Data commit

Task/Pentagram/Nim/pentagram.nim

@@ -0,0 +1,72 @@
+import libgd
+from math import sin, cos, degToRad
+
+const
+  width = 500
+  height = width
+  outerRadius = 200
+
+proc main() =
+
+  proc calcPosition(x: int, y: int, radius: int, posAngle: float): (cint, cint) =
+    var width = int(radius.float * sin(degToRad(posAngle)))
+    var height = int(radius.float * cos(degToRad(posAngle)))
+    return (cast[cint](x + width), cast[cint](y - height))
+
+  proc getPentagonPoints(startAngle = 0, radius: int): array[5, array[2, int]] =
+    let spacingAngle = 360 / 5
+
+    var posAngle = (90 - startAngle).float
+
+    var n = 0
+    var points: array[5, array[2, int]]
+    while n < 5:
+      (points[n][0], points[n][1]) = calcPosition(250, 250, radius, posAngle)
+      n += 1
+      posAngle -= spacingAngle
+
+    return points
+
+  let outerPentagon = getPentagonPoints(18, outerRadius) # rotate 18 degrees
+  let innerPentagon = getPentagonPoints(54, int((cos(degToRad(72.0))/cos(degToRad(36.0))) * outerRadius)) # rotate 54 degrees
+
+  var pentagram: array[10, array[2, int]]
+  var n = 0
+  for i in countup(0, 4):
+    pentagram[n] = outerPentagon[i]
+    inc(n)
+    pentagram[n] = innerPentagon[i]
+    inc(n)
+
+  withGd imageCreate(width, height) as img:
+    discard img.setColor(255, 255, 255)
+
+    let black = img.setColor(0x404040)
+    let blue = img.setColor(0x6495ed)
+
+    img.drawPolygon(
+      points=pentagram,
+      color=blue,
+      fill=true,
+      open=false)
+
+    img.setThickness(4)
+
+    img.drawPolygon(
+      points=pentagram,
+      color=black,
+      fill=false,
+      open=false)
+
+    img.drawPolygon(
+      points=innerPentagon,
+      color=black,
+      fill=false,
+      open=false)
+
+    let png_out = open("pentagram.png", fmWrite)
+    img.writePng(png_out)
+
+    png_out.close()
+
+main()