Move this code back out to C for now, will generate separately.
Shader now takes a mask parameter instead of C0/C1/C2/etc.
Shader does not currently use that parameter and rasterizes whole
pixel stamps always.
Eliminates all this identical yet slightly different code to decide how
shader inputs should be interpolated.
As bonus, don't interpolate the position twice when it is listed in the
TGSI shader inputs.
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.
The triangle rasterizer sets this field to indicate front/back-facing.
It gets passed into the generated fragment code as another parameter.
Used now for stencil front/back selection but will also be used for
fragment shaders in general (see TGSI_SEMANTIC_FACE).
With this commit two-sided stenciling mostly works but there's
still a bug or two...
Currently counting number of tris, how many tiles of each size are
fully covered, partially covered or empty, etc.
Set LP_DEBUG=counters to enable. Results are printed upon context
destruction.
In some corner cases the right-most / bottom-most vertex can be
right on the edge of the framebuffer. Because the maxx, maxy vals
are computed with a series of float/int, pixel/tile transformations
we can end up with maxx >= scene->x_tiles or maxy >= scene->y_tiles.
This leads to putting data into bins that never get processed, or
reset. This becomes stale data that can lead to segfaults.
Clamping fixes this.
The test to determine which of the pixels in a 2x2 quad is now done in
the fragment shader rather than in the calling C code. This is a little
faster but there's a few more things to do.
Note that the step[] array elements are in a different order now. Rather
than being in row-major order for the 4x4 grid, they're in "quad-major"
order. The setup of the step arrays is a little more complicated now.
So is the course/intermediate tile test code, but some lookup tables
help with that.
Next steps:
- early-cull 2x2 quads which are totally outside the triangle.
- skip the in/out test for fully contained quads
- make the in/out comparison code tighter/faster.
It was pretty confusing having an entity named "bin" and another named
"bins", not least because sometimes there was a need to talk about >1
of the "bins" objects, which couldn't be pluralized any further...
Scene is a term used in a bunch of places to talk about what a binner
operates on, so it's a decent choice here.
New lp_bins struct contains all bin information.
More move bin-related code into lp_bin.[ch]
Use new/updated bin-access functions to hide implementation details.
The result is more/cleaner separation between the setup and rast components.
This will make double-buffering of the bins easier, etc.
Previously, each triangle had a pointer to the state to use for shading.
Now we insert state-change commands into the bins. When we execute one
of those commands we just update a 'current state' pointer and use that
pointer when calling the jit shader.
When inserting state-change commands into a bin we check if the previous
command was also a state-change command and simply replace it. This
avoids accumulating useless/redundant state-change commands.
Keith Whitwell
José Fonseca
Brian Paul