The plain scaling is rather rough, and in fact drawing a scaled bitmap the normal way gives much better results (because OutputDevice pre-scales the bitmap before it's drawn). This one may be a bit slow perhaps, but hopefully nobody there's no code that'd extensively use bitmap drawing with custom transformations (wishful thinking).
c44ee2b when drawing a transformed bitmap in opengl backend, scale it better
vcl/opengl/areaScaleFastFragmentShader.glsl | 13 ++++++
vcl/opengl/areaScaleFragmentShader.glsl | 13 ++++++
vcl/opengl/gdiimpl.cxx | 59 ++++++++++++++++++++++++++-
vcl/opengl/scale.cxx | 1 +
4 files changed, 84 insertions(+), 2 deletions(-)
Upstream: cgit.freedesktop.org