### Home Classes Methods

### In Files

- lib/prawn/graphics.rb
- lib/prawn/graphics/gradient.rb
- lib/prawn/graphics/color.rb
- lib/prawn/graphics/transparency.rb
- lib/prawn/graphics/cap_style.rb
- lib/prawn/graphics/transformation.rb
- lib/prawn/graphics/join_style.rb
- lib/prawn/graphics/dash.rb

### Namespace

- MODULE Prawn::Graphics::CapStyle
- MODULE Prawn::Graphics::Color
- MODULE Prawn::Graphics::Dash
- MODULE Prawn::Graphics::Gradient
- MODULE Prawn::Graphics::JoinStyle
- MODULE Prawn::Graphics::Transformation
- MODULE Prawn::Graphics::Transparency

### Methods

- #circle
- #circle_at
- #close_and_stroke
- #close_path
- #curve
- #curve_to
- #ellipse
- #ellipse_at
- #fill
- #fill_and_stroke
- #horizontal_line
- #horizontal_rule
- #line
- #line_to
- #line_width
- #line_width=
- #method_missing
- #move_to
- #polygon
- #rectangle
- #rounded_polygon
- #rounded_rectangle
- #rounded_vertex
- #stroke
- #stroke_bounds
- #vertical_line

### Included Modules

- Prawn::Graphics::Color
- Prawn::Graphics::Dash
- Prawn::Graphics::CapStyle
- Prawn::Graphics::JoinStyle
- Prawn::Graphics::Transparency
- Prawn::Graphics::Transformation
- Prawn::Graphics::Gradient

### Files

- COPYING
- GPLv2
- GPLv3
- LICENSE

### Class/Module Index

Quicksearch

- Prawn
- Prawn::Core
- Prawn::Core::Page
- Prawn::Core::Page::GraphicsState
- Prawn::Core::Reference
- Prawn::Document
- Prawn::Document::BoundingBox
- Prawn::Document::ColumnBox
- Prawn::Document::GraphicsState
- Prawn::Document::Grid
- Prawn::Document::Internals
- Prawn::Document::PageGeometry
- Prawn::Document::Security
- Prawn::Document::Snapshot
- Prawn::Encoding
- Prawn::Errors
- Prawn::Font
- Prawn::Font::AFM
- Prawn::Font::DFont
- Prawn::Font::TTF
- Prawn::GraphicState
- Prawn::GraphicStateStack
- Prawn::Graphics
- Prawn::Graphics::CapStyle
- Prawn::Graphics::Color
- Prawn::Graphics::Dash
- Prawn::Graphics::Gradient
- Prawn::Graphics::JoinStyle
- Prawn::Graphics::Transformation
- Prawn::Graphics::Transparency
- Prawn::Images
- Prawn::Images::JPG
- Prawn::Images::PNG
- Prawn::Layout
- Prawn::Measurements
- Prawn::Outline
- Prawn::Stamp
- Prawn::Table
- Prawn::Table::Cell
- Prawn::Table::Cell::InTable
- Prawn::Table::Cell::Subtable
- Prawn::Table::Cell::Text
- Prawn::Table::Cells
- Prawn::Text
- Prawn::Text::Box
- Prawn::Text::Formatted
- Prawn::Text::Formatted::Box
- Prawn::Text::Formatted::Fragment
- Prawn::Text::Formatted::Parser
- Arcfour
- Numeric

No matching classes.

# Prawn::Graphics

Implements the drawing facilities for Prawn::Document. Use this to draw the most beautiful imaginable things.

This file lifts and modifies several of PDF::Writer's graphics functions ruby-pdf.rubyforge.org

### Constants

KAPPA

  This constant is used to approximate a symmetrical arc using a cubic Bezier curve.

### Public Instance Methods

circle(center, radius) click to toggle source

Draws a circle of radius `radius` with the centre-point at `point` as a complete subpath. The drawing point will be moved to the centre-point upon completion of the drawing the circle.

    pdf.circle [100,100], 25

    # File lib/prawn/graphics.rb, line 196
    def circle(center, radius)
      ellipse(center, radius, radius)
    end

circle_at(point, options) click to toggle source

DEPRECATED: Please use `circle` instead.

    # File lib/prawn/graphics.rb, line 184
    def circle_at(point, options)
      warn "[DEPRECATION] 'circle_at' is deprecated in favor of 'circle'. " +
           "'circle_at' will be removed in release 1.1"
      circle(point, options[:radius])
    end

close_and_stroke() click to toggle source

Closes and strokes the current path. If a block is provided, yields to the block before closing the path. See Graphics::Color for color details.

    # File lib/prawn/graphics.rb, line 296
    def close_and_stroke
      yield if block_given?
      add_content "s"
    end

close_path() click to toggle source

Closes the current path.

    # File lib/prawn/graphics.rb, line 325
    def close_path
      add_content "h"
    end

curve(origin,dest, options={}) click to toggle source

Draws a Bezier curve between two points, bounded by two additional points

    pdf.curve [50,100], [100,100], :bounds => [[90,90],[75,75]]

    # File lib/prawn/graphics.rb, line 173
    def curve(origin,dest, options={})
      move_to(*origin)
      curve_to(dest,options)
    end

curve_to(dest,options={}) click to toggle source

Draws a Bezier curve from the current drawing position to the specified point, bounded by two additional points.

    pdf.curve_to [100,100], :bounds => [[90,90],[75,75]]

    # File lib/prawn/graphics.rb, line 65
    def curve_to(dest,options={})
       options[:bounds] or raise Prawn::Errors::InvalidGraphicsPath,
         "Bounding points for bezier curve must be specified "+
         "as :bounds => [[x1,y1],[x2,y2]]"

       curve_points = (options[:bounds] << dest).map { |e| map_to_absolute(e) }
       add_content("%.3f %.3f %.3f %.3f %.3f %.3f c" %
                     curve_points.flatten )
    end

ellipse(point, r1, r2 = r1) click to toggle source

Draws an ellipse of `x` radius `r1` and `y` radius `r2` with the centre-point at `point` as a complete subpath. The drawing point will be moved to the centre-point upon completion of the drawing the ellipse.

    # draws an ellipse with x-radius 25 and y-radius 50
    pdf.ellipse [100,100], 25, 50

    # File lib/prawn/graphics.rb, line 215
    def ellipse(point, r1, r2 = r1)
      x, y = point
      l1 = r1 * KAPPA
      l2 = r2 * KAPPA

      move_to(x + r1, y)

      # Upper right hand corner
      curve_to [x,  y + r2],
        :bounds => [[x + r1, y + l1], [x + l2, y + r2]]

      # Upper left hand corner
      curve_to [x - r1, y],
        :bounds => [[x - l2, y + r2], [x - r1, y + l1]]

      # Lower left hand corner
      curve_to [x, y - r2],
        :bounds => [[x - r1, y - l1], [x - l2, y - r2]]

      # Lower right hand corner
      curve_to [x + r1, y],
        :bounds => [[x + l2, y - r2], [x + r1, y - l1]]

      move_to(x, y)
    end

ellipse_at(point, r1, r2=r1) click to toggle source

DEPRECATED: Please use `ellipse` instead.

    # File lib/prawn/graphics.rb, line 201
    def ellipse_at(point, r1, r2=r1)
      warn "[DEPRECATION] 'ellipse_at' is deprecated in favor of 'ellipse'. " +
           "'ellipse_at' will be removed in release 1.1"
      ellipse(point, r1, r2)
    end

fill() click to toggle source

Closes and fills the current path. See Graphics::Color for color details.

    # File lib/prawn/graphics.rb, line 309
    def fill
      yield if block_given?
      add_content "f"
    end

fill_and_stroke() click to toggle source

Closes, fills, and strokes the current path. If a block is provided, yields to the block before closing the path. See Graphics::Color for color details.

    # File lib/prawn/graphics.rb, line 318
    def fill_and_stroke
      yield if block_given?
      add_content "b"
    end

horizontal_line(x1,x2,options={}) click to toggle source

Draws a horizontal line from `x1` to `x2` at the current `y` position, or the position specified by the :at option.

    # draw a line from [25, 75] to [100, 75]
    horizontal_line 25, 100, :at => 75

    # File lib/prawn/graphics.rb, line 142
    def horizontal_line(x1,x2,options={})
      if options[:at]
        y1 = options[:at]
      else
        y1 = y - bounds.absolute_bottom
      end

      line(x1,y1,x2,y1)
    end

horizontal_rule() click to toggle source

Draws a horizontal line from the left border to the right border of the bounding box at the current `y` position.

    # File lib/prawn/graphics.rb, line 155
    def horizontal_rule
      horizontal_line(bounds.left, bounds.right)
    end

line(*points) click to toggle source

Draws a line from one point to another. Points may be specified as tuples or flattened argument list:

    pdf.line [100,100], [200,250]
    pdf.line(100,100,200,250)

    # File lib/prawn/graphics.rb, line 130
    def line(*points)
      x0,y0,x1,y1 = points.flatten
      move_to(x0, y0)
      line_to(x1, y1)
    end

line_to(*point) click to toggle source

Draws a line from the current drawing position to the specified point. The destination may be described as a tuple or a flattened list:

    pdf.line_to [50,50]
    pdf.line_to(50,50)

    # File lib/prawn/graphics.rb, line 55
    def line_to(*point)
      x,y = map_to_absolute(point)
      add_content("%.3f %.3f l" % [ x, y ])
    end

line_width(width=nil) click to toggle source

When called without an argument, returns the current line thickness. When called with an argument, sets the line thickness to the specified value (in PDF points)

    pdf.line_width #=> 1
    pdf.line_width(5)
    pdf.line_width #=> 5

    # File lib/prawn/graphics.rb, line 116
    def line_width(width=nil)
      if width
        self.line_width = width
      else
        current_line_width
      end
    end

line_width=(width) click to toggle source

Sets line thickness to the `width` specified.

    # File lib/prawn/graphics.rb, line 103
    def line_width=(width)
      self.current_line_width = width
      write_line_width
    end

method_missing(id,*args,&block) click to toggle source

Provides the following shortcuts:

    stroke_some_method(*args) #=> some_method(*args); stroke
    fill_some_method(*args) #=> some_method(*args); fill
    fill_and_stroke_some_method(*args) #=> some_method(*args); fill_and_stroke

    # File lib/prawn/graphics.rb, line 335
    def method_missing(id,*args,&block)
      case(id.to_s)
      when /^fill_and_stroke_(.*)/
        send($1,*args,&block); fill_and_stroke
      when /^stroke_(.*)/
        send($1,*args,&block); stroke
      when /^fill_(.*)/
        send($1,*args,&block); fill
      else
        super
      end
    end

move_to(*point) click to toggle source

Moves the drawing position to a given point. The point can be specified as a tuple or a flattened argument list

    pdf.move_to [100,50]
    pdf.move_to(100,50)

    # File lib/prawn/graphics.rb, line 44
    def move_to(*point)
      x,y = map_to_absolute(point)
      add_content("%.3f %.3f m" % [ x, y ])
    end

polygon(*points) click to toggle source

Draws a polygon from the specified points.

    # draws a snazzy triangle
    pdf.polygon [100,100], [100,200], [200,200]

    # File lib/prawn/graphics.rb, line 246
    def polygon(*points)
      move_to points[0]
      (points[1..-1] << points[0]).each do |point|
        line_to(*point)
      end
      # close the path
      add_content "h"
    end

rectangle(point,width,height) click to toggle source

Draws a rectangle given `point`, `width` and `height`. The rectangle is bounded by its upper-left corner.

    pdf.rectangle [300,300], 100, 200

    # File lib/prawn/graphics.rb, line 80
    def rectangle(point,width,height)
      x,y = map_to_absolute(point)
      add_content("%.3f %.3f %.3f %.3f re" % [ x, y - height, width, height ])
    end

rounded_polygon(radius, *points) click to toggle source

Draws a rounded polygon from specified points using the radius to define bezier curves

    # draws a rounded filled in polygon
     pdf.fill_and_stroke_rounded_polygon(10, [100, 250], [200, 300], [300, 250],
                   [300, 150], [200, 100], [100, 150])

    # File lib/prawn/graphics.rb, line 260
    def rounded_polygon(radius, *points)
      move_to point_on_line(radius, points[1], points[0])
      sides = points.size
      points << points[0] << points[1]
      (sides).times do |i|
        rounded_vertex(radius, points[i], points[i + 1], points[i + 2])
      end
      # close the path
      add_content "h"
    end

rounded_rectangle(point,width,height,radius) click to toggle source

Draws a rounded rectangle given `point`, `width` and `height` and `radius` for the rounded corner. The rectangle is bounded by its upper-left corner.

    pdf.rounded_rectangle [300,300], 100, 200, 10

    # File lib/prawn/graphics.rb, line 91
    def rounded_rectangle(point,width,height,radius)
      x, y = point
      rounded_polygon(radius, point, [x + width, y], [x + width, y - height], [x, y - height])
    end

rounded_vertex(radius, *points) click to toggle source

Creates a rounded vertex for a line segment used for building a rounded polygon requires a radius to define bezier curve and three points. The first two points define the line segment and the third point helps define the curve for the vertex.

    # File lib/prawn/graphics.rb, line 275
    def rounded_vertex(radius, *points)
      x0,y0,x1,y1,x2,y2 = points.flatten
      radial_point_1 = point_on_line(radius, points[0], points[1])
      bezier_point_1 = point_on_line((radius - radius*KAPPA), points[0], points[1] )
      radial_point_2 = point_on_line(radius, points[2], points[1])
      bezier_point_2 = point_on_line((radius - radius*KAPPA), points[2], points[1])
      line_to(radial_point_1)
      curve_to(radial_point_2, :bounds => [bezier_point_1, bezier_point_2])
    end

stroke() click to toggle source

Strokes the current path. If a block is provided, yields to the block before closing the path. See Graphics::Color for color details.

    # File lib/prawn/graphics.rb, line 288
    def stroke
      yield if block_given?
      add_content "S"
    end

stroke_bounds() click to toggle source

Draws and strokes a rectangle represented by the current bounding box

    # File lib/prawn/graphics.rb, line 303
    def stroke_bounds
      stroke_rectangle bounds.top_left, bounds.width, bounds.height
    end

vertical_line(y1,y2,params) click to toggle source

Draws a vertical line at the x cooordinate given by :at from y1 to y2.

    # draw a line from [25, 100] to [25, 300]
    vertical_line 100, 300, :at => 25

    # File lib/prawn/graphics.rb, line 164
    def vertical_line(y1,y2,params)
      line(params[:at],y1,params[:at],y2)
    end

[Validate]

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