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castano / hemicube.cpp
Created June 20, 2014 09:46
Hemicube Integrator
#include "hemicube.h"
#define PACK_HEMICUBES 1
static void get_hemicube_face_normal(int index, Vector3 *forward, Vector3 *left, Vector3 *up) {
// Unwrapped hemicube with positive-Z in the middle.
switch (index) {
case 0: *forward = Vector3(+1, 0, 0); *left = Vector3( 0, 1, 0); break;
Perfect Quantization of DXT endpoints
-------------------------------------
One of the issues that affect the quality of most DXT compressors is the way floating point colors are rounded.
For example, stb_dxt does:
max16 = (unsigned short)(stb__sclamp((At1_r*yy - At2_r*xy)*frb+0.5f,0,31) << 11);
max16 |= (unsigned short)(stb__sclamp((At1_g*yy - At2_g*xy)*fg +0.5f,0,63) << 5);
max16 |= (unsigned short)(stb__sclamp((At1_b*yy - At2_b*xy)*frb+0.5f,0,31) << 0);
@castano
castano / Sphere.cpp
Last active November 29, 2023 07:37
Welz algorithm and EPOS approximations.
// This code is in the public domain -- Ignacio Castaño <castano@gmail.com>
#include "Sphere.h"
#include "Vector.inl"
#include "Box.inl"
#include <float.h> // FLT_MAX
const float radiusEpsilon = 1e-4f;
// This code is in the public domain -- Ignacio Castaño <castano@gmail.com>
#include "Sphere.h"
#include "Vector.inl"
#include "Box.inl"
#include <float.h> // FLT_MAX
using namespace nv;
@castano
castano / qsort.inl
Last active January 2, 2023 11:13
Using qsort with lambdas
template <typename T>
struct Compare {
T lambda;
#if _MSC_VER || __APPLE__
static int compare(void * cmp, const void * a, const void * b)
#else
static int compare(const void * a, const void * b, void * cmp)
#endif
{
@castano
castano / scope.cpp
Created July 24, 2013 23:49
Various ways to emulate D's scope statements in C++. See http://the-witness.net/news/2012/11/scopeexit-in-c11/
// For C++11 support compile with:
// clang++ -std=c++11 -stdlib=libc++ scope.cpp
#include <stdio.h>
#include <stdlib.h>
template <typename F>
struct ScopeExit {
ScopeExit(F f) : f(f) {}
~ScopeExit() { f(); }
@castano
castano / half_to_float_test.cpp
Created March 21, 2012 18:27
ISPC half to float conversion
#include <intrin.h> // __rdtsc
#include <stdio.h>
typedef unsigned int uint;
typedef unsigned short uint16;
typedef unsigned long long uint64;
// ISPC functions:
extern "C" void half_to_float_test(const uint16 * vin, float * vout, int count);
extern "C" void half_to_float_test_fast(const uint16 * vin, float * vout, int count);
// Emulating gathers using loads and permutevar8. This made the entire compressor about 15% faster. Both methods require AVX2.
// Load 4 uint8 per lane.
__m256i packedClusterIndex = _mm256_load_si256((__m256i *)&s_fourCluster[i]);
if (count <= 8) {
// Load r_sat in one register:
Wide8 r07 = load8(r_sat);
Wide8 g07 = load8(g_sat);
Wide8 b07 = load8(b_sat);
Wide8 besterror8 = broadcast8(FLT_MAX);
Vector3_Wide8 beststart8;
Vector3_Wide8 bestend8;
// check all possible clusters for this total order
for (int i = 0; i < s_fourClusterTotal[count - 1]; i += 8)
{
//uint c0 = s_fourCluster[i].c0;
//uint c1 = s_fourCluster[i].c1;
//uint c2 = s_fourCluster[i].c2;
rgbcx v1.12
icbc v1.0
RMSE PSNR Time
Kodak/Waterloo Image Set:
rgbcx-0 8.128142 29.930977 0.163412
rgbcx-1 8.041399 30.024172 0.182219
rgbcx-2 8.198924 29.855667 0.213994
rgbcx-3 8.005721 30.062794 0.242393