Add Vincent's slides codem, add a blur to rendered background, and dr…

…aw text on top.

.gitignore

@@ -0,0 +1 @@
+*.swp

lib/canvas.rb

@@ -571,9 +571,9 @@ def text(txt="", x=0, y=0)
       # not sure that's worth doing that here
       txt = txt.to_s
       if @registration == :center
-        width = textwidth(txt)
-        x = x - width / 2
-        y = y + @fsize / 2
+        width = text_width(txt)
+        x = ((@width - x) / 2) - (width / 2)
+        y = ((@height - y) / 2) - (@fsize / 2.8)
       end
       CGContextShowTextAtPoint(@ctx, x, y, txt, txt.length)
     end

slides.rb

@@ -0,0 +1,188 @@
+# requires to be put in the same directory as https://github.com/drtoast/macruby_graphics
+
+framework 'Cocoa'
+here = File.expand_path(File.dirname(__FILE__))
+require File.join(here, 'graphics')
+
+SLIDE_WIDTH  = 1024
+SLIDE_HEIGHT = 768
+
+BLUR = 1.2
+
+# there are a few problems with constants resolutions
+# on the last MacRuby anyway so just do it simple
+include MRGraphics
+
+class SlideManager
+  def initialize
+    @current_slide = 0
+    @slides = []
+  end
+
+  def next_slide
+    @current_slide += 1 if @current_slide < @slides.length - 1
+  end
+
+  def previous_slide
+    @current_slide -= 1 if @current_slide > 0
+  end
+
+  def current_slide
+    @slides[@current_slide]
+  end
+
+  def add_slide(&block)
+    @slides << block
+  end
+end
+
+class SlideView < NSView
+  attr_accessor :slide_manager
+
+  def drawRect(rect)
+    NSColor.blackColor.set
+    NSRectFill(rect)
+
+    bounds = self.bounds
+    size = bounds.size
+    ratio = [size.width/SLIDE_WIDTH, size.height/SLIDE_HEIGHT].min
+
+    Canvas.for_rendering(:size => [SLIDE_WIDTH, SLIDE_HEIGHT]) do |c|
+      c.translate(size.width/2 - ((SLIDE_WIDTH/2) * ratio), size.height/2 - ((SLIDE_HEIGHT/2 * ratio)))
+      c.scale(ratio)
+      c.instance_eval(&slide_manager.current_slide)
+      applyFilterAndDrawToView(c.ciimage)
+    end
+
+    Canvas.for_current_context(:size => [SLIDE_WIDTH, SLIDE_HEIGHT]) do |c|
+      c.font "FedraSansDisStd HeavyCond", 200
+      c.registration :center
+      c.text "Eloy Duran"
+    end
+  end
+
+  def applyFilterAndDrawToView(ciimage)
+    blur = CIFilter.filterWithName("CIGaussianBlur")
+    blur.setDefaults
+    blur.setValue(BLUR, forKey:KCIInputRadiusKey)
+    blur.setValue(ciimage, forKey:KCIInputImageKey)
+    cicontext = CIContext.contextWithCGContext(NSGraphicsContext.currentContext.graphicsPort, options:nil)
+    cicontext.drawImage(blur.valueForKey(KCIOutputImageKey), atPoint:bounds.origin, fromRect:bounds)
+  end
+
+  def keyDown(key)
+    case key.keyCode
+    when KVK_Escape
+      exit
+    when KVK_LeftArrow
+      slide_manager.previous_slide
+      setNeedsDisplay true
+    when KVK_RightArrow
+      slide_manager.next_slide
+      setNeedsDisplay true
+    else
+      case key.characters
+      when "f"
+        if @fullscreen
+          exitFullScreenModeWithOptions nil
+          window.makeFirstResponder self
+        else
+          enterFullScreenMode NSScreen.mainScreen, withOptions: {NSFullScreenModeAllScreens => false}
+        end
+        @fullscreen = !@fullscreen
+      when "r"
+        setNeedsDisplay true
+      end
+    end
+  end
+end
+
+slide_manager = SlideManager.new
+
+slide_manager.add_slide do
+  # based on canvas_example.rb
+  background Color.black
+  white = Color.white
+  fill white
+  stroke 0.2
+  stroke_width 1
+  font "Zapfino"
+
+  80.times do
+    font_size rand(170)
+    fill white.copy.darken(rand(0.8))
+    letters = %W{ m a c r u b y }
+    text(letters[rand(letters.size)],
+            rand(SLIDE_WIDTH),
+            rand(SLIDE_HEIGHT))
+  end
+end
+
+slide_manager.add_slide do
+  # based on drawing_iterate_example.rb
+  background Color.white
+
+  # create a petal shape with base at (0,0), size 40×150, and bulge at 30px
+  shape = Path.new
+  shape.petal(0,0,40,150,30)
+  # add a circle
+  shape.oval(-10,20,20,20)
+  # color it red
+  shape.fill Color.red
+
+  # increment shape parameters by the specified amount each iteration,
+  # or by a random value selected from the specified range
+  shape.increment(:rotation, 5.0)
+  shape.increment(:scale_x, 0.99)
+  shape.increment(:scale_y, 0.96)
+  shape.increment(:x, 10.0)
+  shape.increment(:y, 12.0)
+  shape.increment(:hue,-0.02..0.02)
+  shape.increment(:saturation, -0.1..0.1)
+  shape.increment(:brightness, -0.1..0.1)
+  shape.increment(:alpha, -0.1..0.1)
+
+  # draw 200 petals on the canvas
+  translate(SLIDE_WIDTH/2-150, SLIDE_HEIGHT/2+20)
+  draw(shape,0,0,200)
+end
+
+slide_manager.add_slide do
+  # based on spirograph_example.rb
+  background Color.beige
+  fill Color.black
+  font 'Book Antiqua'
+  font_size 12
+  translate SLIDE_WIDTH/2, SLIDE_HEIGHT/2
+
+  # rotate, draw text, repeat
+  180.times do |frame|
+    new_state do
+      rotate((frame*2) + 120)
+      translate(70,0)
+      text('going...', 80, 0)
+      rotate(frame * 6)
+      text('Around and', 20, 0)
+    end
+  end
+end
+
+frame = [0.0, 0.0, SLIDE_WIDTH, SLIDE_HEIGHT]
+app = NSApplication.sharedApplication
+app.setActivationPolicy NSApplicationActivationPolicyRegular
+app.activateIgnoringOtherApps true
+view = SlideView.alloc.initWithFrame(frame)
+view.slide_manager = slide_manager
+
+window = NSWindow.alloc.initWithContentRect(frame,
+        styleMask:NSTitledWindowMask|NSClosableWindowMask|NSMiniaturizableWindowMask, 
+        backing:NSBackingStoreBuffered, 
+        defer:false)
+window.contentView = view
+window.makeFirstResponder view
+window.center
+window.display
+window.makeKeyAndOrderFront(nil)
+window.orderFrontRegardless
+
+app.run