78 lines
3.2 KiB
C#
78 lines
3.2 KiB
C#
using System.Numerics;
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using BitConverter = Lagrange.Core.Utility.Binary.BitConverter;
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namespace Lagrange.Core.Utility;
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internal static class ImageResolver
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{
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public static ImageFormat Resolve(byte[] image, out Vector2 size)
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{
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if (image[..6].SequenceEqual(new byte[] { 0x47, 0x49, 0x46, 0x38, 0x39, 0x61 }) ||
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image[..6].SequenceEqual(new byte[] { 0x47, 0x49, 0x46, 0x38, 0x37, 0x61 })) // GIF89a / GIF87a
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{
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size = new Vector2(BitConverter.ToUInt16(image.AsSpan()[6..8]), BitConverter.ToUInt16(image.AsSpan()[8..10]));
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return ImageFormat.Gif;
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}
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if (image[..2].SequenceEqual(new byte[] { 0xFF, 0xD8 })) // JPEG
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{
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size = Vector2.Zero;
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if (image[2..4].SequenceEqual(new byte[] { 0xFF, 0xE0 })) // JFIF
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{
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for (int i = 4; i < image.Length - 1; i++)
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{
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if (image[i] == 0xFF && image[i + 1] >= 0xC0 && image[i + 1] <= 0xC3) // SOF0 ~ SOF3
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{
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size = new Vector2(BitConverter.ToUInt16(image.AsSpan()[(i + 7)..(i + 9)], false),BitConverter.ToUInt16(image.AsSpan()[(i + 5)..(i + 7)], false));
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break;
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}
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}
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}
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return ImageFormat.Jpeg;
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}
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if (image[..8].SequenceEqual(new byte[] { 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A })) // PNG
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{
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size = new Vector2(BitConverter.ToUInt32(image.AsSpan()[16..20], false), BitConverter.ToUInt32(image.AsSpan()[20..24], false));
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return ImageFormat.Png;
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}
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if (image[..4].SequenceEqual(new byte[] { 0x52, 0x49, 0x46, 0x46 }) && image[8..12].SequenceEqual(new byte[] { 0x57, 0x45, 0x42, 0x50 })) // RIFF WEBP
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{
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if (image[12..16].SequenceEqual(new byte[] { 0x56, 0x50, 0x38, 0x58 })) // VP8X
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size = new Vector2(BitConverter.ToUInt16(image.AsSpan()[24..27]) + 1, BitConverter.ToUInt16(image.AsSpan()[27..30]) + 1);
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else if (image[12..16].SequenceEqual(new byte[] { 0x56, 0x50, 0x38, 0x4C })) // VP8L
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size = new Vector2((BitConverter.ToInt32(image.AsSpan()[21..25]) & 0x3FFF) + 1, ((BitConverter.ToInt32(image.AsSpan()[21..25]) & 0xFFFC000) >> 0x0E) + 1);
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else // VP8
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size = new Vector2(BitConverter.ToUInt16(image.AsSpan()[26..28]), BitConverter.ToUInt16(image.AsSpan()[28..30]));
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return ImageFormat.Webp;
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}
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if (image[..2].SequenceEqual(new byte[] { 0x42, 0x4D })) // BMP
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{
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size = new Vector2(BitConverter.ToUInt16(image.AsSpan()[18..20]), BitConverter.ToUInt16(image.AsSpan()[22..24]));
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return ImageFormat.Bmp;
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}
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if (image[..2].SequenceEqual(new byte[] { 0x49, 0x49 }) || image[..2].SequenceEqual(new byte[] { 0x4D, 0x4D })) // TIFF
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{
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size = new Vector2(BitConverter.ToUInt16(image.AsSpan()[18..20]), BitConverter.ToUInt16(image.AsSpan()[30..32]));
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return ImageFormat.Tiff;
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}
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size = Vector2.Zero;
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return ImageFormat.Unknown;
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}
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}
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internal enum ImageFormat
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{
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Unknown,
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Png,
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Jpeg,
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Gif,
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Webp,
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Bmp,
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Tiff
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} |