I need to modify during runtime the appearence of textures…
Some examples may be rendering them with a gray scale to indicate a deactivation, orange color for selection and so on
A little example that better shows what I would like to achieve
[ATTACH=CONFIG]682[/ATTACH]
Right now my FS looks pretty simple
#version 330
in vec2 fragmentUV;
out vec4 outputColor;
uniform sampler2D textureNode;
void main()
{
outputColor = texture(textureNode, fragmentUV).rgba;
}
I thought I could control these few cases by setting an uniform variable to some hardcoded values…
Just google for examples of Fragment Shaders for greyscale or Hue-Change. There are plenty of tutorials and examples, I can remember how I was looking for this about a year ago.
Yes of course, everything I found worked. Are you sure its the example? Perhaps you have made a small mistake at some point? Are you reading the error logs of the compiler and are you using debug output to see whats happening?