Class: Tioga::Strokes

Inherits:
Object
  • Object
show all
Defined in:
lib/Tioga/Strokes.rb

Overview

These are the attributes for doing stroked lines in PDF graphics. The methods for strokes include #stroke, stroke_line, stroke_rect, stroke_frame, stroke_circle, stroke_oval, and stroke_polyline.

Instance Method Summary collapse

Instance Method Details

#default_line_scale ⇒ Object

:call-seq:

default_line_scale                                     
default_line_scale = a_float

Scaling factor for the width of stroked lines (default is 1). The #stroke operations produce lines with a width determined by the product of the line_width times the default_line_scale.



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# File 'lib/Tioga/Strokes.rb', line 32

def default_line_scale
end

#line_cap ⇒ Object

:call-seq:

line_cap                                     
line_cap = a_line_cap

The line cap style specifies the shape to be used at the ends of open subpaths (and dashes, if any) when they are stroked. Valid values are the predefined constants: LINE_CAP_BUTT, LINE_CAP_ROUND, and LINE_CAP_SQUARE. For LINE_CAP_BUTT, the stroke is squared off at the endpoint of the path. There is no projection beyond the end of the path. For LINE_CAP_ROUND, a semicircular arc with a diameter equal to the line width is drawn around the endpoint and filled in. For LINE_CAP_SQUARE, the stroke continues beyond the endpoint of the path for a distance equal to half the line width and is then squared off. See also line_join.



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# File 'lib/Tioga/Strokes.rb', line 68

def line_cap
end

#line_join ⇒ Object

:call-seq:

line_join                                     
line_join = a_line_join

The line join style specifies the shape to be used at the corners of paths that are stroked. Join styles are significant only at points where consecutive segments of a path connect at an angle; segments that meet or intersect fortuitously receive no special treatment. Valid values are the predefined constants: LINE_JOIN_MITER, LINE_JOIN_ROUND, and LINE_JOIN_BEVEL. For LINE_JOIN_MITER, the outer edges of the strokes for the two segments are extended until they meet at an angle, as in a picture frame. If the segments meet at too sharp an angle (as defined by the miter limit parameter), a bevel join is used instead. For LINE_JOIN_ROUND, an arc of a circle with a diameter equal to the line width is drawn around the point where the two segments meet, connecting the outer edges of the strokes for the two segments. This pieslice-shaped figure is filled in, producing a rounded corner. For LINE_JOIN_BEVEL, the two segments are finished with butt caps and the resulting notch beyond the ends of the segments is filled with a triangle. See also line_cap.



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# File 'lib/Tioga/Strokes.rb', line 87

def line_join
end

#line_type ⇒ Object

:call-seq:

line_type                                     
line_type = a_line_type

The line type controls the pattern of dashes and gaps used to stroke paths. It is specified by a dash array and a dash phase. The dash array’s elements are numbers that specify the lengths of alternating dashes and gaps; the dash phase specifies the distance into the dash pattern at which to start the dash. The elements of both the dash array and the dash phase are expressed in user space units. An empty dash array and zero phase can be used to set the dash pattern to a solid line.

Dashed lines wrap around curves and corners just as solid stroked lines do. The ends of each dash are treated with the current line cap style, and corners within dashes are treated with the current line join style. A stroking operation takes no measures to coordinate the dash pattern with features of the path; it simply dispenses dashes and gaps along the path in the pattern defined by the dash array.

When a path consisting of several subpaths is stroked, each subpath is treated independently – that is, the dash pattern is restarted and the dash phase is reapplied to it at the beginning of each subpath. 



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# File 'lib/Tioga/Strokes.rb', line 112

def line_type
end

#line_width ⇒ Object

:call-seq:

line_width                                     
line_width = a_float

The width of stroked lines. A line width of 0 denotes the thinnest line that can be rendered at device resolution: 1 device pixel wide. However, some devices cannot reproduce 1-pixel lines, and on high-resolution devices, they are nearly invisible. Since the results of rendering such “zero-width” lines are device-dependent, their use is not recommended. The actual line width is adjusted according to the current value of the default_line_scale.



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# File 'lib/Tioga/Strokes.rb', line 44

def line_width
end

#miter_limit ⇒ Object

:call-seq:

miter_limit                                     
miter_limit = a_float

Sets a maximum for the ratio of the miter length to the line width (default is 2). When the limit is exceeded, the line join is converted from a miter to a bevel. This limit is needed since when two line segments meet at a sharp angle and mitered joins have been specified as the line_join, it is possible for the miter to extend far beyond the thickness of the line stroking the path.



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# File 'lib/Tioga/Strokes.rb', line 23

def miter_limit
end

#rescale_lines(scale) ⇒ Object

Adjust default_line_scale by multiplying it by the given scale and adjust the current line_width accordingly.



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# File 'lib/Tioga/Strokes.rb', line 117

def rescale_lines(scale)
end

#stroke_line(x0, y0, x1, y1) ⇒ Object

Calls move_to_point, append_point_to_path, and #stroke.



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# File 'lib/Tioga/Strokes.rb', line 11

def stroke_line(x0, y0, x1, y1)
end

#stroke_polyline(xs, ys, color = nil, legend = nil, type = nil, gaps = nil, close_subpaths = nil) ⇒ Object

Calls #context, then, inside the new context, changes line_type and stroke_color (if those arguments are not nil), calls append_points_with_gaps_to_path, calls #stroke, and then saves the legend information (if legend is not nil). Alias for show_polyline.



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# File 'lib/Tioga/Strokes.rb', line 123

def stroke_polyline(xs, ys, color = nil, legend = nil, type = nil, gaps = nil, close_subpaths = nil)
end

#stroke_width ⇒ Object

:call-seq:

stroke_width                                     
stroke_width = a_float

Alias for line_width.



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# File 'lib/Tioga/Strokes.rb', line 52

def stroke_width
end