grid method

Author: monkstone

docs/_posts/2019-03-01-Using-grid-method.md

@@ -0,0 +1,32 @@
+---
+layout: post
+title:  "Using JRubyArt grid method"
+date:   2019-03-01 12:58:08 +0000
+categories: vecmath update
+---
+
+# Example Usage
+
+```ruby
+# ===== Default : Default
+GEM_HOME = '/home/tux/.gem/ruby/2.6.0'
+require 'vecmath'
+
+rect_mode(CORNER)
+no_stroke
+frame_rate(1) # set the frame rate to 1 draw call per second
+
+def draw
+  background(180) # clear the screen to grey
+  grid_size = 5 # rand(3..12)   # select a rand number of squares each frame
+  gap = 5 # rand(5..50) # select a rand gap between each square
+  # calculate the size of each square for the given number of squares and gap between them
+  cellsize = (width - (grid_size + 1) * gap) / grid_size
+  position = -> (count) { gap * (count + 1) + cellsize * count + rand(-5..5) }
+  grid(grid_size, grid_size) do |x, y|
+    rand(0..5) > 4 ? fill(color('#a11220'), 180.0) : fill(color('#884444'), 180.0)
+    rect(position.call(x), position.call(y), cellsize, cellsize)
+  end
+end
+
+```