Convert color values to and back from premultiplied form for blending.
Finally the rendering result of the blend demo looks much closer to that
of the reference implementation.
Drawing an image in VG_DRAW_IMAGE_STENCIL mode produces per-channel
alpha for use in blending. Add a new shader stage to produce and save
it in TEMP[1].
For other modes that do not need per-channel alpha, the stage does
MOV TEMP[1], TEMP[0].wwww
Add a helper function, blend_generic, that supports all blend modes and
per-channel alpha. Make other blend generators a wrapper to it.
Both the old and new code expects premultiplied colors, yet the input is
non-premultiplied. Per-channel alpha is also not used for stencil
image. They still need to be fixed.
In find_value() check if we've hit the 0th/invalid entry before checking
if the pname matches.
Fixes http://bugs.freedesktop.org/show_bug.cgi?id=31987
NOTE: This is a candidate for the 7.9 branch.
If querying the default/window-system FBO's attachment type, return
GL_FRAMEBUFFER_DEFAULT (per the GL_ARB_framebuffer_object spec).
See http://bugs.freedesktop.org/show_bug.cgi?id=31947
NOTE: This is a candidate for the 7.9 branch.
Return 0 instead of generating an error.
See http://bugs.freedesktop.org/show_bug.cgi?id=30993
Note that piglit fbo-getframebufferattachmentparameter-01 still does
not pass. But Mesa behaves the same as the NVIDIA driver in this case.
Perhaps the test is incorrect.
NOTE: This is a candidate for the 7.9 branch.
It was done in path-to-polygon conversion. That meant that the
results were invalidated when the transformation was modified, and CPU
had to recreate the vertex buffer with new vertices. It could be a
performance hit for apps that animate.
gl_FragCoord.y needs to be flipped upside down if a FBO is bound.
This fixes:
- piglit/fbo-fragcoord
- https://bugs.freedesktop.org/show_bug.cgi?id=29420
Here I add a new program state STATE_FB_WPOS_Y_TRANSFORM, which is set based
on whether a FBO is bound. The state contains a pair of transformations.
It can be either (XY=identity, ZW=transformY) if a FBO is bound,
or (XY=transformY, ZW=identity) otherwise, where identity = (1, 0),
transformY = (-1, height-1).
A classic driver (or st/mesa) may, based on some other state, choose whether
to use XY or ZW, thus negate the conditional "if (is a FBO bound) ...".
The reason for this is that a Gallium driver is allowed to only support WPOS
relative to either the lower left or the upper left corner, so we must flip
the Y axis accordingly again. (the "invert" parameter in emit_wpos_inversion)
NOTE: This is a candidate for the 7.9 branch.
Signed-off-by: Marek Olšák <maraeo@gmail.com>
Signed-off-by: Brian Paul <brianp@vmware.com>
