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View Full Version : Separate shader objects, tessellation program problem



sam_thedancer
07-18-2013, 07:56 AM
Greetings:
Here's the situation: I am using tessellation to draw a Bezier curve with 4 control points. The program runs fine as a single shader program but the problem is it won't draw anything if I modify it to compile separate shader objects bound to a pipeline.

I actually posted about this a few days ago, got some suggestions but couldn't solve the problem.

So, what I have done now is pared the program down to the bare minimum - no uniforms, no projection/modelview matrices even (control points are located to fit the whole curve in the canonical viewing box). It really is short and simple now and, hopefully, doesn't take someone who understands these things more than a few mins. Program and shaders are in a zip file attached. My environment is Win 7/MS VS 2010 (project file included).

The two options of single shader program and separate shader objects are implemented in two blocks statements in setup(). Just uncomment one or the other.

I would be grateful if someone could tell me how to get the separate shader objects version working.

Btw, the shaders are pretty much copied from Bailey/Cunningham and the shader interface declarations are from this Nvidia developer site (https://developer.nvidia.com/content/opengl-sdk-simple-tessellation-shader).

Thanks,
Sam

PS: I am going to post to both beginners and advanced forums just to potentially increase exposure.