Data update

Task/Bitmap-Midpoint-circle-algorithm/Crystal/bitmap-midpoint-circle-algorithm-1.cr

@@ -0,0 +1,40 @@
+require "./pixmap"
+require "./bresenham"
+
+class Pixmap
+  def circle (cx, cy, r, color, fill = false)
+    f = 1 - r
+    ddF_X = 0
+    ddF_Y = -2 * r
+    x = 0
+    y = r
+    self[cx, cy + r] = color
+    self[cx, cy - r] = color
+    p1, p2 = {cx + r, cy}, {cx - r, cy}
+    if fill
+      line(*p1, *p2, color)
+    else
+      self[*p1] = self[*p2] = color
+    end
+    while x < y
+      if f >= 0
+        y -= 1
+        ddF_Y += 2
+        f += ddF_Y
+      end
+      x += 1
+      ddF_X += 2
+      f += ddF_X + 1
+      [{cx - x, cy - y}, {cx + x, cy - y},
+       {cx - x, cy + y}, {cx + x, cy + y},
+       {cx - y, cy - x}, {cx + y, cy - x},
+       {cx - y, cy + x}, {cx + y, cy + x}].each_slice(2, reuse: true) do |(p1, p2)|
+        if fill
+          line(*p1, *p2, color)
+        else
+          self[*p1] = self[*p2] = color
+        end
+      end
+    end
+  end
+end

Task/Bitmap-Midpoint-circle-algorithm/Crystal/bitmap-midpoint-circle-algorithm-2.cr

@@ -0,0 +1,12 @@
+require "./circle"
+require "./write_ppm"
+
+img = Pixmap.new 100, 100, Color::WHITE
+
+img.circle 50, 50, 40, Color::RED, true
+img.circle 70, 60, 15, Color::BLUE, true
+img.circle 40, 20, 20, Color::BLACK
+img.circle 40, 20, 19, Color.new(255, 144, 0)
+img.circle 40, 20, 18, Color::BLACK
+
+img.write "crystal_circles.ppm"