Bump mapping on iphone opengl

Hi,

I am trying to draw a sphere and provide some bump mapping in iphone opengl ES 1.1 in XCode 3.1.4 . But since iphone opengl doesnt support stencil buffer i need to look at different methods for bump mapping. I read somewhere that we can do dot 3 bump mapping but nobody saying how. I cant find any tutorial or example programs. This is the code i tried to do dot 3 bump mapping 
glActiveTexture(GL_TEXTURE0);
	glClientActiveTexture(GL_TEXTURE0); 
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, textures[0]);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY); 
	glTexCoordPointer(2, GL_FLOAT, 0,texCoord);     
		
	
	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE , GL_COMBINE);
	glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_MODULATE);
	glTexEnvi(GL_TEXTURE_ENV, GL_SRC0_RGB,GL_TEXTURE0);
	glTexEnvi(GL_TEXTURE_ENV,GL_SRC1_RGB, GL_PRIMARY_COLOR);
	glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_COLOR);
	glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_COLOR);
	
	
	
	
	glActiveTexture(GL_TEXTURE1);
	glClientActiveTexture(GL_TEXTURE1); 
	glEnable(GL_TEXTURE_2D);
	glBindTexture(GL_TEXTURE_2D, textures[1]);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY); 
	glTexCoordPointer(2, GL_FLOAT, 0,texCoord);   
	
	
	glActiveTexture(GL_TEXTURE1); 
	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE); 
	glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB,GL_DOT3_RGBA); 
	glTexEnvi(GL_TEXTURE_ENV, GL_SRC0_RGB, GL_TEXTURE1); 
	glTexEnvi(GL_TEXTURE_ENV, GL_SRC1_RGB, GL_PREVIOUS); 
	glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_COLOR); 
	glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND1_RGB, GL_SRC_COLOR);
        	glDrawElements(GL_TRIANGLE_STRIP,12000, GL_UNSIGNED_SHORT,gridIndices);	


texture[0] is a plane blue texture and texture[1] is a png image i used as bump texture. I got this code from following link

http://forum.unity3d.com/viewtopic.php?t=15749

I still doesnt understand the code. Is there any way we can do bumpmapping in iphone opengl

did u check out this link : it is an old implementation for bump mapping using texture combiners:

http://www.paulsprojects.net/tutorials/simplebump/simplebump.html

now if ur application target the Iphone3GS wich support shaders (AFAIK) u can use modern code for bump mapping.

The stencil buffer has nothing to do with bumpmapping.

IMG’s PolyBump demo in their SDK demonstrates how to do object-space bumpmapping in ES1.

Texture combiners are scary IMHO. Not that I can’t use them if I have to, but the functionality is limited and it really feels outdated. Shaders is so much better. Now, what is the state of shaders on the iPhone? I don’t develop on iPhone yet but the plan is to port my animation code there, hopefully soon.

On the newer devices i.e. iPhone 3GS and iPod 3rd Gen (32 & 64MB) the GPU is GLES2.0 and supports shaders.

Older devices do not support shaders.

I’ve found that the shader capability on the newer iPhone / iPod GPUs is very capable, easily up to the kind of things I was doing on chips like the ATI x1600 a year or two ago.