mirror of https://github.com/axmolengine/axmol.git
888 lines
32 KiB
C++
888 lines
32 KiB
C++
// ----------------------------------------------------------------------------
|
|
// This confidential and proprietary software may be used only as authorised
|
|
// by a licensing agreement from Arm Limited.
|
|
// (C) COPYRIGHT 2011-2020 Arm Limited, ALL RIGHTS RESERVED
|
|
// The entire notice above must be reproduced on all authorised copies and
|
|
// copies may only be made to the extent permitted by a licensing agreement
|
|
// from Arm Limited.
|
|
// ----------------------------------------------------------------------------
|
|
|
|
/**
|
|
* @brief Functions to pick best ASTC endpoint for a block.
|
|
*/
|
|
|
|
#include "astc_codec_internals.h"
|
|
|
|
#ifdef DEBUG_PRINT_DIAGNOSTICS
|
|
#include <stdio.h>
|
|
#endif
|
|
|
|
/*
|
|
functions to determine, for a given partitioning, which color endpoint formats are the best to use.
|
|
*/
|
|
|
|
// for a given partition, compute for every (integer-component-count, quantization-level)
|
|
// the color error.
|
|
static void compute_color_error_for_every_integer_count_and_quantization_level(int encode_hdr_rgb, // 1 = perform HDR encoding, 0 = perform LDR encoding.
|
|
int encode_hdr_alpha, int partition_index, const partition_info * pi,
|
|
const encoding_choice_errors * eci, // pointer to the structure for the CURRENT partition.
|
|
const endpoints * ep, float4 error_weightings[4],
|
|
// arrays to return results back through.
|
|
float best_error[21][4], int format_of_choice[21][4])
|
|
{
|
|
int i;
|
|
int partition_size = pi->texels_per_partition[partition_index];
|
|
|
|
static const float baseline_quant_error[21] = {
|
|
(65536.0f * 65536.0f / 18.0f), // 2 values, 1 step
|
|
(65536.0f * 65536.0f / 18.0f) / (2 * 2), // 3 values, 2 steps
|
|
(65536.0f * 65536.0f / 18.0f) / (3 * 3), // 4 values, 3 steps
|
|
(65536.0f * 65536.0f / 18.0f) / (4 * 4), // 5 values
|
|
(65536.0f * 65536.0f / 18.0f) / (5 * 5),
|
|
(65536.0f * 65536.0f / 18.0f) / (7 * 7),
|
|
(65536.0f * 65536.0f / 18.0f) / (9 * 9),
|
|
(65536.0f * 65536.0f / 18.0f) / (11 * 11),
|
|
(65536.0f * 65536.0f / 18.0f) / (15 * 15),
|
|
(65536.0f * 65536.0f / 18.0f) / (19 * 19),
|
|
(65536.0f * 65536.0f / 18.0f) / (23 * 23),
|
|
(65536.0f * 65536.0f / 18.0f) / (31 * 31),
|
|
(65536.0f * 65536.0f / 18.0f) / (39 * 39),
|
|
(65536.0f * 65536.0f / 18.0f) / (47 * 47),
|
|
(65536.0f * 65536.0f / 18.0f) / (63 * 63),
|
|
(65536.0f * 65536.0f / 18.0f) / (79 * 79),
|
|
(65536.0f * 65536.0f / 18.0f) / (95 * 95),
|
|
(65536.0f * 65536.0f / 18.0f) / (127 * 127),
|
|
(65536.0f * 65536.0f / 18.0f) / (159 * 159),
|
|
(65536.0f * 65536.0f / 18.0f) / (191 * 191),
|
|
(65536.0f * 65536.0f / 18.0f) / (255 * 255)
|
|
};
|
|
|
|
float4 ep0 = ep->endpt0[partition_index];
|
|
float4 ep1 = ep->endpt1[partition_index];
|
|
|
|
float ep0_max = MAX(MAX(ep0.x, ep0.y), ep0.z);
|
|
float ep0_min = MIN(MIN(ep0.x, ep0.y), ep0.z);
|
|
float ep1_max = MAX(MAX(ep1.x, ep1.y), ep1.z);
|
|
float ep1_min = MIN(MIN(ep1.x, ep1.y), ep1.z);
|
|
|
|
ep0_min = MAX(ep0_min, 0.0f);
|
|
ep1_min = MAX(ep1_min, 0.0f);
|
|
ep0_max = MAX(ep0_max, 1e-10f);
|
|
ep1_max = MAX(ep1_max, 1e-10f);
|
|
|
|
float4 error_weight = error_weightings[partition_index];
|
|
|
|
float error_weight_rgbsum = error_weight.x + error_weight.y + error_weight.z;
|
|
|
|
float range_upper_limit_rgb = encode_hdr_rgb ? 61440.0f : 65535.0f;
|
|
float range_upper_limit_alpha = encode_hdr_alpha ? 61440.0f : 65535.0f;
|
|
|
|
// it is possible to get endpoint colors significantly outside [0,upper-limit]
|
|
// even if the input data are safely contained in [0,upper-limit];
|
|
// we need to add an error term for this situation,
|
|
float4 ep0_range_error_high;
|
|
float4 ep1_range_error_high;
|
|
float4 ep0_range_error_low;
|
|
float4 ep1_range_error_low;
|
|
|
|
ep0_range_error_high.x = MAX(0.0f, ep0.x - range_upper_limit_rgb);
|
|
ep0_range_error_high.y = MAX(0.0f, ep0.y - range_upper_limit_rgb);
|
|
ep0_range_error_high.z = MAX(0.0f, ep0.z - range_upper_limit_rgb);
|
|
ep0_range_error_high.w = MAX(0.0f, ep0.w - range_upper_limit_alpha);
|
|
ep1_range_error_high.x = MAX(0.0f, ep1.x - range_upper_limit_rgb);
|
|
ep1_range_error_high.y = MAX(0.0f, ep1.y - range_upper_limit_rgb);
|
|
ep1_range_error_high.z = MAX(0.0f, ep1.z - range_upper_limit_rgb);
|
|
ep1_range_error_high.w = MAX(0.0f, ep1.w - range_upper_limit_alpha);
|
|
|
|
ep0_range_error_low.x = MIN(0.0f, ep0.x);
|
|
ep0_range_error_low.y = MIN(0.0f, ep0.y);
|
|
ep0_range_error_low.z = MIN(0.0f, ep0.z);
|
|
ep0_range_error_low.w = MIN(0.0f, ep0.w);
|
|
ep1_range_error_low.x = MIN(0.0f, ep1.x);
|
|
ep1_range_error_low.y = MIN(0.0f, ep1.y);
|
|
ep1_range_error_low.z = MIN(0.0f, ep1.z);
|
|
ep1_range_error_low.w = MIN(0.0f, ep1.w);
|
|
|
|
float4 sum_range_error =
|
|
(ep0_range_error_low * ep0_range_error_low) + (ep1_range_error_low * ep1_range_error_low) + (ep0_range_error_high * ep0_range_error_high) + (ep1_range_error_high * ep1_range_error_high);
|
|
float rgb_range_error = dot(sum_range_error.xyz, error_weight.xyz) * 0.5f * partition_size;
|
|
float alpha_range_error = sum_range_error.w * error_weight.w * 0.5f * partition_size;
|
|
|
|
|
|
#ifdef DEBUG_PRINT_DIAGNOSTICS
|
|
if (print_diagnostics)
|
|
{
|
|
printf("%s : partition=%d\nrgb-error_wt=%f alpha_error_wt=%f\n", __func__, partition_index, error_weight_rgbsum, error_weight.w);
|
|
|
|
printf("ep0 = %f %f %f %f\n", ep0.x, ep0.y, ep0.z, ep0.w);
|
|
printf("ep1 = %f %f %f %f\n", ep1.x, ep1.y, ep1.z, ep1.w);
|
|
|
|
|
|
printf("rgb_range_error = %f, alpha_range_error = %f\n", rgb_range_error, alpha_range_error);
|
|
|
|
printf("rgb-luma-error: %f\n", eci->rgb_luma_error);
|
|
}
|
|
#endif
|
|
|
|
if (encode_hdr_rgb)
|
|
{
|
|
|
|
// collect some statistics
|
|
float af, cf;
|
|
if (ep1.x > ep1.y && ep1.x > ep1.z)
|
|
{
|
|
af = ep1.x;
|
|
cf = ep1.x - ep0.x;
|
|
}
|
|
else if (ep1.y > ep1.z)
|
|
{
|
|
af = ep1.y;
|
|
cf = ep1.y - ep0.y;
|
|
}
|
|
else
|
|
{
|
|
af = ep1.z;
|
|
cf = ep1.z - ep0.z;
|
|
}
|
|
|
|
float bf = af - ep1_min; // estimate of color-component spread in high endpoint color
|
|
float3 prd = ep1.xyz - float3(cf, cf, cf);
|
|
float3 pdif = prd - ep0.xyz;
|
|
// estimate of color-component spread in low endpoint color
|
|
float df = MAX(MAX(fabs(pdif.x), fabs(pdif.y)), fabs(pdif.z));
|
|
|
|
int b = (int)bf;
|
|
int c = (int)cf;
|
|
int d = (int)df;
|
|
|
|
// determine which one of the 6 submodes is likely to be used in
|
|
// case of an RGBO-mode
|
|
int rgbo_mode = 5; // 7 bits per component
|
|
// mode 4: 8 7 6
|
|
if (b < 32768 && c < 16384)
|
|
rgbo_mode = 4;
|
|
// mode 3: 9 6 7
|
|
if (b < 8192 && c < 16384)
|
|
rgbo_mode = 3;
|
|
// mode 2: 10 5 8
|
|
if (b < 2048 && c < 16384)
|
|
rgbo_mode = 2;
|
|
// mode 1: 11 6 5
|
|
if (b < 2048 && c < 1024)
|
|
rgbo_mode = 1;
|
|
// mode 0: 11 5 7
|
|
if (b < 1024 && c < 4096)
|
|
rgbo_mode = 0;
|
|
|
|
// determine which one of the 9 submodes is likely to be used in
|
|
// case of an RGB-mode.
|
|
int rgb_mode = 8; // 8 bits per component, except 7 bits for blue
|
|
|
|
// mode 0: 9 7 6 7
|
|
if (b < 16384 && c < 8192 && d < 8192)
|
|
rgb_mode = 0;
|
|
// mode 1: 9 8 6 6
|
|
if (b < 32768 && c < 8192 && d < 4096)
|
|
rgb_mode = 1;
|
|
// mode 2: 10 6 7 7
|
|
if (b < 4096 && c < 8192 && d < 4096)
|
|
rgb_mode = 2;
|
|
// mode 3: 10 7 7 6
|
|
if (b < 8192 && c < 8192 && d < 2048)
|
|
rgb_mode = 3;
|
|
// mode 4: 11 8 6 5
|
|
if (b < 8192 && c < 2048 && d < 512)
|
|
rgb_mode = 4;
|
|
// mode 5: 11 6 8 6
|
|
if (b < 2048 && c < 8192 && d < 1024)
|
|
rgb_mode = 5;
|
|
// mode 6: 12 7 7 5
|
|
if (b < 2048 && c < 2048 && d < 256)
|
|
rgb_mode = 6;
|
|
// mode 7: 12 6 7 6
|
|
if (b < 1024 && c < 2048 && d < 512)
|
|
rgb_mode = 7;
|
|
|
|
static const float rgbo_error_scales[6] = { 4.0f, 4.0f, 16.0f, 64.0f, 256.0f, 1024.0f };
|
|
static const float rgb_error_scales[9] = { 64.0f, 64.0f, 16.0f, 16.0f, 4.0f, 4.0f, 1.0f, 1.0f, 384.0f };
|
|
|
|
float mode7mult = rgbo_error_scales[rgbo_mode] * 0.0015f; // empirically determined ....
|
|
float mode11mult = rgb_error_scales[rgb_mode] * 0.010f; // empirically determined ....
|
|
|
|
|
|
float lum_high = (ep1.x + ep1.y + ep1.z) * (1.0f / 3.0f);
|
|
float lum_low = (ep0.x + ep0.y + ep0.z) * (1.0f / 3.0f);
|
|
float lumdif = lum_high - lum_low;
|
|
float mode23mult = lumdif < 960 ? 4.0f : lumdif < 3968 ? 16.0f : 128.0f;
|
|
|
|
mode23mult *= 0.0005f; // empirically determined ....
|
|
|
|
// pick among the available HDR endpoint modes
|
|
for (i = 0; i < 8; i++)
|
|
{
|
|
best_error[i][3] = 1e30f;
|
|
format_of_choice[i][3] = encode_hdr_alpha ? FMT_HDR_RGBA : FMT_HDR_RGB_LDR_ALPHA;
|
|
best_error[i][2] = 1e30f;
|
|
format_of_choice[i][2] = FMT_HDR_RGB;
|
|
best_error[i][1] = 1e30f;
|
|
format_of_choice[i][1] = FMT_HDR_RGB_SCALE;
|
|
best_error[i][0] = 1e30f;
|
|
format_of_choice[i][0] = FMT_HDR_LUMINANCE_LARGE_RANGE;
|
|
}
|
|
|
|
for (i = 8; i < 21; i++)
|
|
{
|
|
// base_quant_error should depend on the scale-factor that would be used
|
|
// during actual encode of the color value.
|
|
|
|
float base_quant_error = baseline_quant_error[i] * partition_size * 1.0f;
|
|
float rgb_quantization_error = error_weight_rgbsum * base_quant_error * 2.0f;
|
|
float alpha_quantization_error = error_weight.w * base_quant_error * 2.0f;
|
|
float rgba_quantization_error = rgb_quantization_error + alpha_quantization_error;
|
|
|
|
#ifdef DEBUG_PRINT_DIAGNOSTICS
|
|
if (print_diagnostics)
|
|
printf("rgba-quant = %f can_offset_encode=%d\n", rgba_quantization_error, eci->can_offset_encode);
|
|
#endif
|
|
|
|
// for 8 integers, we have two encodings: one with HDR alpha and another one
|
|
// with LDR alpha.
|
|
|
|
float full_hdr_rgba_error = rgba_quantization_error + rgb_range_error + alpha_range_error;
|
|
best_error[i][3] = full_hdr_rgba_error;
|
|
format_of_choice[i][3] = encode_hdr_alpha ? FMT_HDR_RGBA : FMT_HDR_RGB_LDR_ALPHA;
|
|
|
|
// for 6 integers, we have one HDR-RGB encoding
|
|
float full_hdr_rgb_error = (rgb_quantization_error * mode11mult) + rgb_range_error + eci->alpha_drop_error;
|
|
best_error[i][2] = full_hdr_rgb_error;
|
|
format_of_choice[i][2] = FMT_HDR_RGB;
|
|
|
|
// for 4 integers, we have one HDR-RGB-Scale encoding
|
|
float hdr_rgb_scale_error = (rgb_quantization_error * mode7mult) + rgb_range_error + eci->alpha_drop_error + eci->rgb_luma_error;
|
|
|
|
best_error[i][1] = hdr_rgb_scale_error;
|
|
format_of_choice[i][1] = FMT_HDR_RGB_SCALE;
|
|
|
|
// for 2 integers, we assume luminance-with-large-range
|
|
float hdr_luminance_error = (rgb_quantization_error * mode23mult) + rgb_range_error + eci->alpha_drop_error + eci->luminance_error;
|
|
best_error[i][0] = hdr_luminance_error;
|
|
format_of_choice[i][0] = FMT_HDR_LUMINANCE_LARGE_RANGE;
|
|
|
|
#ifdef DEBUG_PRINT_DIAGNOSTICS
|
|
if (print_diagnostics)
|
|
{
|
|
for (int j = 0; j < 4; j++)
|
|
{
|
|
printf("(hdr) quant-level=%d ints=%d format=%d error=%f\n", i, j, format_of_choice[i][j], best_error[i][j]);
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
else
|
|
{
|
|
for (i = 0; i < 4; i++)
|
|
{
|
|
best_error[i][3] = 1e30f;
|
|
best_error[i][2] = 1e30f;
|
|
best_error[i][1] = 1e30f;
|
|
best_error[i][0] = 1e30f;
|
|
|
|
format_of_choice[i][3] = FMT_RGBA;
|
|
format_of_choice[i][2] = FMT_RGB;
|
|
format_of_choice[i][1] = FMT_RGB_SCALE;
|
|
format_of_choice[i][0] = FMT_LUMINANCE;
|
|
}
|
|
|
|
// pick among the available LDR endpoint modes
|
|
for (i = 4; i < 21; i++)
|
|
{
|
|
float base_quant_error = baseline_quant_error[i] * partition_size * 1.0f;
|
|
float rgb_quantization_error = error_weight_rgbsum * base_quant_error;
|
|
float alpha_quantization_error = error_weight.w * base_quant_error;
|
|
float rgba_quantization_error = rgb_quantization_error + alpha_quantization_error;
|
|
|
|
#ifdef DEBUG_PRINT_DIAGNOSTICS
|
|
if (print_diagnostics)
|
|
printf("rgba-quant = %f can_offset_encode=%d\n", rgba_quantization_error, eci->can_offset_encode);
|
|
#endif
|
|
|
|
// for 8 integers, the available encodings are:
|
|
// full LDR RGB-Alpha
|
|
float full_ldr_rgba_error = rgba_quantization_error;
|
|
if (eci->can_blue_contract)
|
|
full_ldr_rgba_error *= 0.625f;
|
|
if (eci->can_offset_encode && i <= 18)
|
|
full_ldr_rgba_error *= 0.5f;
|
|
full_ldr_rgba_error += rgb_range_error + alpha_range_error;
|
|
|
|
best_error[i][3] = full_ldr_rgba_error;
|
|
format_of_choice[i][3] = FMT_RGBA;
|
|
|
|
// for 6 integers, we have:
|
|
// - an LDR-RGB encoding
|
|
// - an RGBS + Alpha encoding (LDR)
|
|
|
|
float full_ldr_rgb_error = rgb_quantization_error;
|
|
if (eci->can_blue_contract)
|
|
full_ldr_rgb_error *= 0.5f;
|
|
if (eci->can_offset_encode && i <= 18)
|
|
full_ldr_rgb_error *= 0.25f;
|
|
full_ldr_rgb_error += eci->alpha_drop_error + rgb_range_error;
|
|
|
|
float rgbs_alpha_error = rgba_quantization_error + eci->rgb_scale_error + rgb_range_error + alpha_range_error;
|
|
|
|
if (rgbs_alpha_error < full_ldr_rgb_error)
|
|
{
|
|
best_error[i][2] = rgbs_alpha_error;
|
|
format_of_choice[i][2] = FMT_RGB_SCALE_ALPHA;
|
|
}
|
|
else
|
|
{
|
|
best_error[i][2] = full_ldr_rgb_error;
|
|
format_of_choice[i][2] = FMT_RGB;
|
|
}
|
|
|
|
// for 4 integers, we have a Luminance-Alpha encoding and the RGBS encoding
|
|
float ldr_rgbs_error = rgb_quantization_error + eci->alpha_drop_error + eci->rgb_scale_error + rgb_range_error;
|
|
|
|
float lum_alpha_error = rgba_quantization_error + eci->luminance_error + rgb_range_error + alpha_range_error;
|
|
|
|
if (ldr_rgbs_error < lum_alpha_error)
|
|
{
|
|
best_error[i][1] = ldr_rgbs_error;
|
|
format_of_choice[i][1] = FMT_RGB_SCALE;
|
|
}
|
|
else
|
|
{
|
|
best_error[i][1] = lum_alpha_error;
|
|
format_of_choice[i][1] = FMT_LUMINANCE_ALPHA;
|
|
}
|
|
|
|
// for 2 integers, we have a Luminance-encoding and an Alpha-encoding.
|
|
float luminance_error = rgb_quantization_error + eci->alpha_drop_error + eci->luminance_error + rgb_range_error;
|
|
|
|
best_error[i][0] = luminance_error;
|
|
format_of_choice[i][0] = FMT_LUMINANCE;
|
|
|
|
#ifdef DEBUG_PRINT_DIAGNOSTICS
|
|
if (print_diagnostics)
|
|
{
|
|
for (int j = 0; j < 4; j++)
|
|
{
|
|
printf(" (ldr) quant-level=%d ints=%d format=%d error=%f\n", i, j, format_of_choice[i][j], best_error[i][j]);
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
}
|
|
|
|
// for 1 partition, find the best combination (one format + a quantization level) for a given bitcount
|
|
static void one_partition_find_best_combination_for_bitcount(float combined_best_error[21][4],
|
|
int formats_of_choice[21][4], int bits_available, int *best_quantization_level, int *best_formats, float *error_of_best_combination)
|
|
{
|
|
int i;
|
|
int best_integer_count = -1;
|
|
float best_integer_count_error = 1e20f;
|
|
for (i = 0; i < 4; i++)
|
|
{
|
|
// compute the quantization level for a given number of integers and a given number of bits.
|
|
int quantization_level = quantization_mode_table[i + 1][bits_available];
|
|
if (quantization_level == -1)
|
|
continue; // used to indicate the case where we don't have enough bits to represent a given endpoint format at all.
|
|
if (combined_best_error[quantization_level][i] < best_integer_count_error)
|
|
{
|
|
best_integer_count_error = combined_best_error[quantization_level][i];
|
|
best_integer_count = i;
|
|
}
|
|
}
|
|
|
|
int ql = quantization_mode_table[best_integer_count + 1][bits_available];
|
|
|
|
*best_quantization_level = ql;
|
|
*error_of_best_combination = best_integer_count_error;
|
|
if (ql >= 0)
|
|
*best_formats = formats_of_choice[ql][best_integer_count];
|
|
else
|
|
*best_formats = FMT_LUMINANCE;
|
|
}
|
|
|
|
// for 2 partitions, find the best format combinations for every (quantization-mode, integer-count) combination
|
|
static void two_partitions_find_best_combination_for_every_quantization_and_integer_count(float best_error[2][21][4], // indexed by (partition, quant-level, integer-pair-count-minus-1)
|
|
int format_of_choice[2][21][4],
|
|
float combined_best_error[21][7], // indexed by (quant-level, integer-pair-count-minus-2)
|
|
int formats_of_choice[21][7][2])
|
|
{
|
|
int i, j;
|
|
|
|
for (i = 0; i < 21; i++)
|
|
for (j = 0; j < 7; j++)
|
|
combined_best_error[i][j] = 1e30f;
|
|
|
|
int quant;
|
|
for (quant = 5; quant < 21; quant++)
|
|
{
|
|
for (i = 0; i < 4; i++) // integer-count for first endpoint-pair
|
|
{
|
|
for (j = 0; j < 4; j++) // integer-count for second endpoint-pair
|
|
{
|
|
int low2 = MIN(i, j);
|
|
int high2 = MAX(i, j);
|
|
if ((high2 - low2) > 1)
|
|
continue;
|
|
|
|
int intcnt = i + j;
|
|
float errorterm = MIN(best_error[0][quant][i] + best_error[1][quant][j], 1e10f);
|
|
if (errorterm <= combined_best_error[quant][intcnt])
|
|
{
|
|
combined_best_error[quant][intcnt] = errorterm;
|
|
formats_of_choice[quant][intcnt][0] = format_of_choice[0][quant][i];
|
|
formats_of_choice[quant][intcnt][1] = format_of_choice[1][quant][j];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// for 2 partitions, find the best combination (two formats + a quantization level) for a given bitcount
|
|
static void two_partitions_find_best_combination_for_bitcount(float combined_best_error[21][7],
|
|
int formats_of_choice[21][7][2],
|
|
int bits_available, int *best_quantization_level, int *best_quantization_level_mod, int *best_formats, float *error_of_best_combination)
|
|
{
|
|
int i;
|
|
|
|
int best_integer_count = 0;
|
|
float best_integer_count_error = 1e20f;
|
|
int integer_count;
|
|
|
|
for (integer_count = 2; integer_count <= 8; integer_count++)
|
|
{
|
|
// compute the quantization level for a given number of integers and a given number of bits.
|
|
int quantization_level = quantization_mode_table[integer_count][bits_available];
|
|
if (quantization_level == -1)
|
|
break; // used to indicate the case where we don't have enough bits to represent a given endpoint format at all.
|
|
float integer_count_error = combined_best_error[quantization_level][integer_count - 2];
|
|
if (integer_count_error < best_integer_count_error)
|
|
{
|
|
best_integer_count_error = integer_count_error;
|
|
best_integer_count = integer_count;
|
|
}
|
|
}
|
|
|
|
int ql = quantization_mode_table[best_integer_count][bits_available];
|
|
int ql_mod = quantization_mode_table[best_integer_count][bits_available + 2];
|
|
|
|
*best_quantization_level = ql;
|
|
*best_quantization_level_mod = ql_mod;
|
|
*error_of_best_combination = best_integer_count_error;
|
|
if (ql >= 0)
|
|
{
|
|
for (i = 0; i < 2; i++)
|
|
best_formats[i] = formats_of_choice[ql][best_integer_count - 2][i];
|
|
}
|
|
else
|
|
{
|
|
for (i = 0; i < 2; i++)
|
|
best_formats[i] = FMT_LUMINANCE;
|
|
}
|
|
}
|
|
|
|
// for 3 partitions, find the best format combinations for every (quantization-mode, integer-count) combination
|
|
static void three_partitions_find_best_combination_for_every_quantization_and_integer_count(float best_error[3][21][4], // indexed by (partition, quant-level, integer-count)
|
|
int format_of_choice[3][21][4], float combined_best_error[21][10], int formats_of_choice[21][10][3])
|
|
{
|
|
int i, j, k;
|
|
|
|
for (i = 0; i < 21; i++)
|
|
for (j = 0; j < 10; j++)
|
|
combined_best_error[i][j] = 1e30f;
|
|
|
|
int quant;
|
|
for (quant = 5; quant < 21; quant++)
|
|
{
|
|
for (i = 0; i < 4; i++) // integer-count for first endpoint-pair
|
|
{
|
|
for (j = 0; j < 4; j++) // integer-count for second endpoint-pair
|
|
{
|
|
int low2 = MIN(i, j);
|
|
int high2 = MAX(i, j);
|
|
if ((high2 - low2) > 1)
|
|
continue;
|
|
for (k = 0; k < 4; k++) // integer-count for third endpoint-pair
|
|
{
|
|
int low3 = MIN(k, low2);
|
|
int high3 = MAX(k, high2);
|
|
if ((high3 - low3) > 1)
|
|
continue;
|
|
|
|
int intcnt = i + j + k;
|
|
float errorterm = MIN(best_error[0][quant][i] + best_error[1][quant][j] + best_error[2][quant][k], 1e10f);
|
|
if (errorterm <= combined_best_error[quant][intcnt])
|
|
{
|
|
combined_best_error[quant][intcnt] = errorterm;
|
|
formats_of_choice[quant][intcnt][0] = format_of_choice[0][quant][i];
|
|
formats_of_choice[quant][intcnt][1] = format_of_choice[1][quant][j];
|
|
formats_of_choice[quant][intcnt][2] = format_of_choice[2][quant][k];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// for 3 partitions, find the best combination (three formats + a quantization level) for a given bitcount
|
|
static void three_partitions_find_best_combination_for_bitcount(float combined_best_error[21][10],
|
|
int formats_of_choice[21][10][3],
|
|
int bits_available, int *best_quantization_level, int *best_quantization_level_mod, int *best_formats, float *error_of_best_combination)
|
|
{
|
|
int i;
|
|
|
|
int best_integer_count = 0;
|
|
float best_integer_count_error = 1e20f;
|
|
int integer_count;
|
|
|
|
for (integer_count = 3; integer_count <= 9; integer_count++)
|
|
{
|
|
// compute the quantization level for a given number of integers and a given number of bits.
|
|
int quantization_level = quantization_mode_table[integer_count][bits_available];
|
|
if (quantization_level == -1)
|
|
break; // used to indicate the case where we don't have enough bits to represent a given endpoint format at all.
|
|
float integer_count_error = combined_best_error[quantization_level][integer_count - 3];
|
|
if (integer_count_error < best_integer_count_error)
|
|
{
|
|
best_integer_count_error = integer_count_error;
|
|
best_integer_count = integer_count;
|
|
}
|
|
}
|
|
|
|
int ql = quantization_mode_table[best_integer_count][bits_available];
|
|
int ql_mod = quantization_mode_table[best_integer_count][bits_available + 5];
|
|
|
|
*best_quantization_level = ql;
|
|
*best_quantization_level_mod = ql_mod;
|
|
*error_of_best_combination = best_integer_count_error;
|
|
if (ql >= 0)
|
|
{
|
|
for (i = 0; i < 3; i++)
|
|
best_formats[i] = formats_of_choice[ql][best_integer_count - 3][i];
|
|
}
|
|
else
|
|
{
|
|
for (i = 0; i < 3; i++)
|
|
best_formats[i] = FMT_LUMINANCE;
|
|
}
|
|
}
|
|
|
|
// for 4 partitions, find the best format combinations for every (quantization-mode, integer-count) combination
|
|
static void four_partitions_find_best_combination_for_every_quantization_and_integer_count(float best_error[4][21][4], // indexed by (partition, quant-level, integer-count)
|
|
int format_of_choice[4][21][4], float combined_best_error[21][13], int formats_of_choice[21][13][4])
|
|
{
|
|
int i, j, k, l;
|
|
|
|
for (i = 0; i < 21; i++)
|
|
for (j = 0; j < 13; j++)
|
|
combined_best_error[i][j] = 1e30f;
|
|
|
|
int quant;
|
|
for (quant = 5; quant < 21; quant++)
|
|
{
|
|
for (i = 0; i < 4; i++) // integer-count for first endpoint-pair
|
|
{
|
|
for (j = 0; j < 4; j++) // integer-count for second endpoint-pair
|
|
{
|
|
int low2 = MIN(i, j);
|
|
int high2 = MAX(i, j);
|
|
if ((high2 - low2) > 1)
|
|
continue;
|
|
for (k = 0; k < 4; k++) // integer-count for third endpoint-pair
|
|
{
|
|
int low3 = MIN(k, low2);
|
|
int high3 = MAX(k, high2);
|
|
if ((high3 - low3) > 1)
|
|
continue;
|
|
for (l = 0; l < 4; l++) // integer-count for fourth endpoint-pair
|
|
{
|
|
int low4 = MIN(l, low3);
|
|
int high4 = MAX(l, high3);
|
|
if ((high4 - low4) > 1)
|
|
continue;
|
|
|
|
int intcnt = i + j + k + l;
|
|
float errorterm = MIN(best_error[0][quant][i] + best_error[1][quant][j] + best_error[2][quant][k] + best_error[3][quant][l], 1e10f);
|
|
if (errorterm <= combined_best_error[quant][intcnt])
|
|
{
|
|
combined_best_error[quant][intcnt] = errorterm;
|
|
formats_of_choice[quant][intcnt][0] = format_of_choice[0][quant][i];
|
|
formats_of_choice[quant][intcnt][1] = format_of_choice[1][quant][j];
|
|
formats_of_choice[quant][intcnt][2] = format_of_choice[2][quant][k];
|
|
formats_of_choice[quant][intcnt][3] = format_of_choice[3][quant][l];
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// for 4 partitions, find the best combination (four formats + a quantization level) for a given bitcount
|
|
static void four_partitions_find_best_combination_for_bitcount(float combined_best_error[21][13],
|
|
int formats_of_choice[21][13][4],
|
|
int bits_available, int *best_quantization_level, int *best_quantization_level_mod, int *best_formats, float *error_of_best_combination)
|
|
{
|
|
int i;
|
|
int best_integer_count = 0;
|
|
float best_integer_count_error = 1e20f;
|
|
int integer_count;
|
|
|
|
for (integer_count = 4; integer_count <= 9; integer_count++)
|
|
{
|
|
// compute the quantization level for a given number of integers and a given number of bits.
|
|
int quantization_level = quantization_mode_table[integer_count][bits_available];
|
|
if (quantization_level == -1)
|
|
break; // used to indicate the case where we don't have enough bits to represent a given endpoint format at all.
|
|
float integer_count_error = combined_best_error[quantization_level][integer_count - 4];
|
|
if (integer_count_error < best_integer_count_error)
|
|
{
|
|
best_integer_count_error = integer_count_error;
|
|
best_integer_count = integer_count;
|
|
}
|
|
}
|
|
|
|
int ql = quantization_mode_table[best_integer_count][bits_available];
|
|
int ql_mod = quantization_mode_table[best_integer_count][bits_available + 8];
|
|
|
|
*best_quantization_level = ql;
|
|
*best_quantization_level_mod = ql_mod;
|
|
*error_of_best_combination = best_integer_count_error;
|
|
if (ql >= 0)
|
|
{
|
|
for (i = 0; i < 4; i++)
|
|
best_formats[i] = formats_of_choice[ql][best_integer_count - 4][i];
|
|
}
|
|
else
|
|
{
|
|
for (i = 0; i < 4; i++)
|
|
best_formats[i] = FMT_LUMINANCE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
The determine_optimal_set_of_endpoint_formats_to_use() function.
|
|
|
|
It identifies, for each mode, which set of color endpoint encodings
|
|
produces the best overall result. It then reports back which 4 modes
|
|
look best, along with the ideal color encoding combination for each.
|
|
|
|
It takes as input:
|
|
a partitioning an imageblock,
|
|
a set of color endpoints.
|
|
for each mode, the number of bits available for color encoding and the error incurred by quantization.
|
|
in case of 2 plane of weights, a specifier for which color component to use for the second plane of weights.
|
|
|
|
It delivers as output for each of the 4 selected modes:
|
|
format specifier
|
|
for each partition
|
|
quantization level to use
|
|
modified quantization level to use
|
|
(when all format specifiers are equal)
|
|
*/
|
|
void determine_optimal_set_of_endpoint_formats_to_use(int xdim, int ydim, int zdim,
|
|
const partition_info * pt, const imageblock * blk, const error_weight_block * ewb,
|
|
const endpoints * ep,
|
|
int separate_component, // separate color component for 2-plane mode; -1 for single-plane mode
|
|
// bitcounts and errors computed for the various quantization methods
|
|
const int *qwt_bitcounts, const float *qwt_errors,
|
|
// output data
|
|
int partition_format_specifiers[4][4], int quantized_weight[4],
|
|
int quantization_level[4], int quantization_level_mod[4])
|
|
{
|
|
int i, j;
|
|
int partition_count = pt->partition_count;
|
|
|
|
int encode_hdr_rgb = blk->rgb_lns[0];
|
|
int encode_hdr_alpha = blk->alpha_lns[0];
|
|
|
|
// call a helper function to compute the errors that result from various
|
|
// encoding choices (such as using luminance instead of RGB, discarding Alpha,
|
|
// using RGB-scale in place of two separate RGB endpoints and so on)
|
|
encoding_choice_errors eci[4];
|
|
compute_encoding_choice_errors(xdim, ydim, zdim, blk, pt, ewb, separate_component, eci);
|
|
|
|
// for each partition, compute the error weights to apply for that partition.
|
|
float4 error_weightings[4];
|
|
float4 dummied_color_scalefactors[4]; // only used to receive data
|
|
compute_partition_error_color_weightings(xdim, ydim, zdim, ewb, pt, error_weightings, dummied_color_scalefactors);
|
|
|
|
float best_error[4][21][4];
|
|
int format_of_choice[4][21][4];
|
|
for (i = 0; i < partition_count; i++)
|
|
compute_color_error_for_every_integer_count_and_quantization_level(encode_hdr_rgb, encode_hdr_alpha, i, pt, &(eci[i]), ep, error_weightings, best_error[i], format_of_choice[i]);
|
|
|
|
float errors_of_best_combination[MAX_WEIGHT_MODES];
|
|
int best_quantization_levels[MAX_WEIGHT_MODES];
|
|
int best_quantization_levels_mod[MAX_WEIGHT_MODES];
|
|
int best_ep_formats[MAX_WEIGHT_MODES][4];
|
|
|
|
// code for the case where the block contains 1 partition
|
|
if (partition_count == 1)
|
|
{
|
|
int best_quantization_level;
|
|
int best_format;
|
|
float error_of_best_combination;
|
|
for (i = 0; i < MAX_WEIGHT_MODES; i++)
|
|
{
|
|
if (qwt_errors[i] >= 1e29f)
|
|
{
|
|
errors_of_best_combination[i] = 1e30f;
|
|
continue;
|
|
}
|
|
|
|
one_partition_find_best_combination_for_bitcount(best_error[0], format_of_choice[0], qwt_bitcounts[i], &best_quantization_level, &best_format, &error_of_best_combination);
|
|
error_of_best_combination += qwt_errors[i];
|
|
|
|
errors_of_best_combination[i] = error_of_best_combination;
|
|
best_quantization_levels[i] = best_quantization_level;
|
|
best_quantization_levels_mod[i] = best_quantization_level;
|
|
best_ep_formats[i][0] = best_format;
|
|
}
|
|
}
|
|
// code for the case where the block contains 2 partitions
|
|
else if (partition_count == 2)
|
|
{
|
|
int best_quantization_level;
|
|
int best_quantization_level_mod;
|
|
int best_formats[2];
|
|
float error_of_best_combination;
|
|
|
|
float combined_best_error[21][7];
|
|
int formats_of_choice[21][7][2];
|
|
|
|
two_partitions_find_best_combination_for_every_quantization_and_integer_count(best_error, format_of_choice, combined_best_error, formats_of_choice);
|
|
|
|
|
|
for (i = 0; i < MAX_WEIGHT_MODES; i++)
|
|
{
|
|
if (qwt_errors[i] >= 1e29f)
|
|
{
|
|
errors_of_best_combination[i] = 1e30f;
|
|
continue;
|
|
}
|
|
|
|
two_partitions_find_best_combination_for_bitcount(combined_best_error, formats_of_choice, qwt_bitcounts[i],
|
|
&best_quantization_level, &best_quantization_level_mod, best_formats, &error_of_best_combination);
|
|
|
|
error_of_best_combination += qwt_errors[i];
|
|
|
|
errors_of_best_combination[i] = error_of_best_combination;
|
|
best_quantization_levels[i] = best_quantization_level;
|
|
best_quantization_levels_mod[i] = best_quantization_level_mod;
|
|
best_ep_formats[i][0] = best_formats[0];
|
|
best_ep_formats[i][1] = best_formats[1];
|
|
}
|
|
}
|
|
// code for the case where the block contains 3 partitions
|
|
else if (partition_count == 3)
|
|
{
|
|
int best_quantization_level;
|
|
int best_quantization_level_mod;
|
|
int best_formats[3];
|
|
float error_of_best_combination;
|
|
|
|
float combined_best_error[21][10];
|
|
int formats_of_choice[21][10][3];
|
|
|
|
three_partitions_find_best_combination_for_every_quantization_and_integer_count(best_error, format_of_choice, combined_best_error, formats_of_choice);
|
|
|
|
for (i = 0; i < MAX_WEIGHT_MODES; i++)
|
|
{
|
|
if (qwt_errors[i] >= 1e29f)
|
|
{
|
|
errors_of_best_combination[i] = 1e30f;
|
|
continue;
|
|
}
|
|
|
|
three_partitions_find_best_combination_for_bitcount(combined_best_error,
|
|
formats_of_choice, qwt_bitcounts[i], &best_quantization_level, &best_quantization_level_mod, best_formats, &error_of_best_combination);
|
|
error_of_best_combination += qwt_errors[i];
|
|
|
|
errors_of_best_combination[i] = error_of_best_combination;
|
|
best_quantization_levels[i] = best_quantization_level;
|
|
best_quantization_levels_mod[i] = best_quantization_level_mod;
|
|
best_ep_formats[i][0] = best_formats[0];
|
|
best_ep_formats[i][1] = best_formats[1];
|
|
best_ep_formats[i][2] = best_formats[2];
|
|
}
|
|
}
|
|
// code for the case where the block contains 4 partitions
|
|
else if (partition_count == 4)
|
|
{
|
|
int best_quantization_level;
|
|
int best_quantization_level_mod;
|
|
int best_formats[4];
|
|
float error_of_best_combination;
|
|
|
|
float combined_best_error[21][13];
|
|
int formats_of_choice[21][13][4];
|
|
|
|
four_partitions_find_best_combination_for_every_quantization_and_integer_count(best_error, format_of_choice, combined_best_error, formats_of_choice);
|
|
|
|
for (i = 0; i < MAX_WEIGHT_MODES; i++)
|
|
{
|
|
if (qwt_errors[i] >= 1e29f)
|
|
{
|
|
errors_of_best_combination[i] = 1e30f;
|
|
continue;
|
|
}
|
|
four_partitions_find_best_combination_for_bitcount(combined_best_error,
|
|
formats_of_choice, qwt_bitcounts[i], &best_quantization_level, &best_quantization_level_mod, best_formats, &error_of_best_combination);
|
|
error_of_best_combination += qwt_errors[i];
|
|
|
|
errors_of_best_combination[i] = error_of_best_combination;
|
|
best_quantization_levels[i] = best_quantization_level;
|
|
best_quantization_levels_mod[i] = best_quantization_level_mod;
|
|
best_ep_formats[i][0] = best_formats[0];
|
|
best_ep_formats[i][1] = best_formats[1];
|
|
best_ep_formats[i][2] = best_formats[2];
|
|
best_ep_formats[i][3] = best_formats[3];
|
|
}
|
|
}
|
|
|
|
// finally, go through the results and pick the 4 best-looking modes.
|
|
int best_error_weights[4];
|
|
|
|
for (i = 0; i < 4; i++)
|
|
{
|
|
float best_ep_error = 1e30f;
|
|
int best_error_index = -1;
|
|
for (j = 0; j < MAX_WEIGHT_MODES; j++)
|
|
{
|
|
if (errors_of_best_combination[j] < best_ep_error && best_quantization_levels[j] >= 5)
|
|
{
|
|
best_ep_error = errors_of_best_combination[j];
|
|
best_error_index = j;
|
|
}
|
|
}
|
|
best_error_weights[i] = best_error_index;
|
|
|
|
if(best_error_index >= 0)
|
|
{
|
|
errors_of_best_combination[best_error_index] = 1e30f;
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < 4; i++)
|
|
{
|
|
quantized_weight[i] = best_error_weights[i];
|
|
if (quantized_weight[i] >= 0)
|
|
{
|
|
quantization_level[i] = best_quantization_levels[best_error_weights[i]];
|
|
quantization_level_mod[i] = best_quantization_levels_mod[best_error_weights[i]];
|
|
for (j = 0; j < partition_count; j++)
|
|
{
|
|
partition_format_specifiers[i][j] = best_ep_formats[best_error_weights[i]][j];
|
|
}
|
|
}
|
|
}
|
|
}
|