forked from disintegration/gift
/
pixels.go
424 lines (378 loc) · 9.64 KB
/
pixels.go
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
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
package gift
import (
"image"
"image/color"
"image/draw"
)
type pixel struct {
R, G, B, A float32
}
type imageType int
const (
itGeneric imageType = iota
itNRGBA
itNRGBA64
itRGBA
itRGBA64
itYCbCr
itGray
itGray16
itPaletted
)
type pixelGetter struct {
imgType imageType
imgBounds image.Rectangle
imgGeneric image.Image
imgNRGBA *image.NRGBA
imgNRGBA64 *image.NRGBA64
imgRGBA *image.RGBA
imgRGBA64 *image.RGBA64
imgYCbCr *image.YCbCr
imgGray *image.Gray
imgGray16 *image.Gray16
imgPaletted *image.Paletted
imgPalette []pixel
}
func newPixelGetter(img image.Image) (p *pixelGetter) {
switch img := img.(type) {
case *image.NRGBA:
p = &pixelGetter{
imgType: itNRGBA,
imgBounds: img.Bounds(),
imgNRGBA: img,
}
case *image.NRGBA64:
p = &pixelGetter{
imgType: itNRGBA64,
imgBounds: img.Bounds(),
imgNRGBA64: img,
}
case *image.RGBA:
p = &pixelGetter{
imgType: itRGBA,
imgBounds: img.Bounds(),
imgRGBA: img,
}
case *image.RGBA64:
p = &pixelGetter{
imgType: itRGBA64,
imgBounds: img.Bounds(),
imgRGBA64: img,
}
case *image.Gray:
p = &pixelGetter{
imgType: itGray,
imgBounds: img.Bounds(),
imgGray: img,
}
case *image.Gray16:
p = &pixelGetter{
imgType: itGray16,
imgBounds: img.Bounds(),
imgGray16: img,
}
case *image.YCbCr:
p = &pixelGetter{
imgType: itYCbCr,
imgBounds: img.Bounds(),
imgYCbCr: img,
}
case *image.Paletted:
p = &pixelGetter{
imgType: itPaletted,
imgBounds: img.Bounds(),
imgPaletted: img,
imgPalette: convertPalette(img.Palette),
}
return
default:
p = &pixelGetter{
imgType: itGeneric,
imgBounds: img.Bounds(),
imgGeneric: img,
}
}
return
}
const (
qf8 = float32(1.0 / 255.0)
qf16 = float32(1.0 / 65535.0)
)
func convertPalette(p []color.Color) []pixel {
plen := len(p)
pnew := make([]pixel, plen)
for i := 0; i < plen; i++ {
r16, g16, b16, a16 := p[i].RGBA()
switch a16 {
case 0:
pnew[i] = pixel{0.0, 0.0, 0.0, 0.0}
case 65535:
r := float32(r16) * qf16
g := float32(g16) * qf16
b := float32(b16) * qf16
pnew[i] = pixel{r, g, b, 1.0}
default:
q := float32(1.0) / float32(a16)
r := float32(r16) * q
g := float32(g16) * q
b := float32(b16) * q
a := float32(a16) * qf16
pnew[i] = pixel{r, g, b, a}
}
}
return pnew
}
func (p *pixelGetter) getPixel(x, y int) (px pixel) {
switch p.imgType {
case itNRGBA:
i := p.imgNRGBA.PixOffset(x, y)
r := float32(p.imgNRGBA.Pix[i+0]) * qf8
g := float32(p.imgNRGBA.Pix[i+1]) * qf8
b := float32(p.imgNRGBA.Pix[i+2]) * qf8
a := float32(p.imgNRGBA.Pix[i+3]) * qf8
px = pixel{r, g, b, a}
case itNRGBA64:
i := p.imgNRGBA64.PixOffset(x, y)
r := float32(uint16(p.imgNRGBA64.Pix[i+0])<<8|uint16(p.imgNRGBA64.Pix[i+1])) * qf16
g := float32(uint16(p.imgNRGBA64.Pix[i+2])<<8|uint16(p.imgNRGBA64.Pix[i+3])) * qf16
b := float32(uint16(p.imgNRGBA64.Pix[i+4])<<8|uint16(p.imgNRGBA64.Pix[i+5])) * qf16
a := float32(uint16(p.imgNRGBA64.Pix[i+6])<<8|uint16(p.imgNRGBA64.Pix[i+7])) * qf16
px = pixel{r, g, b, a}
case itRGBA:
i := p.imgRGBA.PixOffset(x, y)
a8 := p.imgRGBA.Pix[i+3]
switch a8 {
case 0:
px = pixel{0.0, 0.0, 0.0, 0.0}
case 255:
r := float32(p.imgRGBA.Pix[i+0]) * qf8
g := float32(p.imgRGBA.Pix[i+1]) * qf8
b := float32(p.imgRGBA.Pix[i+2]) * qf8
px = pixel{r, g, b, 1.0}
default:
q := float32(1.0) / float32(a8)
r := float32(p.imgRGBA.Pix[i+0]) * q
g := float32(p.imgRGBA.Pix[i+1]) * q
b := float32(p.imgRGBA.Pix[i+2]) * q
a := float32(a8) * qf8
px = pixel{r, g, b, a}
}
case itRGBA64:
i := p.imgRGBA64.PixOffset(x, y)
a16 := uint16(p.imgRGBA64.Pix[i+6])<<8 | uint16(p.imgRGBA64.Pix[i+7])
switch a16 {
case 0:
px = pixel{0.0, 0.0, 0.0, 0.0}
case 65535:
r := float32(uint16(p.imgRGBA64.Pix[i+0])<<8|uint16(p.imgRGBA64.Pix[i+1])) * qf16
g := float32(uint16(p.imgRGBA64.Pix[i+2])<<8|uint16(p.imgRGBA64.Pix[i+3])) * qf16
b := float32(uint16(p.imgRGBA64.Pix[i+4])<<8|uint16(p.imgRGBA64.Pix[i+5])) * qf16
px = pixel{r, g, b, 1.0}
default:
q := float32(1.0) / float32(a16)
r := float32(uint16(p.imgRGBA64.Pix[i+0])<<8|uint16(p.imgRGBA64.Pix[i+1])) * q
g := float32(uint16(p.imgRGBA64.Pix[i+2])<<8|uint16(p.imgRGBA64.Pix[i+3])) * q
b := float32(uint16(p.imgRGBA64.Pix[i+4])<<8|uint16(p.imgRGBA64.Pix[i+5])) * q
a := float32(a16) * qf16
px = pixel{r, g, b, a}
}
case itGray:
i := p.imgGray.PixOffset(x, y)
v := float32(p.imgGray.Pix[i]) * qf8
px = pixel{v, v, v, 1.0}
case itGray16:
i := p.imgGray16.PixOffset(x, y)
v := float32(uint16(p.imgGray16.Pix[i+0])<<8|uint16(p.imgGray16.Pix[i+1])) * qf16
px = pixel{v, v, v, 1.0}
case itYCbCr:
iy := p.imgYCbCr.YOffset(x, y)
ic := p.imgYCbCr.COffset(x, y)
r8, g8, b8 := color.YCbCrToRGB(p.imgYCbCr.Y[iy], p.imgYCbCr.Cb[ic], p.imgYCbCr.Cr[ic])
r := float32(r8) * qf8
g := float32(g8) * qf8
b := float32(b8) * qf8
px = pixel{r, g, b, 1.0}
case itPaletted:
i := p.imgPaletted.PixOffset(x, y)
k := p.imgPaletted.Pix[i]
px = p.imgPalette[k]
case itGeneric:
r16, g16, b16, a16 := p.imgGeneric.At(x, y).RGBA()
switch a16 {
case 0:
px = pixel{0.0, 0.0, 0.0, 0.0}
case 65535:
r := float32(r16) * qf16
g := float32(g16) * qf16
b := float32(b16) * qf16
px = pixel{r, g, b, 1.0}
default:
q := float32(1.0) / float32(a16)
r := float32(r16) * q
g := float32(g16) * q
b := float32(b16) * q
a := float32(a16) * qf16
px = pixel{r, g, b, a}
}
}
return
}
func (p *pixelGetter) getPixelRow(y int, buf *[]pixel) {
*buf = (*buf)[0:0]
for x := p.imgBounds.Min.X; x != p.imgBounds.Max.X; x++ {
*buf = append(*buf, p.getPixel(x, y))
}
}
func (p *pixelGetter) getPixelColumn(x int, buf *[]pixel) {
*buf = (*buf)[0:0]
for y := p.imgBounds.Min.Y; y != p.imgBounds.Max.Y; y++ {
*buf = append(*buf, p.getPixel(x, y))
}
}
func f32u8(val float32) uint8 {
if val > 255.0 {
val = 255.0
} else if val < 0.0 {
val = 0.0
}
return uint8(val + 0.5)
}
func f32u16(val float32) uint16 {
if val > 65535.0 {
val = 65535.0
} else if val < 0.0 {
val = 0.0
}
return uint16(val + 0.5)
}
type pixelSetter struct {
imgType imageType
imgBounds image.Rectangle
imgGeneric draw.Image
imgNRGBA *image.NRGBA
imgNRGBA64 *image.NRGBA64
imgRGBA *image.RGBA
imgRGBA64 *image.RGBA64
imgGray *image.Gray
imgGray16 *image.Gray16
}
func newPixelSetter(img draw.Image) (p *pixelSetter) {
switch img := img.(type) {
case *image.NRGBA:
p = &pixelSetter{
imgType: itNRGBA,
imgBounds: img.Bounds(),
imgNRGBA: img,
}
case *image.NRGBA64:
p = &pixelSetter{
imgType: itNRGBA64,
imgBounds: img.Bounds(),
imgNRGBA64: img,
}
case *image.RGBA:
p = &pixelSetter{
imgType: itRGBA,
imgBounds: img.Bounds(),
imgRGBA: img,
}
case *image.RGBA64:
p = &pixelSetter{
imgType: itRGBA64,
imgBounds: img.Bounds(),
imgRGBA64: img,
}
case *image.Gray:
p = &pixelSetter{
imgType: itGray,
imgBounds: img.Bounds(),
imgGray: img,
}
case *image.Gray16:
p = &pixelSetter{
imgType: itGray16,
imgBounds: img.Bounds(),
imgGray16: img,
}
default:
p = &pixelSetter{
imgType: itGeneric,
imgBounds: img.Bounds(),
imgGeneric: img,
}
}
return
}
func (p *pixelSetter) setPixel(x, y int, px pixel) {
if !image.Pt(x, y).In(p.imgBounds) {
return
}
switch p.imgType {
case itNRGBA:
i := p.imgNRGBA.PixOffset(x, y)
p.imgNRGBA.Pix[i+0] = f32u8(px.R * 255.0)
p.imgNRGBA.Pix[i+1] = f32u8(px.G * 255.0)
p.imgNRGBA.Pix[i+2] = f32u8(px.B * 255.0)
p.imgNRGBA.Pix[i+3] = f32u8(px.A * 255.0)
case itNRGBA64:
r16 := f32u16(px.R * 65535.0)
g16 := f32u16(px.G * 65535.0)
b16 := f32u16(px.B * 65535.0)
a16 := f32u16(px.A * 65535.0)
i := p.imgNRGBA64.PixOffset(x, y)
p.imgNRGBA64.Pix[i+0] = uint8(r16 >> 8)
p.imgNRGBA64.Pix[i+1] = uint8(r16 & 0xff)
p.imgNRGBA64.Pix[i+2] = uint8(g16 >> 8)
p.imgNRGBA64.Pix[i+3] = uint8(g16 & 0xff)
p.imgNRGBA64.Pix[i+4] = uint8(b16 >> 8)
p.imgNRGBA64.Pix[i+5] = uint8(b16 & 0xff)
p.imgNRGBA64.Pix[i+6] = uint8(a16 >> 8)
p.imgNRGBA64.Pix[i+7] = uint8(a16 & 0xff)
case itRGBA:
fa := px.A * 255.0
i := p.imgRGBA.PixOffset(x, y)
p.imgRGBA.Pix[i+0] = f32u8(px.R * fa)
p.imgRGBA.Pix[i+1] = f32u8(px.G * fa)
p.imgRGBA.Pix[i+2] = f32u8(px.B * fa)
p.imgRGBA.Pix[i+3] = f32u8(fa)
case itRGBA64:
fa := px.A * 65535.0
r16 := f32u16(px.R * fa)
g16 := f32u16(px.G * fa)
b16 := f32u16(px.B * fa)
a16 := f32u16(fa)
i := p.imgRGBA64.PixOffset(x, y)
p.imgRGBA64.Pix[i+0] = uint8(r16 >> 8)
p.imgRGBA64.Pix[i+1] = uint8(r16 & 0xff)
p.imgRGBA64.Pix[i+2] = uint8(g16 >> 8)
p.imgRGBA64.Pix[i+3] = uint8(g16 & 0xff)
p.imgRGBA64.Pix[i+4] = uint8(b16 >> 8)
p.imgRGBA64.Pix[i+5] = uint8(b16 & 0xff)
p.imgRGBA64.Pix[i+6] = uint8(a16 >> 8)
p.imgRGBA64.Pix[i+7] = uint8(a16 & 0xff)
case itGray:
i := p.imgGray.PixOffset(x, y)
p.imgGray.Pix[i] = f32u8((0.299*px.R + 0.587*px.G + 0.114*px.B) * px.A * 255.0)
case itGray16:
i := p.imgGray16.PixOffset(x, y)
y16 := f32u16((0.299*px.R + 0.587*px.G + 0.114*px.B) * px.A * 65535.0)
p.imgGray16.Pix[i+0] = uint8(y16 >> 8)
p.imgGray16.Pix[i+1] = uint8(y16 & 0xff)
case itGeneric:
r16 := f32u16(px.R * 65535.0)
g16 := f32u16(px.G * 65535.0)
b16 := f32u16(px.B * 65535.0)
a16 := f32u16(px.A * 65535.0)
p.imgGeneric.Set(x, y, color.NRGBA64{r16, g16, b16, a16})
}
}
func (p *pixelSetter) setPixelRow(y int, buf []pixel) {
for i, x := 0, p.imgBounds.Min.X; i < len(buf); i, x = i+1, x+1 {
p.setPixel(x, y, buf[i])
}
}
func (p *pixelSetter) setPixelColumn(x int, buf []pixel) {
for i, y := 0, p.imgBounds.Min.Y; i < len(buf); i, y = i+1, y+1 {
p.setPixel(x, y, buf[i])
}
}