Warn about mipmap-incomplete texture being used
Submitted by Ruslan Kabatsayev
Assigned to mes..@..op.org
Usage of textures with incomplete mipmap is a common OpenGL pitfall 1, since by default GL_TEXTURE_MIN_FILTER is GL_NEAREST_MIPMAP_LINEAR. Thus it'd be very useful if Mesa called debug callbacks on such errors.
A test case can be found in the attachment. When run, it first tries to draw a full-screen textured quad with a mipmap-incomplete texture, and on a key press it toggles TEXTURE_MIN_FILTER between NEAREST and NEAREST_MIPMAP_LINEAR.
Binary nvidia driver gives me a useful debug notification, leading to the following output from the test program on each frame with mipmap-incomplete texture use:
debug callback called, notification: Texture state usage warning: Texture 1 has no mipmaps, while its min filter requires mipmap.
It would be very useful if Mesa also did this. Currently (as of 17.2) it doesn't emit any relevant messages.