I’m trying to write a shader to control the brightness of
the displayed image.
the shader is activated (by me) before a call to a drawing of a big
component which contains non-textured polygons and textured polygon.
my question is how can I know if the fragment I’m drawing right now comes out of a textured polygon?
I had a shader which worked in previous versions and not working after a version update. it fails on the command “if (gl_TexCoord.st)”
uniform float brt; // brightness [0-1]
uniform sampler2D tex;
vec4 texCol = texture2D(tex,gl_TexCoord.st);