78 lines
2.3 KiB
C#
78 lines
2.3 KiB
C#
using System;
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using System.Collections.Generic;
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using System.IO;
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using SixLabors.ImageSharp;
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using WatchFace.Utils;
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namespace WatchFace.Models
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{
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public class ImageReader
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{
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private readonly BinaryReader _reader;
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private ushort _paletteColors;
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private ushort _bitsPerPixel;
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private ushort _height;
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private List<Rgba32> _palette;
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private ushort _rowLengthInBytes;
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private ushort _transp;
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private ushort _width;
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public ImageReader(Stream stream)
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{
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_reader = new BinaryReader(stream);
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}
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public Image<Rgba32> Read()
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{
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var signature = _reader.ReadChars(4);
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if (signature[0] != 'B' || signature[1] != 'M')
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throw new ArgumentOutOfRangeException("signature", "Signature doesn't match.");
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ReadHeader();
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ReadPalette();
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return ReadImage();
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}
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private void ReadHeader()
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{
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_width = _reader.ReadUInt16();
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_height = _reader.ReadUInt16();
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_rowLengthInBytes = _reader.ReadUInt16();
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_bitsPerPixel = _reader.ReadUInt16();
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_paletteColors = _reader.ReadUInt16();
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_transp = _reader.ReadUInt16();
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}
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private void ReadPalette()
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{
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_palette = new List<Rgba32>(_paletteColors);
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for (var i = 0; i < _paletteColors; i++)
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{
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var r = _reader.ReadByte();
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var g = _reader.ReadByte();
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var b = _reader.ReadByte();
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var a = _reader.ReadByte();
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_palette.Add(new Rgba32 {A = a, R = r, G = g, B = b});
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}
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}
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private Image<Rgba32> ReadImage()
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{
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var image = new Image<Rgba32>(_width, _height);
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for (var i = 0; i < _height; i++)
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{
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var row = _reader.ReadBytes(_rowLengthInBytes);
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var bitReader = new BitReader(row);
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for (var j = 0; j < _width; j++)
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{
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var pixelColorIndex = bitReader.ReadBits(_bitsPerPixel);
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var color = _palette[(int) pixelColorIndex];
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image[j, i] = color;
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}
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}
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return image;
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}
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}
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} |