Shaders and JOGL

OpenGL Development JOGL Development
#1

I’m implementing shaders with glsl in my JOGL applet. Everything works fine, except textures. If I try to access to texture 1 (With MultiTexture activated) , my program access to texture 0. I pass the unit of texture as a uniform to texture2D function. There is no way to say to my fragment shader which texture I need to view.

The fragment shader is very simple:

uniform sampler2D colorMap;
uniform sampler2D envMap;
void main()
{
vec4 color = texture2D(colorMap,gl_TexCoord[0].st);
vec4 env = texture2D(envMap,gl_TexCoord[1].st);
gl_FragColor=color+env*0.4;
}

It gets colorMap=0, envMap=0 . I believe this, because it applies as colorMap texture0 and as envMap texture0

#2

I answer myself. Before calling glUniform you must call glActiveProgram

#3

Could you give me an example of shader to handle Phong model with textures please?

#4

It shouldn’t be that hard to find a Phong implementation on the web and just add some texturing support. I would think all you need to do is calculate the phong lighting from before and then modulate it with the textures.

#5

gouessej, I haven’t one. But there are many samples in the web. In any case, it is not hard to implement one.

Take a look at these tuts

http://www.lighthouse3d.com/opengl/glsl/index.php?ogldir2

http://www.ozone3d.net/tutorials/glsl_lighting_phong.php

#6

Thanks but the main difficulty is to adapt it to handle the textures.

#7

So, the lambertian term should be between 0 and 1. Multiply that value by the R, G, B sample you get from the texture. Then add the ambient to it. Then add the specular to it. Really, not difficult.

#8

Ok thank you very much. I’m a newbie in GLSL, sorry.