On Sat, Mar 08, 2014 at 01:51:15PM +0530, sagar.a.kamble@xxxxxxxxx wrote: > From: Sagar Kamble <sagar.a.kamble@xxxxxxxxx> > > This patch series introduces drm property modelled after glBlendFuc function. For i915 > constant alpha is exposed through this property to start with. Additional new property > value for controlling pre-multiplied alpha is added. > i-g-t test case is to be added. > > These patches are based on following patches which are already under review/reviewed: > > 4ae74f3 Documentation: drm: describing drm properties exposed by various drivers > 134bdfe Propagate the error from intel_update_plane() up through intel_plane_restore() to the caller. > a6ad21c Make drm_property_create_bitmask() a bit more generic by allowing the caller to specify which bits are in fact supported. > > Sagar Kamble (4): > drm: Added plane alpha and color blending property > drm/i915: Enabling constant alpha drm property > drm/i915: Enabling pre-multiplied alpha drm property > Documentation: drm: describing plane alpha and color blending property I'm not sure I follow what's being done with the GL blending equation here. If we want to support a global alpha on the source plane (ie the plane that is going to be blended into the "render target", what's already there), the blending equation looks like: (source is non-premultiplied, note the use of glBlendFuncSeparate()) RGB = ADD(SRC_COLOR*SRC_ALPHA, DST_COLOR*ONE_MINUS_SRC_ALPHA) A = ADD(SRC_COLOR, DST_COLOR*ONE_MINUS_SRC_ALPHA) (source is premultiplied) RGBA = ADD(SRC_COLOR*SRC_ALPHA, DST_COLOR*ONE_MINUS_SRC_ALPHA) The gl blending stuff doesn't know anything about the premultiplied nature of the incoming source color, it has to be programmed accordingly. -- Damien _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
