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Ryujinx/Ryujinx.Graphics.Texture/ETC2Decoder.cs
gdkchan f906eb06c2
Implement a software ETC2 texture decoder (#4121)
* Implement a software ETC2 texture decoder

* Fix output size calculation for non-2D textures

* Address PR feedback
2022-12-21 20:39:58 -03:00

682 lines
24 KiB
C#

using Ryujinx.Common;
using System;
using System.Buffers.Binary;
using System.Runtime.InteropServices;
namespace Ryujinx.Graphics.Texture
{
public static class ETC2Decoder
{
private const uint AlphaMask = 0xff000000u;
private const int BlockWidth = 4;
private const int BlockHeight = 4;
private static readonly int[][] _etc1Lut =
{
new int[] { 2, 8, -2, -8 },
new int[] { 5, 17, -5, -17 },
new int[] { 9, 29, -9, -29 },
new int[] { 13, 42, -13, -42 },
new int[] { 18, 60, -18, -60 },
new int[] { 24, 80, -24, -80 },
new int[] { 33, 106, -33, -106 },
new int[] { 47, 183, -47, -183 }
};
private static readonly int[] _etc2Lut =
{
3, 6, 11, 16, 23, 32, 41, 64
};
private static readonly int[][] _etc2AlphaLut =
{
new int[] { -3, -6, -9, -15, 2, 5, 8, 14 },
new int[] { -3, -7, -10, -13, 2, 6, 9, 12 },
new int[] { -2, -5, -8, -13, 1, 4, 7, 12 },
new int[] { -2, -4, -6, -13, 1, 3, 5, 12 },
new int[] { -3, -6, -8, -12, 2, 5, 7, 11 },
new int[] { -3, -7, -9, -11, 2, 6, 8, 10 },
new int[] { -4, -7, -8, -11, 3, 6, 7, 10 },
new int[] { -3, -5, -8, -11, 2, 4, 7, 10 },
new int[] { -2, -6, -8, -10, 1, 5, 7, 9 },
new int[] { -2, -5, -8, -10, 1, 4, 7, 9 },
new int[] { -2, -4, -8, -10, 1, 3, 7, 9 },
new int[] { -2, -5, -7, -10, 1, 4, 6, 9 },
new int[] { -3, -4, -7, -10, 2, 3, 6, 9 },
new int[] { -1, -2, -3, -10, 0, 1, 2, 9 },
new int[] { -4, -6, -8, -9, 3, 5, 7, 8 },
new int[] { -3, -5, -7, -9, 2, 4, 6, 8 }
};
public static byte[] DecodeRgb(ReadOnlySpan<byte> data, int width, int height, int depth, int levels, int layers)
{
ReadOnlySpan<ulong> dataUlong = MemoryMarshal.Cast<byte, ulong>(data);
int inputOffset = 0;
byte[] output = new byte[CalculateOutputSize(width, height, depth, levels, layers)];
Span<uint> outputUint = MemoryMarshal.Cast<byte, uint>(output);
Span<uint> tile = stackalloc uint[BlockWidth * BlockHeight];
int imageBaseOOffs = 0;
for (int l = 0; l < levels; l++)
{
int wInBlocks = BitUtils.DivRoundUp(width, BlockWidth);
int hInBlocks = BitUtils.DivRoundUp(height, BlockHeight);
for (int l2 = 0; l2 < layers; l2++)
{
for (int z = 0; z < depth; z++)
{
for (int y = 0; y < hInBlocks; y++)
{
int ty = y * BlockHeight;
int bh = Math.Min(BlockHeight, height - ty);
for (int x = 0; x < wInBlocks; x++)
{
int tx = x * BlockWidth;
int bw = Math.Min(BlockWidth, width - tx);
ulong colorBlock = dataUlong[inputOffset++];
DecodeBlock(tile, colorBlock);
for (int py = 0; py < bh; py++)
{
int oOffsBase = imageBaseOOffs + ((ty + py) * width) + tx;
for (int px = 0; px < bw; px++)
{
int oOffs = oOffsBase + px;
outputUint[oOffs] = tile[py * BlockWidth + px] | AlphaMask;
}
}
}
}
imageBaseOOffs += width * height;
}
}
width = Math.Max(1, width >> 1);
height = Math.Max(1, height >> 1);
depth = Math.Max(1, depth >> 1);
}
return output;
}
public static byte[] DecodePta(ReadOnlySpan<byte> data, int width, int height, int depth, int levels, int layers)
{
ReadOnlySpan<ulong> dataUlong = MemoryMarshal.Cast<byte, ulong>(data);
int inputOffset = 0;
byte[] output = new byte[CalculateOutputSize(width, height, depth, levels, layers)];
Span<uint> outputUint = MemoryMarshal.Cast<byte, uint>(output);
Span<uint> tile = stackalloc uint[BlockWidth * BlockHeight];
int imageBaseOOffs = 0;
for (int l = 0; l < levels; l++)
{
int wInBlocks = BitUtils.DivRoundUp(width, BlockWidth);
int hInBlocks = BitUtils.DivRoundUp(height, BlockHeight);
for (int l2 = 0; l2 < layers; l2++)
{
for (int z = 0; z < depth; z++)
{
for (int y = 0; y < hInBlocks; y++)
{
int ty = y * BlockHeight;
int bh = Math.Min(BlockHeight, height - ty);
for (int x = 0; x < wInBlocks; x++)
{
int tx = x * BlockWidth;
int bw = Math.Min(BlockWidth, width - tx);
ulong colorBlock = dataUlong[inputOffset++];
DecodeBlockPta(tile, colorBlock);
for (int py = 0; py < bh; py++)
{
int oOffsBase = imageBaseOOffs + ((ty + py) * width) + tx;
tile.Slice(py * BlockWidth, bw).CopyTo(outputUint.Slice(oOffsBase, bw));
}
}
}
imageBaseOOffs += width * height;
}
}
width = Math.Max(1, width >> 1);
height = Math.Max(1, height >> 1);
depth = Math.Max(1, depth >> 1);
}
return output;
}
public static byte[] DecodeRgba(ReadOnlySpan<byte> data, int width, int height, int depth, int levels, int layers)
{
ReadOnlySpan<ulong> dataUlong = MemoryMarshal.Cast<byte, ulong>(data);
int inputOffset = 0;
byte[] output = new byte[CalculateOutputSize(width, height, depth, levels, layers)];
Span<uint> outputUint = MemoryMarshal.Cast<byte, uint>(output);
Span<uint> tile = stackalloc uint[BlockWidth * BlockHeight];
int imageBaseOOffs = 0;
for (int l = 0; l < levels; l++)
{
int wInBlocks = BitUtils.DivRoundUp(width, BlockWidth);
int hInBlocks = BitUtils.DivRoundUp(height, BlockHeight);
for (int l2 = 0; l2 < layers; l2++)
{
for (int z = 0; z < depth; z++)
{
for (int y = 0; y < hInBlocks; y++)
{
int ty = y * BlockHeight;
int bh = Math.Min(BlockHeight, height - ty);
for (int x = 0; x < wInBlocks; x++)
{
int tx = x * BlockWidth;
int bw = Math.Min(BlockWidth, width - tx);
ulong alphaBlock = dataUlong[inputOffset];
ulong colorBlock = dataUlong[inputOffset + 1];
inputOffset += 2;
DecodeBlock(tile, colorBlock);
byte alphaBase = (byte)alphaBlock;
int[] alphaTable = _etc2AlphaLut[(alphaBlock >> 8) & 0xf];
int alphaMultiplier = (int)(alphaBlock >> 12) & 0xf;
ulong alphaIndices = BinaryPrimitives.ReverseEndianness(alphaBlock);
if (alphaMultiplier != 0)
{
for (int py = 0; py < bh; py++)
{
int oOffsBase = imageBaseOOffs + ((ty + py) * width) + tx;
for (int px = 0; px < bw; px++)
{
int oOffs = oOffsBase + px;
int alphaIndex = (int)((alphaIndices >> (((px * BlockHeight + py) ^ 0xf) * 3)) & 7);
byte a = Saturate(alphaBase + alphaTable[alphaIndex] * alphaMultiplier);
outputUint[oOffs] = tile[py * BlockWidth + px] | ((uint)a << 24);
}
}
}
else
{
uint a = (uint)alphaBase << 24;
for (int py = 0; py < bh; py++)
{
int oOffsBase = imageBaseOOffs + ((ty + py) * width) + tx;
for (int px = 0; px < bw; px++)
{
int oOffs = oOffsBase + px;
outputUint[oOffs] = tile[py * BlockWidth + px] | a;
}
}
}
}
}
imageBaseOOffs += width * height;
}
}
width = Math.Max(1, width >> 1);
height = Math.Max(1, height >> 1);
depth = Math.Max(1, depth >> 1);
}
return output;
}
private static void DecodeBlock(Span<uint> tile, ulong block)
{
uint blockLow = (uint)(block >> 0);
uint blockHigh = (uint)(block >> 32);
uint r1, g1, b1;
uint r2, g2, b2;
bool differentialMode = (blockLow & 0x2000000) != 0;
if (differentialMode)
{
(r1, g1, b1, r2, g2, b2) = UnpackRgb555DiffEndPoints(blockLow);
if (r2 > 31)
{
DecodeBlock59T(tile, blockLow, blockHigh);
}
else if (g2 > 31)
{
DecodeBlock58H(tile, blockLow, blockHigh);
}
else if (b2 > 31)
{
DecodeBlock57P(tile, block);
}
else
{
r1 |= r1 >> 5;
g1 |= g1 >> 5;
b1 |= b1 >> 5;
r2 = (r2 << 3) | (r2 >> 2);
g2 = (g2 << 3) | (g2 >> 2);
b2 = (b2 << 3) | (b2 >> 2);
DecodeBlockETC1(tile, blockLow, blockHigh, r1, g1, b1, r2, g2, b2);
}
}
else
{
r1 = (blockLow & 0x0000f0) >> 0;
g1 = (blockLow & 0x00f000) >> 8;
b1 = (blockLow & 0xf00000) >> 16;
r2 = (blockLow & 0x00000f) << 4;
g2 = (blockLow & 0x000f00) >> 4;
b2 = (blockLow & 0x0f0000) >> 12;
r1 |= r1 >> 4;
g1 |= g1 >> 4;
b1 |= b1 >> 4;
r2 |= r2 >> 4;
g2 |= g2 >> 4;
b2 |= b2 >> 4;
DecodeBlockETC1(tile, blockLow, blockHigh, r1, g1, b1, r2, g2, b2);
}
}
private static void DecodeBlockPta(Span<uint> tile, ulong block)
{
uint blockLow = (uint)(block >> 0);
uint blockHigh = (uint)(block >> 32);
(uint r1, uint g1, uint b1, uint r2, uint g2, uint b2) = UnpackRgb555DiffEndPoints(blockLow);
bool fullyOpaque = (blockLow & 0x2000000) != 0;
if (fullyOpaque)
{
if (r2 > 31)
{
DecodeBlock59T(tile, blockLow, blockHigh);
}
else if (g2 > 31)
{
DecodeBlock58H(tile, blockLow, blockHigh);
}
else if (b2 > 31)
{
DecodeBlock57P(tile, block);
}
else
{
r1 |= r1 >> 5;
g1 |= g1 >> 5;
b1 |= b1 >> 5;
r2 = (r2 << 3) | (r2 >> 2);
g2 = (g2 << 3) | (g2 >> 2);
b2 = (b2 << 3) | (b2 >> 2);
DecodeBlockETC1(tile, blockLow, blockHigh, r1, g1, b1, r2, g2, b2);
}
for (int i = 0; i < tile.Length; i++)
{
tile[i] |= AlphaMask;
}
}
else
{
if (r2 > 31)
{
DecodeBlock59T(tile, blockLow, blockHigh, AlphaMask);
}
else if (g2 > 31)
{
DecodeBlock58H(tile, blockLow, blockHigh, AlphaMask);
}
else if (b2 > 31)
{
DecodeBlock57P(tile, block);
for (int i = 0; i < tile.Length; i++)
{
tile[i] |= AlphaMask;
}
}
else
{
r1 |= r1 >> 5;
g1 |= g1 >> 5;
b1 |= b1 >> 5;
r2 = (r2 << 3) | (r2 >> 2);
g2 = (g2 << 3) | (g2 >> 2);
b2 = (b2 << 3) | (b2 >> 2);
DecodeBlockETC1(tile, blockLow, blockHigh, r1, g1, b1, r2, g2, b2, AlphaMask);
}
}
}
private static (uint, uint, uint, uint, uint, uint) UnpackRgb555DiffEndPoints(uint blockLow)
{
uint r1 = (blockLow & 0x0000f8) >> 0;
uint g1 = (blockLow & 0x00f800) >> 8;
uint b1 = (blockLow & 0xf80000) >> 16;
uint r2 = (uint)((sbyte)(r1 >> 3) + ((sbyte)((blockLow & 0x000007) << 5) >> 5));
uint g2 = (uint)((sbyte)(g1 >> 3) + ((sbyte)((blockLow & 0x000700) >> 3) >> 5));
uint b2 = (uint)((sbyte)(b1 >> 3) + ((sbyte)((blockLow & 0x070000) >> 11) >> 5));
return (r1, g1, b1, r2, g2, b2);
}
private static void DecodeBlock59T(Span<uint> tile, uint blockLow, uint blockHigh, uint alphaMask = 0)
{
uint r1 = (blockLow & 3) | ((blockLow >> 1) & 0xc);
uint g1 = (blockLow >> 12) & 0xf;
uint b1 = (blockLow >> 8) & 0xf;
uint r2 = (blockLow >> 20) & 0xf;
uint g2 = (blockLow >> 16) & 0xf;
uint b2 = (blockLow >> 28) & 0xf;
r1 |= r1 << 4;
g1 |= g1 << 4;
b1 |= b1 << 4;
r2 |= r2 << 4;
g2 |= g2 << 4;
b2 |= b2 << 4;
int dist = _etc2Lut[((blockLow >> 24) & 1) | ((blockLow >> 25) & 6)];
Span<uint> palette = stackalloc uint[4];
palette[0] = Pack(r1, g1, b1);
palette[1] = Pack(r2, g2, b2, dist);
palette[2] = Pack(r2, g2, b2);
palette[3] = Pack(r2, g2, b2, -dist);
blockHigh = BinaryPrimitives.ReverseEndianness(blockHigh);
for (int y = 0; y < BlockHeight; y++)
{
for (int x = 0; x < BlockWidth; x++)
{
int offset = (y * 4) + x;
int index = (x * 4) + y;
int paletteIndex = (int)((blockHigh >> index) & 1) | (int)((blockHigh >> (index + 15)) & 2);
tile[offset] = palette[paletteIndex];
if (alphaMask != 0)
{
if (paletteIndex == 2)
{
tile[offset] = 0;
}
else
{
tile[offset] |= alphaMask;
}
}
}
}
}
private static void DecodeBlock58H(Span<uint> tile, uint blockLow, uint blockHigh, uint alphaMask = 0)
{
uint r1 = (blockLow >> 3) & 0xf;
uint g1 = ((blockLow << 1) & 0xe) | ((blockLow >> 12) & 1);
uint b1 = ((blockLow >> 23) & 1) | ((blockLow >> 7) & 6) | ((blockLow >> 8) & 8);
uint r2 = (blockLow >> 19) & 0xf;
uint g2 = ((blockLow >> 31) & 1) | ((blockLow >> 15) & 0xe);
uint b2 = (blockLow >> 27) & 0xf;
uint rgb1 = Pack4Be(r1, g1, b1);
uint rgb2 = Pack4Be(r2, g2, b2);
r1 |= r1 << 4;
g1 |= g1 << 4;
b1 |= b1 << 4;
r2 |= r2 << 4;
g2 |= g2 << 4;
b2 |= b2 << 4;
int dist = _etc2Lut[(rgb1 >= rgb2 ? 1u : 0u) | ((blockLow >> 23) & 2) | ((blockLow >> 24) & 4)];
Span<uint> palette = stackalloc uint[4];
palette[0] = Pack(r1, g1, b1, dist);
palette[1] = Pack(r1, g1, b1, -dist);
palette[2] = Pack(r2, g2, b2, dist);
palette[3] = Pack(r2, g2, b2, -dist);
blockHigh = BinaryPrimitives.ReverseEndianness(blockHigh);
for (int y = 0; y < BlockHeight; y++)
{
for (int x = 0; x < BlockWidth; x++)
{
int offset = (y * 4) + x;
int index = (x * 4) + y;
int paletteIndex = (int)((blockHigh >> index) & 1) | (int)((blockHigh >> (index + 15)) & 2);
tile[offset] = palette[paletteIndex];
if (alphaMask != 0)
{
if (paletteIndex == 2)
{
tile[offset] = 0;
}
else
{
tile[offset] |= alphaMask;
}
}
}
}
}
private static void DecodeBlock57P(Span<uint> tile, ulong block)
{
int r0 = (int)((block >> 1) & 0x3f);
int g0 = (int)(((block >> 9) & 0x3f) | ((block & 1) << 6));
int b0 = (int)(((block >> 31) & 1) | ((block >> 15) & 6) | ((block >> 16) & 0x18) | ((block >> 3) & 0x20));
int rh = (int)(((block >> 24) & 1) | ((block >> 25) & 0x3e));
int gh = (int)((block >> 33) & 0x7f);
int bh = (int)(((block >> 43) & 0x1f) | ((block >> 27) & 0x20));
int rv = (int)(((block >> 53) & 7) | ((block >> 37) & 0x38));
int gv = (int)(((block >> 62) & 3) | ((block >> 46) & 0x7c));
int bv = (int)((block >> 56) & 0x3f);
r0 = (r0 << 2) | (r0 >> 4);
g0 = (g0 << 1) | (g0 >> 6);
b0 = (b0 << 2) | (b0 >> 4);
rh = (rh << 2) | (rh >> 4);
gh = (gh << 1) | (gh >> 6);
bh = (bh << 2) | (bh >> 4);
rv = (rv << 2) | (rv >> 4);
gv = (gv << 1) | (gv >> 6);
bv = (bv << 2) | (bv >> 4);
for (int y = 0; y < BlockHeight; y++)
{
for (int x = 0; x < BlockWidth; x++)
{
int offset = y * BlockWidth + x;
byte r = Saturate(((x * (rh - r0)) + (y * (rv - r0)) + (r0 * 4) + 2) >> 2);
byte g = Saturate(((x * (gh - g0)) + (y * (gv - g0)) + (g0 * 4) + 2) >> 2);
byte b = Saturate(((x * (bh - b0)) + (y * (bv - b0)) + (b0 * 4) + 2) >> 2);
tile[offset] = Pack(r, g, b);
}
}
}
private static void DecodeBlockETC1(
Span<uint> tile,
uint blockLow,
uint blockHigh,
uint r1,
uint g1,
uint b1,
uint r2,
uint g2,
uint b2,
uint alphaMask = 0)
{
int[] table1 = _etc1Lut[(blockLow >> 29) & 7];
int[] table2 = _etc1Lut[(blockLow >> 26) & 7];
bool flip = (blockLow & 0x1000000) != 0;
if (!flip)
{
for (int y = 0; y < BlockHeight; y++)
{
for (int x = 0; x < BlockWidth / 2; x++)
{
uint color1 = CalculatePixel(r1, g1, b1, x + 0, y, blockHigh, table1, alphaMask);
uint color2 = CalculatePixel(r2, g2, b2, x + 2, y, blockHigh, table2, alphaMask);
int offset1 = y * BlockWidth + x;
int offset2 = y * BlockWidth + x + 2;
tile[offset1] = color1;
tile[offset2] = color2;
}
}
}
else
{
for (int y = 0; y < BlockHeight / 2; y++)
{
for (int x = 0; x < BlockWidth; x++)
{
uint color1 = CalculatePixel(r1, g1, b1, x, y + 0, blockHigh, table1, alphaMask);
uint color2 = CalculatePixel(r2, g2, b2, x, y + 2, blockHigh, table2, alphaMask);
int offset1 = (y * BlockWidth) + x;
int offset2 = ((y + 2) * BlockWidth) + x;
tile[offset1] = color1;
tile[offset2] = color2;
}
}
}
}
private static uint CalculatePixel(uint r, uint g, uint b, int x, int y, uint block, int[] table, uint alphaMask)
{
int index = x * BlockHeight + y;
uint msb = block << 1;
uint tableIndex = index < 8
? ((block >> (index + 24)) & 1) + ((msb >> (index + 8)) & 2)
: ((block >> (index + 8)) & 1) + ((msb >> (index - 8)) & 2);
if (alphaMask != 0)
{
if (tableIndex == 0)
{
return Pack(r, g, b) | alphaMask;
}
else if (tableIndex == 2)
{
return 0;
}
else
{
return Pack(r, g, b, table[tableIndex]) | alphaMask;
}
}
return Pack(r, g, b, table[tableIndex]);
}
private static uint Pack(uint r, uint g, uint b, int offset)
{
r = Saturate((int)(r + offset));
g = Saturate((int)(g + offset));
b = Saturate((int)(b + offset));
return Pack(r, g, b);
}
private static uint Pack(uint r, uint g, uint b)
{
return r | (g << 8) | (b << 16);
}
private static uint Pack4Be(uint r, uint g, uint b)
{
return (r << 8) | (g << 4) | b;
}
private static byte Saturate(int value)
{
return value > byte.MaxValue ? byte.MaxValue : value < byte.MinValue ? byte.MinValue : (byte)value;
}
private static int CalculateOutputSize(int width, int height, int depth, int levels, int layers)
{
int size = 0;
for (int l = 0; l < levels; l++)
{
size += Math.Max(1, width >> l) * Math.Max(1, height >> l) * Math.Max(1, depth >> l) * layers * 4;
}
return size;
}
}
}