loading textures and applying to cylinder

I am using textures for the first time. I am trying to load 6 different textures and apply them to some cylinders.

The textures I am using are bitmaps. Does anyone have any sample code that will load bitmaps or apply a bitmap file to a cylinder.

Thanks

read nehe’s opengl tutorial on how to load textures, and how to texture map

Hi, that’s quite easy, you know

you can check the NeHe lesson about that

in example you can do that:

 AUX_RGBImageRec *LoadBMP(char *Filename)	// Load a BMP		
{
	FILE *File=NULL;						// create a file Handle
	
	if(!Filename)							// Verify if the file was given
	{
		return NULL;						// if not, quits
	}

	File=fopen(Filename,"r");				// Verify the BMP existence

	if(File)
	{
		fclose(File);						// close the file handle created
		return auxDIBImageLoad(Filename);	// load Bmp and return a pointer
	}

	return NULL;
}

int LoadGLTexture()							// load BMP and convert texture
{
	int Status=FALSE;

	AUX_RGBImageRec *TextureImage[4];// image record, store width,height and data

	memset(TextureImage,0,sizeof(void *) *4);// image record cleared now (make sure it's empty)


	if((TextureImage[0]=LoadBMP("myTexture_1.bmp")) && (TextureImage[1]=LoadBMP("myTexture_2.bmp")) && (TextureImage[2]=LoadBMP("myTexture_3.bmp")) && (TextureImage[3]=LoadBMP("myTexture_4.bmp")))
	{
		Status=TRUE;
		glGenTextures(4, &texture[0]);// Create the texture
		for (loop=0; loop<4; loop++)
		{
			glBindTexture(GL_TEXTURE_2D, texture[loop]);	// texture generation using data
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);	// linear filtering (GL_NEAREST for slowest Cpu/Gfxcard)
			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
			glTexImage2D(GL_TEXTURE_2D, 0, 4, TextureImage[loop]->sizeX,TextureImage[loop]->sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, TextureImage[loop]->data);	// generate the texture
		}
	}


/*******************************************# 
*	           ---Free()---                 *                                     
* Il ne faut surtout pas oublier de liberer *
* l'espace utilisé, donc les deux bmp et    *
* aussi Textureimage[loop] qui la stockait  * 
********************************************/
	for (loop=0; loop<4; loop++)
	{
		if(TextureImage[loop])
		{
			if(TextureImage[loop]->data)
			{
				free(TextureImage[loop]->data);
			}
			free(TextureImage[loop]);
		}
	}
	return Status;
}

int InitGL(GLvoid)		// Setup needed by OpenGL
{
	if(!LoadGLTexture())
		{
			return FALSE;
		}
	BuildFont();	// our fonts builded here

	glShadeModel(GL_SMOOTH);// Smooth shading enabled
	glClearColor(0.0f, 0.0f, 0.0f, 0.5f);		// Set background as black
	glClearDepth(1.0f);							// Setup of Depth buffer
					// Depth buffer test enabled
	glDepthFunc(GL_LEQUAL);

	glBlendFunc(GL_SRC_ALPHA,GL_ONE);
	glBindTexture(GL_TEXTURE_2D, texture[0]);
	
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);	// Correction for Perspective view(nice view, bad performance)

	quadratic=gluNewQuadric();
	gluQuadricNormals(quadratic, GLU_SMOOTH);
	gluQuadricTexture(quadratic, GL_TRUE);


	return TRUE;		// In this case all Inits are OK, if they're not it return FALSE then the program quits
}

int DrawGLScene(GLvoid)		
{

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);		// Clear the Scene and the Depth buffer


	glLoadIdentity();
	glEnable(GL_TEXTURE_2D);
	glHint(GL_POLYGON_SMOOTH,GL_NICEST);
	glBindTexture(GL_TEXTURE_2D, texture[2]);

	glTranslatef(0.6f,0.57f,-10.0f);		// tube position
	glRotatef(xrot, 0.0f,0.0f,1.0f);
	gluCylinder(quadratic,1.0f,1.0f,10.0f,64,64);

	return TRUE;			// In this case all operations are OK, if they're not it return FALSE then the program quits
												
} 

ok, this is not a perfect method, and when you compile that it doesn’t work, and this is quite slow and and and…
hey, cool guys :smiley:

anyway my method is developped from NeHe’s method (which is developped from MR. OpenGL method i guess :wink: )

I use it on a little OpenGL example
http://navilinux.free.fr/download/prod/sampleGL.zip

hope that helps juste a little :stuck_out_tongue:

Thanks,

Once I have loaded the textures how can I apply them to a cylinder so that they wrap around.

I am using a function that draws a number of cylinders…

gluCylinder(quadric, 0.1, 0.1, (_3_depth[i])/3, 12, 1);

thanks

glBindTexture allows you to apply texture on the cylinder, but it apply texture on all the cylinder surface ! be careful :slight_smile:

ok so I have:

glBindTexture(GL_TEXTURE_2D, texture[0]);

and gluCylinder(quadric, 0.1, 0.1, (_3_depth[i])/3, 12, 1);

which draws my cylinder… do i need to specify the coordinates for the texture or are they auto generated? is there anything else i need?

Thanks