xenia-canary/third_party/crunch/crnlib/crn_dxt_endpoint_refiner.cpp

363 lines
9.9 KiB
C++

// File: crn_dxt_endpoint_refiner.cpp
// See Copyright Notice and license at the end of inc/crnlib.h
#include "crn_core.h"
#include "crn_dxt_endpoint_refiner.h"
#include "crn_dxt1.h"
namespace crnlib
{
dxt_endpoint_refiner::dxt_endpoint_refiner() :
m_pParams(NULL),
m_pResults(NULL)
{
}
bool dxt_endpoint_refiner::refine(const params& p, results& r)
{
if (!p.m_num_pixels)
return false;
m_pParams = &p;
m_pResults = &r;
r.m_error = cUINT64_MAX;
r.m_low_color = 0;
r.m_high_color = 0;
double alpha2_sum = 0.0f;
double beta2_sum = 0.0f;
double alphabeta_sum = 0.0f;
vec<3, double> alphax_sum( 0.0f );
vec<3, double> betax_sum( 0.0f );
vec<3, double> first_color( 0.0f );
// This linear solver is from Squish.
for( uint i = 0; i < p.m_num_pixels; ++i )
{
uint8 c = p.m_pSelectors[i];
double k;
if (p.m_dxt1_selectors)
k = g_dxt1_to_linear[c] * 1.0f/3.0f;
else
k = g_dxt5_to_linear[c] * 1.0f/7.0f;
double alpha = 1.0f - k;
double beta = k;
vec<3, double> x;
if (p.m_dxt1_selectors)
x.set( p.m_pPixels[i][0] * 1.0f/255.0f, p.m_pPixels[i][1] * 1.0f/255.0f, p.m_pPixels[i][2] * 1.0f/255.0f );
else
x.set( p.m_pPixels[i][p.m_alpha_comp_index]/255.0f );
if (!i)
first_color = x;
alpha2_sum += alpha*alpha;
beta2_sum += beta*beta;
alphabeta_sum += alpha*beta;
alphax_sum += alpha*x;
betax_sum += beta*x;
}
// zero where non-determinate
vec<3, double> a, b;
if( beta2_sum == 0.0f )
{
a = alphax_sum / alpha2_sum;
b.clear();
}
else if( alpha2_sum == 0.0f )
{
a.clear();
b = betax_sum / beta2_sum;
}
else
{
double factor = alpha2_sum*beta2_sum - alphabeta_sum*alphabeta_sum;
if (factor != 0.0f)
{
a = ( alphax_sum*beta2_sum - betax_sum*alphabeta_sum ) / factor;
b = ( betax_sum*alpha2_sum - alphax_sum*alphabeta_sum ) / factor;
}
else
{
a = first_color;
b = first_color;
}
}
vec3F l(0.0f), h(0.0f);
l = a;
h = b;
l.clamp(0.0f, 1.0f);
h.clamp(0.0f, 1.0f);
if (p.m_dxt1_selectors)
optimize_dxt1(l, h);
else
optimize_dxt5(l, h);
//if (r.m_low_color < r.m_high_color)
// utils::swap(r.m_low_color, r.m_high_color);
return r.m_error < p.m_error_to_beat;
}
void dxt_endpoint_refiner::optimize_dxt5(vec3F low_color, vec3F high_color)
{
float nl = low_color[0];
float nh = high_color[0];
#if CRNLIB_DXT_ALT_ROUNDING
nl = math::clamp(nl, 0.0f, .999f);
nh = math::clamp(nh, 0.0f, .999f);
uint il = (int)floor(nl * 256.0f);
uint ih = (int)floor(nh * 256.0f);
#else
uint il = (int)floor(.5f + math::clamp(nl, 0.0f, 1.0f) * 255.0f);
uint ih = (int)floor(.5f + math::clamp(nh, 0.0f, 1.0f) * 255.0f);
#endif
crnlib::vector<uint> trial_solutions;
trial_solutions.reserve(256);
trial_solutions.push_back(il | (ih << 8));
sparse_bit_array flags;
flags.resize(256 * 256);
flags.set_bit((il * 256) + ih);
const int cProbeAmount = 11;
for (int l_delta = -cProbeAmount; l_delta <= cProbeAmount; l_delta++)
{
const int l = il + l_delta;
if (l < 0)
continue;
else if (l > 255)
break;
const uint bit_index = l * 256;
for (int h_delta = -cProbeAmount; h_delta <= cProbeAmount; h_delta++)
{
const int h = ih + h_delta;
if (h < 0)
continue;
else if (h > 255)
break;
if ((flags.get_bit(bit_index + h)) || (flags.get_bit(h * 256 + l)))
continue;
flags.set_bit(bit_index + h);
trial_solutions.push_back(l | (h << 8));
}
}
for (uint trial = 0; trial < trial_solutions.size(); trial++)
{
uint l = trial_solutions[trial] & 0xFF;
uint h = trial_solutions[trial] >> 8;
if (l == h)
{
if (h)
h--;
else
l++;
}
else if (l < h)
{
utils::swap(l, h);
}
CRNLIB_ASSERT(l > h);
uint values[cDXT5SelectorValues];
dxt5_block::get_block_values8(values, l, h);
uint total_error = 0;
for (uint j = 0; j < m_pParams->m_num_pixels; j++)
{
int p = m_pParams->m_pPixels[j][m_pParams->m_alpha_comp_index];
int c = values[m_pParams->m_pSelectors[j]];
int error = p - c;
error *= error;
total_error += error;
if (total_error > m_pResults->m_error)
break;
}
if (total_error < m_pResults->m_error)
{
m_pResults->m_error = total_error;
m_pResults->m_low_color = static_cast<uint16>(l);
m_pResults->m_high_color = static_cast<uint16>(h);
if (m_pResults->m_error == 0)
return;
}
}
}
void dxt_endpoint_refiner::optimize_dxt1(vec3F low_color, vec3F high_color)
{
uint selector_hist[4];
utils::zero_object(selector_hist);
for (uint i = 0; i < m_pParams->m_num_pixels; i++)
selector_hist[m_pParams->m_pSelectors[i]]++;
dxt1_solution_coordinates c(low_color, high_color);
for (uint pass = 0; pass < 8; pass++)
{
const uint64 initial_error = m_pResults->m_error;
dxt1_solution_coordinates_vec coords_to_try;
coords_to_try.resize(0);
color_quad_u8 lc(dxt1_block::unpack_color(c.m_low_color, false));
color_quad_u8 hc(dxt1_block::unpack_color(c.m_high_color, false));
for (int i = 0; i < 27; i++)
{
if (13 == i) continue;
const int ir = (i % 3) - 1;
const int ig = ((i / 3) % 3) - 1;
const int ib = ((i / 9) % 3) - 1;
int r = lc.r + ir;
int g = lc.g + ig;
int b = lc.b + ib;
if ((r < 0) || (r > 31)|| (g < 0) || (g > 63) || (b < 0) || (b > 31)) continue;
coords_to_try.push_back(
dxt1_solution_coordinates(dxt1_block::pack_color(r, g, b, false), c.m_high_color)
);
}
for (int i = 0; i < 27; i++)
{
if (13 == i) continue;
const int ir = (i % 3) - 1;
const int ig = ((i / 3) % 3) - 1;
const int ib = ((i / 9) % 3) - 1;
int r = hc.r + ir;
int g = hc.g + ig;
int b = hc.b + ib;
if ((r < 0) || (r > 31)|| (g < 0) || (g > 63) || (b < 0) || (b > 31)) continue;
coords_to_try.push_back(dxt1_solution_coordinates(c.m_low_color, dxt1_block::pack_color(r, g, b, false)));
}
std::sort(coords_to_try.begin(), coords_to_try.end());
dxt1_solution_coordinates_vec::const_iterator p_last = std::unique(coords_to_try.begin(), coords_to_try.end());
uint num_coords_to_try = (uint)(p_last - coords_to_try.begin());
for (uint i = 0; i < num_coords_to_try; i++)
{
color_quad_u8 block_colors[4];
uint16 l = coords_to_try[i].m_low_color;
uint16 h = coords_to_try[i].m_high_color;
if (l < h)
utils::swap(l, h);
else if (l == h)
{
color_quad_u8 lc(dxt1_block::unpack_color(l, false));
color_quad_u8 hc(dxt1_block::unpack_color(h, false));
bool retry = false;
if ((selector_hist[0] + selector_hist[2]) > (selector_hist[1] + selector_hist[3]))
{
// l affects the output more than h, so muck with h
if (hc[2] != 0)
hc[2]--;
else if (hc[0] != 0)
hc[0]--;
else if (hc[1] != 0)
hc[1]--;
else
retry = true;
}
else
{
// h affects the output more than l, so muck with l
if (lc[2] != 31)
lc[2]++;
else if (lc[0] != 31)
lc[0]++;
else if (lc[1] != 63)
lc[1]++;
else
retry = true;
}
if (retry)
{
if (l == 0)
l++;
else
h--;
}
else
{
l = dxt1_block::pack_color(lc, false);
h = dxt1_block::pack_color(hc, false);
}
CRNLIB_ASSERT(l > h);
}
dxt1_block::get_block_colors4(block_colors, l, h);
uint total_error = 0;
for (uint j = 0; j < m_pParams->m_num_pixels; j++)
{
const color_quad_u8& c = block_colors[m_pParams->m_pSelectors[j]];
total_error += color::color_distance(m_pParams->m_perceptual, c, m_pParams->m_pPixels[j], false);
if (total_error > m_pResults->m_error)
break;
}
if (total_error < m_pResults->m_error)
{
m_pResults->m_error = total_error;
m_pResults->m_low_color = l;
m_pResults->m_high_color = h;
CRNLIB_ASSERT(l > h);
if (m_pResults->m_error == 0)
return;
}
}
if (m_pResults->m_error == initial_error)
break;
c.m_low_color = m_pResults->m_low_color;
c.m_high_color = m_pResults->m_high_color;
}
}
} // namespace crnlib