Aquarium(void);
	void drawAquarium(void);
};
#endif

#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>
#include <gl\glut.h>

#include "BMP.h"
#include "Aquarium_Objekt.h"

int Aquarium::init(GLvoid){								// All Setup For OpenGL Goes Here
	if (!Aquarium::bitmap->LoadGLTextures())			// Jump To Texture Loading Routine ( NEW )
		return FALSE;									// If Texture Didn't Load Return FALSE
	return TRUE;										// Initialization Went OK
}

// Methode zum Zeichnen eines Teils des Aquariums
// x-, y- und z-Koordinate, sowie x-, y- und z-Groesse werden uebergeben
void Aquarium::drawAquariumPart(float xCoord, float yCoord, float zCoord, float xSize, float ySize, float zSize){	
	// Legt die aktuelle Matrix auf den Stack
	glPushMatrix();	
		// Setzt die aktuelle Farbe auf hellblau
		glColor4f(0.3, 0.3, 0.5, 0.7);
		// Verschiebt den erzeugten Würfel um xCoord, yCoord, zCoord
		glTranslatef(xCoord, yCoord, zCoord);
		// Streckt den erzeugten Würfel um xSize, ySize, zSize
		glScalef(xSize, ySize, zSize);
		// Erzeugt einen soliden Würfel, der gestreckt und verschoben wird
		glutSolidCube(1);
	// Nimmt die aktuelle Matrix vom Stack
	glPopMatrix();

} // end drawAquariumPart


	// Methode zum Zeichnen des Wassers
void Aquarium::drawWater(void){
	// Transparenz aktivieren
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	// Legt die aktuelle Matrix auf den Stack
	glPushMatrix();	
		// Setzt die aktuelle Farbe auf hellblau
		glColor4f(0.15, 0.45, 0.5, 0.2);
		// Verschiebt den erzeugten Würfel um xCoord, yCoord, zCoord
		glTranslatef(15, 5, -7.6);
		// Streckt den erzeugten Würfel um xSize, ySize, zSize
		glScalef(24.6, 9.6, 9.8);
		// Erzeugt einen soliden Würfel, der gestreckt und verschoben wird
		glutSolidCube(1);
	// Nimmt die aktuelle Matrix vom Stack
	glPopMatrix();
	// Transparenz deaktivieren
	glDisable(GL_BLEND);
} // end drawWater

void Aquarium::drawQuad(void){
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, Aquarium::bitmap->getTextur());

	glPushMatrix();	
	glTranslatef(15, 5, -10);	

	glBegin(GL_QUADS);
		// Front Face
		glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  0.0f);	// Bottom Left Of The Texture and Quad
		glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  0.0f);	// Top Left Of The Texture and Quad
		glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  0.0f);	// Top Right Of The Texture and Quad
		glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  0.0f);	// Bottom Right Of The Texture and Quad
	glEnd();
	glPopMatrix();
	glDisable(GL_TEXTURE_2D); /* disable texture mapping */
}

void Aquarium::drawWasserPflanzen(void){
	this->drawQuad();
}

Aquarium::Aquarium(){
	Aquarium::bitmap = new BMP();
	if(!this->init())
		printf("Konnte Textur nicht laden\n");
        else
	        printf("Laden der Textur erfolgreich\n");
}

Aquarium::~Aquarium(){}

void Aquarium::drawAquarium(){
	this->drawWasserPflanzen();
	this->drawWater();
	// Transparenz aktivieren
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	// Erzeugt vordere Scheibe
	drawAquariumPart(15,5,-2.6,25,10,0.2);
	// Erzeugt linke Scheibe
	drawAquariumPart(2.6,5,-7.5,0.2,10,10);
	// Erzeugt rechte Scheibe
	drawAquariumPart(27.4,5,-7.5,0.2,10,10);
	// Erzeugt hintere Scheibe
	drawAquariumPart(15,5,-12.6,25,10,0.2);
	// Erzeugt untere Scheibe
	drawAquariumPart(15,0.1,-7.5,24.6,0.2,10);
	// Transparenz deaktivieren
	glDisable(GL_BLEND);
} // end drawAquarium

And this is my display function
void display(void)
{
	if (deltaMove)
		moveMeFlat(deltaMove);
	if (deltaAngle) {
		angle += deltaAngle;
		orientMe(angle);
	}

	frame++;
	time=glutGet(GLUT_ELAPSED_TIME);
	if (time - timebase > 1000) {
		printf("FPS:%4.2f\n",frame*1000.0/(time-timebase));
		timebase = time;		
		frame = 0;
	}

	// Das bisherige Bild wird gelöscht indem das komplette Bild mit der Hintergrundfarbe überdeckt wird.
	// Dazu wird das Bild komplett in Hintergrundfarbe gezeichnet und Verdeckungsrechnung initialisiert.
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	
	for(int x =0; x<fischanzahl; x++){
		fische[x]->moveFisch();
		fische[x]->drawFisch();
	}
	
	spotlight->drawSpotLight();
	tisch->drawTable();
	aquarium->drawAquarium();
	// ---

	// Sorge dafür, dass wirklich alle glBefehle abgearbeitet und nicht gepuffert werden
	glFlush();

	// Vertausche die Backbuffer und Frontbuffer: das fertig
	// gezeichnete Bild soll jetzt angezeigt werden
	glutSwapBuffers();

	// Sorge dafür, dass das Bild im nächsten Schleifendurchlauf
	// der glutMainLoop wieder gezeichnet wird
	glutPostRedisplay();

} // end display

Now my problem... i do not get the textur on the quad. I have no idea why :) Perhaps anybody can help me.

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Where are you telling it what texture to use? Also where are the definitions for your Aquarium class? You show us they are there but not what is inside. You draw function makes calls to it but we cant see that code, which is a major suspect in something like this.

90% of my texture problems have been loading problems or not setting the correct texture value. For loading make sure you have a good error report stratagy to let you know if something failed

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Ok sorry for the bad information i'v gave :)

in the class BMP under LoadGLTextures, there i tell to use a bmp file. Than under LoadBMP i load this bmp file. After that i create the texture in LoadGLTextures -> glGenTextures(1, &texture[0]); // Create The Texture


To get accecc on this textur i wrote this to functions

GLuint BMP::getTextur(void){
return BMP::texture[0];
}

GLuint* BMP::getTexturPointer(void){
return BMP::texture;
}



I call this functions under the Aquarium class in void Aquarium::drawQuad(void).

I think there is no error on creating the texture in the memory, because LoadGLTextures returns true if all is ok.

Thanks for the fast replay :)

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Hi.

Try to work with glIsTexture, glGetError and glGetTexImage at particular sections,
so it might be more clear to figure out where the problem lies.

For example:
In your render function, test if the pixels are uploaded, with glGetTexImage.
or,
after glTexImage2D make a call to glGetError, to figure out, if you have
specified wrong parameters.

First, try this.

int BMP::LoadGLTextures(void){ // Load Bitmaps And Convert To Textures
int Status=FALSE; // Status Indicator
AUX_RGBImageRec *TextureImage[1]; // 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/NeHe.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);
////////////////////////////////////////////////////////////////////////
///////////// HERE, make modi, and test err with the debugger.
GLenum err = glGetError() ;
////////////////////////////////////////////////////////////////////////

glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
}
if (TextureImage[0]){ ...




Alex

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Ok,

i think you guys are right. When i debugg i saw this:

On this line "(TextureImage[0]=LoadBMP("Data/NeHe.bmp"))" i get the value 'î' in TextureImage[0]->data (i think that not enough for a whole bmp file???), in TextureImage[0]->sizeX and ->sizeY is the value 256. 256 is the right value (size of the pic) for the bmp file. But i guess there is an error in ->data.

In texture i have got the value "3452816845" it is not null or something like that.

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Hi.

If you think that there is a error within ->data, so make an array on the stack
put the pixels in there and look over it with the debugger to ensure, that this might be a problem.
Another way to figure out data values which are stored on the heap, I cant deliver.

But I think, the char 'î' is just the first color value component of the pixel data.

And as I said, use glError, glIsTexture and/or glGetTexImage at particular sections to reveal problems.

And also another good solution is to put the code to be tested into a more
simple environment, to see how exactly it works.

Alex

P.S.
Every code I saw till now has utilized this

glPixelStorei( GL_UNPACK_ALIGNMENT, 1 ) ;



Maybe this makes a problem. My code works without it, but who knows!?
Put it in front of the glTexImage2D() call.

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No change....

i don't know what to do now... how do you guys read in textures and bind it on a quad? Could you give me same inspiration or examples, how to get a texture on the f***ing quad :-)

Thanks a lot

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First of all, chill out.

Second.
1.) How sure are you that the texture is loaded?!
2.) How sure are you that there is no problem with glTexImage2D?!
For example, the texels arent uploaded...
or the texture is not pow of 2.
3.) How sure are you that the texture is bound? Hence 2.) must be
erroneous.
4.) Have you set all necessary parameters, for texturing.
5.) Have you used glBend* or something, so maybe you have fogotten
to put parameters back to GL_ADD or similar, for example when you have activated
glBendEquation with GL_ZERO, so the texture isnt drawn because of this.
Call glDisable(GL_BLEND) to avoid problems coming from this direction.

Thrid.
Get rid of all the geometry which mustn't be drawn and just draw one simple geometric obj, so you can deduce what exacly went wrong!!!

The most important thing is, make it as simple as possible, e.g. use a single and simple Quad, and put your texture on it, and not on your most complex geometry if you havent textured before.
This might sound trivial and stupid, but this is your only chance to get organized.
After successfully putting your texture onto the Quad, you can use an arbi geometry.

But first, try to answer the questions above, to give some more information!

Alex

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Chilling is that what i need :)

Ok now i answer your questions.

1.) How sure are you that the texture is loaded?!

Arm, not realy sure... but when i look to the ->data i think this is not enough for a whole file... if it is the first color of die pic, where is the rest?

2.) How sure are you that there is no problem with glTexImage2D?!
For example, the texels arent uploaded...
or the texture is not pow of 2.

Im pretty sure, because i copied it from link. When i run this it works... only in my workspace it don't wanna put the texture on the quad.

3.) How sure are you that the texture is bound? Hence 2.) must be
erroneous.

I don't realy know what you mean, but i guess you mean this:

void Aquarium::drawWasserPflanzen(void){
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, Aquarium::bitmap->getTextur());
this->drawQuad();
glDisable(GL_TEXTURE_2D); /* disable texture mapping */
}



4.) Have you set all necessary parameters, for texturing.

Again i'm not pretty sure, i try to figure is out. But when i take a look on the lesson above, i think i have all necessary parameters.

5.) Have you used glBend* or something, so maybe you have fogotten ...

No they are all disabled.

Thrid.
Get rid of all the geometry which mustn't be drawn and just draw one simple geometric obj, so you can deduce what exacly went wrong!!!.....

I only sure a quad

void Aquarium::drawQuad(void){
glPushMatrix();
glTranslatef(15, 5, -10);
glBegin(GL_QUADS);
// Front Face
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 0.0f); // Bottom Left Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 0.0f); // Top Left Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 0.0f); // Top Right Of The Texture and Quad
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 0.0f); // Bottom Right Of The Texture and Quad
glEnd();
glPopMatrix();

}



I hope you can help me :)

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I don't have the time right now to sift through your code but I will try and offer what little I can at the moment.

To get a texture going you

1) You have to set up blending when you init OpenGL. E.G. you must enable blending blah blah. If you don't you can load textures fine and still not get anything.

2) you must set your texture(which I think you are from the looks of it.)

3) be loading the texture correctly. Which is the most complicated error prone part. Now since you are most likly having problems with your BMP loader I'm going to recommend you toss the code out all together. Reason being you're better off having a loader for say TGA files. BMP is kinda the easiest but it's not the best format to be using. More than likely your are going to go though this all again with a better format. So just skip past all this and move on.

I'm going to recommend TGA because it supports some basic compression, supports alpha channels, is highly supported in both code and in art programs. All that means is you can have smaller files, have everything you need for various texturing, and won't have any trouble finding coding examples or programs to handle the art.

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