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Corrected logic in HuffmanScan to Emit bytes. (Decoding still is inco…
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…rrect).

Add more BitReader tests
Correct logic in BitReader to throw when writing more than 64 bits of a 64 bit value.

More work in JpegState for encoding and decoding, closer to having something working but not quite there yet...

Block.CopyScaled
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@juliusfriedman
juliusfriedman committed Nov 1, 2024
1 parent 514b74a commit e0d5847
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Showing 8 changed files with 581 additions and 96 deletions.
152 changes: 152 additions & 0 deletions Codecs/Image/Jpeg/Classes/Block.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -1413,4 +1413,156 @@ public override int GetHashCode()
}

#endregion

#region ScaledCopy

[MethodImpl(MethodImplOptions.AggressiveInlining)]
public void ScaledCopyFrom(ref float areaOrigin, int areaStride) =>
CopyFrom1x1Scale(ref Unsafe.As<float, byte>(ref areaOrigin), ref Array[Offset], areaStride);

[MethodImpl(MethodImplOptions.AggressiveInlining)]
public void ScaledCopyTo(ref float areaOrigin, int areaStride, int horizontalScale, int verticalScale)
{
if (horizontalScale == 1 && verticalScale == 1)
{
CopyTo1x1Scale(ref Array[Offset], ref Unsafe.As<float, byte>(ref areaOrigin), areaStride);
return;
}

if (horizontalScale == 2 && verticalScale == 2)
{
CopyTo2x2Scale(ref areaOrigin, areaStride);
return;
}

// TODO: Optimize: implement all cases with scale-specific, loopless code!
CopyArbitraryScale(ref areaOrigin, (uint)areaStride, (uint)horizontalScale, (uint)verticalScale);
}

private void CopyTo2x2Scale(ref float areaOrigin, int areaStride)
{
ref Vector2 destBase = ref Unsafe.As<float, Vector2>(ref areaOrigin);
nuint destStride = (uint)areaStride / 2;

var vector = V0L;

WidenCopyRowImpl2x2(ref vector, ref destBase, 0, destStride);
WidenCopyRowImpl2x2(ref vector, ref destBase, 1, destStride);
WidenCopyRowImpl2x2(ref vector, ref destBase, 2, destStride);
WidenCopyRowImpl2x2(ref vector, ref destBase, 3, destStride);
WidenCopyRowImpl2x2(ref vector, ref destBase, 4, destStride);
WidenCopyRowImpl2x2(ref vector, ref destBase, 5, destStride);
WidenCopyRowImpl2x2(ref vector, ref destBase, 6, destStride);
WidenCopyRowImpl2x2(ref vector, ref destBase, 7, destStride);

[MethodImpl(MethodImplOptions.AggressiveInlining)]
static void WidenCopyRowImpl2x2(ref Vector4 selfBase, ref Vector2 destBase, nuint row, nuint destStride)
{
ref Vector4 sLeft = ref Unsafe.Add(ref selfBase, 2 * row);
ref Vector4 sRight = ref Unsafe.Add(ref sLeft, 1);

nuint offset = 2 * row * destStride;
ref Vector4 dTopLeft = ref Unsafe.As<Vector2, Vector4>(ref Unsafe.Add(ref destBase, offset));
ref Vector4 dBottomLeft = ref Unsafe.As<Vector2, Vector4>(ref Unsafe.Add(ref destBase, offset + destStride));

var xyLeft = new Vector4(sLeft.X);
xyLeft.Z = sLeft.Y;
xyLeft.W = sLeft.Y;

var zwLeft = new Vector4(sLeft.Z);
zwLeft.Z = sLeft.W;
zwLeft.W = sLeft.W;

var xyRight = new Vector4(sRight.X);
xyRight.Z = sRight.Y;
xyRight.W = sRight.Y;

var zwRight = new Vector4(sRight.Z);
zwRight.Z = sRight.W;
zwRight.W = sRight.W;

dTopLeft = xyLeft;
Unsafe.Add(ref dTopLeft, 1) = zwLeft;
Unsafe.Add(ref dTopLeft, 2) = xyRight;
Unsafe.Add(ref dTopLeft, 3) = zwRight;

dBottomLeft = xyLeft;
Unsafe.Add(ref dBottomLeft, 1) = zwLeft;
Unsafe.Add(ref dBottomLeft, 2) = xyRight;
Unsafe.Add(ref dBottomLeft, 3) = zwRight;
}
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
private void CopyArbitraryScale(ref float areaOrigin, uint areaStride, uint horizontalScale, uint verticalScale)
{
for (nuint y = 0; y < 8; y++)
{
nuint yy = y * verticalScale;
nuint y8 = y * 8;

for (nuint x = 0; x < 8; x++)
{
nuint xx = x * horizontalScale;

float value = this[(int)(y8 + x)];
nuint baseIdx = (yy * areaStride) + xx;

for (nuint i = 0; i < verticalScale; i++, baseIdx += areaStride)
{
for (nuint j = 0; j < horizontalScale; j++)
{
// area[xx + j, yy + i] = value;
Unsafe.Add(ref areaOrigin, baseIdx + j) = value;
}
}
}
}
}

private static void CopyTo1x1Scale(ref byte origin, ref byte dest, int areaStride)
{
int destStride = areaStride * sizeof(float);

CopyRowImpl(ref origin, ref dest, destStride, 0);
CopyRowImpl(ref origin, ref dest, destStride, 1);
CopyRowImpl(ref origin, ref dest, destStride, 2);
CopyRowImpl(ref origin, ref dest, destStride, 3);
CopyRowImpl(ref origin, ref dest, destStride, 4);
CopyRowImpl(ref origin, ref dest, destStride, 5);
CopyRowImpl(ref origin, ref dest, destStride, 6);
CopyRowImpl(ref origin, ref dest, destStride, 7);

[MethodImpl(MethodImplOptions.AggressiveInlining)]
static void CopyRowImpl(ref byte origin, ref byte dest, int destStride, int row)
{
origin = ref Unsafe.Add(ref origin, (uint)row * 8 * sizeof(float));
dest = ref Unsafe.Add(ref dest, (uint)(row * destStride));
Unsafe.CopyBlock(ref dest, ref origin, 8 * sizeof(float));
}
}

private static void CopyFrom1x1Scale(ref byte origin, ref byte dest, int areaStride)
{
int destStride = areaStride * sizeof(float);

CopyRowImpl(ref origin, ref dest, destStride, 0);
CopyRowImpl(ref origin, ref dest, destStride, 1);
CopyRowImpl(ref origin, ref dest, destStride, 2);
CopyRowImpl(ref origin, ref dest, destStride, 3);
CopyRowImpl(ref origin, ref dest, destStride, 4);
CopyRowImpl(ref origin, ref dest, destStride, 5);
CopyRowImpl(ref origin, ref dest, destStride, 6);
CopyRowImpl(ref origin, ref dest, destStride, 7);

[MethodImpl(MethodImplOptions.AggressiveInlining)]
static void CopyRowImpl(ref byte origin, ref byte dest, int sourceStride, int row)
{
origin = ref Unsafe.Add(ref origin, (uint)(row * sourceStride));
dest = ref Unsafe.Add(ref dest, (uint)row * 8 * sizeof(float));
Unsafe.CopyBlock(ref dest, ref origin, 8 * sizeof(float));
}
}

#endregion
}
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