diff options
| author | Arseny Kapoulkine <arseny.kapoulkine@gmail.com> | 2023-11-02 14:03:02 -0700 |
|---|---|---|
| committer | Arseny Kapoulkine <arseny.kapoulkine@gmail.com> | 2023-11-02 14:10:39 -0700 |
| commit | c5f73a1783fbf35e2601134678c52ec813837384 (patch) | |
| tree | eca1765c727834381795cea027db1e23535fdcca /thirdparty/meshoptimizer/quantization.cpp | |
| parent | b733901e9e650fc2f1a43627be2379f5ba200f8d (diff) | |
| download | redot-engine-c5f73a1783fbf35e2601134678c52ec813837384.tar.gz | |
Update thirdparty/meshoptimizer to v0.20
Note: this change completely overwrites the meshoptimizer library source
(from git SHA c21d3be6ddf627f8ca852ba4b6db9903b0557858)
without including any patches; a distance error metric patch is still
needed and will be reapplied in the next commit.
The changes elsewhere are due to a signature change for
meshopt_simplifyWithAttributes.
Diffstat (limited to 'thirdparty/meshoptimizer/quantization.cpp')
| -rw-r--r-- | thirdparty/meshoptimizer/quantization.cpp | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/thirdparty/meshoptimizer/quantization.cpp b/thirdparty/meshoptimizer/quantization.cpp new file mode 100644 index 0000000000..09a314d602 --- /dev/null +++ b/thirdparty/meshoptimizer/quantization.cpp @@ -0,0 +1,70 @@ +// This file is part of meshoptimizer library; see meshoptimizer.h for version/license details +#include "meshoptimizer.h" + +#include <assert.h> + +unsigned short meshopt_quantizeHalf(float v) +{ + union { float f; unsigned int ui; } u = {v}; + unsigned int ui = u.ui; + + int s = (ui >> 16) & 0x8000; + int em = ui & 0x7fffffff; + + // bias exponent and round to nearest; 112 is relative exponent bias (127-15) + int h = (em - (112 << 23) + (1 << 12)) >> 13; + + // underflow: flush to zero; 113 encodes exponent -14 + h = (em < (113 << 23)) ? 0 : h; + + // overflow: infinity; 143 encodes exponent 16 + h = (em >= (143 << 23)) ? 0x7c00 : h; + + // NaN; note that we convert all types of NaN to qNaN + h = (em > (255 << 23)) ? 0x7e00 : h; + + return (unsigned short)(s | h); +} + +float meshopt_quantizeFloat(float v, int N) +{ + assert(N >= 0 && N <= 23); + + union { float f; unsigned int ui; } u = {v}; + unsigned int ui = u.ui; + + const int mask = (1 << (23 - N)) - 1; + const int round = (1 << (23 - N)) >> 1; + + int e = ui & 0x7f800000; + unsigned int rui = (ui + round) & ~mask; + + // round all numbers except inf/nan; this is important to make sure nan doesn't overflow into -0 + ui = e == 0x7f800000 ? ui : rui; + + // flush denormals to zero + ui = e == 0 ? 0 : ui; + + u.ui = ui; + return u.f; +} + +float meshopt_dequantizeHalf(unsigned short h) +{ + unsigned int s = unsigned(h & 0x8000) << 16; + int em = h & 0x7fff; + + // bias exponent and pad mantissa with 0; 112 is relative exponent bias (127-15) + int r = (em + (112 << 10)) << 13; + + // denormal: flush to zero + r = (em < (1 << 10)) ? 0 : r; + + // infinity/NaN; note that we preserve NaN payload as a byproduct of unifying inf/nan cases + // 112 is an exponent bias fixup; since we already applied it once, applying it twice converts 31 to 255 + r += (em >= (31 << 10)) ? (112 << 23) : 0; + + union { float f; unsigned int ui; } u; + u.ui = s | r; + return u.f; +} |