private static int LeastDistance(byte[][] palette, byte[] colour, int offset) { if (colour[offset + 3] < (byte)8) { return(3); } int num1 = int.MaxValue; int num2 = 0; for (int index = 0; index < palette.Length && palette[index][3] == byte.MaxValue; ++index) { int num3 = ImageDataFormat.Distance(palette[index], 0, colour, offset); if (num3 < num1) { if (num3 == 0) { return(index); } num1 = num3; num2 = index; } } return(num2); }
private static byte[] ConvertBlockToQuaterCmpr(byte[] block) { int num1; int num2 = num1 = -1; int num3 = num1; int num4 = num1; bool flag = false; byte[] numArray = new byte[8]; for (int index1 = 0; index1 < 15; ++index1) { if (block[index1 * 4 + 3] < (byte)16) { flag = true; } else { for (int index2 = index1 + 1; index2 < 16; ++index2) { int num5 = ImageDataFormat.Distance(block, index1 * 4, block, index2 * 4); if (num5 > num4) { num4 = num5; num3 = index1; num2 = index2; } } } } byte[][] palette; if (num4 == -1) { palette = new byte[4][] { new byte[4] { (byte)0, (byte)0, (byte)0, byte.MaxValue }, new byte[4] { byte.MaxValue, byte.MaxValue, byte.MaxValue, byte.MaxValue }, null, null }; } else { palette = new byte[4][] { new byte[4], new byte[4], null, null }; Array.Copy((Array)block, num3 * 4, (Array)palette[0], 0, 3); palette[0][3] = byte.MaxValue; Array.Copy((Array)block, num2 * 4, (Array)palette[1], 0, 3); palette[1][3] = byte.MaxValue; if ((int)palette[0][0] >> 3 == (int)palette[1][0] >> 3 && (int)palette[0][1] >> 2 == (int)palette[1][1] >> 2 && (int)palette[0][2] >> 3 == (int)palette[1][2] >> 3) { int num5 = (int)palette[0][0] >> 3 != 0 || (int)palette[0][1] >> 2 != 0 ? 1 : ((int)palette[0][2] >> 3 != 0 ? 1 : 0); palette[1][0] = num5 != 0 ? (palette[1][1] = palette[1][2] = (byte)0) : (palette[1][1] = palette[1][2] = byte.MaxValue); } } numArray[0] = (byte)((int)palette[0][2] & 248 | (int)palette[0][1] >> 5); numArray[1] = (byte)((int)palette[0][1] << 3 & 224 | (int)palette[0][0] >> 3); numArray[2] = (byte)((int)palette[1][2] & 248 | (int)palette[1][1] >> 5); numArray[3] = (byte)((int)palette[1][1] << 3 & 224 | (int)palette[1][0] >> 3); if (((int)numArray[0] > (int)numArray[2] ? 1 : ((int)numArray[0] != (int)numArray[2] ? 0 : ((int)numArray[1] >= (int)numArray[3] ? 1 : 0))) == (flag ? 1 : 0)) { Array.Copy((Array)numArray, 0, (Array)numArray, 4, 2); Array.Copy((Array)numArray, 2, (Array)numArray, 0, 2); Array.Copy((Array)numArray, 4, (Array)numArray, 2, 2); palette[2] = palette[0]; palette[0] = palette[1]; palette[1] = palette[2]; } if (!flag) { palette[2] = new byte[4] { (byte)((((int)palette[0][0] << 1) + (int)palette[1][0]) / 3), (byte)((((int)palette[0][1] << 1) + (int)palette[1][1]) / 3), (byte)((((int)palette[0][2] << 1) + (int)palette[1][2]) / 3), byte.MaxValue }; palette[3] = new byte[4] { (byte)(((int)palette[0][0] + ((int)palette[1][0] << 1)) / 3), (byte)(((int)palette[0][1] + ((int)palette[1][1] << 1)) / 3), (byte)(((int)palette[0][2] + ((int)palette[1][2] << 1)) / 3), byte.MaxValue }; } else { palette[2] = new byte[4] { (byte)((int)palette[0][0] + (int)palette[1][0] >> 1), (byte)((int)palette[0][1] + (int)palette[1][1] >> 1), (byte)((int)palette[0][2] + (int)palette[1][2] >> 1), byte.MaxValue }; palette[3] = new byte[4]; } for (int index = 0; index < block.Length >> 4; ++index) { numArray[4 + index] = (byte)(ImageDataFormat.LeastDistance(palette, block, index * 16) << 6 | ImageDataFormat.LeastDistance(palette, block, index * 16 + 4) << 4 | ImageDataFormat.LeastDistance(palette, block, index * 16 + 8) << 2 | ImageDataFormat.LeastDistance(palette, block, index * 16 + 12)); } return(numArray); }