class Magick::Draw
Constants
- ALIGN_TYPE_NAMES
Thse hashes are used to map
Magick
constant values to the strings used in the primitives.- ANCHOR_TYPE_NAMES
- DECORATION_TYPE_NAMES
- FONT_WEIGHT_NAMES
- GRAVITY_NAMES
- PAINT_METHOD_NAMES
- STRETCH_TYPE_NAMES
- STYLE_TYPE_NAMES
Public Instance Methods
Apply coordinate transformations to support scaling (s), rotation ®, and translation (t). Angles are specified in radians.
# File lib/rmagick_internal.rb, line 280 def affine(sx, rx, ry, sy, tx, ty) primitive 'affine ' + sprintf('%g,%g,%g,%g,%g,%g', sx, rx, ry, sy, tx, ty) end
Set alpha (make transparent) in image according to the specified colorization rule
# File lib/rmagick_internal.rb, line 286 def alpha(x, y, method) Kernel.raise ArgumentError, 'Unknown paint method' unless PAINT_METHOD_NAMES.key?(method.to_i) name = Gem::Version.new(Magick::IMAGEMAGICK_VERSION) > Gem::Version.new('7.0.0') ? 'alpha ' : 'matte ' primitive name + sprintf('%g,%g, %s', x, y, PAINT_METHOD_NAMES[method.to_i]) end
Draw
an arc.
# File lib/rmagick_internal.rb, line 293 def arc(start_x, start_y, end_x, end_y, start_degrees, end_degrees) primitive 'arc ' + sprintf( '%g,%g %g,%g %g,%g', start_x, start_y, end_x, end_y, start_degrees, end_degrees ) end
Draw
a bezier curve.
# File lib/rmagick_internal.rb, line 301 def bezier(*points) if points.length.zero? Kernel.raise ArgumentError, 'no points specified' elsif points.length.odd? Kernel.raise ArgumentError, 'odd number of arguments specified' end primitive 'bezier ' + points.map! { |x| sprintf('%g', x) }.join(',') end
Draw
a circle
# File lib/rmagick_internal.rb, line 311 def circle(origin_x, origin_y, perim_x, perim_y) primitive 'circle ' + sprintf('%g,%g %g,%g', origin_x, origin_y, perim_x, perim_y) end
Invoke a clip-path defined by def_clip_path.
# File lib/rmagick_internal.rb, line 316 def clip_path(name) primitive "clip-path #{name}" end
Define the clipping rule.
# File lib/rmagick_internal.rb, line 321 def clip_rule(rule) Kernel.raise ArgumentError, "Unknown clipping rule #{rule}" unless %w[evenodd nonzero].include?(rule.downcase) primitive "clip-rule #{rule}" end
Define the clip units
# File lib/rmagick_internal.rb, line 327 def clip_units(unit) Kernel.raise ArgumentError, "Unknown clip unit #{unit}" unless %w[userspace userspaceonuse objectboundingbox].include?(unit.downcase) primitive "clip-units #{unit}" end
Set color in image according to specified colorization rule. Rule is one of point, replace, floodfill, filltoborder,reset
# File lib/rmagick_internal.rb, line 334 def color(x, y, method) Kernel.raise ArgumentError, "Unknown PaintMethod: #{method}" unless PAINT_METHOD_NAMES.key?(method.to_i) primitive 'color ' + sprintf('%g,%g,%s', x, y, PAINT_METHOD_NAMES[method.to_i]) end
Specify EITHER the text decoration (none, underline, overline, line-through) OR the text solid background color (any color name or spec)
# File lib/rmagick_internal.rb, line 341 def decorate(decoration) if DECORATION_TYPE_NAMES.key?(decoration.to_i) primitive "decorate #{DECORATION_TYPE_NAMES[decoration.to_i]}" else primitive "decorate #{enquote(decoration)}" end end
Define a clip-path. A clip-path is a sequence of primitives bracketed by the “push clip-path <name>” and “pop clip-path” primitives. Upon advice from the IM guys, we also bracket the clip-path primitives with “push(pop) defs” and “push (pop) graphic-context”.
# File lib/rmagick_internal.rb, line 354 def define_clip_path(name) push('defs') push("clip-path \"#{name}\"") push('graphic-context') yield ensure pop('graphic-context') pop('clip-path') pop('defs') end
Draw
an ellipse
# File lib/rmagick_internal.rb, line 366 def ellipse(origin_x, origin_y, width, height, arc_start, arc_end) primitive 'ellipse ' + sprintf( '%g,%g %g,%g %g,%g', origin_x, origin_y, width, height, arc_start, arc_end ) end
Let anything through, but the only defined argument is “UTF-8”. All others are apparently ignored.
# File lib/rmagick_internal.rb, line 375 def encoding(encoding) primitive "encoding #{encoding}" end
Specify object fill, a color name or pattern name
# File lib/rmagick_internal.rb, line 380 def fill(colorspec) primitive "fill #{enquote(colorspec)}" end
Specify fill opacity (use “xx%” to indicate percentage)
# File lib/rmagick_internal.rb, line 387 def fill_opacity(opacity) check_opacity(opacity) primitive "fill-opacity #{opacity}" end
# File lib/rmagick_internal.rb, line 392 def fill_rule(rule) Kernel.raise ArgumentError, "Unknown fill rule #{rule}" unless %w[evenodd nonzero].include?(rule.downcase) primitive "fill-rule #{rule}" end
Specify text drawing font
# File lib/rmagick_internal.rb, line 398 def font(name) primitive "font \'#{name}\'" end
# File lib/rmagick_internal.rb, line 402 def font_family(name) primitive "font-family \'#{name}\'" end
# File lib/rmagick_internal.rb, line 406 def font_stretch(stretch) Kernel.raise ArgumentError, 'Unknown stretch type' unless STRETCH_TYPE_NAMES.key?(stretch.to_i) primitive "font-stretch #{STRETCH_TYPE_NAMES[stretch.to_i]}" end
# File lib/rmagick_internal.rb, line 411 def font_style(style) Kernel.raise ArgumentError, 'Unknown style type' unless STYLE_TYPE_NAMES.key?(style.to_i) primitive "font-style #{STYLE_TYPE_NAMES[style.to_i]}" end
The font weight argument can be either a font weight constant or [100,200,…,900]
# File lib/rmagick_internal.rb, line 418 def font_weight(weight) if weight.is_a?(WeightType) primitive "font-weight #{FONT_WEIGHT_NAMES[weight.to_i]}" else primitive "font-weight #{Integer(weight)}" end end
Specify the text positioning gravity, one of: NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast
# File lib/rmagick_internal.rb, line 428 def gravity(grav) Kernel.raise ArgumentError, 'Unknown text positioning gravity' unless GRAVITY_NAMES.key?(grav.to_i) primitive "gravity #{GRAVITY_NAMES[grav.to_i]}" end
# File lib/rmagick_internal.rb, line 433 def image(composite, x, y, width, height, image_file_path) Kernel.raise ArgumentError, 'Unknown composite' unless composite.is_a?(CompositeOperator) composite_name = composite.to_s.sub!('CompositeOp', '') primitive 'image ' + sprintf('%s %g,%g %g,%g %s', composite_name, x, y, width, height, enquote(image_file_path)) end
IM 6.5.5-8 and later
# File lib/rmagick_internal.rb, line 440 def interline_spacing(space) begin Float(space) rescue ArgumentError Kernel.raise ArgumentError, 'invalid value for interline_spacing' rescue TypeError Kernel.raise TypeError, "can't convert #{space.class} into Float" end primitive "interline-spacing #{space}" end
IM 6.4.8-3 and later
# File lib/rmagick_internal.rb, line 452 def interword_spacing(space) begin Float(space) rescue ArgumentError Kernel.raise ArgumentError, 'invalid value for interword_spacing' rescue TypeError Kernel.raise TypeError, "can't convert #{space.class} into Float" end primitive "interword-spacing #{space}" end
IM 6.4.8-3 and later
# File lib/rmagick_internal.rb, line 464 def kerning(space) begin Float(space) rescue ArgumentError Kernel.raise ArgumentError, 'invalid value for kerning' rescue TypeError Kernel.raise TypeError, "can't convert #{space.class} into Float" end primitive "kerning #{space}" end
Draw
a line
# File lib/rmagick_internal.rb, line 476 def line(start_x, start_y, end_x, end_y) primitive 'line ' + sprintf('%g,%g %g,%g', start_x, start_y, end_x, end_y) end
Specify drawing fill and stroke opacities. If the value is a string ending with a %, the number will be multiplied by 0.01.
# File lib/rmagick_internal.rb, line 482 def opacity(opacity) check_opacity(opacity) primitive "opacity #{opacity}" end
Draw
using SVG-compatible path drawing commands. Note that the primitive requires that the commands be surrounded by quotes or apostrophes. Here we simply use apostrophes.
# File lib/rmagick_internal.rb, line 490 def path(cmds) primitive "path '" + cmds + "'" end
Define a pattern. In the block, call primitive methods to draw the pattern. Reference the pattern by using its name as the argument to the 'fill' or 'stroke' methods
# File lib/rmagick_internal.rb, line 497 def pattern(name, x, y, width, height) push('defs') push("pattern #{name} " + sprintf('%g %g %g %g', x, y, width, height)) push('graphic-context') yield ensure pop('graphic-context') pop('pattern') pop('defs') end
Set point to fill color.
# File lib/rmagick_internal.rb, line 509 def point(x, y) primitive 'point ' + sprintf('%g,%g', x, y) end
Specify the font size in points. Yes, the primitive is “font-size” but in other places this value is called the “pointsize”. Give it both names.
# File lib/rmagick_internal.rb, line 515 def pointsize(points) primitive 'font-size ' + sprintf('%g', points) end
Draw
a polygon
# File lib/rmagick_internal.rb, line 521 def polygon(*points) if points.length.zero? Kernel.raise ArgumentError, 'no points specified' elsif points.length.odd? Kernel.raise ArgumentError, 'odd number of points specified' end primitive 'polygon ' + points.map! { |x| sprintf('%g', x) }.join(',') end
Draw
a polyline
# File lib/rmagick_internal.rb, line 531 def polyline(*points) if points.length.zero? Kernel.raise ArgumentError, 'no points specified' elsif points.length.odd? Kernel.raise ArgumentError, 'odd number of points specified' end primitive 'polyline ' + points.map! { |x| sprintf('%g', x) }.join(',') end
Return to the previously-saved set of whatever pop('graphic-context') (the default if no arguments) pop('defs') pop('gradient') pop('pattern')
# File lib/rmagick_internal.rb, line 546 def pop(*what) if what.length.zero? primitive 'pop graphic-context' else # to_s allows a Symbol to be used instead of a String primitive 'pop ' + what.map(&:to_s).join(' ') end end
Push the current set of drawing options. Also you can use push('graphic-context') (the default if no arguments) push('defs') push('gradient') push('pattern')
# File lib/rmagick_internal.rb, line 560 def push(*what) if what.length.zero? primitive 'push graphic-context' else # to_s allows a Symbol to be used instead of a String primitive 'push ' + what.map(&:to_s).join(' ') end end
Draw
a rectangle
# File lib/rmagick_internal.rb, line 570 def rectangle(upper_left_x, upper_left_y, lower_right_x, lower_right_y) primitive 'rectangle ' + sprintf( '%g,%g %g,%g', upper_left_x, upper_left_y, lower_right_x, lower_right_y ) end
Specify coordinate space rotation. “angle” is measured in degrees
# File lib/rmagick_internal.rb, line 578 def rotate(angle) primitive 'rotate ' + sprintf('%g', angle) end
Draw
a rectangle with rounded corners
# File lib/rmagick_internal.rb, line 583 def roundrectangle(center_x, center_y, width, height, corner_width, corner_height) primitive 'roundrectangle ' + sprintf( '%g,%g,%g,%g,%g,%g', center_x, center_y, width, height, corner_width, corner_height ) end
Specify scaling to be applied to coordinate space on subsequent drawing commands.
# File lib/rmagick_internal.rb, line 591 def scale(x, y) primitive 'scale ' + sprintf('%g,%g', x, y) end
# File lib/rmagick_internal.rb, line 595 def skewx(angle) primitive 'skewX ' + sprintf('%g', angle) end
# File lib/rmagick_internal.rb, line 599 def skewy(angle) primitive 'skewY ' + sprintf('%g', angle) end
Specify the object stroke, a color name or pattern name.
# File lib/rmagick_internal.rb, line 604 def stroke(colorspec) primitive "stroke #{enquote(colorspec)}" end
Specify if stroke should be antialiased or not
# File lib/rmagick_internal.rb, line 611 def stroke_antialias(bool) bool = bool ? '1' : '0' primitive "stroke-antialias #{bool}" end
Specify a stroke dash pattern
# File lib/rmagick_internal.rb, line 617 def stroke_dasharray(*list) if list.length.zero? primitive 'stroke-dasharray none' else list.each do |x| Kernel.raise ArgumentError, "dash array elements must be > 0 (#{x} given)" if x <= 0 end primitive "stroke-dasharray #{list.join(',')}" end end
Specify the initial offset in the dash pattern
# File lib/rmagick_internal.rb, line 629 def stroke_dashoffset(value = 0) primitive 'stroke-dashoffset ' + sprintf('%g', value) end
# File lib/rmagick_internal.rb, line 633 def stroke_linecap(value) Kernel.raise ArgumentError, "Unknown linecap type: #{value}" unless %w[butt round square].include?(value.downcase) primitive "stroke-linecap #{value}" end
# File lib/rmagick_internal.rb, line 638 def stroke_linejoin(value) Kernel.raise ArgumentError, "Unknown linejoin type: #{value}" unless %w[round miter bevel].include?(value.downcase) primitive "stroke-linejoin #{value}" end
# File lib/rmagick_internal.rb, line 643 def stroke_miterlimit(value) Kernel.raise ArgumentError, 'miterlimit must be >= 1' if value < 1 primitive "stroke-miterlimit #{value}" end
Specify opacity of stroke drawing color
(use "xx%" to indicate percentage)
# File lib/rmagick_internal.rb, line 650 def stroke_opacity(opacity) check_opacity(opacity) primitive "stroke-opacity #{opacity}" end
Specify stroke (outline) width in pixels.
# File lib/rmagick_internal.rb, line 656 def stroke_width(pixels) primitive 'stroke-width ' + sprintf('%g', pixels) end
Draw
text at position x,y. Add quotes to text that is not already quoted.
# File lib/rmagick_internal.rb, line 661 def text(x, y, text) Kernel.raise ArgumentError, 'missing text argument' if text.to_s.empty? if text.length > 2 && /\A(?:\"[^\"]+\"|\'[^\']+\'|\{[^\}]+\})\z/.match(text) # text already quoted elsif !text['\''] text = '\'' + text + '\'' elsif !text['"'] text = '"' + text + '"' elsif !(text['{'] || text['}']) text = '{' + text + '}' else # escape existing braces, surround with braces text = '{' + text.gsub(/[}]/) { |b| '\\' + b } + '}' end primitive 'text ' + sprintf('%g,%g %s', x, y, text) end
Specify text alignment relative to a given point
# File lib/rmagick_internal.rb, line 679 def text_align(alignment) Kernel.raise ArgumentError, "Unknown alignment constant: #{alignment}" unless ALIGN_TYPE_NAMES.key?(alignment.to_i) primitive "text-align #{ALIGN_TYPE_NAMES[alignment.to_i]}" end
SVG-compatible version of text_align
# File lib/rmagick_internal.rb, line 685 def text_anchor(anchor) Kernel.raise ArgumentError, "Unknown anchor constant: #{anchor}" unless ANCHOR_TYPE_NAMES.key?(anchor.to_i) primitive "text-anchor #{ANCHOR_TYPE_NAMES[anchor.to_i]}" end
Specify if rendered text is to be antialiased.
# File lib/rmagick_internal.rb, line 691 def text_antialias(boolean) boolean = boolean ? '1' : '0' primitive "text-antialias #{boolean}" end
Specify color underneath text
# File lib/rmagick_internal.rb, line 697 def text_undercolor(color) primitive "text-undercolor #{enquote(color)}" end
Specify center of coordinate space to use for subsequent drawing commands.
# File lib/rmagick_internal.rb, line 703 def translate(x, y) primitive 'translate ' + sprintf('%g,%g', x, y) end
Private Instance Methods
# File lib/rmagick_internal.rb, line 269 def check_opacity(opacity) return if opacity.is_a?(String) && opacity['%'] value = Float(opacity) Kernel.raise ArgumentError, 'opacity must be >= 0 and <= 1.0' if value < 0 || value > 1.0 end
# File lib/rmagick_internal.rb, line 261 def enquote(str) if str.length > 2 && /\A(?:\"[^\"]+\"|\'[^\']+\'|\{[^\}]+\})\z/.match(str) str else '"' + str + '"' end end