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

const float radiusEpsilon = 1e-4f;

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

#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;