Prawn::Graphics::Gradient

    # File lib/prawn/graphics/gradient.rb, line 26
26:       def fill_gradient(point, width, height, color1, color2, options = {})
27:         set_gradient(:fill, point, width, height, color1, color2, options)
28:       end

    # File lib/prawn/graphics/gradient.rb, line 33
33:       def stroke_gradient(point, width, height, color1, color2, options = {})
34:         set_gradient(:stroke, point, width, height, color1, color2, options)
35:       end

    # File lib/prawn/graphics/gradient.rb, line 39
39:       def set_gradient(type, point, width, height, color1, color2, options)
40:         if options[:stroke_bounds]
41:           stroke_color 0, 0, 0, 100
42:           stroke_rectangle point, width, height
43:         end
44: 
45:         if color_type(color1) != color_type(color2)
46:           raise ArgumentError, 'both colors must be of the same type: RGB or CMYK'
47:         end
48: 
49:         process_color color1
50:         process_color color2
51: 
52:         shader = ref!({
53:           :FunctionType => 2,
54:           :Domain => [0.0, 1.0],
55:           :C0 => normalize_color(color1),
56:           :C1 => normalize_color(color2),
57:           :N => 1,
58:         })
59: 
60:         shading = ref!({
61:           :ShadingType => 2, # axial shading
62:           :ColorSpace => color_type(color1) == :RGB ? :DeviceRGB : :DeviceCMYK,
63:           :Coords => [0.0, 0.0, 1.0, 0.0],
64:           :Function => shader,
65:           :Extend => [true, true],
66:         })
67: 
68:         x, y = *point
69:         shading_pattern = ref!({
70:           :PatternType => 2, # shading pattern
71:           :Shading => shading,
72:           :Matrix => [0,-height, -width, 0, x, y],
73:         })
74: 
75:         patterns = page.resources[:Pattern] ||= {}
76:         id = patterns.empty? ? 'SP1' : patterns.keys.sort.last.succ
77:         patterns[id] = shading_pattern
78: 
79:         set_color type, id, :pattern => true
80:       end