282d703f6b
This PR adds a clear on creation for draw region framebuffers, which fixes issue https://projects.blender.org/blender/blender/issues/139443. When using the "Lock Interface" option, redrawing is disabled until the rendering process has finished. When the GPU driver does not initialize framebuffer textures with zero, this means that visual corruption can be perceived when resizing the main window while rendering. This fix makes sure that framebuffer textures are initialized with zero on all GPU platforms. Pull Request: https://projects.blender.org/blender/blender/pulls/139445