1Prima::Drawable::Path(3U)ser Contributed Perl DocumentatiPornima::Drawable::Path(3)
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6 Prima::Drawable::Path - stroke and fill complex paths
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9 The module augments the "Prima::Drawable" drawing and plotting
10 functionality by implementing paths that allow arbitrary combination of
11 polylines, splines, and arcs, to be used for drawing or clipping
12 shapes.
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15 # draws elliptic spiral
16 my ( $d1, $dx ) = ( 0.8, 0.05 );
17 $canvas-> new_path->
18 rotate(45)->
19 translate(200, 100)->
20 scale(200, 100)->
21 arc( 0, 0, $d1 + $dx * 0, $d1 + $dx * 1, 0, 90)->
22 arc( 0, 0, $d1 + $dx * 2, $d1 + $dx * 1, 90, 180)->
23 arc( 0, 0, $d1 + $dx * 2, $d1 + $dx * 3, 180, 270)->
24 arc( 0, 0, $d1 + $dx * 4, $d1 + $dx * 3, 270, 360)->
25 stroke;
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28 Primitives
29 All primitives come in two versions, with absolute and relative
30 coordinates. The absolute version draws a graphic primitive so that
31 its starting point (or a reference point) is at (0,0). The relative
32 version, called with an 'r' (f.ex. "line" vs "rline") has its starting
33 point as the ending point of the previous primitive (or (0,0) if
34 there's none).
35 arc CENTER_X, CENTER_Y, DIAMETER_X, DIAMETER_Y, ANGLE_START, ANGLE_END,
37 TILT = 0
38 Adds elliptic arc to path centered around (CENTER_X,CENTER_Y).
39 Important: if the intention is an immediate rendering, especially
41 with 1-pixel line width, consider decreasing diameters by 1. This
42 is because all arc calculations are made with floating point, where
43 diameter is also given not in pixels but in geometrical
44 coordinates, to allow for matrix transformations. Before rendering
45 is performed, arcs are tranformed into spline vertices and then
46 transformation matrix is applied, and by that time the notion of an
47 arc diameter is lost to be successfully converted into pixel size
48 minus one.
49 close, open
51 Closes the current shape and opens a new one close() is same as
52 open() but makes sure the shape's first point is equal to its last
53 point.
54 circular_arc ANGLE_START, ANGLE_END
56 Adds circular arc to the path. Note that adding transformations
57 will effectively make it into elliptic arc, which is used
58 internally by "arc" and "rarc".
59 chord CENTER_X, CENTER_Y, DIAMETER_X, DIAMETER_Y, ANGLE_START,
61 ANGLE_END.
62 Adds chord to the path. Is there only for compatibility with
63 "Prima::Drawable".
64 ellipse CENTER_X, CENTER_Y, DIAMETER_X, DIAMETER_Y = DIAMETER_X, TILT =
66 0
67 Adds full ellipse to the path.
68 glyph INDEX, %OPTIONS
70 Adds glyph outline to the path. %OPTIONS are passed as is to
71 "renger_glyph" in Prima::Drawable. Note that filled glyphs require
72 "fillMode" without the "fm::Overlay" bit set and "fill" option set
73 to generate proper shapes with holes.
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