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 223 def affine(sx, rx, ry, sy, tx, ty) primitive 'affine ' + sprintf('%g,%g,%g,%g,%g,%g', sx, rx, ry, sy, tx, ty) end
Draw an arc.
# File lib/rmagick_internal.rb, line 228 def arc(startX, startY, endX, endY, startDegrees, endDegrees) primitive 'arc ' + sprintf('%g,%g %g,%g %g,%g', startX, startY, endX, endY, startDegrees, endDegrees) end
Draw a bezier curve.
# File lib/rmagick_internal.rb, line 234 def bezier(*points) if points.length == 0 Kernel.raise ArgumentError, 'no points specified' elsif points.length.odd? Kernel.raise ArgumentError, 'odd number of arguments specified' end primitive 'bezier ' + points.join(',') end
Draw a circle
# File lib/rmagick_internal.rb, line 244 def circle(originX, originY, perimX, perimY) primitive 'circle ' + sprintf('%g,%g %g,%g', originX, originY, perimX, perimY) end
Invoke a clip-path defined by def_clip_path.
# File lib/rmagick_internal.rb, line 249 def clip_path(name) primitive "clip-path #{name}" end
Define the clipping rule.
# File lib/rmagick_internal.rb, line 254 def clip_rule(rule) unless ['evenodd', 'nonzero'].include?(rule.downcase) Kernel.raise ArgumentError, "Unknown clipping rule #{rule}" end primitive "clip-rule #{rule}" end
Define the clip units
# File lib/rmagick_internal.rb, line 262 def clip_units(unit) unless ['userspace', 'userspaceonuse', 'objectboundingbox'].include?(unit.downcase) Kernel.raise ArgumentError, "Unknown clip unit #{unit}" end 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 271 def color(x, y, method) unless PAINT_METHOD_NAMES.has_key?(method.to_i) Kernel.raise ArgumentError, "Unknown PaintMethod: #{method}" end primitive "color #{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 280 def decorate(decoration) if DECORATION_TYPE_NAMES.has_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 293 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 305 def ellipse(originX, originY, width, height, arcStart, arcEnd) primitive 'ellipse ' + sprintf('%g,%g %g,%g %g,%g', originX, originY, width, height, arcStart, arcEnd) end
Let anything through, but the only defined argument is “UTF-8”. All others are apparently ignored.
# File lib/rmagick_internal.rb, line 312 def encoding(encoding) primitive "encoding #{encoding}" end
Specify object fill, a color name or pattern name
# File lib/rmagick_internal.rb, line 317 def fill(colorspec) primitive "fill #{enquote(colorspec)}" end
Specify fill opacity (use “xx%” to indicate percentage)
# File lib/rmagick_internal.rb, line 324 def fill_opacity(opacity) primitive "fill-opacity #{opacity}" end
# File lib/rmagick_internal.rb, line 328 def fill_rule(rule) unless ['evenodd', 'nonzero'].include?(rule.downcase) Kernel.raise ArgumentError, "Unknown fill rule #{rule}" end primitive "fill-rule #{rule}" end
Specify text drawing font
# File lib/rmagick_internal.rb, line 336 def font(name) primitive "font \'#{name}\'" end
# File lib/rmagick_internal.rb, line 340 def font_family(name) primitive "font-family \'#{name}\'" end
# File lib/rmagick_internal.rb, line 344 def font_stretch(stretch) unless STRETCH_TYPE_NAMES.has_key?(stretch.to_i) Kernel.raise ArgumentError, 'Unknown stretch type' end primitive "font-stretch #{STRETCH_TYPE_NAMES[stretch.to_i]}" end
# File lib/rmagick_internal.rb, line 351 def font_style(style) unless STYLE_TYPE_NAMES.has_key?(style.to_i) Kernel.raise ArgumentError, 'Unknown style type' end 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 360 def font_weight(weight) if FONT_WEIGHT_NAMES.has_key?(weight.to_i) primitive "font-weight #{FONT_WEIGHT_NAMES[weight.to_i]}" else primitive "font-weight #{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 370 def gravity(grav) unless GRAVITY_NAMES.has_key?(grav.to_i) Kernel.raise ArgumentError, 'Unknown text positioning gravity' end primitive "gravity #{GRAVITY_NAMES[grav.to_i]}" end
IM 6.5.5-8 and later
# File lib/rmagick_internal.rb, line 378 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 390 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 402 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 414 def line(startX, startY, endX, endY) primitive 'line ' + sprintf('%g,%g %g,%g', startX, startY, endX, endY) end
Set matte (make transparent) in image according to the specified colorization rule
# File lib/rmagick_internal.rb, line 420 def matte(x, y, method) unless PAINT_METHOD_NAMES.has_key?(method.to_i) Kernel.raise ArgumentError, 'Unknown paint method' end primitive "matte #{x},#{y} #{PAINT_METHOD_NAMES[method.to_i]}" 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 429 def opacity(opacity) if (Numeric === opacity) if opacity < 0 || opacity > 1.0 Kernel.raise ArgumentError, 'opacity must be >= 0 and <= 1.0' end end 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 441 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 448 def pattern(name, x, y, width, height) push('defs') push("pattern #{name} #{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 460 def point(x, y) primitive "point #{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 466 def pointsize(points) primitive "font-size #{points}" end
Draw a polygon
# File lib/rmagick_internal.rb, line 472 def polygon(*points) if points.length == 0 Kernel.raise ArgumentError, 'no points specified' elsif points.length.odd? Kernel.raise ArgumentError, 'odd number of points specified' end primitive 'polygon ' + points.join(',') end
Draw a polyline
# File lib/rmagick_internal.rb, line 482 def polyline(*points) if points.length == 0 Kernel.raise ArgumentError, 'no points specified' elsif points.length.odd? Kernel.raise ArgumentError, 'odd number of points specified' end primitive 'polyline ' + points.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 497 def pop(*what) if what.length == 0 primitive 'pop graphic-context' else # to_s allows a Symbol to be used instead of a String primitive 'pop ' + what.map {|w| w.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 511 def push(*what) if what.length == 0 primitive 'push graphic-context' else # to_s allows a Symbol to be used instead of a String primitive 'push ' + what.map {|w| w.to_s}.join(' ') end end
Draw a rectangle
# File lib/rmagick_internal.rb, line 521 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 527 def rotate(angle) primitive "rotate #{angle}" end
Draw a rectangle with rounded corners
# File lib/rmagick_internal.rb, line 532 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 538 def scale(x, y) primitive "scale #{x},#{y}" end
# File lib/rmagick_internal.rb, line 542 def skewx(angle) primitive "skewX #{angle}" end
# File lib/rmagick_internal.rb, line 546 def skewy(angle) primitive "skewY #{angle}" end
Specify the object stroke, a color name or pattern name.
# File lib/rmagick_internal.rb, line 551 def stroke(colorspec) primitive "stroke #{enquote(colorspec)}" end
Specify if stroke should be antialiased or not
# File lib/rmagick_internal.rb, line 558 def stroke_antialias(bool) bool = bool ? '1' : '0' primitive "stroke-antialias #{bool}" end
Specify a stroke dash pattern
# File lib/rmagick_internal.rb, line 564 def stroke_dasharray(*list) if list.length == 0 primitive 'stroke-dasharray none' else list.each do |x| if x <= 0 Kernel.raise ArgumentError, "dash array elements must be > 0 (#{x} given)" end end primitive "stroke-dasharray #{list.join(',')}" end end
Specify the initial offset in the dash pattern
# File lib/rmagick_internal.rb, line 578 def stroke_dashoffset(value=0) primitive "stroke-dashoffset #{value}" end
# File lib/rmagick_internal.rb, line 582 def stroke_linecap(value) unless ['butt', 'round', 'square'].include?(value.downcase) Kernel.raise ArgumentError, "Unknown linecap type: #{value}" end primitive "stroke-linecap #{value}" end
# File lib/rmagick_internal.rb, line 589 def stroke_linejoin(value) unless ['round', 'miter', 'bevel'].include?(value.downcase) Kernel.raise ArgumentError, "Unknown linejoin type: #{value}" end primitive "stroke-linejoin #{value}" end
# File lib/rmagick_internal.rb, line 596 def stroke_miterlimit(value) if value < 1 Kernel.raise ArgumentError, 'miterlimit must be >= 1' end primitive "stroke-miterlimit #{value}" end
Specify opacity of stroke drawing color
(use "xx%" to indicate percentage)
# File lib/rmagick_internal.rb, line 605 def stroke_opacity(value) primitive "stroke-opacity #{value}" end
Specify stroke (outline) width in pixels.
# File lib/rmagick_internal.rb, line 610 def stroke_width(pixels) primitive "stroke-width #{pixels}" end
Draw text at position x,y. Add quotes to text that is not already quoted.
# File lib/rmagick_internal.rb, line 615 def text(x, y, text) if text.to_s.empty? Kernel.raise ArgumentError, 'missing text argument' end 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 #{x},#{y} #{text}" end
Specify text alignment relative to a given point
# File lib/rmagick_internal.rb, line 635 def text_align(alignment) unless ALIGN_TYPE_NAMES.has_key?(alignment.to_i) Kernel.raise ArgumentError, "Unknown alignment constant: #{alignment}" end primitive "text-align #{ALIGN_TYPE_NAMES[alignment.to_i]}" end
SVG-compatible version of #text_align
# File lib/rmagick_internal.rb, line 643 def text_anchor(anchor) unless ANCHOR_TYPE_NAMES.has_key?(anchor.to_i) Kernel.raise ArgumentError, "Unknown anchor constant: #{anchor}" end primitive "text-anchor #{ANCHOR_TYPE_NAMES[anchor.to_i]}" end
Specify if rendered text is to be antialiased.
# File lib/rmagick_internal.rb, line 651 def text_antialias(boolean) boolean = boolean ? '1' : '0' primitive "text-antialias #{boolean}" end
Specify color underneath text
# File lib/rmagick_internal.rb, line 657 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 663 def translate(x, y) primitive "translate #{x},#{y}" end
Private Instance Methods
# File lib/rmagick_internal.rb, line 211 def enquote(str) if str.length > 2 && /\A(?:\"[^\"]+\"|\[^\]+\|\{[^\}]+\})\z/.match(str) return str else return '"' + str + '"' end end