about summary refs log tree commit diff stats
path: root/505colors.mu
blob: 3185f9f7db37a6a5109ee1e3f43dfdaa1080ce20 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
# Hue/saturation/luminance for an rgb triple.
# rgb are in [0, 256)
# hsl are also returned in [0, 256)
# from https://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl
fn hsl r: int, g: int, b: int -> _/ecx: int, _/edx: int, _/ebx: int {
  var _max/eax: int <- maximum r, g
  _max <- maximum _max, b
  var max/ecx: int <- copy _max
  var _min/eax: int <- minimum r, g
  _min <- minimum _min, b
  var min/edx: int <- copy _min
  var luminance/ebx: int <- copy min
  luminance <- add max
  luminance <- shift-right 1  # TODO: round up instead of down
  # if rgb are all equal, it's a shade of grey
  compare min, max
  {
    break-if-!=
    return 0, 0, luminance
  }
  # saturation =
  #   luminance < 128 | 255*(max-min)/         (max+min)
  #   otherwise       | 255*(max-min)/(2*255 - (max+min))
  var nr/esi: int <- copy max
  nr <- subtract min
  var dr/eax: int <- copy 0
  compare luminance, 0x80
  {
    break-if->=
    dr <- copy max
    dr <- add min
  }
  {
    break-if-<
    dr <- copy 0xff
    dr <- shift-left 1
    dr <- subtract max
    dr <- subtract min
  }
  var q/xmm0: float <- convert nr
  var tmp/xmm1: float <- convert dr
  q <- divide tmp
  var int-255/eax: int <- copy 0xff
  tmp <- convert int-255
  q <- multiply tmp
  var saturation/esi: int <- convert q
  # hue = 
  #   red is max   | 256.0/6*       (g-b)/(max-min)
  #   green is max | 256.0/6*(2.0 + (b-r)/(max-min))
  #   blue is max  | 256.0/6*(4.0 + (r-g)/(max-min))
  var zero/eax: int <- copy 0
  var hue-f/xmm0: float <- convert zero
  var dr/eax: int <- copy max
  dr <- subtract min
  var dr-f/xmm1: float <- convert dr
  $hsl:compute-hue-normalized: {
    compare r, max
    {
      break-if-!=
      var nr/eax: int <- copy g
      nr <- subtract b
      hue-f <- convert nr
      hue-f <- divide dr-f
      break $hsl:compute-hue-normalized
    }
    compare g, max
    {
      break-if-!=
      var nr/eax: int <- copy b
      nr <- subtract r
      var f/xmm2: float <- convert nr
      f <- divide dr-f
      var two/ecx: int <- copy 2
      hue-f <- convert two
      hue-f <- add f
      break $hsl:compute-hue-normalized
    }
    compare b, max
    {
      break-if-!=
      var nr/eax: int <- copy r
      nr <- subtract g
      var f/xmm2: float <- convert nr
      f <- divide dr-f
      var two/ecx: int <- copy 4
      hue-f <- convert two
      hue-f <- add f
      break $hsl:compute-hue-normalized
    }
  }
  var int-256/eax: int <- copy 0x100
  var scaling-factor/xmm1: float <- convert int-256
  var int-6/eax: int <- copy 6
  var six-f/xmm2: float <- convert int-6
  scaling-factor <- divide six-f
  hue-f <- multiply scaling-factor
  var hue/eax: int <- convert hue-f
  # if hue < 0, hue = 256 - hue
  compare hue, 0
  {
    break-if->=
    var tmp/ecx: int <- copy 0x100
    tmp <- subtract hue
    hue <- copy tmp
  }
  return hue, saturation, luminance
}

fn test-hsl-black {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0, 0, 0
  check-ints-equal h, 0, "F - test-hsl-black/hue"
  check-ints-equal s, 0, "F - test-hsl-black/saturation"
  check-ints-equal l, 0, "F - test-hsl-black/luminance"
}

fn test-hsl-white {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0xff, 0xff, 0xff
  check-ints-equal h, 0, "F - test-hsl-white/hue"
  check-ints-equal s, 0, "F - test-hsl-white/saturation"
  check-ints-equal l, 0xff, "F - test-hsl-white/luminance"
}

fn test-hsl-grey {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0x30, 0x30, 0x30
  check-ints-equal h, 0, "F - test-hsl-grey/hue"
  check-ints-equal s, 0, "F - test-hsl-grey/saturation"
  check-ints-equal l, 0x30, "F - test-hsl-grey/luminance"
}

# red hues: 0-0x54
fn test-hsl-slightly-red {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0xff, 0xfe, 0xfe
  check-ints-equal h, 0, "F - test-hsl-slightly-red/hue"
  check-ints-equal s, 0xff, "F - test-hsl-slightly-red/saturation"
  check-ints-equal l, 0xfe, "F - test-hsl-slightly-red/luminance"  # TODO: should round up
}

fn test-hsl-extremely-red {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0xff, 0, 0
  check-ints-equal h, 0, "F - test-hsl-extremely-red/hue"
  check-ints-equal s, 0xff, "F - test-hsl-extremely-red/saturation"
  check-ints-equal l, 0x7f, "F - test-hsl-extremely-red/luminance"  # TODO: should round up
}

# green hues: 0x55-0xaa
fn test-hsl-slightly-green {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0xfe, 0xff, 0xfe
  check-ints-equal h, 0x55, "F - test-hsl-slightly-green/hue"
  check-ints-equal s, 0xff, "F - test-hsl-slightly-green/saturation"
  check-ints-equal l, 0xfe, "F - test-hsl-slightly-green/luminance"  # TODO: should round up
}

fn test-hsl-extremely-green {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0, 0xff, 0
  check-ints-equal h, 0x55, "F - test-hsl-extremely-green/hue"
  check-ints-equal s, 0xff, "F - test-hsl-extremely-green/saturation"
  check-ints-equal l, 0x7f, "F - test-hsl-extremely-green/luminance"  # TODO: should round up
}

# blue hues: 0xab-0xff
fn test-hsl-slightly-blue {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0xfe, 0xfe, 0xff
  check-ints-equal h, 0xab, "F - test-hsl-slightly-blue/hue"
  check-ints-equal s, 0xff, "F - test-hsl-slightly-blue/saturation"
  check-ints-equal l, 0xfe, "F - test-hsl-slightly-blue/luminance"  # TODO: should round up
}

fn test-hsl-extremely-blue {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0, 0, 0xff
  check-ints-equal h, 0xab, "F - test-hsl-extremely-blue/hue"
  check-ints-equal s, 0xff, "F - test-hsl-extremely-blue/saturation"
  check-ints-equal l, 0x7f, "F - test-hsl-extremely-blue/luminance"  # TODO: should round up
}

# cyan: 0x7f

fn test-hsl-cyan {
  var h/ecx: int <- copy 0
  var s/edx: int <- copy 0
  var l/ebx: int <- copy 0
  h, s, l <- hsl 0, 0xff, 0xff
  check-ints-equal h, 0x80, "F - test-hsl-cyan/hue"
  check-ints-equal s, 0xff, "F - test-hsl-cyan/saturation"
  check-ints-equal l, 0x7f, "F - test-hsl-cyan/luminance"  # TODO: should round up
}

###

fn maximum a: int, b: int -> _/eax: int {
  var a2/eax: int <- copy a
  compare a2, b
  {
    break-if-<
    return a
  }
  return b
}

fn minimum a: int, b: int -> _/eax: int {
  var a2/eax: int <- copy a
  compare a2, b
  {
    break-if->
    return a
  }
  return b
}