godot/thirdparty/astcenc/astcenc_image.cpp

559 lines
15 KiB
C++

// SPDX-License-Identifier: Apache-2.0
// ----------------------------------------------------------------------------
// Copyright 2011-2024 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 for creating in-memory ASTC image structures.
*/
#include <cassert>
#include <cstring>
#include "astcenc_internal.h"
/**
* @brief Loader pipeline function type for data fetch from memory.
*/
using pixel_loader = vfloat4(*)(const void*, int);
/**
* @brief Loader pipeline function type for swizzling data in a vector.
*/
using pixel_swizzler = vfloat4(*)(vfloat4, const astcenc_swizzle&);
/**
* @brief Loader pipeline function type for converting data in a vector to LNS.
*/
using pixel_converter = vfloat4(*)(vfloat4, vmask4);
/**
* @brief Load a 8-bit UNORM texel from a data array.
*
* @param data The data pointer.
* @param base_offset The index offset to the start of the pixel.
*/
static vfloat4 load_texel_u8(
const void* data,
int base_offset
) {
const uint8_t* data8 = static_cast<const uint8_t*>(data);
return int_to_float(vint4(data8 + base_offset)) / 255.0f;
}
/**
* @brief Load a 16-bit fp16 texel from a data array.
*
* @param data The data pointer.
* @param base_offset The index offset to the start of the pixel.
*/
static vfloat4 load_texel_f16(
const void* data,
int base_offset
) {
const uint16_t* data16 = static_cast<const uint16_t*>(data);
int r = data16[base_offset ];
int g = data16[base_offset + 1];
int b = data16[base_offset + 2];
int a = data16[base_offset + 3];
return float16_to_float(vint4(r, g, b, a));
}
/**
* @brief Load a 32-bit float texel from a data array.
*
* @param data The data pointer.
* @param base_offset The index offset to the start of the pixel.
*/
static vfloat4 load_texel_f32(
const void* data,
int base_offset
) {
const float* data32 = static_cast<const float*>(data);
return vfloat4(data32 + base_offset);
}
/**
* @brief Dummy no-op swizzle function.
*
* @param data The source RGBA vector to swizzle.
* @param swz The swizzle to use.
*/
static vfloat4 swz_texel_skip(
vfloat4 data,
const astcenc_swizzle& swz
) {
(void)swz;
return data;
}
/**
* @brief Swizzle a texel into a new arrangement.
*
* @param data The source RGBA vector to swizzle.
* @param swz The swizzle to use.
*/
static vfloat4 swz_texel(
vfloat4 data,
const astcenc_swizzle& swz
) {
ASTCENC_ALIGNAS float datas[6];
storea(data, datas);
datas[ASTCENC_SWZ_0] = 0.0f;
datas[ASTCENC_SWZ_1] = 1.0f;
return vfloat4(datas[swz.r], datas[swz.g], datas[swz.b], datas[swz.a]);
}
/**
* @brief Encode a texel that is entirely LDR linear.
*
* @param data The RGBA data to encode.
* @param lns_mask The mask for the HDR channels than need LNS encoding.
*/
static vfloat4 encode_texel_unorm(
vfloat4 data,
vmask4 lns_mask
) {
(void)lns_mask;
return data * 65535.0f;
}
/**
* @brief Encode a texel that includes at least some HDR LNS texels.
*
* @param data The RGBA data to encode.
* @param lns_mask The mask for the HDR channels than need LNS encoding.
*/
static vfloat4 encode_texel_lns(
vfloat4 data,
vmask4 lns_mask
) {
vfloat4 datav_unorm = data * 65535.0f;
vfloat4 datav_lns = float_to_lns(data);
return select(datav_unorm, datav_lns, lns_mask);
}
/* See header for documentation. */
void load_image_block(
astcenc_profile decode_mode,
const astcenc_image& img,
image_block& blk,
const block_size_descriptor& bsd,
unsigned int xpos,
unsigned int ypos,
unsigned int zpos,
const astcenc_swizzle& swz
) {
unsigned int xsize = img.dim_x;
unsigned int ysize = img.dim_y;
unsigned int zsize = img.dim_z;
blk.xpos = xpos;
blk.ypos = ypos;
blk.zpos = zpos;
// True if any non-identity swizzle
bool needs_swz = (swz.r != ASTCENC_SWZ_R) || (swz.g != ASTCENC_SWZ_G) ||
(swz.b != ASTCENC_SWZ_B) || (swz.a != ASTCENC_SWZ_A);
int idx = 0;
vfloat4 data_min(1e38f);
vfloat4 data_mean(0.0f);
vfloat4 data_mean_scale(1.0f / static_cast<float>(bsd.texel_count));
vfloat4 data_max(-1e38f);
vmask4 grayscalev(true);
// This works because we impose the same choice everywhere during encode
uint8_t rgb_lns = (decode_mode == ASTCENC_PRF_HDR) ||
(decode_mode == ASTCENC_PRF_HDR_RGB_LDR_A) ? 1 : 0;
uint8_t a_lns = decode_mode == ASTCENC_PRF_HDR ? 1 : 0;
vint4 use_lns(rgb_lns, rgb_lns, rgb_lns, a_lns);
vmask4 lns_mask = use_lns != vint4::zero();
// Set up the function pointers for loading pipeline as needed
pixel_loader loader = load_texel_u8;
if (img.data_type == ASTCENC_TYPE_F16)
{
loader = load_texel_f16;
}
else if (img.data_type == ASTCENC_TYPE_F32)
{
loader = load_texel_f32;
}
pixel_swizzler swizzler = swz_texel_skip;
if (needs_swz)
{
swizzler = swz_texel;
}
pixel_converter converter = encode_texel_unorm;
if (any(lns_mask))
{
converter = encode_texel_lns;
}
for (unsigned int z = 0; z < bsd.zdim; z++)
{
unsigned int zi = astc::min(zpos + z, zsize - 1);
void* plane = img.data[zi];
for (unsigned int y = 0; y < bsd.ydim; y++)
{
unsigned int yi = astc::min(ypos + y, ysize - 1);
for (unsigned int x = 0; x < bsd.xdim; x++)
{
unsigned int xi = astc::min(xpos + x, xsize - 1);
vfloat4 datav = loader(plane, (4 * xsize * yi) + (4 * xi));
datav = swizzler(datav, swz);
datav = converter(datav, lns_mask);
// Compute block metadata
data_min = min(data_min, datav);
data_mean += datav * data_mean_scale;
data_max = max(data_max, datav);
grayscalev = grayscalev & (datav.swz<0,0,0,0>() == datav.swz<1,1,2,2>());
blk.data_r[idx] = datav.lane<0>();
blk.data_g[idx] = datav.lane<1>();
blk.data_b[idx] = datav.lane<2>();
blk.data_a[idx] = datav.lane<3>();
blk.rgb_lns[idx] = rgb_lns;
blk.alpha_lns[idx] = a_lns;
idx++;
}
}
}
// Reverse the encoding so we store origin block in the original format
vfloat4 data_enc = blk.texel(0);
vfloat4 data_enc_unorm = data_enc / 65535.0f;
vfloat4 data_enc_lns = vfloat4::zero();
if (rgb_lns || a_lns)
{
data_enc_lns = float16_to_float(lns_to_sf16(float_to_int(data_enc)));
}
blk.origin_texel = select(data_enc_unorm, data_enc_lns, lns_mask);
// Store block metadata
blk.data_min = data_min;
blk.data_mean = data_mean;
blk.data_max = data_max;
blk.grayscale = all(grayscalev);
}
/* See header for documentation. */
void load_image_block_fast_ldr(
astcenc_profile decode_mode,
const astcenc_image& img,
image_block& blk,
const block_size_descriptor& bsd,
unsigned int xpos,
unsigned int ypos,
unsigned int zpos,
const astcenc_swizzle& swz
) {
(void)swz;
(void)decode_mode;
unsigned int xsize = img.dim_x;
unsigned int ysize = img.dim_y;
blk.xpos = xpos;
blk.ypos = ypos;
blk.zpos = zpos;
vfloat4 data_min(1e38f);
vfloat4 data_mean = vfloat4::zero();
vfloat4 data_max(-1e38f);
vmask4 grayscalev(true);
int idx = 0;
const uint8_t* plane = static_cast<const uint8_t*>(img.data[0]);
for (unsigned int y = ypos; y < ypos + bsd.ydim; y++)
{
unsigned int yi = astc::min(y, ysize - 1);
for (unsigned int x = xpos; x < xpos + bsd.xdim; x++)
{
unsigned int xi = astc::min(x, xsize - 1);
vint4 datavi = vint4(plane + (4 * xsize * yi) + (4 * xi));
vfloat4 datav = int_to_float(datavi) * (65535.0f / 255.0f);
// Compute block metadata
data_min = min(data_min, datav);
data_mean += datav;
data_max = max(data_max, datav);
grayscalev = grayscalev & (datav.swz<0,0,0,0>() == datav.swz<1,1,2,2>());
blk.data_r[idx] = datav.lane<0>();
blk.data_g[idx] = datav.lane<1>();
blk.data_b[idx] = datav.lane<2>();
blk.data_a[idx] = datav.lane<3>();
idx++;
}
}
// Reverse the encoding so we store origin block in the original format
blk.origin_texel = blk.texel(0) / 65535.0f;
// Store block metadata
blk.rgb_lns[0] = 0;
blk.alpha_lns[0] = 0;
blk.data_min = data_min;
blk.data_mean = data_mean / static_cast<float>(bsd.texel_count);
blk.data_max = data_max;
blk.grayscale = all(grayscalev);
}
/* See header for documentation. */
void store_image_block(
astcenc_image& img,
const image_block& blk,
const block_size_descriptor& bsd,
unsigned int xpos,
unsigned int ypos,
unsigned int zpos,
const astcenc_swizzle& swz
) {
unsigned int x_size = img.dim_x;
unsigned int x_start = xpos;
unsigned int x_end = astc::min(x_size, xpos + bsd.xdim);
unsigned int x_count = x_end - x_start;
unsigned int x_nudge = bsd.xdim - x_count;
unsigned int y_size = img.dim_y;
unsigned int y_start = ypos;
unsigned int y_end = astc::min(y_size, ypos + bsd.ydim);
unsigned int y_count = y_end - y_start;
unsigned int y_nudge = (bsd.ydim - y_count) * bsd.xdim;
unsigned int z_size = img.dim_z;
unsigned int z_start = zpos;
unsigned int z_end = astc::min(z_size, zpos + bsd.zdim);
// True if any non-identity swizzle
bool needs_swz = (swz.r != ASTCENC_SWZ_R) || (swz.g != ASTCENC_SWZ_G) ||
(swz.b != ASTCENC_SWZ_B) || (swz.a != ASTCENC_SWZ_A);
// True if any swizzle uses Z reconstruct
bool needs_z = (swz.r == ASTCENC_SWZ_Z) || (swz.g == ASTCENC_SWZ_Z) ||
(swz.b == ASTCENC_SWZ_Z) || (swz.a == ASTCENC_SWZ_Z);
int idx = 0;
if (img.data_type == ASTCENC_TYPE_U8)
{
for (unsigned int z = z_start; z < z_end; z++)
{
// Fetch the image plane
uint8_t* data8 = static_cast<uint8_t*>(img.data[z]);
for (unsigned int y = y_start; y < y_end; y++)
{
uint8_t* data8_row = data8 + (4 * x_size * y) + (4 * x_start);
for (unsigned int x = 0; x < x_count; x += ASTCENC_SIMD_WIDTH)
{
unsigned int max_texels = ASTCENC_SIMD_WIDTH;
unsigned int used_texels = astc::min(x_count - x, max_texels);
// Unaligned load as rows are not always SIMD_WIDTH long
vfloat data_r(blk.data_r + idx);
vfloat data_g(blk.data_g + idx);
vfloat data_b(blk.data_b + idx);
vfloat data_a(blk.data_a + idx);
vint data_ri = float_to_int_rtn(min(data_r, 1.0f) * 255.0f);
vint data_gi = float_to_int_rtn(min(data_g, 1.0f) * 255.0f);
vint data_bi = float_to_int_rtn(min(data_b, 1.0f) * 255.0f);
vint data_ai = float_to_int_rtn(min(data_a, 1.0f) * 255.0f);
if (needs_swz)
{
vint swizzle_table[7];
swizzle_table[ASTCENC_SWZ_0] = vint(0);
swizzle_table[ASTCENC_SWZ_1] = vint(255);
swizzle_table[ASTCENC_SWZ_R] = data_ri;
swizzle_table[ASTCENC_SWZ_G] = data_gi;
swizzle_table[ASTCENC_SWZ_B] = data_bi;
swizzle_table[ASTCENC_SWZ_A] = data_ai;
if (needs_z)
{
vfloat data_x = (data_r * vfloat(2.0f)) - vfloat(1.0f);
vfloat data_y = (data_a * vfloat(2.0f)) - vfloat(1.0f);
vfloat data_z = vfloat(1.0f) - (data_x * data_x) - (data_y * data_y);
data_z = max(data_z, 0.0f);
data_z = (sqrt(data_z) * vfloat(0.5f)) + vfloat(0.5f);
swizzle_table[ASTCENC_SWZ_Z] = float_to_int_rtn(min(data_z, 1.0f) * 255.0f);
}
data_ri = swizzle_table[swz.r];
data_gi = swizzle_table[swz.g];
data_bi = swizzle_table[swz.b];
data_ai = swizzle_table[swz.a];
}
// Errors are NaN encoded - convert to magenta error color
// Branch is OK here - it is almost never true so predicts well
vmask nan_mask = data_r != data_r;
if (any(nan_mask))
{
data_ri = select(data_ri, vint(0xFF), nan_mask);
data_gi = select(data_gi, vint(0x00), nan_mask);
data_bi = select(data_bi, vint(0xFF), nan_mask);
data_ai = select(data_ai, vint(0xFF), nan_mask);
}
vint data_rgbai = interleave_rgba8(data_ri, data_gi, data_bi, data_ai);
vmask store_mask = vint::lane_id() < vint(used_texels);
store_lanes_masked(data8_row, data_rgbai, store_mask);
data8_row += ASTCENC_SIMD_WIDTH * 4;
idx += used_texels;
}
idx += x_nudge;
}
idx += y_nudge;
}
}
else if (img.data_type == ASTCENC_TYPE_F16)
{
for (unsigned int z = z_start; z < z_end; z++)
{
// Fetch the image plane
uint16_t* data16 = static_cast<uint16_t*>(img.data[z]);
for (unsigned int y = y_start; y < y_end; y++)
{
uint16_t* data16_row = data16 + (4 * x_size * y) + (4 * x_start);
for (unsigned int x = 0; x < x_count; x++)
{
vint4 color;
// NaNs are handled inline - no need to special case
if (needs_swz)
{
float data[7];
data[ASTCENC_SWZ_0] = 0.0f;
data[ASTCENC_SWZ_1] = 1.0f;
data[ASTCENC_SWZ_R] = blk.data_r[idx];
data[ASTCENC_SWZ_G] = blk.data_g[idx];
data[ASTCENC_SWZ_B] = blk.data_b[idx];
data[ASTCENC_SWZ_A] = blk.data_a[idx];
if (needs_z)
{
float xN = (data[0] * 2.0f) - 1.0f;
float yN = (data[3] * 2.0f) - 1.0f;
float zN = 1.0f - xN * xN - yN * yN;
if (zN < 0.0f)
{
zN = 0.0f;
}
data[ASTCENC_SWZ_Z] = (astc::sqrt(zN) * 0.5f) + 0.5f;
}
vfloat4 colorf(data[swz.r], data[swz.g], data[swz.b], data[swz.a]);
color = float_to_float16(colorf);
}
else
{
vfloat4 colorf = blk.texel(idx);
color = float_to_float16(colorf);
}
// TODO: Vectorize with store N shorts?
data16_row[0] = static_cast<uint16_t>(color.lane<0>());
data16_row[1] = static_cast<uint16_t>(color.lane<1>());
data16_row[2] = static_cast<uint16_t>(color.lane<2>());
data16_row[3] = static_cast<uint16_t>(color.lane<3>());
data16_row += 4;
idx++;
}
idx += x_nudge;
}
idx += y_nudge;
}
}
else // if (img.data_type == ASTCENC_TYPE_F32)
{
assert(img.data_type == ASTCENC_TYPE_F32);
for (unsigned int z = z_start; z < z_end; z++)
{
// Fetch the image plane
float* data32 = static_cast<float*>(img.data[z]);
for (unsigned int y = y_start; y < y_end; y++)
{
float* data32_row = data32 + (4 * x_size * y) + (4 * x_start);
for (unsigned int x = 0; x < x_count; x++)
{
vfloat4 color = blk.texel(idx);
// NaNs are handled inline - no need to special case
if (needs_swz)
{
float data[7];
data[ASTCENC_SWZ_0] = 0.0f;
data[ASTCENC_SWZ_1] = 1.0f;
data[ASTCENC_SWZ_R] = color.lane<0>();
data[ASTCENC_SWZ_G] = color.lane<1>();
data[ASTCENC_SWZ_B] = color.lane<2>();
data[ASTCENC_SWZ_A] = color.lane<3>();
if (needs_z)
{
float xN = (data[0] * 2.0f) - 1.0f;
float yN = (data[3] * 2.0f) - 1.0f;
float zN = 1.0f - xN * xN - yN * yN;
if (zN < 0.0f)
{
zN = 0.0f;
}
data[ASTCENC_SWZ_Z] = (astc::sqrt(zN) * 0.5f) + 0.5f;
}
color = vfloat4(data[swz.r], data[swz.g], data[swz.b], data[swz.a]);
}
store(color, data32_row);
data32_row += 4;
idx++;
}
idx += x_nudge;
}
idx += y_nudge;
}
}
}