Vulkan without VK_EXT_provoking_vertex, DX9 and DX11 take flat-shaded
colors from the first vertex, while on Dreamcast it's the last. For the
depth-sorted triangle list, setFirstProvokingVertex() copied each
triangle's last vertex colors onto its first vertex. But sortTriangles()
builds these triangles from strips, so neighbors share vertices:
tri0=(P0,P1,P2), tri1=(P2,P1,P3). P2 is tri0's source and tri1's
destination, and the list is processed in depth order, so one
triangle's flat color can overwrite another's before it's read. In
strips of three or more triangles, consecutive triangles even share
their first vertex. Flat-shaded translucent polygons then pick up a
neighbor's color, e.g. the player shadow decals in Tony Hawk's Pro
Skater 2 and Mat Hoffman's Pro BMX turn uniformly dark.
Each sorted triangle has its own three slots in idx, so rotate them
(a,b,c) -> (c,a,b) instead. The winding is unchanged and the provoking
vertex comes first, without touching shared vertices. Strips keep the
color copy, which is safe there.
Adds SorterTest, which fails on the old code and passes with this change.
Co-authored-by: Claude Opus 5.5 <[email protected]>
[ci skip]
Sort triangles during ta_parse. Use the same index as other polys. Store
results in rend_context.
Use primitive restart if available to avoid too many degenerate
triangles.
Update renderers.
Merging polygons in per-triangle can produces a large number of
degenerate triangles (up to x3), which must then be sorted, resulting in
a performance hit. This is useless since the sorted triangles are merged
after being sorted. (Regression introduced by
20d25059bf)
Issue #818
In per-strip mode, polygons are now sorted before creating the index and
merging. So it doesn't have to be done in the renderer anymore.
dx11: naomi2 support
n2: ambient color was swapping red and blue
gl, dx11: don't write depth in per-strip to avoid missing geometry,
prefer wrong depth order/blending for now
optimize naomi2 per-triangle sorting
elan: Get rid of geometry shader and do geometry clipping manually.
pvr: Aggressively merge transparent polys in per-triangl and OIT mode, duplicating the last vertex to merge opposite cull mode strips.
gl4: reset OIT pointers in final shader. No need for clear pass.
gl4: alternate between 2 buffers for verts.index/tr poly params.
gl4: use gl_VertexID + poly number for poly index.
gl: new GlBuffer class.
Writes current TA_OL_BASE to all tiles OPB block. Read from region array
at render time to identify context.
Fixes vf4 water reflections RTT
get rid of dump_frame/read_frame
Joe Mattiello