Ryujinx/Ryujinx.Graphics.Texture/Astc/AstcPixel.cs

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C#
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using System;
using System.Diagnostics;
2019-10-13 08:02:07 +02:00
namespace Ryujinx.Graphics.Texture.Astc
{
class AstcPixel
{
public short R { get; set; }
public short G { get; set; }
public short B { get; set; }
public short A { get; set; }
byte[] _bitDepth = new byte[4];
public AstcPixel(short a, short r, short g, short b)
{
A = a;
R = r;
G = g;
B = b;
for (int i = 0; i < 4; i++)
_bitDepth[i] = 8;
}
public void ClampByte()
{
R = Math.Min(Math.Max(R, (short)0), (short)255);
G = Math.Min(Math.Max(G, (short)0), (short)255);
B = Math.Min(Math.Max(B, (short)0), (short)255);
A = Math.Min(Math.Max(A, (short)0), (short)255);
}
public short GetComponent(int index)
{
switch(index)
{
case 0: return A;
case 1: return R;
case 2: return G;
case 3: return B;
}
return 0;
}
public void SetComponent(int index, int value)
{
switch (index)
{
case 0:
A = (short)value;
break;
case 1:
R = (short)value;
break;
case 2:
G = (short)value;
break;
case 3:
B = (short)value;
break;
}
}
public void ChangeBitDepth(byte[] depth)
{
for (int i = 0; i< 4; i++)
{
int value = ChangeBitDepth(GetComponent(i), _bitDepth[i], depth[i]);
SetComponent(i, value);
_bitDepth[i] = depth[i];
}
}
short ChangeBitDepth(short value, byte oldDepth, byte newDepth)
{
Debug.Assert(newDepth <= 8);
Debug.Assert(oldDepth <= 8);
if (oldDepth == newDepth)
{
// Do nothing
return value;
}
else if (oldDepth == 0 && newDepth != 0)
{
return (short)((1 << newDepth) - 1);
}
else if (newDepth > oldDepth)
{
return (short)BitArrayStream.Replicate(value, oldDepth, newDepth);
}
else
{
// oldDepth > newDepth
if (newDepth == 0)
{
return 0xFF;
}
else
{
byte bitsWasted = (byte)(oldDepth - newDepth);
short tempValue = value;
tempValue = (short)((tempValue + (1 << (bitsWasted - 1))) >> bitsWasted);
tempValue = Math.Min(Math.Max((short)0, tempValue), (short)((1 << newDepth) - 1));
return (byte)(tempValue);
}
}
}
public int Pack()
{
AstcPixel newPixel = new AstcPixel(A, R, G, B);
byte[] eightBitDepth = { 8, 8, 8, 8 };
newPixel.ChangeBitDepth(eightBitDepth);
return (byte)newPixel.A << 24 |
(byte)newPixel.B << 16 |
(byte)newPixel.G << 8 |
(byte)newPixel.R << 0;
}
// Adds more precision to the blue channel as described
// in C.2.14
public static AstcPixel BlueContract(int a, int r, int g, int b)
{
return new AstcPixel((short)(a),
(short)((r + b) >> 1),
(short)((g + b) >> 1),
(short)(b));
}
}
}