Mang0e
New member
- Joined
- Jun 5, 2020
- Messages
- 3
- Programming Experience
- Beginner
I'm attempting to make myself a tool that will convert a byte array into an image, specifically one that is rgba (DXT5)
The program below works fine, but I can't figure out where to input my byte array. It's in C#, maybe someone could take a look at it and give me a summary of what I should do? I'm guessing I'm going to have to write a program that will utilize the program below, and run my byte array through the program below.
Basically, I need help figuring out where I need to input my byte array in the program below, and how I should go about doing it. Thanks and stay safe.
The program below works fine, but I can't figure out where to input my byte array. It's in C#, maybe someone could take a look at it and give me a summary of what I should do? I'm guessing I'm going to have to write a program that will utilize the program below, and run my byte array through the program below.
Basically, I need help figuring out where I need to input my byte array in the program below, and how I should go about doing it. Thanks and stay safe.
C#:
using System;
using System.IO;
using PakReader.Parsers.Objects;
using SkiaSharp;
namespace PakReader
{
static class TextureDecoder
{
public static SKImage DecodeImage(byte[] sequence, int width, int height, int depth, EPixelFormat format)
{
byte[] data;
SKColorType colorType;
switch (format)
{
case EPixelFormat.PF_DXT5:
data = DXTDecoder.DecodeDXT5(sequence, width, height, depth);
colorType = SKColorType.Rgba8888;
break;
case EPixelFormat.PF_DXT1:
data = DXTDecoder.DecodeDXT1(sequence, width, height, depth);
colorType = SKColorType.Rgba8888;
break;
case EPixelFormat.PF_B8G8R8A8:
data = sequence;
colorType = SKColorType.Bgra8888;
break;
case EPixelFormat.PF_BC5:
data = BCDecoder.DecodeBC5(sequence, width, height);
colorType = SKColorType.Bgra8888;
break;
case EPixelFormat.PF_BC4:
data = BCDecoder.DecodeBC4(sequence, width, height);
colorType = SKColorType.Bgra8888;
break;
case EPixelFormat.PF_G8:
data = sequence;
colorType = SKColorType.Gray8;
break;
case EPixelFormat.PF_FloatRGBA:
data = sequence;
colorType = SKColorType.RgbaF16;
break;
default:
throw new NotImplementedException($"Cannot decode {format} format");
}
using (var bitmap = new SKBitmap(new SKImageInfo(width, height, colorType, SKAlphaType.Unpremul)))
{
unsafe
{
fixed (byte* p = data)
{
bitmap.SetPixels(new IntPtr(p));
}
}
return SKImage.FromBitmap(bitmap);
}
}
static class BCDecoder
{
public static byte[] DecodeBC4(byte[] inp, int width, int height)
{
byte[] ret = new byte[width * height * 4];
using var reader = new BinaryReader(new MemoryStream(inp));
for (int y_block = 0; y_block < height / 4; y_block++)
{
for (int x_block = 0; x_block < width / 4; x_block++)
{
var r_bytes = DecodeBC3Block(reader);
for (int i = 0; i < 16; i++)
{
ret[GetPixelLoc(width, x_block * 4 + (i % 4), y_block * 4 + (i / 4), 4, 0)] = r_bytes[i];
}
}
}
return ret;
}
public static byte[] DecodeBC5(byte[] inp, int width, int height)
{
byte[] ret = new byte[width * height * 4];
using var reader = new BinaryReader(new MemoryStream(inp));
for (int y_block = 0; y_block < height / 4; y_block++)
{
for (int x_block = 0; x_block < width / 4; x_block++)
{
var r_bytes = DecodeBC3Block(reader);
var g_bytes = DecodeBC3Block(reader);
for (int i = 0; i < 16; i++)
{
ret[GetPixelLoc(width, x_block * 4 + (i % 4), y_block * 4 + (i / 4), 4, 0)] = r_bytes[i];
ret[GetPixelLoc(width, x_block * 4 + (i % 4), y_block * 4 + (i / 4), 4, 1)] = g_bytes[i];
ret[GetPixelLoc(width, x_block * 4 + (i % 4), y_block * 4 + (i / 4), 4, 2)] = GetZNormal(r_bytes[i], g_bytes[i]);
}
}
}
return ret;
}
static int GetPixelLoc(int width, int x, int y, int bpp, int off) => (y * width + x) * bpp + off;
static byte GetZNormal(byte x, byte y)
{
var xf = (x / 127.5f) - 1;
var yf = (y / 127.5f) - 1;
var zval = 1 - xf * xf - yf * yf;
var zval_ = (float)Math.Sqrt(zval > 0 ? zval : 0);
zval = zval_ < 1 ? zval_ : 1;
return (byte)((zval * 127) + 128);
}
static byte[] DecodeBC3Block(BinaryReader reader)
{
float ref0 = reader.ReadByte();
float ref1 = reader.ReadByte();
float[] ref_sl = new float[8];
ref_sl[0] = ref0;
ref_sl[1] = ref1;
if (ref0 > ref1)
{
ref_sl[2] = (6 * ref0 + 1 * ref1) / 7;
ref_sl[3] = (5 * ref0 + 2 * ref1) / 7;
ref_sl[4] = (4 * ref0 + 3 * ref1) / 7;
ref_sl[5] = (3 * ref0 + 4 * ref1) / 7;
ref_sl[6] = (2 * ref0 + 5 * ref1) / 7;
ref_sl[7] = (1 * ref0 + 6 * ref1) / 7;
}
else
{
ref_sl[2] = (4 * ref0 + 1 * ref1) / 5;
ref_sl[3] = (3 * ref0 + 2 * ref1) / 5;
ref_sl[4] = (2 * ref0 + 3 * ref1) / 5;
ref_sl[5] = (1 * ref0 + 4 * ref1) / 5;
ref_sl[6] = 0;
ref_sl[7] = 255;
}
byte[] index_block1 = GetBC3Indices(reader.ReadBytes(3));
byte[] index_block2 = GetBC3Indices(reader.ReadBytes(3));
byte[] bytes = new byte[16];
for (int i = 0; i < 8; i++)
{
bytes[7 - i] = (byte)ref_sl[index_block1[i]];
}
for (int i = 0; i < 8; i++)
{
bytes[15 - i] = (byte)ref_sl[index_block2[i]];
}
return bytes;
}
static byte[] GetBC3Indices(byte[] buf_block) =>
new byte[] {
(byte)((buf_block[2] & 0b1110_0000) >> 5),
(byte)((buf_block[2] & 0b0001_1100) >> 2),
(byte)(((buf_block[2] & 0b0000_0011) << 1) | ((buf_block[1] & 0b1 << 7) >> 7)),
(byte)((buf_block[1] & 0b0111_0000) >> 4),
(byte)((buf_block[1] & 0b0000_1110) >> 1),
(byte)(((buf_block[1] & 0b0000_0001) << 2) | ((buf_block[0] & 0b11 << 6) >> 6)),
(byte)((buf_block[0] & 0b0011_1000) >> 3),
(byte)(buf_block[0] & 0b0000_0111)
};
}
static class DXTDecoder
{
struct Colour8888
{
public byte red;
public byte green;
public byte blue;
public byte alpha;
}
public static byte[] DecodeDXT1(byte[] inp, int width, int height, int depth)
{
var bpp = 4;
var bps = width * bpp * 1;
var sizeofplane = bps * height;
byte[] rawData = new byte[depth * sizeofplane + height * bps + width * bpp];
var colours = new Colour8888[4];
colours[0].alpha = 0xFF;
colours[1].alpha = 0xFF;
colours[2].alpha = 0xFF;
unsafe
{
fixed (byte* bytePtr = inp)
{
byte* temp = bytePtr;
for (int z = 0; z < depth; z++)
{
for (int y = 0; y < height; y += 4)
{
for (int x = 0; x < width; x += 4)
{
ushort colour0 = *((ushort*)temp);
ushort colour1 = *((ushort*)(temp + 2));
DxtcReadColor(colour0, ref colours[0]);
DxtcReadColor(colour1, ref colours[1]);
uint bitmask = ((uint*)temp)[1];
temp += 8;
if (colour0 > colour1)
{
// Four-color block: derive the other two colors.
// 00 = color_0, 01 = color_1, 10 = color_2, 11 = color_3
// These 2-bit codes correspond to the 2-bit fields
// stored in the 64-bit block.
colours[2].blue = (byte)((2 * colours[0].blue + colours[1].blue + 1) / 3);
colours[2].green = (byte)((2 * colours[0].green + colours[1].green + 1) / 3);
colours[2].red = (byte)((2 * colours[0].red + colours[1].red + 1) / 3);
//colours[2].alpha = 0xFF;
colours[3].blue = (byte)((colours[0].blue + 2 * colours[1].blue + 1) / 3);
colours[3].green = (byte)((colours[0].green + 2 * colours[1].green + 1) / 3);
colours[3].red = (byte)((colours[0].red + 2 * colours[1].red + 1) / 3);
colours[3].alpha = 0xFF;
}
else
{
// Three-color block: derive the other color.
// 00 = color_0, 01 = color_1, 10 = color_2,
// 11 = transparent.
// These 2-bit codes correspond to the 2-bit fields
// stored in the 64-bit block.
colours[2].blue = (byte)((colours[0].blue + colours[1].blue) / 2);
colours[2].green = (byte)((colours[0].green + colours[1].green) / 2);
colours[2].red = (byte)((colours[0].red + colours[1].red) / 2);
//colours[2].alpha = 0xFF;
colours[3].blue = (byte)((colours[0].blue + 2 * colours[1].blue + 1) / 3);
colours[3].green = (byte)((colours[0].green + 2 * colours[1].green + 1) / 3);
colours[3].red = (byte)((colours[0].red + 2 * colours[1].red + 1) / 3);
colours[3].alpha = 0x00;
}
for (int j = 0, k = 0; j < 4; j++)
{
for (int i = 0; i < 4; i++, k++)
{
int select = (int)((bitmask & (0x03 << k * 2)) >> k * 2);
Colour8888 col = colours[select];
if (((x + i) < width) && ((y + j) < height))
{
uint offset = (uint)(z * sizeofplane + (y + j) * bps + (x + i) * bpp);
rawData[offset + 0] = col.red;
rawData[offset + 1] = col.green;
rawData[offset + 2] = col.blue;
rawData[offset + 3] = col.alpha;
}
}
}
}
}
}
}
}
return rawData;
}
public static byte[] DecodeDXT5(byte[] inp, int width, int height, int depth)
{
var bpp = 4;
var bps = width * bpp * 1;
var sizeofplane = bps * height;
byte[] rawData = new byte[depth * sizeofplane + height * bps + width * bpp];
var colours = new Colour8888[4];
ushort[] alphas = new ushort[8];
unsafe
{
fixed (byte* bytePtr = inp)
{
byte* temp = bytePtr;
for (int z = 0; z < depth; z++)
{
for (int y = 0; y < height; y += 4)
{
for (int x = 0; x < width; x += 4)
{
if (y >= height || x >= width)
break;
alphas[0] = temp[0];
alphas[1] = temp[1];
byte* alphamask = (temp + 2);
temp += 8;
DxtcReadColors(temp, colours);
uint bitmask = ((uint*)temp)[1];
temp += 8;
// Four-color block: derive the other two colors.
// 00 = color_0, 01 = color_1, 10 = color_2, 11 = color_3
// These 2-bit codes correspond to the 2-bit fields
// stored in the 64-bit block.
colours[2].blue = (byte)((2 * colours[0].blue + colours[1].blue + 1) / 3);
colours[2].green = (byte)((2 * colours[0].green + colours[1].green + 1) / 3);
colours[2].red = (byte)((2 * colours[0].red + colours[1].red + 1) / 3);
//colours[2].alpha = 0xFF;
colours[3].blue = (byte)((colours[0].blue + 2 * colours[1].blue + 1) / 3);
colours[3].green = (byte)((colours[0].green + 2 * colours[1].green + 1) / 3);
colours[3].red = (byte)((colours[0].red + 2 * colours[1].red + 1) / 3);
//colours[3].alpha = 0xFF;
int k = 0;
for (int j = 0; j < 4; j++)
{
for (int i = 0; i < 4; k++, i++)
{
int select = (int)((bitmask & (0x03 << k * 2)) >> k * 2);
Colour8888 col = colours[select];
// only put pixels out < width or height
if (((x + i) < width) && ((y + j) < height))
{
uint offset = (uint)(z * sizeofplane + (y + j) * bps + (x + i) * bpp);
rawData[offset] = col.red;
rawData[offset + 1] = col.green;
rawData[offset + 2] = col.blue;
}
}
}
// 8-alpha or 6-alpha block?
if (alphas[0] > alphas[1])
{
// 8-alpha block: derive the other six alphas.
// Bit code 000 = alpha_0, 001 = alpha_1, others are interpolated.
alphas[2] = (ushort)((6 * alphas[0] + 1 * alphas[1] + 3) / 7); // bit code 010
alphas[3] = (ushort)((5 * alphas[0] + 2 * alphas[1] + 3) / 7); // bit code 011
alphas[4] = (ushort)((4 * alphas[0] + 3 * alphas[1] + 3) / 7); // bit code 100
alphas[5] = (ushort)((3 * alphas[0] + 4 * alphas[1] + 3) / 7); // bit code 101
alphas[6] = (ushort)((2 * alphas[0] + 5 * alphas[1] + 3) / 7); // bit code 110
alphas[7] = (ushort)((1 * alphas[0] + 6 * alphas[1] + 3) / 7); // bit code 111
}
else
{
// 6-alpha block.
// Bit code 000 = alpha_0, 001 = alpha_1, others are interpolated.
alphas[2] = (ushort)((4 * alphas[0] + 1 * alphas[1] + 2) / 5); // Bit code 010
alphas[3] = (ushort)((3 * alphas[0] + 2 * alphas[1] + 2) / 5); // Bit code 011
alphas[4] = (ushort)((2 * alphas[0] + 3 * alphas[1] + 2) / 5); // Bit code 100
alphas[5] = (ushort)((1 * alphas[0] + 4 * alphas[1] + 2) / 5); // Bit code 101
alphas[6] = 0x00; // Bit code 110
alphas[7] = 0xFF; // Bit code 111
}
// Note: Have to separate the next two loops,
// it operates on a 6-byte system.
// First three bytes
//uint bits = (uint)(alphamask[0]);
uint bits = (uint)((alphamask[0]) | (alphamask[1] << 8) | (alphamask[2] << 16));
for (int j = 0; j < 2; j++)
{
for (int i = 0; i < 4; i++)
{
// only put pixels out < width or height
if (((x + i) < width) && ((y + j) < height))
{
uint offset = (uint)(z * sizeofplane + (y + j) * bps + (x + i) * bpp + 3);
rawData[offset] = (byte)alphas[bits & 0x07];
}
bits >>= 3;
}
}
// Last three bytes
//bits = (uint)(alphamask[3]);
bits = (uint)((alphamask[3]) | (alphamask[4] << 8) | (alphamask[5] << 16));
for (int j = 2; j < 4; j++)
{
for (int i = 0; i < 4; i++)
{
// only put pixels out < width or height
if (((x + i) < width) && ((y + j) < height))
{
uint offset = (uint)(z * sizeofplane + (y + j) * bps + (x + i) * bpp + 3);
rawData[offset] = (byte)alphas[bits & 0x07];
}
bits >>= 3;
}
}
}
}
}
}
return rawData;
}
}
static unsafe void DxtcReadColors(byte* data, Colour8888[] op)
{
byte buf = (byte)((data[1] & 0xF8) >> 3);
op[0].red = (byte)(buf << 3 | buf >> 2);
buf = (byte)(((data[0] & 0xE0) >> 5) | ((data[1] & 0x7) << 3));
op[0].green = (byte)(buf << 2 | buf >> 3);
buf = (byte)(data[0] & 0x1F);
op[0].blue = (byte)(buf << 3 | buf >> 2);
buf = (byte)((data[3] & 0xF8) >> 3);
op[1].red = (byte)(buf << 3 | buf >> 2);
buf = (byte)(((data[2] & 0xE0) >> 5) | ((data[3] & 0x7) << 3));
op[1].green = (byte)(buf << 2 | buf >> 3);
buf = (byte)(data[2] & 0x1F);
op[1].blue = (byte)(buf << 3 | buf >> 2);
}
static void DxtcReadColor(ushort data, ref Colour8888 op)
{
byte buf = (byte)((data & 0xF800) >> 11);
op.red = (byte)(buf << 3 | buf >> 2);
buf = (byte)((data & 0x7E0) >> 5);
op.green = (byte)(buf << 2 | buf >> 3);
buf = (byte)(data & 0x1f);
op.blue = (byte)(buf << 3 | buf >> 2);
}
}
}
}
