@@ -2,18 +2,18 @@ # contextfreeart.org module Processing - + class ContextFree - + include Processing::Proxy - + attr_accessor :rules, :app - + AVAILABLE_OPTIONS = [:x, :y, :rotation, :size, :flip, :color, :hue, :saturation, :brightness, :alpha] HSB_ORDER = {:hue => 0, :saturation => 1, :brightness => 2, :alpha => 3} TRIANGLE_TOP = -1 / Math.sqrt(3) TRIANGLE_BOTTOM = Math.sqrt(3) / 6 - + # Define a context-free system. Use this method to create a ContextFree # object. Call render() on it to make it draw. def self.define(&block) @@ -21,8 +21,8 @@ module Processing cf.instance_eval &block cf end - - + + # Initialize a bare ContextFree object with empty recursion stacks. def initialize @app = $app @@ -32,8 +32,8 @@ module Processing @rewind_stack = [] @matrix_stack = [] end - - + + # Create an accessor for the current value of every option. We use a values # object so that all the state can be saved and restored as a unit. AVAILABLE_OPTIONS.each do |option_name| @@ -41,13 +41,13 @@ module Processing @values[option_name] end end - - - # Here's the first serious method: A Rule has an - # identifying name, a probability, and is associated with - # a block of code. These code blocks are saved, and indexed + + + # Here's the first serious method: A Rule has an + # identifying name, a probability, and is associated with + # a block of code. These code blocks are saved, and indexed # by name in a hash, to be run later, when needed. - # The method then dynamically defines a method of the same + # The method then dynamically defines a method of the same # name here, in order to determine which rule to run. def rule(rule_name, prob=1, &proc) @rules[rule_name] ||= {:procs => [], :total => 0} @@ -70,8 +70,8 @@ module Processing end end end - - + + # Rule choice is random, based on the assigned probabilities. def determine_rule(rule_name) rule = @rules[rule_name] @@ -79,8 +79,8 @@ module Processing pick = @rules[rule_name][:procs].select {|the_proc| the_proc[0].include?(chance) } return pick.flatten end - - + + # At each step of the way, any of the options may change, slightly. # Many of them have different strategies for being merged. def merge_options(old_ops, new_ops) @@ -109,9 +109,9 @@ module Processing end end end - - - # Using an unknown key let's you set arbitrary values, + + + # Using an unknown key let's you set arbitrary values, # to keep track of for your own ends. def merge_unknown_key(key, value, old_ops) key_s = key.to_s @@ -126,9 +126,9 @@ module Processing end end end - - - # Doing a 'split' saves the context, and proceeds from there, + + + # Doing a 'split' saves the context, and proceeds from there, # allowing you to rewind to where you split from at any moment. def split(options=nil, &block) save_context @@ -136,35 +136,35 @@ module Processing yield restore_context end - - - # Saving the context means the values plus the coordinate matrix. + + + # Saving the context means the values plus the coordinate matrix. def save_context @rewind_stack.push @values.dup @matrix_stack << @graphics.get_matrix end - - + + # Restore the values and the coordinate matrix as the recursion unwinds. def restore_context - @values = @rewind_stack.pop + @values = @rewind_stack.pop @graphics.set_matrix @matrix_stack.pop end - - + + # Rewinding goes back one step. def rewind @finished = false restore_context save_context end - - - # Render the is method that kicks it all off, initializing the options + + + # Render the is method that kicks it all off, initializing the options # and calling the first rule. def render(rule_name, starting_values={}) - @values = {:x => 0, :y => 0, - :rotation => 0, :flip => false, + @values = {:x => 0, :y => 0, + :rotation => 0, :flip => false, :size => 20, :width => 20, :height => 20, :start_x => width/2, :start_y => height/2, :color => [0.5, 0.5, 0.5, 1], @@ -179,8 +179,8 @@ module Processing @app.translate @values[:start_x], @values[:start_y] self.send(rule_name, {}) end - - + + # Before actually drawing the next step, we need to move to the appropriate # location. def get_ready_to_draw @@ -188,8 +188,8 @@ module Processing sign = (@values[:flip] ? -1 : 1) @app.rotate(sign * @values[:rotation]) end - - + + # Compute the rendering parameters for drawing a shape. def get_shape_values(some_options) old_ops = @values.dup @@ -197,16 +197,16 @@ module Processing @app.fill *old_ops[:color] return old_ops[:size], old_ops end - - + + # Square, circle, and ellipse are the primitive drawing # methods, but hopefully triangles will be added soon. def square(some_options=nil) size, options = *get_shape_values(some_options) @app.rect(0, 0, size, size) end - - + + def circle(some_options=nil) size, options = *get_shape_values(some_options) @app.ellipse(0, 0, size, size) @@ -219,8 +219,8 @@ module Processing @app.triangle(0, TRIANGLE_TOP * size, 0.5 * size, TRIANGLE_BOTTOM * size, -0.5 * size, TRIANGLE_BOTTOM * size) @app.rotate(-rot) if rot end - - + + def ellipse(some_options={}) rot = some_options[:rotation] @app.rotate(rot) if rot @@ -231,7 +231,7 @@ module Processing @app.rotate(-rot) if rot end alias_method :oval, :ellipse - + end - + end context_free.rb samples/levy.rb 4c94f7ff403207c32244e0e224d7f7610f155c93 Jeremy Ashkenas jashkenas@gmail.com http://github.com/jashkenas/context_free/commit/ed79110f3a4387600f264bb47ab1f317ec1d4fdd ed79110f3a4387600f264bb47ab1f317ec1d4fdd 2009-11-08T12:40:29-08:00 2009-11-08T12:40:29-08:00 merging monkstone and whitespace 6be065deaf1c553dfdf3aee7033e870f4688d961 Jeremy Ashkenas jashkenas@gmail.com