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