Mailing Lists: Apple Mailing Lists
Image of Mac OS face in stamp
 
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

fbo + multitexturing + glsl problem

I've been having a lot of problems using multiple textures sent to a glsl shader when using the framebuffer. Here is the basic problem:

I create two checkers textures that are floating point textures. I send the textures to a glsl shader. The result (combines the textures) is fine when not using the framebuffer. However I get black when using the framebuffer.

I'm using OpenGL 2.0 on a Mac with OSX 10.4.10. I'm using the FBO class from this site. I use GL_TEXTURE_2D and GL_RGBA32F_ARB (I tried GL_RGBA16F_ARB, but it doesn't change anything). It works fine when I download it and run it with the sample program (edge filter on the teapot and tori). It works [i]fine[/i] with a [i]single checkers texture[/i] as well. It's just when I try to do multiple texturing.

The shader looks like this:

uniform sampler2D texUnit;
uniform sampler2D texUnit2;
void main(void)
{
const float offset = 1.0 / 512.0;
vec2 texCoord = gl_TexCoord[0].xy;
vec4 c = texture2D(texUnit, texCoord);
vec4 c2 = texture2D(texUnit2, texCoord);
vec4 bl = texture2D(texUnit, texCoord + vec2(-offset, -offset));
vec4 l = texture2D(texUnit, texCoord + vec2(-offset, 0.0));
vec4 tl = texture2D(texUnit, texCoord + vec2(-offset, offset));
vec4 t = texture2D(texUnit, texCoord + vec2( 0.0, offset));
vec4 ur = texture2D(texUnit, texCoord + vec2( offset, offset));
vec4 r = texture2D(texUnit, texCoord + vec2( offset, 0.0));
vec4 br = texture2D(texUnit, texCoord + vec2( offset, offset));
vec4 b = texture2D(texUnit, texCoord + vec2( 0.0, -offset));
gl_FragColor = c2 + (8.0 * (c + -0.125 * (bl + l + tl + t + ur + r + br + b)));
}


The texture activation looks like:

	glActiveTexture(GL_TEXTURE0);
	glBindTexture(GL_TEXTURE_2D, _iTexture[2]);
        glUniform1i(_texUnit, 0);
	glActiveTexture(GL_TEXTURE1);
	glBindTexture(GL_TEXTURE_2D, _iTexture[3]);
	glUniform1i(_texUnit2, 1);

Any help is greatly appreciated. I've been at this for two weeks with no proress and its driving me crazy.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Mac-opengl mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/mac-opengl/email@hidden

This email sent to email@hidden


Visit the Apple Store online or at retail locations.
1-800-MY-APPLE

Contact Apple | Terms of Use | Privacy Policy

Copyright © 2007 Apple Inc. All rights reserved.