Re: [pygame] Re: Data transferring from main python program to GLSL shader not happens in my case

[Ian Mallett <geometrian@xxxxxxxxx>]

Hi,

Your problem is that the shader is not bound (use something like glUseProgram(blah)) when you try to get the variable.

In your second code, -1 means that the variable does not exist in the shader (i.e., the compiler optimized it out, because it's not used).  Notice that the variable "colorr" is declared in two different scopes, which is why the compiler optimized out the uniform (because the local variable masks it).  

When setting colors, it's a good idea to specify the alpha component too.  Although it seems to work now, as I recall, gl_FragColor is actually undefined until set.  

Ian