Ensure that always one shader is on the ShaderStack with GL2
author Martin Gräßlin
()
committer Martin Gräßlin
()
commit cab2fee5c934ade31d457d470b042b578f74b9d8
tree 2ae7d2f19846bf9053aa441ca2bdeeedc7c789e2
parent d4b83c3b37d3671ce0707adce26a4c1483a5b406
Ensure that always one shader is on the ShaderStack with GL2

This brings some consistency with GLES2 where also one shader
is always on the stack and allows to use the test whether a shader
is bound to see if the GL2 code path is used. This fixes an issue
with cover/flip switch which tested for a bound shader before the
shader was pushed in multi screen setups.

As well it should bring some improvements as the simple screen
shader is not unbound and rebound in each rendered frame.

BUG: 283609
FIXED-IN: 4.7.3
kwin/scene_opengl_glx.cpp