| Port fzakaria.com design to Hugo and add a homepage profile 1bdbd06 Romain Gautier 21h ago | 1 | {{- /* |
| 2 | Plots a Catmull-Rom curve through the 32 bytes of SHA-256(url), one sample |
| 3 | per byte, emitted as an SVG path. Port of _plugins/signal.rb. |
| 4 | */ -}} |
| 5 | {{- $url := . -}} |
| 6 | {{- $hash := crypto.SHA256 $url -}} |
| 7 | {{- $hexVal := dict "0" 0 "1" 1 "2" 2 "3" 3 "4" 4 "5" 5 "6" 6 "7" 7 "8" 8 "9" 9 "a" 10 "b" 11 "c" 12 "d" 13 "e" 14 "f" 15 -}} |
| 8 | |
| 9 | {{- $width := 1000.0 -}} |
| 10 | {{- $height := 100.0 -}} |
| 11 | {{- $pad := 18.0 -}} |
| 12 | {{- $tension := 0.72 -}} |
| 13 | {{- $n := 32 -}} |
| 14 | {{- $last := sub $n 1 -}} |
| 15 | {{- $span := sub $height (mul 2 $pad) -}} |
| 16 | {{- $step := div $width (sub $n 1.0) -}} |
| 17 | |
| 18 | {{- $bytes := slice -}} |
| 19 | {{- range $i := seq 0 $last -}} |
| 20 | {{- $hi := index $hexVal (substr $hash (mul $i 2) 1) -}} |
| 21 | {{- $lo := index $hexVal (substr $hash (add (mul $i 2) 1) 1) -}} |
| 22 | {{- $bytes = $bytes | append (add (mul $hi 16) $lo) -}} |
| 23 | {{- end -}} |
| 24 | |
| 25 | {{- $pts := slice -}} |
| 26 | {{- range $i, $b := $bytes -}} |
| 27 | {{- $x := mul (float $i) $step -}} |
| 28 | {{- $y := add $pad (mul (sub 1.0 (div (float $b) 255.0)) $span) -}} |
| 29 | {{- $pts = $pts | append (dict "x" $x "y" $y) -}} |
| 30 | {{- end -}} |
| 31 | |
| 32 | {{- $p0 := index $pts 0 -}} |
| 33 | {{- $d := printf "M%s,%s" (partial "signal-num.html" $p0.x) (partial "signal-num.html" $p0.y) -}} |
| 34 | |
| 35 | {{- range $i := seq 0 (sub $last 1) -}} |
| 36 | {{- $p0idx := 0 -}} |
| 37 | {{- if ge $i 1 }}{{ $p0idx = sub $i 1 }}{{ end -}} |
| 38 | {{- $p3idx := add $i 2 -}} |
| 39 | {{- if gt $p3idx $last }}{{ $p3idx = $last }}{{ end -}} |
| 40 | |
| 41 | {{- $pp0 := index $pts $p0idx -}} |
| 42 | {{- $pp1 := index $pts $i -}} |
| 43 | {{- $pp2 := index $pts (add $i 1) -}} |
| 44 | {{- $pp3 := index $pts $p3idx -}} |
| 45 | |
| 46 | {{- $c1x := add $pp1.x (mul (div (sub $pp2.x $pp0.x) 6.0) $tension) -}} |
| 47 | {{- $c1y := add $pp1.y (mul (div (sub $pp2.y $pp0.y) 6.0) $tension) -}} |
| 48 | {{- $c2x := sub $pp2.x (mul (div (sub $pp3.x $pp1.x) 6.0) $tension) -}} |
| 49 | {{- $c2y := sub $pp2.y (mul (div (sub $pp3.y $pp1.y) 6.0) $tension) -}} |
| 50 | |
| 51 | {{- $d = printf "%s C%s,%s %s,%s %s,%s" $d |
| 52 | (partial "signal-num.html" $c1x) (partial "signal-num.html" $c1y) |
| 53 | (partial "signal-num.html" $c2x) (partial "signal-num.html" $c2y) |
| 54 | (partial "signal-num.html" $pp2.x) (partial "signal-num.html" $pp2.y) -}} |
| 55 | {{- end -}} |
| 56 | |
| 57 | {{- return (dict "hash" $hash "path" $d) -}} |