Class: SmartImage::JavaCanvas
- Inherits:
-
BaseCanvas
- Object
- BaseCanvas
- SmartImage::JavaCanvas
- Defined in:
- lib/smart_image/java_canvas.rb
Overview
Canvas object backed by Java Graphics2D
Instance Method Summary collapse
-
#alpha_mask(image_data, options = {}) ⇒ Object
Load the given file as an alpha mask for the image.
-
#composite(image_data, options = {}) ⇒ Object
Composite the given image data onto the canvas.
-
#destroy ⇒ Object
Stub out destroy since Java actually garbage collects crap, unlike…
-
#encode(format, options = {}) ⇒ Object
Encode the image to the given format.
-
#initialize(width, height) ⇒ JavaCanvas
constructor
A new instance of JavaCanvas.
Methods inherited from BaseCanvas
Constructor Details
#initialize(width, height) ⇒ JavaCanvas
Returns a new instance of JavaCanvas.
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# File 'lib/smart_image/java_canvas.rb', line 12 def initialize(width, height) @canvas = BufferedImage.new width, height, BufferedImage::TYPE_INT_ARGB end |
Instance Method Details
#alpha_mask(image_data, options = {}) ⇒ Object
Load the given file as an alpha mask for the image
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# File 'lib/smart_image/java_canvas.rb', line 39 def alpha_mask(image_data, = {}) input_stream = ByteArrayInputStream.new image_data.to_java_bytes mask = ImageIO.read input_stream width = mask.width image_data, mask_data = Java::int[width].new, Java::int[width].new mask.height.times do |y| # fetch a line of data from each image @canvas.get_rgb 0, y, width, 1, image_data, 0, 1 mask.get_rgb 0, y, width, 1, mask_data, 0, 1 width.times do |x| # mask away the alpha color = image_data[x] & 0x00FFFFFF # turn red from the mask into alpha alpha = (mask_data[x] & 0x00FF0000) << 8 image_data[x] = color | alpha end @canvas.set_rgb 0, y, width, 1, image_data, 0, 1 end end |
#composite(image_data, options = {}) ⇒ Object
Composite the given image data onto the canvas
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# File 'lib/smart_image/java_canvas.rb', line 21 def composite(image_data, = {}) info = SmartImage.info image_data opts = { :width => info.width, :height => info.height, :x => 0, :y => 0 }.merge() input_stream = ByteArrayInputStream.new image_data.to_java_bytes image = ImageIO.read input_stream raise FormatError, "invalid image" unless image graphics = @canvas.graphics graphics.draw_image image, opts[:x], opts[:y], opts[:width], opts[:height], nil end |
#destroy ⇒ Object
Stub out destroy since Java actually garbage collects crap, unlike… C
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# File 'lib/smart_image/java_canvas.rb', line 17 def destroy end |
#encode(format, options = {}) ⇒ Object
Encode the image to the given format
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# File 'lib/smart_image/java_canvas.rb', line 66 def encode(format, = {}) output_stream = ByteArrayOutputStream.new ImageIO.write(@canvas, format.to_s, output_stream) String.from_java_bytes output_stream.to_byte_array end |