using CommunityToolkit.HighPerformance;

namespace BCnEncoder.Shared

{

internal static class ImageToBlocks

{

#region Blocks to colors

internal static ColorRgba32[] ColorsFromRawBlocks(RawBlock4X4Rgba32[,] blocks, int pixelWidth, int pixelHeight)

{

var output = new ColorRgba32[pixelWidth * pixelHeight];

for (var y = 0; y < pixelHeight; y++)

{

for (var x = 0; x < pixelWidth; x++)

{

var blockIndexX = x >> 2;

var blockIndexY = y >> 2;

var blockInternalIndexX = x & 3;

var blockInternalIndexY = y & 3;

output[x + y * pixelWidth] = blocks[blockIndexX, blockIndexY][blockInternalIndexX, blockInternalIndexY];

}

}

return output;

}

internal static ColorRgba32[] ColorsFromRawBlocks(RawBlock4X4Rgba32[] blocks, int pixelWidth, int pixelHeight)

{

var blocksWidth = ((pixelWidth + 3) & ~3) >> 2;

var output = new ColorRgba32[pixelWidth * pixelHeight];

for (var y = 0; y < pixelHeight; y++)

{

for (var x = 0; x < pixelWidth; x++)

{

var blockIndexX = x >> 2;

var blockIndexY = y >> 2;

var blockInternalIndexX = x & 3;

var blockInternalIndexY = y & 3;

var blockIndex = blockIndexX + blockIndexY * blocksWidth;

output[x + y * pixelWidth] = blocks[blockIndex][blockInternalIndexX, blockInternalIndexY];

}

}

return output;

}

internal static ColorRgbFloat[] ColorsFromRawBlocks(RawBlock4X4RgbFloat[] blocks, int pixelWidth, int pixelHeight)

{

var blocksWidth = ((pixelWidth + 3) & ~3) >> 2;

var output = new ColorRgbFloat[pixelWidth * pixelHeight];

for (var y = 0; y < pixelHeight; y++)

{

for (var x = 0; x < pixelWidth; x++)

{

var blockIndexX = x >> 2;

var blockIndexY = y >> 2;

var blockInternalIndexX = x & 3;

var blockInternalIndexY = y & 3;

var blockIndex = blockIndexX + blockIndexY * blocksWidth;

output[x + y * pixelWidth] = blocks[blockIndex][blockInternalIndexX, blockInternalIndexY];

}

}

return output;

}

#endregion

#region Image to blocks

internal static RawBlock4X4Rgba32[] ImageTo4X4(ReadOnlyMemory2D<ColorRgba32> image, out int blocksWidth, out int blocksHeight)

{

blocksWidth = ((image.Width + 3) & ~3) >> 2;

blocksHeight = ((image.Height + 3) & ~3) >> 2;

var output = new RawBlock4X4Rgba32[blocksWidth * blocksHeight];

var span = image.Span;

for (var y = 0; y < image.Height; y++)

{

for (var x = 0; x < image.Width; x++)

{

var color = span[y, x];

var blockIndexX = x >> 2;

var blockIndexY = y >> 2;

var blockInternalIndexX = x & 3;

var blockInternalIndexY = y & 3;

output[blockIndexX + blockIndexY * blocksWidth][blockInternalIndexX, blockInternalIndexY] = color;

}

}

// Fill in block y with edge color

if ((image.Height & 3) != 0)

{

var yPaddingStart = image.Height & 3;

for (var i = 0; i < blocksWidth; i++)

{

var lastBlock = output[i + blocksWidth * (blocksHeight - 1)];

for (var y = yPaddingStart; y < 4; y++)

{

for (var x = 0; x < 4; x++)

{

lastBlock[x, y] = lastBlock[x, y - 1];

}

}

output[i + blocksWidth * (blocksHeight - 1)] = lastBlock;

}

}

// Fill in block x with edge color

if ((image.Width & 3) != 0)

{

var xPaddingStart = image.Width & 3;

for (var i = 0; i < blocksHeight; i++)

{

var lastBlock = output[blocksWidth - 1 + i * blocksWidth];

for (var x = xPaddingStart; x < 4; x++)

{

for (var y = 0; y < 4; y++)

{

lastBlock[x, y] = lastBlock[x - 1, y];

}

}

output[blocksWidth - 1 + i * blocksWidth] = lastBlock;

}

}

return output;

}

internal static RawBlock4X4RgbFloat[] ImageTo4X4(ReadOnlyMemory2D<ColorRgbFloat> image, out int blocksWidth, out int blocksHeight)

{

blocksWidth = ((image.Width + 3) & ~3) >> 2;

blocksHeight = ((image.Height + 3) & ~3) >> 2;

var output = new RawBlock4X4RgbFloat[blocksWidth * blocksHeight];

var span = image.Span;

for (var y = 0; y < image.Height; y++)

{

for (var x = 0; x < image.Width; x++)

{

var color = span[y, x];

var blockIndexX = x >> 2;

var blockIndexY = y >> 2;

var blockInternalIndexX = x & 3;

var blockInternalIndexY = y & 3;

output[blockIndexX + blockIndexY * blocksWidth][blockInternalIndexX, blockInternalIndexY] = color;

}

}

// Fill in block y with edge color

if ((image.Height & 3) != 0)

{

var yPaddingStart = image.Height & 3;

for (var i = 0; i < blocksWidth; i++)

{

var lastBlock = output[i + blocksWidth * (blocksHeight - 1)];

for (var y = yPaddingStart; y < 4; y++)

{

for (var x = 0; x < 4; x++)

{

lastBlock[x, y] = lastBlock[x, y - 1];

}

}

output[i + blocksWidth * (blocksHeight - 1)] = lastBlock;

}

}

// Fill in block x with edge color

if ((image.Width & 3) != 0)

{

var xPaddingStart = image.Width & 3;

for (var i = 0; i < blocksHeight; i++)

{

var lastBlock = output[blocksWidth - 1 + i * blocksWidth];

for (var x = xPaddingStart; x < 4; x++)

{

for (var y = 0; y < 4; y++)

{

lastBlock[x, y] = lastBlock[x - 1, y];

}

}

output[blocksWidth - 1 + i * blocksWidth] = lastBlock;

}

}

return output;

}

#endregion

public static int CalculateNumOfBlocks(int pixelWidth, int pixelHeight)

{

var blocksWidth = ((pixelWidth + 3) & ~3) >> 2;

var blocksHeight = ((pixelHeight + 3) & ~3) >> 2;

return blocksWidth * blocksHeight;

}

public static void CalculateNumOfBlocks(int pixelWidth, int pixelHeight, out int blocksWidth, out int blocksHeight)

{

blocksWidth = ((pixelWidth + 3) & ~3) >> 2;

blocksHeight = ((pixelHeight + 3) & ~3) >> 2;

}

}

}