Prima::Drawable::Gradient(3pm)

1Prima::Drawable::GradieUnste(r3)Contributed Perl DocumenPtraitmiao:n:Drawable::Gradient(3)
2
3
4

NAME

6       Prima::Drawable::Gradient - gradient fills for primitives
7

DESCRIPTION

9       Prima offers primitive gradient services to draw gradually changing
10       colors.  A gradient is requested by setting of at least two colors and
11       optionally a set of quadratic spline points that, when, projected,
12       generate the transition curve between the colors.
13
14       The module augments the "Prima::Drawable" drawing functionality by
15       adding "new_gradient" function.
16

SYNOPSIS

18               $canvas-> new_gradient(
19                       palette => [ cl::White, cl::Blue, cl::White ],
20               )-> sector(50,50,100,100,0,360);
21

API

23   Methods
24       new $CANVAS, %OPTIONS
25           Here are %OPTIONS understood in the gradient request:
26
27           clone %OPTIONS
28               Creates a new gradient object with %OPTIONS replaced.
29
30           widgetClass INTEGER
31               Points to a widget class to resolve generic colors like
32               "cl::Back", that may differ from widget class to widget class.
33
34           palette @COLORS
35               Each color is a "cl::" value. The gradient is calculated as
36               polyline where each its vertex corresponds to a certain blend
37               between two neighbouring colors in the palette. F.ex. the
38               simplest palette going from "cl::White" to "cl::Black" over a
39               polyline 0..1 (default), produces pure white color at the start
40               and pure black color at the end, filling all available shades
41               of gray in between, and changing monotonically.
42
43           poly @VERTICES
44               Set of 2-integer polyline vertexes where the first integer is a
45               coordinate (x, y, or whatever required by the drawing
46               primitive) between 0 and 1, and the second is the color blend
47               value between 0 and 1.
48
49               Default: ((0,0),(1,1))
50
51           spline \@VERTICES, %OPTIONS
52               Serving same purpose as "poly" but vertexes are projected first
53               to a B-spline curve using render_spline and %OPTIONS. The
54               resulting polyline is treated as "poly".
55
56           vertical BOOLEAN
57               Only used in bar, to set gradient direction.
58
59           See also: bar, stripes .
60
61       bar X1, Y1, X2, Y2, VERTICAL = 0
62           Draws a filled rectangle within (X1,Y1) - (X2,Y2) extents
63
64           Context used: fillPattern, rop, rop2
65
66       ellipse X, Y, DIAM_X, DIAM_Y
67           Draws a filled ellipse with center in (X,Y) and diameters
68           (DIAM_X,DIAM_Y)
69
70           Context used: fillPattern, rop, rop2
71
72       sector X, Y, DIAM_X, DIAM_Y, START_ANGLE, END_ANGLE
73           Draws a filled sector with center in (X,Y) and diameters
74           (DIAM_X,DIAM_Y) from START_ANGLE to END_ANGLE
75
76           Context used: fillPattern, rop, rop2
77
78       stripes BREADTH
79           Returns an array consisting of integer pairs, where the first one
80           is a color value, and the second is the breadth of the color strip.
81           bar uses this information to draw a gradient fill, where each color
82           strip is drawn with its own color. Can be used for implementing
83           other gradient-aware primitives (see examples/f_fill.pl )
84

AUTHOR

86       Dmitry Karasik, <dmitry@karasik.eu.org>.
87

NAME

DESCRIPTION

SYNOPSIS

API

AUTHOR

SEE ALSO