godot/thirdparty/astcenc/astcenc_decompress_symbolic.cpp
K. S. Ernest (iFire) Lee 696346f4cc
Add ASTC compression and decompression with Arm astcenc.
Co-authored-by: Gordon A Macpherson <gordon.a.macpherson@gmail.com>
Co-authored-by: Rémi Verschelde <rverschelde@gmail.com>
2023-01-19 16:27:59 +01:00

624 lines
19 KiB
C++

// SPDX-License-Identifier: Apache-2.0
// ----------------------------------------------------------------------------
// Copyright 2011-2023 Arm Limited
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy
// of the License at:
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations
// under the License.
// ----------------------------------------------------------------------------
/**
* @brief Functions to decompress a symbolic block.
*/
#include "astcenc_internal.h"
#include <stdio.h>
#include <assert.h>
/**
* @brief Compute the integer linear interpolation of two color endpoints.
*
* @param decode_mode The ASTC profile (linear or sRGB)
* @param color0 The endpoint0 color.
* @param color1 The endpoint1 color.
* @param weights The interpolation weight (between 0 and 64).
*
* @return The interpolated color.
*/
static vint4 lerp_color_int(
astcenc_profile decode_mode,
vint4 color0,
vint4 color1,
vint4 weights
) {
vint4 weight1 = weights;
vint4 weight0 = vint4(64) - weight1;
if (decode_mode == ASTCENC_PRF_LDR_SRGB)
{
color0 = asr<8>(color0);
color1 = asr<8>(color1);
}
vint4 color = (color0 * weight0) + (color1 * weight1) + vint4(32);
color = asr<6>(color);
if (decode_mode == ASTCENC_PRF_LDR_SRGB)
{
color = color * vint4(257);
}
return color;
}
/**
* @brief Convert integer color value into a float value for the decoder.
*
* @param data The integer color value post-interpolation.
* @param lns_mask If set treat lane as HDR (LNS) else LDR (unorm16).
*
* @return The float color value.
*/
static inline vfloat4 decode_texel(
vint4 data,
vmask4 lns_mask
) {
vint4 color_lns = vint4::zero();
vint4 color_unorm = vint4::zero();
if (any(lns_mask))
{
color_lns = lns_to_sf16(data);
}
if (!all(lns_mask))
{
color_unorm = unorm16_to_sf16(data);
}
// Pick components and then convert to FP16
vint4 datai = select(color_unorm, color_lns, lns_mask);
return float16_to_float(datai);
}
/* See header for documentation. */
void unpack_weights(
const block_size_descriptor& bsd,
const symbolic_compressed_block& scb,
const decimation_info& di,
bool is_dual_plane,
int weights_plane1[BLOCK_MAX_TEXELS],
int weights_plane2[BLOCK_MAX_TEXELS]
) {
// Safe to overshoot as all arrays are allocated to full size
if (!is_dual_plane)
{
// Build full 64-entry weight lookup table
vint4 tab0(reinterpret_cast<const int*>(scb.weights + 0));
vint4 tab1(reinterpret_cast<const int*>(scb.weights + 16));
vint4 tab2(reinterpret_cast<const int*>(scb.weights + 32));
vint4 tab3(reinterpret_cast<const int*>(scb.weights + 48));
vint tab0p, tab1p, tab2p, tab3p;
vtable_prepare(tab0, tab1, tab2, tab3, tab0p, tab1p, tab2p, tab3p);
for (unsigned int i = 0; i < bsd.texel_count; i += ASTCENC_SIMD_WIDTH)
{
vint summed_value(8);
vint weight_count(di.texel_weight_count + i);
int max_weight_count = hmax(weight_count).lane<0>();
promise(max_weight_count > 0);
for (int j = 0; j < max_weight_count; j++)
{
vint texel_weights(di.texel_weights_tr[j] + i);
vint texel_weights_int(di.texel_weight_contribs_int_tr[j] + i);
summed_value += vtable_8bt_32bi(tab0p, tab1p, tab2p, tab3p, texel_weights) * texel_weights_int;
}
store(lsr<4>(summed_value), weights_plane1 + i);
}
}
else
{
// Build a 32-entry weight lookup table per plane
// Plane 1
vint4 tab0_plane1(reinterpret_cast<const int*>(scb.weights + 0));
vint4 tab1_plane1(reinterpret_cast<const int*>(scb.weights + 16));
vint tab0_plane1p, tab1_plane1p;
vtable_prepare(tab0_plane1, tab1_plane1, tab0_plane1p, tab1_plane1p);
// Plane 2
vint4 tab0_plane2(reinterpret_cast<const int*>(scb.weights + 32));
vint4 tab1_plane2(reinterpret_cast<const int*>(scb.weights + 48));
vint tab0_plane2p, tab1_plane2p;
vtable_prepare(tab0_plane2, tab1_plane2, tab0_plane2p, tab1_plane2p);
for (unsigned int i = 0; i < bsd.texel_count; i += ASTCENC_SIMD_WIDTH)
{
vint sum_plane1(8);
vint sum_plane2(8);
vint weight_count(di.texel_weight_count + i);
int max_weight_count = hmax(weight_count).lane<0>();
promise(max_weight_count > 0);
for (int j = 0; j < max_weight_count; j++)
{
vint texel_weights(di.texel_weights_tr[j] + i);
vint texel_weights_int(di.texel_weight_contribs_int_tr[j] + i);
sum_plane1 += vtable_8bt_32bi(tab0_plane1p, tab1_plane1p, texel_weights) * texel_weights_int;
sum_plane2 += vtable_8bt_32bi(tab0_plane2p, tab1_plane2p, texel_weights) * texel_weights_int;
}
store(lsr<4>(sum_plane1), weights_plane1 + i);
store(lsr<4>(sum_plane2), weights_plane2 + i);
}
}
}
/**
* @brief Return an FP32 NaN value for use in error colors.
*
* This NaN encoding will turn into 0xFFFF when converted to an FP16 NaN.
*
* @return The float color value.
*/
static float error_color_nan()
{
if32 v;
v.u = 0xFFFFE000U;
return v.f;
}
/* See header for documentation. */
void decompress_symbolic_block(
astcenc_profile decode_mode,
const block_size_descriptor& bsd,
int xpos,
int ypos,
int zpos,
const symbolic_compressed_block& scb,
image_block& blk
) {
blk.xpos = xpos;
blk.ypos = ypos;
blk.zpos = zpos;
blk.data_min = vfloat4::zero();
blk.data_mean = vfloat4::zero();
blk.data_max = vfloat4::zero();
blk.grayscale = false;
// If we detected an error-block, blow up immediately.
if (scb.block_type == SYM_BTYPE_ERROR)
{
for (unsigned int i = 0; i < bsd.texel_count; i++)
{
blk.data_r[i] = error_color_nan();
blk.data_g[i] = error_color_nan();
blk.data_b[i] = error_color_nan();
blk.data_a[i] = error_color_nan();
blk.rgb_lns[i] = 0;
blk.alpha_lns[i] = 0;
}
return;
}
if ((scb.block_type == SYM_BTYPE_CONST_F16) ||
(scb.block_type == SYM_BTYPE_CONST_U16))
{
vfloat4 color;
uint8_t use_lns = 0;
// UNORM16 constant color block
if (scb.block_type == SYM_BTYPE_CONST_U16)
{
vint4 colori(scb.constant_color);
// For sRGB decoding a real decoder would just use the top 8 bits for color conversion.
// We don't color convert, so rescale the top 8 bits into the full 16 bit dynamic range.
if (decode_mode == ASTCENC_PRF_LDR_SRGB)
{
colori = asr<8>(colori) * 257;
}
vint4 colorf16 = unorm16_to_sf16(colori);
color = float16_to_float(colorf16);
}
// FLOAT16 constant color block
else
{
switch (decode_mode)
{
case ASTCENC_PRF_LDR_SRGB:
case ASTCENC_PRF_LDR:
color = vfloat4(error_color_nan());
break;
case ASTCENC_PRF_HDR_RGB_LDR_A:
case ASTCENC_PRF_HDR:
// Constant-color block; unpack from FP16 to FP32.
color = float16_to_float(vint4(scb.constant_color));
use_lns = 1;
break;
}
}
for (unsigned int i = 0; i < bsd.texel_count; i++)
{
blk.data_r[i] = color.lane<0>();
blk.data_g[i] = color.lane<1>();
blk.data_b[i] = color.lane<2>();
blk.data_a[i] = color.lane<3>();
blk.rgb_lns[i] = use_lns;
blk.alpha_lns[i] = use_lns;
}
return;
}
// Get the appropriate partition-table entry
int partition_count = scb.partition_count;
const auto& pi = bsd.get_partition_info(partition_count, scb.partition_index);
// Get the appropriate block descriptors
const auto& bm = bsd.get_block_mode(scb.block_mode);
const auto& di = bsd.get_decimation_info(bm.decimation_mode);
bool is_dual_plane = static_cast<bool>(bm.is_dual_plane);
// Unquantize and undecimate the weights
int plane1_weights[BLOCK_MAX_TEXELS];
int plane2_weights[BLOCK_MAX_TEXELS];
unpack_weights(bsd, scb, di, is_dual_plane, plane1_weights, plane2_weights);
// Now that we have endpoint colors and weights, we can unpack texel colors
int plane2_component = scb.plane2_component;
vmask4 plane2_mask = vint4::lane_id() == vint4(plane2_component);
for (int i = 0; i < partition_count; i++)
{
// Decode the color endpoints for this partition
vint4 ep0;
vint4 ep1;
bool rgb_lns;
bool a_lns;
unpack_color_endpoints(decode_mode,
scb.color_formats[i],
scb.color_values[i],
rgb_lns, a_lns,
ep0, ep1);
vmask4 lns_mask(rgb_lns, rgb_lns, rgb_lns, a_lns);
int texel_count = pi.partition_texel_count[i];
for (int j = 0; j < texel_count; j++)
{
int tix = pi.texels_of_partition[i][j];
vint4 weight = select(vint4(plane1_weights[tix]), vint4(plane2_weights[tix]), plane2_mask);
vint4 color = lerp_color_int(decode_mode, ep0, ep1, weight);
vfloat4 colorf = decode_texel(color, lns_mask);
blk.data_r[tix] = colorf.lane<0>();
blk.data_g[tix] = colorf.lane<1>();
blk.data_b[tix] = colorf.lane<2>();
blk.data_a[tix] = colorf.lane<3>();
}
}
}
#if !defined(ASTCENC_DECOMPRESS_ONLY)
/* See header for documentation. */
float compute_symbolic_block_difference_2plane(
const astcenc_config& config,
const block_size_descriptor& bsd,
const symbolic_compressed_block& scb,
const image_block& blk
) {
// If we detected an error-block, blow up immediately.
if (scb.block_type == SYM_BTYPE_ERROR)
{
return ERROR_CALC_DEFAULT;
}
assert(scb.block_mode >= 0);
assert(scb.partition_count == 1);
assert(bsd.get_block_mode(scb.block_mode).is_dual_plane == 1);
// Get the appropriate block descriptor
const block_mode& bm = bsd.get_block_mode(scb.block_mode);
const decimation_info& di = bsd.get_decimation_info(bm.decimation_mode);
// Unquantize and undecimate the weights
int plane1_weights[BLOCK_MAX_TEXELS];
int plane2_weights[BLOCK_MAX_TEXELS];
unpack_weights(bsd, scb, di, true, plane1_weights, plane2_weights);
vmask4 plane2_mask = vint4::lane_id() == vint4(scb.plane2_component);
vfloat4 summa = vfloat4::zero();
// Decode the color endpoints for this partition
vint4 ep0;
vint4 ep1;
bool rgb_lns;
bool a_lns;
unpack_color_endpoints(config.profile,
scb.color_formats[0],
scb.color_values[0],
rgb_lns, a_lns,
ep0, ep1);
// Unpack and compute error for each texel in the partition
unsigned int texel_count = bsd.texel_count;
for (unsigned int i = 0; i < texel_count; i++)
{
vint4 weight = select(vint4(plane1_weights[i]), vint4(plane2_weights[i]), plane2_mask);
vint4 colori = lerp_color_int(config.profile, ep0, ep1, weight);
vfloat4 color = int_to_float(colori);
vfloat4 oldColor = blk.texel(i);
// Compare error using a perceptual decode metric for RGBM textures
if (config.flags & ASTCENC_FLG_MAP_RGBM)
{
// Fail encodings that result in zero weight M pixels. Note that this can cause
// "interesting" artifacts if we reject all useful encodings - we typically get max
// brightness encodings instead which look just as bad. We recommend users apply a
// bias to their stored M value, limiting the lower value to 16 or 32 to avoid
// getting small M values post-quantization, but we can't prove it would never
// happen, especially at low bit rates ...
if (color.lane<3>() == 0.0f)
{
return -ERROR_CALC_DEFAULT;
}
// Compute error based on decoded RGBM color
color = vfloat4(
color.lane<0>() * color.lane<3>() * config.rgbm_m_scale,
color.lane<1>() * color.lane<3>() * config.rgbm_m_scale,
color.lane<2>() * color.lane<3>() * config.rgbm_m_scale,
1.0f
);
oldColor = vfloat4(
oldColor.lane<0>() * oldColor.lane<3>() * config.rgbm_m_scale,
oldColor.lane<1>() * oldColor.lane<3>() * config.rgbm_m_scale,
oldColor.lane<2>() * oldColor.lane<3>() * config.rgbm_m_scale,
1.0f
);
}
vfloat4 error = oldColor - color;
error = min(abs(error), 1e15f);
error = error * error;
summa += min(dot(error, blk.channel_weight), ERROR_CALC_DEFAULT);
}
return summa.lane<0>();
}
/* See header for documentation. */
float compute_symbolic_block_difference_1plane(
const astcenc_config& config,
const block_size_descriptor& bsd,
const symbolic_compressed_block& scb,
const image_block& blk
) {
assert(bsd.get_block_mode(scb.block_mode).is_dual_plane == 0);
// If we detected an error-block, blow up immediately.
if (scb.block_type == SYM_BTYPE_ERROR)
{
return ERROR_CALC_DEFAULT;
}
assert(scb.block_mode >= 0);
// Get the appropriate partition-table entry
unsigned int partition_count = scb.partition_count;
const auto& pi = bsd.get_partition_info(partition_count, scb.partition_index);
// Get the appropriate block descriptor
const block_mode& bm = bsd.get_block_mode(scb.block_mode);
const decimation_info& di = bsd.get_decimation_info(bm.decimation_mode);
// Unquantize and undecimate the weights
int plane1_weights[BLOCK_MAX_TEXELS];
unpack_weights(bsd, scb, di, false, plane1_weights, nullptr);
vfloat4 summa = vfloat4::zero();
for (unsigned int i = 0; i < partition_count; i++)
{
// Decode the color endpoints for this partition
vint4 ep0;
vint4 ep1;
bool rgb_lns;
bool a_lns;
unpack_color_endpoints(config.profile,
scb.color_formats[i],
scb.color_values[i],
rgb_lns, a_lns,
ep0, ep1);
// Unpack and compute error for each texel in the partition
unsigned int texel_count = pi.partition_texel_count[i];
for (unsigned int j = 0; j < texel_count; j++)
{
unsigned int tix = pi.texels_of_partition[i][j];
vint4 colori = lerp_color_int(config.profile, ep0, ep1,
vint4(plane1_weights[tix]));
vfloat4 color = int_to_float(colori);
vfloat4 oldColor = blk.texel(tix);
// Compare error using a perceptual decode metric for RGBM textures
if (config.flags & ASTCENC_FLG_MAP_RGBM)
{
// Fail encodings that result in zero weight M pixels. Note that this can cause
// "interesting" artifacts if we reject all useful encodings - we typically get max
// brightness encodings instead which look just as bad. We recommend users apply a
// bias to their stored M value, limiting the lower value to 16 or 32 to avoid
// getting small M values post-quantization, but we can't prove it would never
// happen, especially at low bit rates ...
if (color.lane<3>() == 0.0f)
{
return -ERROR_CALC_DEFAULT;
}
// Compute error based on decoded RGBM color
color = vfloat4(
color.lane<0>() * color.lane<3>() * config.rgbm_m_scale,
color.lane<1>() * color.lane<3>() * config.rgbm_m_scale,
color.lane<2>() * color.lane<3>() * config.rgbm_m_scale,
1.0f
);
oldColor = vfloat4(
oldColor.lane<0>() * oldColor.lane<3>() * config.rgbm_m_scale,
oldColor.lane<1>() * oldColor.lane<3>() * config.rgbm_m_scale,
oldColor.lane<2>() * oldColor.lane<3>() * config.rgbm_m_scale,
1.0f
);
}
vfloat4 error = oldColor - color;
error = min(abs(error), 1e15f);
error = error * error;
summa += min(dot(error, blk.channel_weight), ERROR_CALC_DEFAULT);
}
}
return summa.lane<0>();
}
/* See header for documentation. */
float compute_symbolic_block_difference_1plane_1partition(
const astcenc_config& config,
const block_size_descriptor& bsd,
const symbolic_compressed_block& scb,
const image_block& blk
) {
// If we detected an error-block, blow up immediately.
if (scb.block_type == SYM_BTYPE_ERROR)
{
return ERROR_CALC_DEFAULT;
}
assert(scb.block_mode >= 0);
assert(bsd.get_partition_info(scb.partition_count, scb.partition_index).partition_count == 1);
// Get the appropriate block descriptor
const block_mode& bm = bsd.get_block_mode(scb.block_mode);
const decimation_info& di = bsd.get_decimation_info(bm.decimation_mode);
// Unquantize and undecimate the weights
alignas(ASTCENC_VECALIGN) int plane1_weights[BLOCK_MAX_TEXELS];
unpack_weights(bsd, scb, di, false, plane1_weights, nullptr);
// Decode the color endpoints for this partition
vint4 ep0;
vint4 ep1;
bool rgb_lns;
bool a_lns;
unpack_color_endpoints(config.profile,
scb.color_formats[0],
scb.color_values[0],
rgb_lns, a_lns,
ep0, ep1);
// Pre-shift sRGB so things round correctly
if (config.profile == ASTCENC_PRF_LDR_SRGB)
{
ep0 = asr<8>(ep0);
ep1 = asr<8>(ep1);
}
// Unpack and compute error for each texel in the partition
vfloatacc summav = vfloatacc::zero();
vint lane_id = vint::lane_id();
vint srgb_scale(config.profile == ASTCENC_PRF_LDR_SRGB ? 257 : 1);
unsigned int texel_count = bsd.texel_count;
for (unsigned int i = 0; i < texel_count; i += ASTCENC_SIMD_WIDTH)
{
// Compute EP1 contribution
vint weight1 = vint::loada(plane1_weights + i);
vint ep1_r = vint(ep1.lane<0>()) * weight1;
vint ep1_g = vint(ep1.lane<1>()) * weight1;
vint ep1_b = vint(ep1.lane<2>()) * weight1;
vint ep1_a = vint(ep1.lane<3>()) * weight1;
// Compute EP0 contribution
vint weight0 = vint(64) - weight1;
vint ep0_r = vint(ep0.lane<0>()) * weight0;
vint ep0_g = vint(ep0.lane<1>()) * weight0;
vint ep0_b = vint(ep0.lane<2>()) * weight0;
vint ep0_a = vint(ep0.lane<3>()) * weight0;
// Shift so things round correctly
vint colori_r = asr<6>(ep0_r + ep1_r + vint(32)) * srgb_scale;
vint colori_g = asr<6>(ep0_g + ep1_g + vint(32)) * srgb_scale;
vint colori_b = asr<6>(ep0_b + ep1_b + vint(32)) * srgb_scale;
vint colori_a = asr<6>(ep0_a + ep1_a + vint(32)) * srgb_scale;
// Compute color diff
vfloat color_r = int_to_float(colori_r);
vfloat color_g = int_to_float(colori_g);
vfloat color_b = int_to_float(colori_b);
vfloat color_a = int_to_float(colori_a);
vfloat color_orig_r = loada(blk.data_r + i);
vfloat color_orig_g = loada(blk.data_g + i);
vfloat color_orig_b = loada(blk.data_b + i);
vfloat color_orig_a = loada(blk.data_a + i);
vfloat color_error_r = min(abs(color_orig_r - color_r), vfloat(1e15f));
vfloat color_error_g = min(abs(color_orig_g - color_g), vfloat(1e15f));
vfloat color_error_b = min(abs(color_orig_b - color_b), vfloat(1e15f));
vfloat color_error_a = min(abs(color_orig_a - color_a), vfloat(1e15f));
// Compute squared error metric
color_error_r = color_error_r * color_error_r;
color_error_g = color_error_g * color_error_g;
color_error_b = color_error_b * color_error_b;
color_error_a = color_error_a * color_error_a;
vfloat metric = color_error_r * blk.channel_weight.lane<0>()
+ color_error_g * blk.channel_weight.lane<1>()
+ color_error_b * blk.channel_weight.lane<2>()
+ color_error_a * blk.channel_weight.lane<3>();
// Mask off bad lanes
vmask mask = lane_id < vint(texel_count);
lane_id += vint(ASTCENC_SIMD_WIDTH);
haccumulate(summav, metric, mask);
}
return hadd_s(summav);
}
#endif