Module: PSD::Image::Export::PNG

Included in:
PSD::Image, Node::BuildPreview
Defined in:
lib/psd/image_exports/png.rb

Overview

PNG image export. This is the default export format.

Instance Method Summary collapse

Instance Method Details

#mask_to_png ⇒ Object 



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# File 'lib/psd/image_exports/png.rb', line 77

def mask_to_png
  return unless has_mask?

  png = ChunkyPNG::Canvas.new(@layer.mask.width.to_i, @layer.mask.height.to_i, ChunkyPNG::Color::TRANSPARENT)

  i = 0
  @layer.mask.height.times do |y|
    @layer.mask.width.times do |x|
      png[x, y] = ChunkyPNG::Color.grayscale(@mask_data[i])
      i += 1
    end
  end

  png
end

#save_as_png(file) ⇒ Object

Saves the PNG data to disk.



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# File 'lib/psd/image_exports/png.rb', line 94

def save_as_png(file)
  to_png.save(file, :fast_rgba)
end

#to_png ⇒ Object Also known as: export

Load the image pixels into a PNG file and return a reference to the data.



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# File 'lib/psd/image_exports/png.rb', line 9

def to_png
  return @png if @png

  PSD.logger.debug "Beginning PNG export"
  @png = ChunkyPNG::Canvas.new(width.to_i, height.to_i, ChunkyPNG::Color::TRANSPARENT)

  i = 0
  height.times do |y|
    width.times do |x|
      @png[x,y] = @pixel_data[i]
      i += 1
    end
  end

  @png
end

#to_png_with_mask ⇒ Object 



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# File 'lib/psd/image_exports/png.rb', line 27

def to_png_with_mask
  return to_png unless has_mask?
  return @png_with_mask if @png_with_mask

  PSD.logger.debug "Beginning PNG export with mask"

  # We generate the preview at the document size instead to make applying the mask
  # significantly easier.
  width = @layer.header.width.to_i
  height = @layer.header.height.to_i
  @png_with_mask = ChunkyPNG::Canvas.new(width, height, ChunkyPNG::Color::TRANSPARENT)

  i = 0
  @layer.height.times do |y|
    @layer.width.times do |x|
      offset_x = x + @layer.left
      offset_y = y + @layer.top

      i +=1 and next if offset_x < 0 || offset_y < 0 || offset_x >= @png_with_mask.width || offset_y >= @png_with_mask.height

      @png_with_mask[offset_x, offset_y] = @pixel_data[i]
      i += 1
    end
  end

  # Now we apply the mask
  i = 0
  @layer.mask.height.times do |y|
    @layer.mask.width.times do |x|
      offset_x = @layer.mask.left + x
      offset_y = @layer.mask.top + y

      i += 1 and next if offset_x < 0 || offset_y < 0 || offset_x >= @png_with_mask.width || offset_y >= @png_with_mask.height

      color = ChunkyPNG::Color.to_truecolor_alpha_bytes(@png_with_mask[offset_x, offset_y])
      color[3] = color[3] * @mask_data[i] / 255

      @png_with_mask[offset_x, offset_y] = ChunkyPNG::Color.rgba(*color)
      i += 1
    end
  end

  crop_left = PSD::Util.clamp(@layer.left, 0, @png_with_mask.width)
  crop_top = PSD::Util.clamp(@layer.top, 0, @png_with_mask.height)
  crop_width = PSD::Util.clamp(@layer.width.to_i, 0, @png_with_mask.width - crop_left)
  crop_height = PSD::Util.clamp(@layer.height.to_i, 0, @png_with_mask.height - crop_top)

  @png_with_mask.crop!(crop_left, crop_top, crop_width, crop_height)
end