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',         }.freeze
 {         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 (r), and translation (t). Angles are specified in radians.

[Source]

     # File lib/RMagick.rb, line 220
220:     def affine(sx, rx, ry, sy, tx, ty)
221:         primitive "affine " + sprintf("%g,%g,%g,%g,%g,%g", sx, rx, ry, sy, tx, ty)
222:     end

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

Draw an arc.

[Source]

     # File lib/RMagick.rb, line 225
225:     def arc(startX, startY, endX, endY, startDegrees, endDegrees)
226:         primitive "arc " + sprintf("%g,%g %g,%g %g,%g",
227:                     startX, startY, endX, endY, startDegrees, endDegrees)
228:     end

bezier(*points)

Draw a bezier curve.

[Source]

     # File lib/RMagick.rb, line 231
231:     def bezier(*points)
232:         if points.length == 0
233:             Kernel.raise ArgumentError, "no points specified"
234:         elsif points.length % 2 != 0
235:             Kernel.raise ArgumentError, "odd number of arguments specified"
236:         end
237:         primitive "bezier " + points.join(',')
238:     end

circle(originX, originY, perimX, perimY)

Draw a circle

[Source]

     # File lib/RMagick.rb, line 241
241:     def circle(originX, originY, perimX, perimY)
242:         primitive "circle " + sprintf("%g,%g %g,%g", originX, originY, perimX, perimY)
243:     end

clip_path(name)

Invoke a clip-path defined by def_clip_path.

[Source]

     # File lib/RMagick.rb, line 246
246:     def clip_path(name)
247:         primitive "clip-path #{name}"
248:     end

clip_rule(rule)

Define the clipping rule.

[Source]

     # File lib/RMagick.rb, line 251
251:     def clip_rule(rule)
252:         if ( not ["evenodd", "nonzero"].include?(rule.downcase) )
253:             Kernel.raise ArgumentError, "Unknown clipping rule #{rule}"
254:         end
255:         primitive "clip-rule #{rule}"
256:     end

clip_units(unit)

Define the clip units

[Source]

     # File lib/RMagick.rb, line 259
259:     def clip_units(unit)
260:         if ( not ["userspace", "userspaceonuse", "objectboundingbox"].include?(unit.downcase) )
261:             Kernel.raise ArgumentError, "Unknown clip unit #{unit}"
262:         end
263:         primitive "clip-units #{unit}"
264:     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 268
268:     def color(x, y, method)
269:         if ( not PAINT_METHOD_NAMES.has_key?(method.to_i) )
270:             Kernel.raise ArgumentError, "Unknown PaintMethod: #{method}"
271:         end
272:         primitive "color #{x},#{y},#{PAINT_METHOD_NAMES[method.to_i]}"
273:     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 277
277:     def decorate(decoration)
278:         if ( DECORATION_TYPE_NAMES.has_key?(decoration.to_i) )
279:             primitive "decorate #{DECORATION_TYPE_NAMES[decoration.to_i]}"
280:         else
281:             primitive "decorate #{enquote(decoration)}"
282:         end
283:     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 290
290:     def define_clip_path(name)
291:         begin
292:             push('defs')
293:             push('clip-path', name)
294:             push('graphic-context')
295:             yield
296:         ensure
297:             pop('graphic-context')
298:             pop('clip-path')
299:             pop('defs')
300:         end
301:     end

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

Draw an ellipse

[Source]

     # File lib/RMagick.rb, line 304
304:     def ellipse(originX, originY, width, height, arcStart, arcEnd)
305:         primitive "ellipse " + sprintf("%g,%g %g,%g %g,%g",
306:                         originX, originY, width, height, arcStart, arcEnd)
307:     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 311
311:     def encoding(encoding)
312:         primitive "encoding #{encoding}"
313:     end

fill(colorspec)

Specify object fill, a color name or pattern name

[Source]

     # File lib/RMagick.rb, line 316
316:     def fill(colorspec)
317:         primitive "fill #{enquote(colorspec)}"
318:     end

fill_color(colorspec)

Alias for fill

fill_opacity(opacity)

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

[Source]

     # File lib/RMagick.rb, line 323
323:     def fill_opacity(opacity)
324:         primitive "fill-opacity #{opacity}"
325:     end

fill_pattern(colorspec)

Alias for fill

fill_rule(rule)

[Source]

     # File lib/RMagick.rb, line 327
327:     def fill_rule(rule)
328:         if ( not ["evenodd", "nonzero"].include?(rule.downcase) )
329:             Kernel.raise ArgumentError, "Unknown fill rule #{rule}"
330:         end
331:         primitive "fill-rule #{rule}"
332:     end

font(name)

Specify text drawing font

[Source]

     # File lib/RMagick.rb, line 335
335:     def font(name)
336:         primitive "font #{name}"
337:     end

font_family(name)

[Source]

     # File lib/RMagick.rb, line 339
339:     def font_family(name)
340:         primitive "font-family \'#{name}\'"
341:     end

font_size(points)

Alias for pointsize

font_stretch(stretch)

[Source]

     # File lib/RMagick.rb, line 343
343:     def font_stretch(stretch)
344:         if ( not STRETCH_TYPE_NAMES.has_key?(stretch.to_i) )
345:             Kernel.raise ArgumentError, "Unknown stretch type"
346:         end
347:         primitive "font-stretch #{STRETCH_TYPE_NAMES[stretch.to_i]}"
348:     end

font_style(style)

[Source]

     # File lib/RMagick.rb, line 350
350:     def font_style(style)
351:         if ( not STYLE_TYPE_NAMES.has_key?(style.to_i) )
352:             Kernel.raise ArgumentError, "Unknown style type"
353:         end
354:         primitive "font-style #{STYLE_TYPE_NAMES[style.to_i]}"
355:     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 359
359:     def font_weight(weight)
360:         if ( FONT_WEIGHT_NAMES.has_key?(weight.to_i) )
361:             primitive "font-weight #{FONT_WEIGHT_NAMES[weight.to_i]}"
362:         else
363:             primitive "font-weight #{weight}"
364:         end
365:     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 369
369:     def gravity(grav)
370:         if ( not GRAVITY_NAMES.has_key?(grav.to_i) )
371:             Kernel.raise ArgumentError, "Unknown text positioning gravity"
372:         end
373:         primitive "gravity #{GRAVITY_NAMES[grav.to_i]}"
374:     end

interline_spacing(space)

IM 6.5.5-8 and later

[Source]

     # File lib/RMagick.rb, line 377
377:      def interline_spacing(space)
378:          begin
379:              Float(space)
380:          rescue ArgumentError
381:              Kernel.raise ArgumentError, "invalid value for interline_spacing"
382:          rescue TypeError
383:              Kernel.raise TypeError, "can't convert #{space.class} into Float"
384:          end
385:          primitive "interline-spacing #{space}"
386:      end

interword_spacing(space)

IM 6.4.8-3 and later

[Source]

     # File lib/RMagick.rb, line 389
389:     def interword_spacing(space)
390:         begin
391:             Float(space)
392:         rescue ArgumentError
393:             Kernel.raise ArgumentError, "invalid value for interword_spacing"
394:         rescue TypeError
395:             Kernel.raise TypeError, "can't convert #{space.class} into Float"
396:         end
397:         primitive "interword-spacing #{space}"
398:     end

kerning(space)

IM 6.4.8-3 and later

[Source]

     # File lib/RMagick.rb, line 401
401:     def kerning(space)
402:         begin
403:             Float(space)
404:         rescue ArgumentError
405:             Kernel.raise ArgumentError, "invalid value for kerning"
406:         rescue TypeError
407:             Kernel.raise TypeError, "can't convert #{space.class} into Float"
408:         end
409:         primitive "kerning #{space}"
410:     end

line(startX, startY, endX, endY)

Draw a line

[Source]

     # File lib/RMagick.rb, line 413
413:     def line(startX, startY, endX, endY)
414:         primitive "line " + sprintf("%g,%g %g,%g", startX, startY, endX, endY)
415:     end

matte(x, y, method)

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

[Source]

     # File lib/RMagick.rb, line 419
419:     def matte(x, y, method)
420:         if ( not PAINT_METHOD_NAMES.has_key?(method.to_i) )
421:             Kernel.raise ArgumentError, "Unknown paint method"
422:         end
423:         primitive "matte #{x},#{y} #{PAINT_METHOD_NAMES[method.to_i]}"
424:     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 428
428:     def opacity(opacity)
429:         if (Numeric === opacity)
430:             if (opacity < 0 || opacity > 1.0)
431:                 Kernel.raise ArgumentError, "opacity must be >= 0 and <= 1.0"
432:             end
433:         end
434:         primitive "opacity #{opacity}"
435:     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 440
440:     def path(cmds)
441:         primitive "path '" + cmds + "'"
442:     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 447
447:     def pattern(name, x, y, width, height)
448:         begin
449:             push('defs')
450:             push("pattern #{name} #{x} #{y} #{width} #{height}")
451:             push('graphic-context')
452:             yield
453:         ensure
454:             pop('graphic-context')
455:             pop('pattern')
456:             pop('defs')
457:         end
458:     end

point(x, y)

Set point to fill color.

[Source]

     # File lib/RMagick.rb, line 461
461:     def point(x, y)
462:         primitive "point #{x},#{y}"
463:     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 467
467:     def pointsize(points)
468:         primitive "font-size #{points}"
469:     end

polygon(*points)

Draw a polygon

[Source]

     # File lib/RMagick.rb, line 473
473:     def polygon(*points)
474:         if points.length == 0
475:             Kernel.raise ArgumentError, "no points specified"
476:         elsif points.length % 2 != 0
477:             Kernel.raise ArgumentError, "odd number of points specified"
478:         end
479:         primitive "polygon " + points.join(',')
480:     end

polyline(*points)

Draw a polyline

[Source]

     # File lib/RMagick.rb, line 483
483:     def polyline(*points)
484:         if points.length == 0
485:             Kernel.raise ArgumentError, "no points specified"
486:         elsif points.length % 2 != 0
487:             Kernel.raise ArgumentError, "odd number of points specified"
488:         end
489:         primitive "polyline " + points.join(',')
490:     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 498
498:     def pop(*what)
499:         if what.length == 0
500:             primitive "pop graphic-context"
501:         else
502:             # to_s allows a Symbol to be used instead of a String
503:             primitive "pop " + what.map {|w| w.to_s}.join(' ')
504:         end
505:     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 512
512:     def push(*what)
513:         if what.length == 0
514:             primitive "push graphic-context"
515:         else
516:             # to_s allows a Symbol to be used instead of a String
517:             primitive "push " + what.map {|w| w.to_s}.join(' ')
518:         end
519:     end

rectangle(upper_left_x, upper_left_y, lower_right_x, lower_right_y)

Draw a rectangle

[Source]

     # File lib/RMagick.rb, line 522
522:     def rectangle(upper_left_x, upper_left_y, lower_right_x, lower_right_y)
523:         primitive "rectangle " + sprintf("%g,%g %g,%g",
524:                 upper_left_x, upper_left_y, lower_right_x, lower_right_y)
525:     end

rotate(angle)

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

[Source]

     # File lib/RMagick.rb, line 528
528:     def rotate(angle)
529:         primitive "rotate #{angle}"
530:     end

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

Draw a rectangle with rounded corners

[Source]

     # File lib/RMagick.rb, line 533
533:     def roundrectangle(center_x, center_y, width, height, corner_width, corner_height)
534:         primitive "roundrectangle " + sprintf("%g,%g,%g,%g,%g,%g",
535:             center_x, center_y, width, height, corner_width, corner_height)
536:     end

scale(x, y)

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

[Source]

     # File lib/RMagick.rb, line 539
539:     def scale(x, y)
540:         primitive "scale #{x},#{y}"
541:     end

skewx(angle)

[Source]

     # File lib/RMagick.rb, line 543
543:     def skewx(angle)
544:         primitive "skewX #{angle}"
545:     end

skewy(angle)

[Source]

     # File lib/RMagick.rb, line 547
547:     def skewy(angle)
548:         primitive "skewY #{angle}"
549:     end

stroke(colorspec)

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

[Source]

     # File lib/RMagick.rb, line 552
552:     def stroke(colorspec)
553:         primitive "stroke #{enquote(colorspec)}"
554:     end

stroke_antialias(bool)

Specify if stroke should be antialiased or not

[Source]

     # File lib/RMagick.rb, line 559
559:     def stroke_antialias(bool)
560:         bool = bool ? '1' : '0'
561:         primitive "stroke-antialias #{bool}"
562:     end

stroke_color(colorspec)

Alias for stroke

stroke_dasharray(*list)

Specify a stroke dash pattern

[Source]

     # File lib/RMagick.rb, line 565
565:     def stroke_dasharray(*list)
566:         if list.length == 0
567:             primitive "stroke-dasharray none"
568:         else
569:             list.each { |x|
570:                 if x <= 0 then
571:                     Kernel.raise ArgumentError, "dash array elements must be > 0 (#{x} given)"
572:                 end
573:             }
574:             primitive "stroke-dasharray #{list.join(',')}"
575:         end
576:     end

stroke_dashoffset(value=0)

Specify the initial offset in the dash pattern

[Source]

     # File lib/RMagick.rb, line 579
579:     def stroke_dashoffset(value=0)
580:         primitive "stroke-dashoffset #{value}"
581:     end

stroke_linecap(value)

[Source]

     # File lib/RMagick.rb, line 583
583:     def stroke_linecap(value)
584:         if ( not ["butt", "round", "square"].include?(value.downcase) )
585:             Kernel.raise ArgumentError, "Unknown linecap type: #{value}"
586:         end
587:         primitive "stroke-linecap #{value}"
588:     end

stroke_linejoin(value)

[Source]

     # File lib/RMagick.rb, line 590
590:     def stroke_linejoin(value)
591:         if ( not ["round", "miter", "bevel"].include?(value.downcase) )
592:             Kernel.raise ArgumentError, "Unknown linejoin type: #{value}"
593:         end
594:         primitive "stroke-linejoin #{value}"
595:     end

stroke_miterlimit(value)

[Source]

     # File lib/RMagick.rb, line 597
597:     def stroke_miterlimit(value)
598:         if (value < 1)
599:             Kernel.raise ArgumentError, "miterlimit must be >= 1"
600:         end
601:         primitive "stroke-miterlimit #{value}"
602:     end

stroke_opacity(value)

Specify opacity of stroke drawing color

 (use "xx%" to indicate percentage)

[Source]

     # File lib/RMagick.rb, line 606
606:     def stroke_opacity(value)
607:         primitive "stroke-opacity #{value}"
608:     end

stroke_pattern(colorspec)

Alias for stroke

stroke_width(pixels)

Specify stroke (outline) width in pixels.

[Source]

     # File lib/RMagick.rb, line 611
611:     def stroke_width(pixels)
612:         primitive "stroke-width #{pixels}"
613:     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 616
616:     def text(x, y, text)
617:         if text.to_s.empty?
618:             Kernel.raise ArgumentError, "missing text argument"
619:         end
620:         if text.length > 2 && /\A(?:\"[^\"]+\"|\'[^\']+\'|\{[^\}]+\})\z/.match(text)
621:             ; # text already quoted
622:         elsif !text['\'']
623:             text = '\''+text+'\''
624:         elsif !text['"']
625:             text = '"'+text+'"'
626:         elsif !(text['{'] || text['}'])
627:             text = '{'+text+'}'
628:         else
629:             # escape existing braces, surround with braces
630:             text = '{' +  text.gsub(/[}]/) { |b| '\\' + b } + '}'
631:         end
632:         primitive "text #{x},#{y} #{text}"
633:     end

text_align(alignment)

Specify text alignment relative to a given point

[Source]

     # File lib/RMagick.rb, line 636
636:     def text_align(alignment)
637:         if ( not ALIGN_TYPE_NAMES.has_key?(alignment.to_i) )
638:             Kernel.raise ArgumentError, "Unknown alignment constant: #{alignment}"
639:         end
640:         primitive "text-align #{ALIGN_TYPE_NAMES[alignment.to_i]}"
641:     end

text_anchor(anchor)

SVG-compatible version of text_align

[Source]

     # File lib/RMagick.rb, line 644
644:     def text_anchor(anchor)
645:         if ( not ANCHOR_TYPE_NAMES.has_key?(anchor.to_i) )
646:             Kernel.raise ArgumentError, "Unknown anchor constant: #{anchor}"
647:         end
648:         primitive "text-anchor #{ANCHOR_TYPE_NAMES[anchor.to_i]}"
649:     end

text_antialias(boolean)

Specify if rendered text is to be antialiased.

[Source]

     # File lib/RMagick.rb, line 652
652:     def text_antialias(boolean)
653:         boolean = boolean ? '1' : '0'
654:         primitive "text-antialias #{boolean}"
655:     end

text_undercolor(color)

Specify color underneath text

[Source]

     # File lib/RMagick.rb, line 658
658:     def text_undercolor(color)
659:         primitive "text-undercolor #{enquote(color)}"
660:     end

translate(x, y)

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

[Source]

     # File lib/RMagick.rb, line 664
664:     def translate(x, y)
665:         primitive "translate #{x},#{y}"
666:     end

Private Instance methods

enquote(str)

[Source]

     # File lib/RMagick.rb, line 208
208:     def enquote(str)
209:         if str.length > 2 && /\A(?:\"[^\"]+\"|\'[^\']+\'|\{[^\}]+\})\z/.match(str)
210:             return str
211:         else
212:             return '"' + str + '"'
213:         end
214:     end

Methods

Constants

Public Instance methods

Private Instance methods