Impl identicons serverside, broken though for some reason

shared/identicon/block.go

@@ -0,0 +1,100 @@
+package identicon
+
+import (
+	"git.mstar.dev/mstar/canvas"
+	mathutils "git.mstar.dev/mstar/goutils/math"
+)
+
+type vec2 struct {
+	X, Y float64
+}
+
+type block struct {
+	canvas    *canvas.Canvas
+	blockType int
+	primary   string
+	secondary string
+	hash      int
+	pos       vec2
+	cellSize  int
+	margin    int
+	scale     float64
+}
+
+func (b *block) Offset() {
+	b.canvas.Save()
+	b.canvas.Translate(0.6*b.scale, -0.6*b.scale)
+}
+
+func (b *block) ResetOffset() {
+	b.canvas.Restore()
+}
+
+func (b *block) MakePath(hash int, offset int) {
+	mod := mathutils.Abs(hash+offset) % 4
+	switch mod {
+	case 0:
+		// Top
+		b.canvas.BeginPath()
+		b.canvas.MoveTo(float64(b.pos.X), float64(b.pos.Y))
+		b.canvas.LineTo(b.pos.X+float64(int(b.cellSize)), float64(b.pos.Y))
+		b.canvas.LineTo(b.pos.X+float64(int(b.cellSize)), b.pos.Y+float64(int(b.cellSize)))
+		b.canvas.ClosePath()
+	case 1:
+		// Right
+		b.canvas.BeginPath()
+		b.canvas.MoveTo(b.pos.X+float64(int(b.cellSize)), float64(b.pos.Y))
+		b.canvas.LineTo(b.pos.X+float64(int(b.cellSize)), b.pos.Y+float64(int(b.cellSize)))
+		b.canvas.LineTo(float64(b.pos.X), b.pos.Y+float64(int(b.cellSize)))
+		b.canvas.ClosePath()
+	case 2:
+		// Bottom
+		b.canvas.BeginPath()
+		b.canvas.MoveTo(float64(b.pos.X), float64(b.pos.Y))
+		b.canvas.LineTo(float64(b.pos.X), b.pos.Y+float64(int(b.cellSize)))
+		b.canvas.LineTo(b.pos.X+float64(int(b.cellSize)), b.pos.Y+float64(int(b.cellSize)))
+		b.canvas.ClosePath()
+	case 3:
+		// Left
+		b.canvas.BeginPath()
+		b.canvas.MoveTo(float64(b.pos.X), float64(b.pos.Y))
+		b.canvas.LineTo(b.pos.X+float64(int(b.cellSize)), float64(b.pos.Y))
+		b.canvas.LineTo(float64(b.pos.X), b.pos.Y+float64(int(b.cellSize)))
+		b.canvas.ClosePath()
+	default:
+		// Top
+		b.canvas.BeginPath()
+		b.canvas.MoveTo(float64(b.pos.X), float64(b.pos.Y))
+		b.canvas.LineTo(b.pos.X+float64(int(b.cellSize)), float64(b.pos.Y))
+		b.canvas.LineTo(b.pos.X+float64(int(b.cellSize)), b.pos.Y+float64(int(b.cellSize)))
+		b.canvas.ClosePath()
+	}
+}
+
+func (b *block) Draw() {
+	b.Offset()
+	switch b.blockType {
+	case 1:
+		b.MakePath(b.hash, b.hash%3)
+		b.canvas.SetFillStyle(b.primary)
+		b.canvas.Fill()
+		b.MakePath(b.hash, b.hash%5)
+		b.canvas.SetFillStyle(b.secondary)
+		b.canvas.Fill()
+	case 2:
+		b.MakePath(b.hash, b.hash%4)
+		b.canvas.SetFillStyle(b.secondary)
+		b.canvas.Fill()
+		b.MakePath(b.hash, b.hash%3)
+		b.canvas.SetFillStyle(b.primary)
+		b.canvas.Fill()
+	default:
+		b.MakePath(b.hash, b.hash%7)
+		b.canvas.SetFillStyle(b.secondary)
+		b.canvas.Fill()
+		b.MakePath(b.hash, b.hash%8)
+		b.canvas.SetFillStyle(b.primary)
+		b.canvas.Fill()
+	}
+	b.ResetOffset()
+}