Each queued primitive adds its vertex flags (alpha, fog, colors) to its
state, and states are optimized for those flags before their items are
distributed. A state can still gain primitives after some of its items
are in tiles. Re-optimizing it then changed its pixel and sampler
functions and IDs while threads drew with them. With the x86 pixel JIT,
the span function could turn null between checking and calling it, as
in Coded Arms' frame dump. God of War hit this about four times a frame.
Now a state is live once any of its items is in a tile, until the tiles
are drawn and reset, and a live state isn't changed. A primitive that
would change a live state's flags starts a new, unoptimized state from
the same registers instead, optimized for its own primitives only.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
A texture that fits in the GE's 8 KB texture cache keeps what was first
read until TEXFLUSH, across primitives and draws, so a later self-textured
draw doesn't see an earlier one's writes (gpu/probe exp174: three passes
over a 16x16 4444 buffer differ in 177 pixels with and without a flush
between them, both now exact). FF Type-0's (NPJH50443) blur; two of its
PSP replays become exact.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The GE samples through its texture cache, so a primitive that textures from
its own render target mostly reads the old contents (geprobe exp81, exp159,
exp160). Give each such primitive a snapshot, refreshing only the rows the
previous one drew.
3rd Birthday (ULUS10567) bloom becomes exact on PSP replays, Burnout
Dominator's glare 93% -> 98% and Ridge Racer's blur 40% -> 94% of pixels.
The remaining differences are rows where the cache's lazily loaded 8-row
blocks already see the primitive's own writes.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Blending is slow, and often games do effects like smoke, sun, etc. that
has a lot of zero alpha in them. Many games do this with alpha testing
off, which is cheap compared to blending.
Since we're already checking the CLUT, we can tell if it doesn't contain
zero alpha, in which case a != 0 test will never fail. This is actually
pretty common, even when texture alpha is not always FF.
Might be some other ways, like doing this directly in a vertex reader.
Also am thinking about doing things regarding UVs or positions.
Flags not yet used, keeping separate for perf checks.
This generally detects overlap more accurately using a dirty rectangles
approach. Also detects render to self much more accurately, including
with depth.
Unfortunately, it has a pretty noticeable speed impact, even at the basic
"assume everything's written" level. Compiled off by default, but at
least it's there.
Doesn't account for tests (i.e. alpha test skipping write) so still not
perfectly accurate.
