byjp.me
A tool for archiving & converting scans of postcards, and information about them.
feat: polish for first pass of svg creator
Includes: handling postcards with no back, commented out (!) code for not-quite-working bezier curves, ensure ignored transparency images have no transparency enocded
+1
cmd/postcards/main.go
+1
cmd/postcards/main.go
+3
-2
formats/web/codec.go
+3
-2
formats/web/codec.go
···
32
32
type capabilities struct {
33
33
lossless bool
34
34
transparency bool
35
+
masking bool
35
36
}
36
37
37
38
func (c capabilities) String() string {
···
57
58
"jpeg": {},
58
59
"webp": {lossless: true, transparency: true},
59
60
"png": {lossless: true, transparency: true},
60
-
"svg": {transparency: true},
61
+
"svg": {transparency: true, masking: true},
61
62
}
62
63
63
64
// Only returns true if the capabilities on struct owning this method meet the needs of the provided capabilities object.
···
78
79
return codec{formats: fmts}, nil
79
80
}
80
81
81
-
var DefaultCodec, _ = Codec("jpeg", "webp")
82
+
var DefaultCodec, _ = Codec("jpeg", "webp", "svg")
82
83
var SVGCodec, _ = Codec("svg")
83
84
84
85
func (c codec) Name() string { return codecName }
+3
-2
formats/web/encode.go
+3
-2
formats/web/encode.go
···
65
65
66
66
combinedImg := image.NewRGBA(combinedSize)
67
67
// Fill the backdrop with the card colour if we're ignoring transparency
68
-
if opts.IgnoreTransparency() {
68
+
// or where the transparency is completed as a mask
69
+
if opts.IgnoreTransparency() || formatCapabilities[format].masking {
69
70
bg := &image.Uniform{pc.Meta.Physical.GetCardColor()}
70
71
draw.Draw(combinedImg, combinedImg.Bounds(), bg, image.Point{}, draw.Src)
71
72
}
···
91
92
case "jpeg":
92
93
err = images.WriteJPEG(w, combinedImg, xmpData)
93
94
case "svg":
94
-
err = writeSVG(w, pc, combinedImg, xmpData)
95
+
err = writeSVG(w, pc, combinedImg, xmpData, pc.Meta.HasTransparency)
95
96
default:
96
97
err = fmt.Errorf("unsupported output image format: %s", format)
97
98
}
+17
-6
formats/web/postcard.svg.qtpl
+17
-6
formats/web/postcard.svg.qtpl
···
1
1
{% func SVG(v svgVars) %}
2
2
<svg
3
3
xmlns="http://www.w3.org/2000/svg"
4
-
{% if v.size.HasPhysical() %}
5
-
{% code
4
+
{%- code
5
+
h := v.size.PxHeight
6
+
if v.hasBack {
7
+
h *= 2
8
+
}
9
+
-%}
10
+
{%- if v.size.HasPhysical() -%}
11
+
{%- code
6
12
cmW, cmH := v.size.MustPhysical()
7
-
%}
13
+
if v.hasBack {
14
+
cmH *= 2
15
+
}
16
+
-%}
8
17
width="{%f.2 cmW %}cm"
9
-
height="{%f.2 cmH * 2 %}cm"
10
-
{% endif %}
11
-
viewBox="0 0 {%d v.size.PxWidth %} {%d v.size.PxHeight * 2 %}"
18
+
height="{%f.2 cmH %}cm"
19
+
{%- endif -%}
20
+
viewBox="0 0 {%d v.size.PxWidth %} {%d h %}"
12
21
version="1.1"
13
22
>
14
23
<defs>
15
24
<clipPath id="edge">
16
25
<path d="{%s pointsToPath(v.frontPoints, v.size.PxWidth, v.size.PxHeight, false) %}"/>
26
+
{%- if v.hasBack -%}
17
27
<path d="{%s pointsToPath(v.backPoints, v.size.PxWidth, v.size.PxHeight, true) %}"/>
28
+
{%- endif -%}
18
29
</clipPath>
19
30
</defs>
20
31
<image
+59
-47
formats/web/postcard.svg.qtpl.go
+59
-47
formats/web/postcard.svg.qtpl.go
···
23
23
qw422016.N().S(`
24
24
<svg
25
25
xmlns="http://www.w3.org/2000/svg"
26
-
`)
27
-
//line postcard.svg.qtpl:4
26
+
`)
27
+
//line postcard.svg.qtpl:5
28
+
h := v.size.PxHeight
29
+
if v.hasBack {
30
+
h *= 2
31
+
}
32
+
33
+
//line postcard.svg.qtpl:10
28
34
if v.size.HasPhysical() {
29
-
//line postcard.svg.qtpl:4
30
-
qw422016.N().S(`
31
-
`)
32
-
//line postcard.svg.qtpl:6
35
+
//line postcard.svg.qtpl:12
33
36
cmW, cmH := v.size.MustPhysical()
37
+
if v.hasBack {
38
+
cmH *= 2
39
+
}
34
40
35
-
//line postcard.svg.qtpl:7
36
-
qw422016.N().S(`
37
-
width="`)
38
-
//line postcard.svg.qtpl:8
41
+
//line postcard.svg.qtpl:16
42
+
qw422016.N().S(` width="`)
43
+
//line postcard.svg.qtpl:17
39
44
qw422016.N().FPrec(cmW, 2)
40
-
//line postcard.svg.qtpl:8
45
+
//line postcard.svg.qtpl:17
41
46
qw422016.N().S(`cm"
42
47
height="`)
43
-
//line postcard.svg.qtpl:9
44
-
qw422016.N().FPrec(cmH*2, 2)
45
-
//line postcard.svg.qtpl:9
48
+
//line postcard.svg.qtpl:18
49
+
qw422016.N().FPrec(cmH, 2)
50
+
//line postcard.svg.qtpl:18
46
51
qw422016.N().S(`cm"
47
-
`)
48
-
//line postcard.svg.qtpl:10
52
+
`)
53
+
//line postcard.svg.qtpl:19
49
54
}
50
-
//line postcard.svg.qtpl:10
51
-
qw422016.N().S(`
52
-
viewBox="0 0 `)
53
-
//line postcard.svg.qtpl:11
55
+
//line postcard.svg.qtpl:19
56
+
qw422016.N().S(` viewBox="0 0 `)
57
+
//line postcard.svg.qtpl:20
54
58
qw422016.N().D(v.size.PxWidth)
55
-
//line postcard.svg.qtpl:11
59
+
//line postcard.svg.qtpl:20
56
60
qw422016.N().S(` `)
57
-
//line postcard.svg.qtpl:11
58
-
qw422016.N().D(v.size.PxHeight * 2)
59
-
//line postcard.svg.qtpl:11
61
+
//line postcard.svg.qtpl:20
62
+
qw422016.N().D(h)
63
+
//line postcard.svg.qtpl:20
60
64
qw422016.N().S(`"
61
65
version="1.1"
62
66
>
63
67
<defs>
64
68
<clipPath id="edge">
65
69
<path d="`)
66
-
//line postcard.svg.qtpl:16
70
+
//line postcard.svg.qtpl:25
67
71
qw422016.E().S(pointsToPath(v.frontPoints, v.size.PxWidth, v.size.PxHeight, false))
68
-
//line postcard.svg.qtpl:16
72
+
//line postcard.svg.qtpl:25
69
73
qw422016.N().S(`"/>
70
-
<path d="`)
71
-
//line postcard.svg.qtpl:17
72
-
qw422016.E().S(pointsToPath(v.backPoints, v.size.PxWidth, v.size.PxHeight, true))
73
-
//line postcard.svg.qtpl:17
74
-
qw422016.N().S(`"/>
75
-
</clipPath>
74
+
`)
75
+
//line postcard.svg.qtpl:26
76
+
if v.hasBack {
77
+
//line postcard.svg.qtpl:26
78
+
qw422016.N().S(` <path d="`)
79
+
//line postcard.svg.qtpl:27
80
+
qw422016.E().S(pointsToPath(v.backPoints, v.size.PxWidth, v.size.PxHeight, true))
81
+
//line postcard.svg.qtpl:27
82
+
qw422016.N().S(`"/>
83
+
`)
84
+
//line postcard.svg.qtpl:28
85
+
}
86
+
//line postcard.svg.qtpl:28
87
+
qw422016.N().S(` </clipPath>
76
88
</defs>
77
89
<image
78
90
x="0"
···
82
94
preserveAspectRatio="none"
83
95
clip-path="url(#edge)"
84
96
href="data:image/jpeg;base64,`)
85
-
//line postcard.svg.qtpl:27
97
+
//line postcard.svg.qtpl:38
86
98
qw422016.E().S(v.b64Img)
87
-
//line postcard.svg.qtpl:27
99
+
//line postcard.svg.qtpl:38
88
100
qw422016.N().S(`"
89
101
/>
90
102
</svg>
91
103
`)
92
-
//line postcard.svg.qtpl:30
104
+
//line postcard.svg.qtpl:41
93
105
}
94
106
95
-
//line postcard.svg.qtpl:30
107
+
//line postcard.svg.qtpl:41
96
108
func WriteSVG(qq422016 qtio422016.Writer, v svgVars) {
97
-
//line postcard.svg.qtpl:30
109
+
//line postcard.svg.qtpl:41
98
110
qw422016 := qt422016.AcquireWriter(qq422016)
99
-
//line postcard.svg.qtpl:30
111
+
//line postcard.svg.qtpl:41
100
112
StreamSVG(qw422016, v)
101
-
//line postcard.svg.qtpl:30
113
+
//line postcard.svg.qtpl:41
102
114
qt422016.ReleaseWriter(qw422016)
103
-
//line postcard.svg.qtpl:30
115
+
//line postcard.svg.qtpl:41
104
116
}
105
117
106
-
//line postcard.svg.qtpl:30
118
+
//line postcard.svg.qtpl:41
107
119
func SVG(v svgVars) string {
108
-
//line postcard.svg.qtpl:30
120
+
//line postcard.svg.qtpl:41
109
121
qb422016 := qt422016.AcquireByteBuffer()
110
-
//line postcard.svg.qtpl:30
122
+
//line postcard.svg.qtpl:41
111
123
WriteSVG(qb422016, v)
112
-
//line postcard.svg.qtpl:30
124
+
//line postcard.svg.qtpl:41
113
125
qs422016 := string(qb422016.B)
114
-
//line postcard.svg.qtpl:30
126
+
//line postcard.svg.qtpl:41
115
127
qt422016.ReleaseByteBuffer(qb422016)
116
-
//line postcard.svg.qtpl:30
128
+
//line postcard.svg.qtpl:41
117
129
return qs422016
118
-
//line postcard.svg.qtpl:30
130
+
//line postcard.svg.qtpl:41
119
131
}
+87
-31
formats/web/svg.go
+87
-31
formats/web/svg.go
···
3
3
import (
4
4
"bytes"
5
5
"encoding/base64"
6
-
"encoding/json"
7
6
"fmt"
8
7
"image"
9
8
"io"
···
21
20
b64Img string
22
21
frontPoints []geom3d.Point
23
22
backPoints []geom3d.Point
24
-
metadata []byte
23
+
hasBack bool
25
24
}
26
25
27
26
// This keeps the whole JPEG in memory. TODO: Figure out how to do this while streaming
28
-
func writeSVG(w io.Writer, pc types.Postcard, combinedImg image.Image, xmpData []byte) error {
29
-
frontPoints, err := images.Outline(pc.Front, false, false)
30
-
if err != nil {
31
-
return fmt.Errorf("front image can't be outlined: %w", err)
27
+
func writeSVG(w io.Writer, pc types.Postcard, combinedImg image.Image, xmpData []byte, hasTransparency bool) error {
28
+
v := svgVars{
29
+
size: pc.Meta.Physical.FrontDimensions,
30
+
hasBack: pc.Back != nil,
32
31
}
33
-
// TODO: Handle no back
34
-
backPoints, err := images.Outline(pc.Back, false, false)
35
-
if err != nil {
36
-
return fmt.Errorf("back image can't be outlined: %w", err)
32
+
33
+
if hasTransparency {
34
+
frontPoints, err := images.Outline(pc.Front, false, false)
35
+
if err != nil {
36
+
return fmt.Errorf("front image can't be outlined: %w", err)
37
+
}
38
+
v.frontPoints = frontPoints
39
+
40
+
if v.hasBack {
41
+
backPoints, err := images.Outline(pc.Back, false, false)
42
+
if err != nil {
43
+
return fmt.Errorf("back image can't be outlined: %w", err)
44
+
}
45
+
v.backPoints = backPoints
46
+
}
37
47
}
38
48
39
49
var buf bytes.Buffer
···
41
51
if err := images.WriteJPEG(b64W, combinedImg, xmpData); err != nil {
42
52
return err
43
53
}
54
+
v.b64Img = buf.String()
44
55
45
-
meta, err := json.Marshal(pc.Meta)
46
-
if err != nil {
47
-
return err
48
-
}
56
+
WriteSVG(w, v)
57
+
return nil
58
+
}
49
59
50
-
v := svgVars{
51
-
size: pc.Meta.Physical.FrontDimensions,
52
-
b64Img: buf.String(),
53
-
frontPoints: frontPoints,
54
-
backPoints: backPoints,
55
-
metadata: meta,
56
-
}
60
+
// TODO: Figure out if bezier curves are worth it
61
+
// const (
62
+
// bezierTension = 1.0 / 6.0
63
+
// smoothUnderAngle = 45
64
+
// )
57
65
58
-
WriteSVG(w, v)
59
-
return nil
66
+
type bezierPoint struct {
67
+
px, py float64
68
+
// TODO: Figure out if bezier curves are worth it
69
+
// c1x, c1y float64
70
+
// c2x, c2y float64
60
71
}
61
72
62
73
func pointsToPath(points []geom3d.Point, w, h int, back bool) string {
···
65
76
offsetH = h
66
77
}
67
78
68
-
var path strings.Builder
79
+
bp := make([]bezierPoint, len(points))
69
80
for i, p := range points {
81
+
bp[i].px = p.X * float64(w)
82
+
bp[i].py = p.Y*float64(h) + float64(offsetH)
83
+
}
84
+
// TODO: Figure out if bezier curves are worth it
85
+
// for i, p := range bp {
86
+
// p0, p1, p2, p3 := bp[(i-1+len(bp))%len(bp)], p, bp[(i+1)%len(bp)], bp[(i+2)%len(bp)]
87
+
88
+
// angle := calcAngle(p0, p1, p2)
89
+
// if angle < smoothUnderAngle {
90
+
// bp[i].c1x = p1.px + (p2.px-p0.px)*bezierTension
91
+
// bp[i].c1y = p1.py + (p2.py-p0.py)*bezierTension
92
+
// bp[i].c2x = p2.px + (p3.px-p1.px)*bezierTension
93
+
// bp[i].c2y = p2.py + (p3.py-p1.py)*bezierTension
94
+
// }
95
+
// }
96
+
97
+
var path strings.Builder
98
+
for i, p := range bp {
70
99
if i == 0 {
71
-
path.WriteString("M")
100
+
path.WriteString(fmt.Sprintf(
101
+
"M%.1f %.1f",
102
+
p.px, p.py,
103
+
))
104
+
// TODO: Figure out if bezier curves are worth it
105
+
// } else if p.c1x != 0 && p.c1y != 0 && p.c2x != 0 && p.c2y != 0 {
106
+
// path.WriteString(fmt.Sprintf(
107
+
// "C%.1f %.1f,%.1f %.1f,%.1f %.1f",
108
+
// p.c1x, p.c1y,
109
+
// p.c2x, p.c2y,
110
+
// p.px, p.py,
111
+
// ))
72
112
} else {
73
-
path.WriteString("L")
113
+
path.WriteString(fmt.Sprintf(
114
+
"L%.1f %.1f",
115
+
p.px, p.py,
116
+
))
74
117
}
75
-
x := p.X * float64(w)
76
-
y := p.Y*float64(h) + float64(offsetH)
77
-
path.WriteString(fmt.Sprintf("%.1f %.1f", x, y))
78
-
79
118
}
80
-
path.WriteString("Z")
81
119
return path.String()
82
120
}
121
+
122
+
// TODO: Figure out if bezier curves are worth it
123
+
// func calcAngle(p0, p1, p2 bezierPoint) float64 {
124
+
// v1x, v1y := p1.px-p0.px, p1.py-p0.py
125
+
// v2x, v2y := p2.px-p1.px, p2.py-p1.py
126
+
127
+
// dot := v1x*v2x + v1y*v2y
128
+
// mag1 := math.Hypot(v1x, v1y)
129
+
// mag2 := math.Hypot(v2x, v2y)
130
+
131
+
// // Points are on top of each other, treat as straight
132
+
// if mag1 == 0 || mag2 == 0 {
133
+
// return 180
134
+
// }
135
+
136
+
// cosTheta := dot / (mag1 * mag2)
137
+
// return 180 * math.Acos(math.Max(-1, math.Min(1, cosTheta))) / math.Pi
138
+
// }