castano

#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);

castano

/*===========================================================================
	Title: BSpline.cpp
	Module: Pi/MathLib
	Author: Ignacio Castaño
	Date: 29/05/2000
	License: Public Domain
===========================================================================*/

/*----------------------------------------------------------------------------
	Doc:

castano

// 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

#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;

castano

I didn't think there was much to gain from optimizing quantization intervals for vertex compression, but I thought it would give it a try and see it for myself.

I have a set of vertices X that I want to quantize. The trivial way to do that is to transform them to the [0,1] range and store them using an integer UNORM format.

At runtime the vertices are reconstructed as follows:

X = Q * m + a

Where:

castano

// 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

                 RMSE           PSNR            Time

Kodak/Waterloo Image Set:

stb              8.202766       29.851597       0.258041
stb-hq           8.009301       30.058910       0.284019
nvtt-fast        8.089954       29.971882       0.445670

nvtt             7.616215       30.496019       6.806233
nvtt-hq          7.562366       30.557650       13.081200

castano

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

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

castano

    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;