As my struggle with uniform arrays of structs led me to nowhere, I decided to split those arrays to single uniforms, this time, the locations are caught right, but I encountered a problem, bug perhaps, when trying to index the arrays in a loop.
Well, not only in a loop - I can’t index them by any variable - only by constants, which is quite pointless and annoying.
The situation looks like follows:
I have an array which looks like this:
uniform unsigned int lightType[MAX_LIGHTS];
(MAX_LIGHTS - #defined to be 10)
Then indexing the lightType:
float test = 1.0f; unsigned int index = 0; test = lightType / 18.0f; // 18.0f is the value I send - this line works fine, and yields value of 1 test = lightType[index] / 18.0f; // this line apparently returns 0 const unsigned int index2 = 0; // maybe if index is const... test = lightType[index2] / 18.0f; // yep, it works fine again outColor = vec3(test, 0.0f, 0.0f); // ... as checked in here
It turns out, that the only accepted indices are constant values. It is quite uncomfortable.
I noticed the problems, when I switched my computer from one with NVidia GPU, to one with Radeon.
Apparently Radeons have strange issues with GL, as I today updated the drivers, thinking it could be the problem, but instead shaders suddenly stopped to compile returning me empty error log, just saying something like Vertex shader compile failed: and instead of log, there was one empty line.
Changing #version to different ones were actually giving me some errors in the log, but using 420 apparently fixed it.
But the indexing issue still is present.
I have also read somewhere on the net, that it could be related to exceeding maximum active uniforms, but when I checked GL_MAX_UNIFORM_LOCATIONS it returned 33390, while number of active uniforms if 20.
What could cause it, and how to index the array by a variable?