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
This constant is used to approximate a symmetrical arc using a cubic Bezier curve.
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_at [100,100], :radius => 25
# File lib/prawn/graphics.rb, line 187 def circle_at(point, options) x,y = point ellipse_at [x, y], options[:radius] end
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 171 def curve(origin,dest, options={}) move_to(*origin) curve_to(dest,options) end
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 63 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
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_at [100,100], 25, 50
# File lib/prawn/graphics.rb, line 200 def ellipse_at(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
Fills and closes the current path. See Graphic::Color for color details
# File lib/prawn/graphics.rb, line 281 def fill yield if block_given? add_content "f" end
Fills, strokes, and closes the current path. See Graphic::Color for color details
# File lib/prawn/graphics.rb, line 288 def fill_and_stroke yield if block_given? add_content "b" end
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 140 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
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 153 def horizontal_rule horizontal_line(bounds.left, bounds.right) end
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 128 def line(*points) x0,y0,x1,y1 = points.flatten move_to(x0, y0) line_to(x1, y1) end
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 53 def line_to(*point) x,y = map_to_absolute(point) add_content("%.3f %.3f l" % [ x, y ]) end
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 114 def line_width(width=nil) if width self.line_width = width else (defined?(@line_width) && @line_width) || 1 end end
Sets line thickness to the width specified.
# File lib/prawn/graphics.rb, line 101 def line_width=(width) @line_width = width add_content("#{width} w") end
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 42 def move_to(*point) x,y = map_to_absolute(point) add_content("%.3f %.3f m" % [ x, y ]) end
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 231 def polygon(*points) move_to points[0] (points[1..-1] << points[0]).each do |point| line_to(*point) end end
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 78 def rectangle(point,width,height) x,y = map_to_absolute(point) add_content("%.3f %.3f %.3f %.3f re" % [ x, y - height, width, height ]) end
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 243 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 end
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 89 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
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 256 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
Strokes and closes the current path. See Graphic::Color for color details
# File lib/prawn/graphics.rb, line 268 def stroke yield if block_given? add_content "S" end
Draws and strokes a rectangle represented by the current bounding box
# File lib/prawn/graphics.rb, line 275 def stroke_bounds stroke_rectangle bounds.top_left, bounds.width, bounds.height end
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 162 def vertical_line(y1,y2,params) line(params[:at],y1,params[:at],y2) end
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