1 +
using System;
2 +
using System.IO;
3 +
using System.Runtime.InteropServices;
4 + 5 + 6 +
// my bad C# translation of this - https://github.com/phoboslab/qoi/blob/master/qoi.h
7 +
namespace QoiFileTypeNet {
8 +
[StructLayout(LayoutKind.Sequential)]
9 +
internal struct QoiRgba : IEquatable<QoiRgba> {
10 +
public byte r;
11 +
public byte g;
12 +
public byte b;
13 +
public byte a;
14 + 15 +
public override bool Equals(object obj) => obj is QoiRgba other && this.Equals(other);
16 + 17 +
public bool Equals(QoiRgba other) {
18 +
return this.r == other.r &&
19 +
this.g == other.g &&
20 +
this.b == other.b &&
21 +
this.a == other.a;
22 +
}
23 + 24 +
public override int GetHashCode() => (r, g, b, a).GetHashCode();
25 + 26 +
public static bool operator ==(QoiRgba a, QoiRgba b) => a.Equals(b);
27 +
public static bool operator !=(QoiRgba a, QoiRgba b) => !a.Equals(b);
28 +
}
29 + 30 +
internal struct QoiDesc {
31 +
public const int QOI_SRGB = 0x00;
32 +
public const int QOI_SRGB_LINEAR_ALPHA = 0x01;
33 +
public const int QOI_LINEAR = 0x0F;
34 + 35 +
public int width;
36 +
public int height;
37 +
public int channels;
38 +
public int colorspace;
39 +
}
40 + 41 +
internal static class QoiFile {
42 +
private const int QOI_INDEX = 0x00; // 00xxxxxx
43 +
private const int QOI_RUN_8 = 0x40; // 010xxxxx
44 +
private const int QOI_RUN_16 = 0x60; // 011xxxxx
45 +
private const int QOI_DIFF_8 = 0x80; // 10xxxxxx
46 +
private const int QOI_DIFF_16 = 0xC0; // 110xxxxx
47 +
private const int QOI_DIFF_24 = 0xE0; // 1110xxxx
48 +
private const int QOI_COLOR = 0xF0; // 1111xxxx
49 + 50 +
private const int QOI_MASK_2 = 0xC0; // 11000000
51 +
private const int QOI_MASK_3 = 0xE0; // 11100000
52 +
private const int QOI_MASK_4 = 0xF0; // 11110000
53 + 54 +
private const int QOI_MAGIC = (((int)'q') << 24 | ((int)'o') << 16 | ((int)'i') << 8 | ((int)'f'));
55 + 56 +
private const int QOI_HEADER_SIZE = 14;
57 +
private const int QOI_PADDING = 4;
58 + 59 +
private static int ColorHash(ref QoiRgba c) {
60 +
return c.r ^ c.g ^ c.b ^ c.a;
61 +
}
62 + 63 +
private static uint SwapBytes(uint x) {
64 +
return ((x & 0x000000ff) << 24) |
65 +
((x & 0x0000ff00) << 8) |
66 +
((x & 0x00ff0000) >> 8) |
67 +
((x & 0xff000000) >> 24);
68 +
}
69 + 70 +
private static int SwapBytes(int x) {
71 +
return (int)SwapBytes((uint)x);
72 +
}
73 + 74 +
public static QoiRgba[] Load(Stream input, ref QoiDesc desc) {
75 +
QoiRgba[] result = null;
76 +
desc.width = 0;
77 +
desc.height = 0;
78 + 79 +
int fileSize = (int)input.Length;
80 +
if (fileSize < (QOI_HEADER_SIZE + QOI_PADDING)) {
81 +
return result;
82 +
}
83 + 84 +
using (BinaryReader reader = new BinaryReader(input)) {
85 +
uint headerMagic = SwapBytes(reader.ReadUInt32());
86 +
if (headerMagic != QOI_MAGIC) {
87 +
return result;
88 +
}
89 + 90 +
desc.width = SwapBytes(reader.ReadInt32());
91 +
desc.height = SwapBytes(reader.ReadInt32());
92 +
desc.channels = reader.ReadByte();
93 +
desc.colorspace = reader.ReadByte();
94 + 95 +
if (desc.width == 0 || desc.height == 0 || desc.channels < 3 || desc.channels > 4) {
96 +
return null;
97 +
}
98 + 99 +
int numPixels = (int)(desc.width * desc.height);
100 +
result = new QoiRgba[numPixels];
101 + 102 +
QoiRgba px = new QoiRgba { r = 0, g = 0, b = 0, a = 255 };
103 +
QoiRgba[] index = new QoiRgba[64];
104 + 105 +
int run = 0;
106 +
int chunksLen = fileSize - QOI_PADDING;
107 +
for (int i = 0; i < numPixels; ++i) {
108 +
if (run > 0) {
109 +
run--;
110 +
} else if (reader.BaseStream.Position < chunksLen) {
111 +
byte b1 = reader.ReadByte();
112 + 113 +
if ((b1 & QOI_MASK_2) == QOI_INDEX) {
114 +
px = index[b1 ^ QOI_INDEX];
115 +
} else if ((b1 & QOI_MASK_3) == QOI_RUN_8) {
116 +
run = b1 & 0x1F;
117 +
} else if ((b1 & QOI_MASK_3) == QOI_RUN_16) {
118 +
byte b2 = reader.ReadByte();
119 +
run = (((b1 & 0x1f) << 8) | (b2)) + 32;
120 +
} else if ((b1 & QOI_MASK_2) == QOI_DIFF_8) {
121 +
px.r += (byte)(((b1 >> 4) & 0x03) - 2);
122 +
px.g += (byte)(((b1 >> 2) & 0x03) - 2);
123 +
px.b += (byte)((b1 & 0x03) - 2);
124 +
} else if ((b1 & QOI_MASK_3) == QOI_DIFF_16) {
125 +
byte b2 = reader.ReadByte();
126 +
px.r += (byte)((b1 & 0x1f) - 16);
127 +
px.g += (byte)((b2 >> 4) - 8);
128 +
px.b += (byte)((b2 & 0x0f) - 8);
129 +
} else if ((b1 & QOI_MASK_4) == QOI_DIFF_24) {
130 +
byte b2 = reader.ReadByte();
131 +
byte b3 = reader.ReadByte();
132 +
px.r += (byte)((((b1 & 0x0f) << 1) | (b2 >> 7)) - 16);
133 +
px.g += (byte)(((b2 & 0x7c) >> 2) - 16);
134 +
px.b += (byte)((((b2 & 0x03) << 3) | ((b3 & 0xe0) >> 5)) - 16);
135 +
px.a += (byte)((b3 & 0x1f) - 16);
136 +
} else if ((b1 & QOI_MASK_4) == QOI_COLOR) {
137 +
if ((b1 & 8) == 8) { px.r = reader.ReadByte(); }
138 +
if ((b1 & 4) == 4) { px.g = reader.ReadByte(); }
139 +
if ((b1 & 2) == 2) { px.b = reader.ReadByte(); }
140 +
if ((b1 & 1) == 1) { px.a = reader.ReadByte(); }
141 +
}
142 + 143 +
index[ColorHash(ref px) % 64] = px;
144 +
}
145 + 146 +
result[i] = px;
147 +
}
148 +
}
149 + 150 +
return result;
151 +
}
152 + 153 +
public static void Save(Stream output, ref QoiDesc desc, QoiRgba[] pixels) {
154 +
BinaryWriter writer = new BinaryWriter(output);
155 + 156 +
writer.Write(SwapBytes(QOI_MAGIC));
157 +
writer.Write(SwapBytes(desc.width));
158 +
writer.Write(SwapBytes(desc.height));
159 +
writer.Write((byte)desc.channels);
160 +
writer.Write((byte)desc.colorspace);
161 + 162 +
QoiRgba px = new QoiRgba { r = 0, g = 0, b = 0, a = 255 };
163 +
QoiRgba pxPrev = px;
164 +
QoiRgba[] index = new QoiRgba[64];
165 + 166 +
int run = 0;
167 +
int numPixels = desc.width * desc.height;
168 +
for (int i = 0; i < numPixels; ++i) {
169 +
px = pixels[i];
170 + 171 +
if (px == pxPrev) {
172 +
run++;
173 +
}
174 + 175 +
if (run > 0 && (run == 0x2020 || px != pxPrev || i == (numPixels - 1))) {
176 +
if (run < 33) {
177 +
run -= 1;
178 +
writer.Write((byte)(QOI_RUN_8 | run));
179 +
} else {
180 +
run -= 33;
181 +
writer.Write((byte)(QOI_RUN_16 | run >> 8));
182 +
writer.Write((byte)run);
183 +
}
184 +
run = 0;
185 +
}
186 + 187 +
if (px != pxPrev) {
188 +
int indexPos = ColorHash(ref px) % 64;
189 + 190 +
if (index[indexPos] == px) {
191 +
writer.Write((byte)(QOI_INDEX | indexPos));
192 +
} else {
193 +
index[indexPos] = px;
194 + 195 +
int vr = px.r - pxPrev.r;
196 +
int vg = px.g - pxPrev.g;
197 +
int vb = px.b - pxPrev.b;
198 +
int va = px.a - pxPrev.a;
199 + 200 +
if (vr > -17 && vr < 16 &&
201 +
vg > -17 && vg < 16 &&
202 +
vb > -17 && vb < 16 &&
203 +
va > -17 && va < 16) {
204 +
if (va == 0 &&
205 +
vr > -3 && vr < 2 &&
206 +
vg > -3 && vg < 2 &&
207 +
vb > -3 && vb < 2) {
208 +
writer.Write((byte)(QOI_DIFF_8 | ((vr + 2) << 4) | (vg + 2) << 2 | (vb + 2)));
209 +
} else if (va == 0 &&
210 +
vr > -17 && vr < 16 &&
211 +
vg > -9 && vg < 8 &&
212 +
vb > -9 && vb < 8 ) {
213 +
writer.Write((byte)(QOI_DIFF_16 | (vr + 16)));
214 +
writer.Write((byte)((vg + 8) << 4 | (vb + 8)));
215 +
} else {
216 +
writer.Write((byte)(QOI_DIFF_24 | (vr + 16) >> 1));
217 +
writer.Write((byte)((vr + 16) << 7 | (vg + 16) << 2 | (vb + 16) >> 3));
218 +
writer.Write((byte)((vb + 16) << 5 | (va + 16)));
219 +
}
220 +
} else {
221 +
writer.Write((byte)(QOI_COLOR | ((vr != 0) ? 8 : 0) | ((vg != 0) ? 4 : 0) | ((vb != 0) ? 2 : 0) | ((va != 0) ? 1 : 0)));
222 +
if (vr != 0) { writer.Write(px.r); }
223 +
if (vg != 0) { writer.Write(px.g); }
224 +
if (vb != 0) { writer.Write(px.b); }
225 +
if (va != 0) { writer.Write(px.a); }
226 +
}
227 +
}
228 +
}
229 + 230 +
pxPrev = px;
231 +
}
232 + 233 +
for (int i = 0; i < QOI_PADDING; ++i) {
234 +
writer.Write((byte)0);
235 +
}
236 +
}
237 +
}
238 +
}
RetroSearch is an open source project built by @garambo | Open a GitHub Issue
Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo
HTML:
3.2
| Encoding:
UTF-8
| Version:
0.7.4