Data commit

Task/Polyspiral/Julia/polyspiral.julia

@@ -0,0 +1,60 @@
+using Gtk, Graphics, Colors
+
+const can = @GtkCanvas()
+const win = GtkWindow(can, "Polyspiral", 360, 360)
+
+const drawiters = 72
+const colorseq = [colorant"blue", colorant"red", colorant"green", colorant"black", colorant"gold"]
+const angleiters = [0, 0, 0]
+const angles = [75, 100, 135, 160]
+
+Base.length(v::Vec2) = sqrt(v.x * v.x + v.y * v.y)
+
+function drawline(ctx, p1, p2, color, width=1)
+    move_to(ctx, p1.x, p1.y)
+    set_source(ctx, color)
+    line_to(ctx, p2.x, p2.y)
+    set_line_width(ctx, width)
+    stroke(ctx)
+end
+
+@guarded draw(can) do widget
+    δ(r, θ) = Vec2(r * cospi(θ/180), r * sinpi(θ/180))
+    nextpoint(p, r, θ) = (dp = δ(r, θ); Point(p.x + dp.x, p.y + dp.y))
+    colorindex = (angleiters[1] % 5) + 1
+    colr = colorseq[colorindex]
+    ctx = getgc(can)
+    h = height(can)
+    w = width(can)
+    x = 0.5 * w
+    y = 0.5 * h
+    θ = angleiters[2] * rand() * 3
+    δθ = angleiters[2]
+    r = 5
+    δr = 3
+    p1 = Point(x, y)
+    for i in 1:drawiters
+        if angleiters[3] == 0
+            set_source(ctx, colorant"gray90")
+            rectangle(ctx, 0, 0, w, h)
+            fill(ctx)
+            continue
+        end
+        p2 = nextpoint(p1, r, θ)
+        drawline(ctx, p1, p2, colr, 2)
+        θ = θ + δθ
+        r = r + δr
+        p1 = p2
+    end
+end
+
+show(can)
+
+while true
+    angleiters[2] = angles[angleiters[1] % 3 + 1]
+    angleiters[1] += 1
+    angleiters[3] = angleiters[3] == 0 ? 1 : 0
+    draw(can)
+    yield()
+    sleep(0.5)
+end