The GE keeps the specular and spot exponents to 5 significant bits,
truncated, and from 512 up (infinity and NaN included) uses 496. Only
the specular one was truncated, and neither saturated. A huge or NaN
exponent overflowed pspPow's bits: highlights wrong on every backend,
and on D3D11, where the overflowing float to int conversion gives a
NaN, black (Everybody's Golf, #22418). With the exponent clamped, t
stays in range for every base the backends produce.
Measured, now bit exact in the software renderer and within 4 levels
on Vulkan.
Fixes#22418
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Environment map S and T are (N.L + 1) / 2 with L the light's vector as
lighting uses it: from the vertex to the light for point and spot lights,
a zero vector staying zero, and the half vector for a light that does
specular. Whether lighting or the light is enabled still doesn't matter
(gpu/lighting/shademap).
The vertex shader ID now carries the type and computation of the shade
mapping lights (the ubershader reads them from u_lightControl), so both
shader caches get a new version.
Fixes the hair shine in iDOLM@STER SP (#12376).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The GE computes these powers as exp2(e * log2(x)), with log2 and exp2
each a straight line between powers of two (Mitchell's approximation),
and only uses the top 4 bits of the specular coefficient's mantissa.
Through a highlight's falloff a true pow is 10-30 steps of 255 brighter
at the exponents games use. Measured in gpu/lighting/specular.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The GLES sampler uniforms and texture slots for the control points and
weights, the Vulkan storage buffer bindings, and the u_spline_counts
uniform, which becomes padding (the C++ side already was).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The cache loader indexed &vec[0] on vectors that can legitimately be empty (a
header-sized file with zero counts passes both sanity checks), and the counts
are signed ints where only the upper bound was checked - a negative count would
reach resize() as a huge size_t.
The 3D texture branch had the out-of-memory assert but not the bail-out the 2D
branch has, so an ignored assert fell straight into memset(nullptr).
