Class: Magick::Draw

Constants

 Thse hashes are used to map Magick constant
values to the strings used in the primitives.
 {         StartAnchor.to_i => 'start',         MiddleAnchor.to_i => 'middle',         EndAnchor.to_i => 'end'
 {         NoDecoration.to_i => 'none',         UnderlineDecoration.to_i => 'underline',         OverlineDecoration.to_i => 'overline',         LineThroughDecoration.to_i => 'line-through'
 {         AnyWeight.to_i => 'all',         NormalWeight.to_i => 'normal',         BoldWeight.to_i => 'bold',         BolderWeight.to_i => 'bolder',         LighterWeight.to_i => 'lighter',         }
 {         NorthWestGravity.to_i => 'northwest',         NorthGravity.to_i => 'north',         NorthEastGravity.to_i => 'northeast',         WestGravity.to_i => 'west',         CenterGravity.to_i => 'center',         EastGravity.to_i => 'east',         SouthWestGravity.to_i => 'southwest',         SouthGravity.to_i => 'south',         SouthEastGravity.to_i => 'southeast'
 {         PointMethod.to_i => 'point',         ReplaceMethod.to_i => 'replace',         FloodfillMethod.to_i => 'floodfill',         FillToBorderMethod.to_i => 'filltoborder',         ResetMethod.to_i => 'reset'
 {         NormalStretch.to_i => 'normal',         UltraCondensedStretch.to_i => 'ultra-condensed',         ExtraCondensedStretch.to_i => 'extra-condensed',         CondensedStretch.to_i => 'condensed',         SemiCondensedStretch.to_i => 'semi-condensed',         SemiExpandedStretch.to_i => 'semi-expanded',         ExpandedStretch.to_i => 'expanded',         ExtraExpandedStretch.to_i => 'extra-expanded',         UltraExpandedStretch.to_i => 'ultra-expanded',         AnyStretch.to_i => 'all'
 {         NormalStyle.to_i => 'normal',         ItalicStyle.to_i => 'italic',         ObliqueStyle.to_i => 'oblique',         AnyStyle.to_i => 'all'

Public Instance methods

affine(sx, rx, ry, sy, tx, ty)

Apply coordinate transformations to support scaling (s), rotation ®, and translation (t). Angles are specified in radians.

[Source]

     # File lib/RMagick.rb, line 180
180:     def affine(sx, rx, ry, sy, tx, ty)
181:         primitive "affine " + sprintf("%g,%g,%g,%g,%g,%g", sx, rx, ry, sy, tx, ty)
182:     end

arc(startX, startY, endX, endY, startDegrees, endDegrees)

Draw an arc.

[Source]

     # File lib/RMagick.rb, line 185
185:     def arc(startX, startY, endX, endY, startDegrees, endDegrees)
186:         primitive "arc " + sprintf("%g,%g %g,%g %g,%g",
187:                     startX, startY, endX, endY, startDegrees, endDegrees)
188:     end

bezier(*points)

Draw a bezier curve.

[Source]

     # File lib/RMagick.rb, line 191
191:     def bezier(*points)
192:         if points.length == 0
193:             raise ArgumentError, "no points specified"
194:         elsif points.length % 2 != 0
195:             raise ArgumentError, "odd number of arguments specified"
196:         end
197:         primitive "bezier " + points.join(',')
198:     end

circle(originX, originY, perimX, perimY)

Draw a circle

[Source]

     # File lib/RMagick.rb, line 201
201:     def circle(originX, originY, perimX, perimY)
202:         primitive "circle " + sprintf("%g,%g %g,%g", originX, originY, perimX, perimY)
203:     end

clip_path(name)

Invoke a clip-path defined by def_clip_path.

[Source]

     # File lib/RMagick.rb, line 206
206:     def clip_path(name)
207:         primitive "clip-path #{name}"
208:     end

clip_rule(rule)

Define the clipping rule.

[Source]

     # File lib/RMagick.rb, line 211
211:     def clip_rule(rule)
212:         if ( not ["evenodd", "nonzero"].include?(rule.downcase) )
213:             raise ArgumentError, "Unknown clipping rule #{rule}"
214:         end
215:         primitive "clip-rule #{rule}"
216:     end

clip_units(unit)

Define the clip units

[Source]

     # File lib/RMagick.rb, line 219
219:     def clip_units(unit)
220:         if ( not ["userspace", "userspaceonuse", "objectboundingbox"].include?(unit.downcase) )
221:             raise ArgumentError, "Unknown clip unit #{unit}"
222:         end
223:         primitive "clip-units #{unit}"
224:     end

color(x, y, method)

Set color in image according to specified colorization rule. Rule is one of point, replace, floodfill, filltoborder,reset

[Source]

     # File lib/RMagick.rb, line 228
228:     def color(x, y, method)
229:         if ( not PAINT_METHOD_NAMES.has_key?(method.to_i) )
230:             raise ArgumentError, "Unknown PaintMethod: #{method}"
231:         end
232:         primitive "color #{x},#{y},#{PAINT_METHOD_NAMES[method.to_i]}"
233:     end

decorate(decoration)

Specify EITHER the text decoration (none, underline, overline, line-through) OR the text solid background color (any color name or spec)

[Source]

     # File lib/RMagick.rb, line 237
237:     def decorate(decoration)
238:         if ( DECORATION_TYPE_NAMES.has_key?(decoration.to_i) )
239:             primitive "decorate #{DECORATION_TYPE_NAMES[decoration.to_i]}"
240:         else
241:             primitive "decorate #{enquote(decoration)}"
242:         end
243:     end

define_clip_path(name) {|| ...}

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".

[Source]

     # File lib/RMagick.rb, line 250
250:     def define_clip_path(name)
251:         begin
252:             push('defs')
253:             push('clip-path ', name)
254:             push('graphic-context')
255:             yield
256:         ensure
257:             pop('graphic-context')
258:             pop('clip-path')
259:             pop('defs')
260:         end
261:     end

ellipse(originX, originY, width, height, arcStart, arcEnd)

Draw an ellipse

[Source]

     # File lib/RMagick.rb, line 264
264:     def ellipse(originX, originY, width, height, arcStart, arcEnd)
265:         primitive "ellipse " + sprintf("%g,%g %g,%g %g,%g",
266:                         originX, originY, width, height, arcStart, arcEnd)
267:     end

encoding(encoding)

Let anything through, but the only defined argument is "UTF-8". All others are apparently ignored.

[Source]

     # File lib/RMagick.rb, line 271
271:     def encoding(encoding)
272:         primitive "encoding #{encoding}"
273:     end

fill(colorspec)

Specify object fill, a color name or pattern name

[Source]

     # File lib/RMagick.rb, line 276
276:     def fill(colorspec)
277:         primitive "fill #{enquote(colorspec)}"
278:     end

fill_color(colorspec)

Alias for fill

fill_opacity(opacity)

Specify fill opacity (use "xx%" to indicate percentage)

[Source]

     # File lib/RMagick.rb, line 283
283:     def fill_opacity(opacity)
284:         primitive "fill-opacity #{opacity}"
285:     end

fill_pattern(colorspec)

Alias for fill

fill_rule(rule)

[Source]

     # File lib/RMagick.rb, line 287
287:     def fill_rule(rule)
288:         if ( not ["evenodd", "nonzero"].include?(rule.downcase) )
289:             raise ArgumentError, "Unknown fill rule #{rule}"
290:         end
291:         primitive "fill-rule #{rule}"
292:     end

font(name)

Specify text drawing font

[Source]

     # File lib/RMagick.rb, line 295
295:     def font(name)
296:         primitive "font #{name}"
297:     end

font_family(name)

[Source]

     # File lib/RMagick.rb, line 299
299:     def font_family(name)
300:         primitive "font-family \'#{name}\'"
301:     end

font_size(points)

Alias for pointsize

font_stretch(stretch)

[Source]

     # File lib/RMagick.rb, line 303
303:     def font_stretch(stretch)
304:         if ( not STRETCH_TYPE_NAMES.has_key?(stretch.to_i) )
305:             raise ArgumentError, "Unknown stretch type"
306:         end
307:         primitive "font-stretch #{STRETCH_TYPE_NAMES[stretch.to_i]}"
308:     end

font_style(style)

[Source]

     # File lib/RMagick.rb, line 310
310:     def font_style(style)
311:         if ( not STYLE_TYPE_NAMES.has_key?(style.to_i) )
312:             raise ArgumentError, "Unknown style type"
313:         end
314:         primitive "font-style #{STYLE_TYPE_NAMES[style.to_i]}"
315:     end

font_weight(weight)

The font weight argument can be either a font weight constant or [100,200,…,900]

[Source]

     # File lib/RMagick.rb, line 319
319:     def font_weight(weight)
320:         if ( FONT_WEIGHT_NAMES.has_key?(weight.to_i) )
321:             primitive "font-weight #{FONT_WEIGHT_NAMES[weight.to_i]}"
322:         else
323:             primitive "font-weight #{weight}"
324:         end
325:     end

gravity(grav)

Specify the text positioning gravity, one of: NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast

[Source]

     # File lib/RMagick.rb, line 329
329:     def gravity(grav)
330:         if ( not GRAVITY_NAMES.has_key?(grav.to_i) )
331:             raise ArgumentError, "Unknown text positioning gravity"
332:         end
333:         primitive "gravity #{GRAVITY_NAMES[grav.to_i]}"
334:     end

line(startX, startY, endX, endY)

Draw a line

[Source]

     # File lib/RMagick.rb, line 337
337:     def line(startX, startY, endX, endY)
338:         primitive "line " + sprintf("%g,%g %g,%g", startX, startY, endX, endY)
339:     end

matte(x, y, rule)

Set matte (make transparent) in image according to the specified colorization rule

[Source]

     # File lib/RMagick.rb, line 343
343:     def matte(x, y, rule)
344:         if ( not PAINT_METHOD_NAMES.has_key?(method.to_i) )
345:             raise ArgumentError, "Unknown paint method"
346:         end
347:         primitive "matte #{x},#{y} #{PAINT_METHOD_NAMES[method.to_i]}"
348:     end

opacity(opacity)

Specify drawing fill and stroke opacities. If the value is a string ending with a %, the number will be multiplied by 0.01.

[Source]

     # File lib/RMagick.rb, line 352
352:     def opacity(opacity)
353:         if (Numeric === opacity)
354:             if (opacity < 0 || opacity > 1.0)
355:                 raise ArgumentError, "opacity must be >= 0 and <= 1.0"
356:             end
357:         end
358:         primitive "opacity #{opacity}"
359:     end

path(cmds)

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.

[Source]

     # File lib/RMagick.rb, line 364
364:     def path(cmds)
365:         primitive "path '" + cmds + "'"
366:     end

pattern(name, x, y, width, height) {|| ...}

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

[Source]

     # File lib/RMagick.rb, line 371
371:     def pattern(name, x, y, width, height)
372:         begin
373:             push('defs')
374:             push("pattern #{name} #{x} #{y} #{width} #{height}")
375:             push('graphic-context')
376:             yield
377:         ensure
378:             pop('graphic-context')
379:             pop('pattern')
380:             pop('defs')
381:         end
382:     end

point(x, y)

Set point to fill color.

[Source]

     # File lib/RMagick.rb, line 385
385:     def point(x, y)
386:         primitive "point #{x},#{y}"
387:     end

pointsize(points)

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.

[Source]

     # File lib/RMagick.rb, line 391
391:     def pointsize(points)
392:         primitive "font-size #{points}"
393:     end

polygon(*points)

Draw a polygon

[Source]

     # File lib/RMagick.rb, line 397
397:     def polygon(*points)
398:         if points.length == 0
399:             raise ArgumentError, "no points specified"
400:         elsif points.length % 2 != 0
401:             raise ArgumentError, "odd number of points specified"
402:         end
403:         primitive "polygon " + points.join(',')
404:     end

polyline(*points)

Draw a polyline

[Source]

     # File lib/RMagick.rb, line 407
407:     def polyline(*points)
408:         if points.length == 0
409:             raise ArgumentError, "no points specified"
410:         elsif points.length % 2 != 0
411:             raise ArgumentError, "odd number of points specified"
412:         end
413:         primitive "polyline " + points.join(',')
414:     end

pop(*what)

Return to the previously-saved set of whatever pop(‘graphic-context’) (the default if no arguments) pop(‘defs’) pop(‘gradient’) pop(‘pattern’)

[Source]

     # File lib/RMagick.rb, line 422
422:     def pop(*what)
423:         if what.length == 0
424:             primitive "pop graphic-context"
425:         else
426:             # to_s allows a Symbol to be used instead of a String
427:             primitive "pop " + what.to_s
428:         end
429:     end

push(*what)

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’)

[Source]

     # File lib/RMagick.rb, line 436
436:     def push(*what)
437:         if what.length == 0
438:             primitive "push graphic-context"
439:         else
440:             # to_s allows a Symbol to be used instead of a String
441:             primitive "push " + what.to_s
442:         end
443:     end

rectangle(upper_left_x, upper_left_y, lower_right_x, lower_right_y)

Draw a rectangle

[Source]

     # File lib/RMagick.rb, line 446
446:     def rectangle(upper_left_x, upper_left_y, lower_right_x, lower_right_y)
447:         primitive "rectangle " + sprintf("%g,%g %g,%g",
448:                 upper_left_x, upper_left_y, lower_right_x, lower_right_y)
449:     end

rotate(angle)

Specify coordinate space rotation. "angle" is measured in degrees

[Source]

     # File lib/RMagick.rb, line 452
452:     def rotate(angle)
453:         primitive "rotate #{angle}"
454:     end

roundrectangle(center_x, center_y, width, height, corner_width, corner_height)

Draw a rectangle with rounded corners

[Source]

     # File lib/RMagick.rb, line 457
457:     def roundrectangle(center_x, center_y, width, height, corner_width, corner_height)
458:         primitive "roundrectangle " + sprintf("%g,%g,%g,%g,%g,%g",
459:             center_x, center_y, width, height, corner_width, corner_height)
460:     end

scale(x, y)

Specify scaling to be applied to coordinate space on subsequent drawing commands.

[Source]

     # File lib/RMagick.rb, line 463
463:     def scale(x, y)
464:         primitive "scale #{x},#{y}"
465:     end

skewx(angle)

[Source]

     # File lib/RMagick.rb, line 467
467:     def skewx(angle)
468:         primitive "skewX #{angle}"
469:     end

skewy(angle)

[Source]

     # File lib/RMagick.rb, line 471
471:     def skewy(angle)
472:         primitive "skewY #{angle}"
473:     end

stroke(colorspec)

Specify the object stroke, a color name or pattern name.

[Source]

     # File lib/RMagick.rb, line 476
476:     def stroke(colorspec)
477:         primitive "stroke #{enquote(colorspec)}"
478:     end

stroke_antialias(bool)

Specify if stroke should be antialiased or not

[Source]

     # File lib/RMagick.rb, line 483
483:     def stroke_antialias(bool)
484:         bool = bool ? '1' : '0'
485:         primitive "stroke-antialias #{bool}"
486:     end

stroke_color(colorspec)

Alias for stroke

stroke_dasharray(*list)

Specify a stroke dash pattern

[Source]

     # File lib/RMagick.rb, line 489
489:     def stroke_dasharray(*list)
490:         if list.length == 0
491:             primitive "stroke-dasharray none"
492:         else
493:             list.each { |x|
494:                 if x <= 0 then
495:                     raise ArgumentError, "dash array elements must be > 0 (#{x} given)"
496:                 end
497:             }
498:             primitive "stroke-dasharray #{list.join(',')}"
499:         end
500:     end

stroke_dashoffset(value=0)

Specify the initial offset in the dash pattern

[Source]

     # File lib/RMagick.rb, line 503
503:     def stroke_dashoffset(value=0)
504:         primitive "stroke-dashoffset #{value}"
505:     end

stroke_linecap(value)

[Source]

     # File lib/RMagick.rb, line 507
507:     def stroke_linecap(value)
508:         if ( not ["butt", "round", "square"].include?(value.downcase) )
509:             raise ArgumentError, "Unknown linecap type: #{value}"
510:         end
511:         primitive "stroke-linecap #{value}"
512:     end

stroke_linejoin(value)

[Source]

     # File lib/RMagick.rb, line 514
514:     def stroke_linejoin(value)
515:         if ( not ["round", "miter", "bevel"].include?(value.downcase) )
516:             raise ArgumentError, "Unknown linejoin type: #{value}"
517:         end
518:         primitive "stroke-linejoin #{value}"
519:     end

stroke_miterlimit(value)

[Source]

     # File lib/RMagick.rb, line 521
521:     def stroke_miterlimit(value)
522:         if (value < 1)
523:             raise ArgumentError, "miterlimit must be >= 1"
524:         end
525:         primitive "stroke-miterlimit #{value}"
526:     end

stroke_opacity(value)

Specify opacity of stroke drawing color

 (use "xx%" to indicate percentage)

[Source]

     # File lib/RMagick.rb, line 530
530:     def stroke_opacity(value)
531:         primitive "stroke-opacity #{value}"
532:     end

stroke_pattern(colorspec)

Alias for stroke

stroke_width(pixels)

Specify stroke (outline) width in pixels.

[Source]

     # File lib/RMagick.rb, line 535
535:     def stroke_width(pixels)
536:         primitive "stroke-width #{pixels}"
537:     end

text(x, y, text)

Draw text at position x,y. Add quotes to text that is not already quoted.

[Source]

     # File lib/RMagick.rb, line 540
540:     def text(x, y, text)
541:         if text.to_s.empty?
542:             raise ArgumentError, "missing text argument"
543:         end
544:         if text.length > 2 && /\A(?:\"[^\"]+\"|\'[^\']+\'|\{[^\}]+\})\z/.match(text)
545:             ; # text already quoted
546:         elsif !text['\'']
547:             text = '\''+text+'\''
548:         elsif !text['"']
549:             text = '"'+text+'"'
550:         elsif !(text['{'] || text['}'])
551:             text = '{'+text+'}'
552:         else
553:             # escape existing braces, surround with braces
554:             text = '{' +  text.gsub(/[}]/) { |b| '\\' + b } + '}'
555:         end
556:         primitive "text #{x},#{y} #{text}"
557:     end

text_align(alignment)

Specify text alignment relative to a given point

[Source]

     # File lib/RMagick.rb, line 560
560:     def text_align(alignment)
561:         if ( not ALIGN_TYPE_NAMES.has_key?(alignment.to_i) )
562:             raise ArgumentError, "Unknown alignment constant: #{alignment}"
563:         end
564:         primitive "text-align #{ALIGN_TYPE_NAMES[alignment.to_i]}"
565:     end

text_anchor(anchor)

SVG-compatible version of text_align

[Source]

     # File lib/RMagick.rb, line 568
568:     def text_anchor(anchor)
569:         if ( not ANCHOR_TYPE_NAMES.has_key?(anchor.to_i) )
570:             raise ArgumentError, "Unknown anchor constant: #{anchor}"
571:         end
572:         primitive "text-anchor #{ANCHOR_TYPE_NAMES[anchor.to_i]}"
573:     end

text_antialias(boolean)

Specify if rendered text is to be antialiased.

[Source]

     # File lib/RMagick.rb, line 576
576:     def text_antialias(boolean)
577:         boolean = boolean ? '1' : '0'
578:         primitive "text-antialias #{boolean}"
579:     end

text_undercolor(color)

Specify color underneath text

[Source]

     # File lib/RMagick.rb, line 582
582:     def text_undercolor(color)
583:         primitive "text-undercolor #{enquote(color)}"
584:     end

translate(x, y)

Specify center of coordinate space to use for subsequent drawing commands.

[Source]

     # File lib/RMagick.rb, line 588
588:     def translate(x, y)
589:         primitive "translate #{x},#{y}"
590:     end

Private Instance methods

enquote(str)

[Source]

     # File lib/RMagick.rb, line 168
168:     def enquote(str)
169:         if str.length > 2 && /\A(?:\"[^\"]+\"|\'[^\']+\'|\{[^\}]+\})\z/.match(str)
170:             return str
171:         else
172:             return '"' + str + '"'
173:         end
174:     end

Methods

Constants

Public Instance methods

Private Instance methods