How to change the color of an invalid texture?

Question

In openGL, when I don't bind a texture, or I bind a texture that was loaded incorrectly, any calls to texture2D/texelFetch in the shader will return vec4(0, 0, 0, 1), is there a way to change this to return vec4(1, 1, 1, 1) instead?

Initially I looked for a way to test if the sampler2D was valid, and when I couldn't find that I tried using glColor4f, but that doesn't seem to work either--although that could be the amdgpu driver, it seems to have some trouble with the old pipeline calls generally.

Is there someway to change what this default return color is?

Answer 1

There is no way to change that.

For incomplete textures the color is vec4(0, 0, 0, 1) as required by the OpenGL specification for float textures.

Integer textures return undefined values.

Shadow samplers return 0.