Squashed commit of the following:
commit 04c5fa2cbb8e89d6f2fa5a75af1cca03b1f6b852
Author: José Fonseca <jfonseca@vmware.com>
Date: Tue Apr 23 17:37:18 2013 +0100
gallium: s/lower_left_origin/bottom_edge_rule/
commit 4dff4f64fa83b9737def136fffd161d55e4f1722
Author: José Fonseca <jfonseca@vmware.com>
Date: Tue Apr 23 17:35:04 2013 +0100
gallium: Move diagram to docs.
commit 442a63012c8c3c3797f45e03f2ca20ad5f399832
Author: James Benton <jbenton@vmware.com>
Date: Fri May 11 17:50:55 2012 +0100
gallium: Replace gl_rasterization_rules with lower_left_origin and half_pixel_center.
This change is necessary to achieve correct results when using OpenGL
FBOs.
Reviewed-by: Marek Olšák <maraeo@gmail.com>
draw module calls back into the driver and sets certain parts
of the state to whatever it needs, unfortunately unless you
get the ordering of calls to draw just right you'll end up
reseting your own driver state. That's what was happening to us
draw module would under certain conditions reset our own driver
state.
Reviewed-by: Brian Paul <brianp@vmware.com>
Emit the SVGA3D_RS_POINTSPRITEENABLE render state.
When sprite_coord_mode=PIPE_SPRITE_COORD_LOWER_LEFT emit extra frag
shader code to invert the Y coordinate of the incoming texcoord.
Use front/back instead of cw/ccw throughout.
Also, use offset_point/line/fill instead of offset_cw/ccw.
Brings gallium representation of this state into line with its main
user, and also what turns out to be the most common hardware
representation.
This fixes a long-standing bias in the interface towards the
architecture of the software rasterizer.
When points or lines are decomposed into triangles, we need to be sure
to disable polygon culling, stippling, "un-filled" modes, etc.
This patch sets the rasterization state to disable those things prior to
drawing points/lines with triangles, then restores the previous state
afterward.
The new piglit point-no-line-cull test checks this problem & solution.
Don't need sprite coord origin per coord.
Also, don't need separate sprite enable bit - if all coords have it diabled,
then there are no point sprites (technically, there's a distinction in pre-GL3,
but it only differs in having more leniency in clamping to max size, something
the state tracker would need to handle and the hardware won't bother anyway).
Also, use packed field for the per-coord enables.
All in all, should save 3 dwords in rasterizer state (from 10 down to 7).
The state tracker is responsible for clamping to any graphics API enforced
size min/max limits for both the static point_size setting as well as per
vertex point size (in the vertex shader).
Note that mesa state tracker didn't actually use these values.
