Hello,
I have just set up a debug message callback, and I'm seeing lots of these errors:
[LWJGL] OpenGL debug message
ID: 0x501
Source: API
Type: ERROR
Severity: HIGH
Message: GL_INVALID_VALUE error generated. Element exceeds maximum supported number of combined texture image units.
I have only created 6 textures, and I am only binding 1 at a time. When I print the value of glGetInteger(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS) I get 192, so I don't understand what limit I am hitting here.
Can anyone please offer some insight?
Thanks,
Dan
The first step is to identify, which GL call caused this error. If you are using LWJGL 3, then the easiest way is to start your JVM with the LWJGLX/debug agent: https://github.com/LWJGLX/debug
You can download it directly from here: https://build.lwjgl.org/addons/lwjglx-debug/lwjglx-debug-1.0.0.jar
Then start the JVM with the JVM argument -javaagent:/path/to/lwjglx-debug-1.0.0.jar and you should see a stack trace when you hit the error.
Thank you so much, that was really helpful.
The problem was that I was doing this:
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, textureId);
glUniform1i(uniformLoc, GL_TEXTURE0);
Instead of this:
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, textureId);
glUniform1i(uniformLoc, 0);
GL_TEXTURE0 has the value 33984, whereas samplers have to have a value in the value [0, GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS).
(Source: https://www.khronos.org/opengl/wiki/Texture#Samplers)
Thanks again.
Dan