Module: Prawn::Graphics
- Includes:
- CapStyle, Color, Dash, JoinStyle, Patterns, Transformation, Transparency
- Included in:
- Document
- Defined in:
- lib/prawn/graphics.rb,
lib/prawn/graphics/dash.rb,
lib/prawn/graphics/color.rb,
lib/prawn/graphics/patterns.rb,
lib/prawn/graphics/cap_style.rb,
lib/prawn/graphics/join_style.rb,
lib/prawn/graphics/transparency.rb,
lib/prawn/graphics/transformation.rb
Overview
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
Defined Under Namespace
Modules: CapStyle, Color, Dash, JoinStyle, Patterns, Transformation, Transparency
Stable API collapse
- KAPPA =
This constant is used to approximate a symmetrical arc using a cubic Bezier curve.
4.0 * ((Math.sqrt(2) - 1.0) / 3.0)
Constants included from JoinStyle
Constants included from CapStyle
Stable API collapse
-
#circle(center, radius) ⇒ Object
Draws a circle of radius
radius
with the centre-point atpoint
as a complete subpath. -
#close_and_stroke ⇒ Object
Closes and strokes the current path.
-
#close_path ⇒ Object
Closes the current path.
-
#curve(origin, dest, options = {}) ⇒ Object
Draws a Bezier curve between two points, bounded by two additional points.
-
#curve_to(dest, options = {}) ⇒ Object
Draws a Bezier curve from the current drawing position to the specified point, bounded by two additional points.
-
#ellipse(point, r1, r2 = r1) ⇒ Object
Draws an ellipse of
x
radiusr1
andy
radiusr2
with the centre-point atpoint
as a complete subpath. -
#fill(options = {}) ⇒ Object
Closes and fills the current path.
-
#fill_and_stroke(options = {}) ⇒ Object
Closes, fills, and strokes the current path.
-
#horizontal_line(x1, x2, options = {}) ⇒ Object
Draws a horizontal line from
x1
tox2
at the currenty
position, or the position specified by the :at option. -
#horizontal_rule ⇒ Object
Draws a horizontal line from the left border to the right border of the bounding box at the current
y
position. -
#line(*points) ⇒ Object
Draws a line from one point to another.
-
#line_to(*point) ⇒ Object
Draws a line from the current drawing position to the specified point.
-
#line_width(width = nil) ⇒ Object
When called without an argument, returns the current line thickness.
-
#line_width=(width) ⇒ Object
Sets line thickness to the
width
specified. -
#move_to(*point) ⇒ Object
Moves the drawing position to a given point.
-
#polygon(*points) ⇒ Object
Draws a polygon from the specified points.
-
#rectangle(point, width, height) ⇒ Object
Draws a rectangle given
point
,width
andheight
. -
#rounded_polygon(radius, *points) ⇒ Object
Draws a rounded polygon from specified points using the radius to define bezier curves.
-
#rounded_rectangle(point, width, height, radius) ⇒ Object
Draws a rounded rectangle given
point
,width
andheight
andradius
for the rounded corner. -
#rounded_vertex(radius, *points) ⇒ Object
Creates a rounded vertex for a line segment used for building a rounded polygon requires a radius to define bezier curve and three points.
-
#stroke ⇒ Object
Strokes the current path.
-
#stroke_axis(options = {}) ⇒ Object
Draws and strokes X and Y axes rulers beginning at the current bounding box origin (or at a custom location).
-
#stroke_bounds ⇒ Object
Draws and strokes a rectangle represented by the current bounding box.
-
#vertical_line(y1, y2, params) ⇒ Object
Draws a vertical line at the x cooordinate given by :at from y1 to y2.
Methods included from Patterns
#fill_gradient, #stroke_gradient
Methods included from Transformation
#rotate, #scale, #transformation_matrix, #translate
Methods included from Transparency
Methods included from JoinStyle
Methods included from CapStyle
Methods included from Dash
Methods included from Color
#fill_color, hex2rgb, rgb2hex, #stroke_color
Instance Method Details
#circle(center, radius) ⇒ Object
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
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# File 'lib/prawn/graphics.rb', line 193 def circle(center, radius) ellipse(center, radius, radius) end |
#close_and_stroke ⇒ Object
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.
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# File 'lib/prawn/graphics.rb', line 285 def close_and_stroke yield if block_given? add_content "s" end |
#close_path ⇒ Object
Closes the current path.
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# File 'lib/prawn/graphics.rb', line 386 def close_path add_content "h" end |
#curve(origin, dest, options = {}) ⇒ Object
Draws a Bezier curve between two points, bounded by two additional points
pdf.curve [50,100], [100,100], :bounds => [[90,90],[75,75]]
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# File 'lib/prawn/graphics.rb', line 177 def curve(origin,dest, ={}) move_to(*origin) curve_to(dest,) end |
#curve_to(dest, options = {}) ⇒ Object
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]]
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# File 'lib/prawn/graphics.rb', line 69 def curve_to(dest,={}) [:bounds] or raise Prawn::Errors::InvalidGraphicsPath, "Bounding points for bezier curve must be specified "+ "as :bounds => [[x1,y1],[x2,y2]]" curve_points = ([: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) ⇒ Object
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
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# File 'lib/prawn/graphics.rb', line 205 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 + l2], [x + l1, y + r2]] # Upper left hand corner curve_to [x - r1, y], :bounds => [[x - l1, y + r2], [x - r1, y + l2]] # Lower left hand corner curve_to [x, y - r2], :bounds => [[x - r1, y - l2], [x - l1, y - r2]] # Lower right hand corner curve_to [x + r1, y], :bounds => [[x + l1, y - r2], [x + r1, y - l2]] move_to(x, y) end |
#fill(options = {}) ⇒ Object
Closes and fills the current path. See Graphics::Color for color details.
If the option :fill_rule => :even_odd is specified, Prawn will use the even-odd rule to fill the path. Otherwise, the nonzero winding number rule will be used. See the PDF reference, “Graphics -> Path Construction and Painting -> Clipping Path Operators” for details on the difference.
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# File 'lib/prawn/graphics.rb', line 365 def fill(={}) yield if block_given? add_content([:fill_rule] == :even_odd ? "f*" : "f") end |
#fill_and_stroke(options = {}) ⇒ Object
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.
If the option :fill_rule => :even_odd is specified, Prawn will use the even-odd rule to fill the path. Otherwise, the nonzero winding number rule will be used. See the PDF reference, “Graphics -> Path Construction and Painting -> Clipping Path Operators” for details on the difference.
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# File 'lib/prawn/graphics.rb', line 379 def fill_and_stroke(={}) yield if block_given? add_content([:fill_rule] == :even_odd ? "b*" : "b") end |
#horizontal_line(x1, x2, options = {}) ⇒ Object
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
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# File 'lib/prawn/graphics.rb', line 146 def horizontal_line(x1,x2,={}) if [:at] y1 = [:at] else y1 = y - bounds.absolute_bottom end line(x1,y1,x2,y1) end |
#horizontal_rule ⇒ Object
Draws a horizontal line from the left border to the right border of the bounding box at the current y
position.
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# File 'lib/prawn/graphics.rb', line 159 def horizontal_rule horizontal_line(bounds.left, bounds.right) end |
#line(*points) ⇒ Object
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)
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# File 'lib/prawn/graphics.rb', line 134 def line(*points) x0,y0,x1,y1 = points.flatten move_to(x0, y0) line_to(x1, y1) end |
#line_to(*point) ⇒ Object
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)
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# File 'lib/prawn/graphics.rb', line 59 def line_to(*point) x,y = map_to_absolute(point) add_content("%.3f %.3f l" % [ x, y ]) end |
#line_width(width = nil) ⇒ Object
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
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# File 'lib/prawn/graphics.rb', line 120 def line_width(width=nil) if width self.line_width = width else current_line_width end end |
#line_width=(width) ⇒ Object
Sets line thickness to the width
specified.
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# File 'lib/prawn/graphics.rb', line 107 def line_width=(width) self.current_line_width = width write_line_width end |
#move_to(*point) ⇒ Object
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)
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# File 'lib/prawn/graphics.rb', line 48 def move_to(*point) x,y = map_to_absolute(point) add_content("%.3f %.3f m" % [ x, y ]) end |
#polygon(*points) ⇒ Object
Draws a polygon from the specified points.
# draws a snazzy triangle
pdf.polygon [100,100], [100,200], [200,200]
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# File 'lib/prawn/graphics.rb', line 236 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) ⇒ Object
Draws a rectangle given point
, width
and height
. The rectangle is bounded by its upper-left corner.
pdf.rectangle [300,300], 100, 200
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# File 'lib/prawn/graphics.rb', line 84 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) ⇒ Object
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])
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# File 'lib/prawn/graphics.rb', line 250 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) ⇒ Object
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
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# File 'lib/prawn/graphics.rb', line 95 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) ⇒ Object
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.
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# File 'lib/prawn/graphics.rb', line 265 def rounded_vertex(radius, *points) 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 ⇒ Object
Strokes the current path. If a block is provided, yields to the block before closing the path. See Graphics::Color for color details.
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# File 'lib/prawn/graphics.rb', line 277 def stroke yield if block_given? add_content "S" end |
#stroke_axis(options = {}) ⇒ Object
Draws and strokes X and Y axes rulers beginning at the current bounding box origin (or at a custom location).
Options
:at
-
Origin of the X and Y axes (default: [0, 0] = origin of the bounding box)
:width
-
Length of the X axis (default: width of the bounding box)
:height
-
Length of the Y axis (default: height of the bounding box)
:step_length
-
Length of the step between markers (default: 100)
:negative_axes_length
-
Length of the negative parts of the axes (default: 20)
:color
:
The color of the axes and the text.
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# File 'lib/prawn/graphics.rb', line 320 def stroke_axis( = {}) = { :at => [0,0], :height => bounds.height.to_i - ([:at] || [0,0])[1], :width => bounds.width.to_i - ([:at] || [0,0])[0], :step_length => 100, :negative_axes_length => 20, :color => "000000", }.merge() Prawn.([:at, :width, :height, :step_length, :negative_axes_length, :color], ) save_graphics_state do fill_color([:color]) stroke_color([:color]) dash(1, :space => 4) stroke_horizontal_line([:at][0] - [:negative_axes_length], [:at][0] + [:width], :at => [:at][1]) stroke_vertical_line([:at][1] - [:negative_axes_length], [:at][1] + [:height], :at => [:at][0]) undash fill_circle([:at], 1) ([:step_length]..[:width]).step([:step_length]) do |point| fill_circle([[:at][0] + point, [:at][1]], 1) draw_text(point, :at => [[:at][0] + point - 5, [:at][1] - 10], :size => 7) end ([:step_length]..[:height]).step([:step_length]) do |point| fill_circle([[:at][0], [:at][1] + point], 1) draw_text(point, :at => [[:at][0] - 17, [:at][1] + point - 2], :size => 7) end end end |
#stroke_bounds ⇒ Object
Draws and strokes a rectangle represented by the current bounding box
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# File 'lib/prawn/graphics.rb', line 292 def stroke_bounds stroke_rectangle bounds.top_left, bounds.width, bounds.height end |
#vertical_line(y1, y2, params) ⇒ Object
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
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# File 'lib/prawn/graphics.rb', line 168 def vertical_line(y1,y2,params) line(params[:at],y1,params[:at],y2) end |