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 211
211:     def affine(sx, rx, ry, sy, tx, ty)
212:         primitive "affine " + sprintf("%g,%g,%g,%g,%g,%g", sx, rx, ry, sy, tx, ty)
213:     end

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

Draw an arc.

[Source]

     # File lib/RMagick.rb, line 216
216:     def arc(startX, startY, endX, endY, startDegrees, endDegrees)
217:         primitive "arc " + sprintf("%g,%g %g,%g %g,%g",
218:                     startX, startY, endX, endY, startDegrees, endDegrees)
219:     end

bezier(*points)

Draw a bezier curve.

[Source]

     # File lib/RMagick.rb, line 222
222:     def bezier(*points)
223:         if points.length == 0
224:             Kernel.raise ArgumentError, "no points specified"
225:         elsif points.length % 2 != 0
226:             Kernel.raise ArgumentError, "odd number of arguments specified"
227:         end
228:         primitive "bezier " + points.join(',')
229:     end

circle(originX, originY, perimX, perimY)

Draw a circle

[Source]

     # File lib/RMagick.rb, line 232
232:     def circle(originX, originY, perimX, perimY)
233:         primitive "circle " + sprintf("%g,%g %g,%g", originX, originY, perimX, perimY)
234:     end

clip_path(name)

Invoke a clip-path defined by def_clip_path.

[Source]

     # File lib/RMagick.rb, line 237
237:     def clip_path(name)
238:         primitive "clip-path #{name}"
239:     end

clip_rule(rule)

Define the clipping rule.

[Source]

     # File lib/RMagick.rb, line 242
242:     def clip_rule(rule)
243:         if ( not ["evenodd", "nonzero"].include?(rule.downcase) )
244:             Kernel.raise ArgumentError, "Unknown clipping rule #{rule}"
245:         end
246:         primitive "clip-rule #{rule}"
247:     end

clip_units(unit)

Define the clip units

[Source]

     # File lib/RMagick.rb, line 250
250:     def clip_units(unit)
251:         if ( not ["userspace", "userspaceonuse", "objectboundingbox"].include?(unit.downcase) )
252:             Kernel.raise ArgumentError, "Unknown clip unit #{unit}"
253:         end
254:         primitive "clip-units #{unit}"
255:     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 259
259:     def color(x, y, method)
260:         if ( not PAINT_METHOD_NAMES.has_key?(method.to_i) )
261:             Kernel.raise ArgumentError, "Unknown PaintMethod: #{method}"
262:         end
263:         primitive "color #{x},#{y},#{PAINT_METHOD_NAMES[method.to_i]}"
264:     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 268
268:     def decorate(decoration)
269:         if ( DECORATION_TYPE_NAMES.has_key?(decoration.to_i) )
270:             primitive "decorate #{DECORATION_TYPE_NAMES[decoration.to_i]}"
271:         else
272:             primitive "decorate #{enquote(decoration)}"
273:         end
274:     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 281
281:     def define_clip_path(name)
282:         begin
283:             push('defs')
284:             push('clip-path', name)
285:             push('graphic-context')
286:             yield
287:         ensure
288:             pop('graphic-context')
289:             pop('clip-path')
290:             pop('defs')
291:         end
292:     end

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

Draw an ellipse

[Source]

     # File lib/RMagick.rb, line 295
295:     def ellipse(originX, originY, width, height, arcStart, arcEnd)
296:         primitive "ellipse " + sprintf("%g,%g %g,%g %g,%g",
297:                         originX, originY, width, height, arcStart, arcEnd)
298:     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 302
302:     def encoding(encoding)
303:         primitive "encoding #{encoding}"
304:     end

fill(colorspec)

Specify object fill, a color name or pattern name

[Source]

     # File lib/RMagick.rb, line 307
307:     def fill(colorspec)
308:         primitive "fill #{enquote(colorspec)}"
309:     end

fill_color(colorspec)

Alias for fill

fill_opacity(opacity)

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

[Source]

     # File lib/RMagick.rb, line 314
314:     def fill_opacity(opacity)
315:         primitive "fill-opacity #{opacity}"
316:     end

fill_pattern(colorspec)

Alias for fill

fill_rule(rule)

[Source]

     # File lib/RMagick.rb, line 318
318:     def fill_rule(rule)
319:         if ( not ["evenodd", "nonzero"].include?(rule.downcase) )
320:             Kernel.raise ArgumentError, "Unknown fill rule #{rule}"
321:         end
322:         primitive "fill-rule #{rule}"
323:     end

font(name)

Specify text drawing font

[Source]

     # File lib/RMagick.rb, line 326
326:     def font(name)
327:         primitive "font #{name}"
328:     end

font_family(name)

[Source]

     # File lib/RMagick.rb, line 330
330:     def font_family(name)
331:         primitive "font-family \'#{name}\'"
332:     end

font_size(points)

Alias for pointsize

font_stretch(stretch)

[Source]

     # File lib/RMagick.rb, line 334
334:     def font_stretch(stretch)
335:         if ( not STRETCH_TYPE_NAMES.has_key?(stretch.to_i) )
336:             Kernel.raise ArgumentError, "Unknown stretch type"
337:         end
338:         primitive "font-stretch #{STRETCH_TYPE_NAMES[stretch.to_i]}"
339:     end

font_style(style)

[Source]

     # File lib/RMagick.rb, line 341
341:     def font_style(style)
342:         if ( not STYLE_TYPE_NAMES.has_key?(style.to_i) )
343:             Kernel.raise ArgumentError, "Unknown style type"
344:         end
345:         primitive "font-style #{STYLE_TYPE_NAMES[style.to_i]}"
346:     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 350
350:     def font_weight(weight)
351:         if ( FONT_WEIGHT_NAMES.has_key?(weight.to_i) )
352:             primitive "font-weight #{FONT_WEIGHT_NAMES[weight.to_i]}"
353:         else
354:             primitive "font-weight #{weight}"
355:         end
356:     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 360
360:     def gravity(grav)
361:         if ( not GRAVITY_NAMES.has_key?(grav.to_i) )
362:             Kernel.raise ArgumentError, "Unknown text positioning gravity"
363:         end
364:         primitive "gravity #{GRAVITY_NAMES[grav.to_i]}"
365:     end

interword_spacing(space)

IM 6.4.8-3 and later

[Source]

     # File lib/RMagick.rb, line 368
368:     def interword_spacing(space)
369:         begin
370:             Float(space)
371:         rescue ArgumentError
372:             Kernel.raise ArgumentError, "invalid value for interword_spacing"
373:         rescue TypeError
374:             Kernel.raise TypeError, "can't convert #{space.class} into Float"
375:         end
376:         primitive "interword-spacing #{space}"
377:     end

kerning(space)

IM 6.4.8-3 and later

[Source]

     # File lib/RMagick.rb, line 380
380:     def kerning(space)
381:         begin
382:             Float(space)
383:         rescue ArgumentError
384:             Kernel.raise ArgumentError, "invalid value for kerning"
385:         rescue TypeError
386:             Kernel.raise TypeError, "can't convert #{space.class} into Float"
387:         end
388:         primitive "kerning #{space}"
389:     end

line(startX, startY, endX, endY)

Draw a line

[Source]

     # File lib/RMagick.rb, line 392
392:     def line(startX, startY, endX, endY)
393:         primitive "line " + sprintf("%g,%g %g,%g", startX, startY, endX, endY)
394:     end

matte(x, y, method)

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

[Source]

     # File lib/RMagick.rb, line 398
398:     def matte(x, y, method)
399:         if ( not PAINT_METHOD_NAMES.has_key?(method.to_i) )
400:             Kernel.raise ArgumentError, "Unknown paint method"
401:         end
402:         primitive "matte #{x},#{y} #{PAINT_METHOD_NAMES[method.to_i]}"
403:     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 407
407:     def opacity(opacity)
408:         if (Numeric === opacity)
409:             if (opacity < 0 || opacity > 1.0)
410:                 Kernel.raise ArgumentError, "opacity must be >= 0 and <= 1.0"
411:             end
412:         end
413:         primitive "opacity #{opacity}"
414:     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 419
419:     def path(cmds)
420:         primitive "path '" + cmds + "'"
421:     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 426
426:     def pattern(name, x, y, width, height)
427:         begin
428:             push('defs')
429:             push("pattern #{name} #{x} #{y} #{width} #{height}")
430:             push('graphic-context')
431:             yield
432:         ensure
433:             pop('graphic-context')
434:             pop('pattern')
435:             pop('defs')
436:         end
437:     end

point(x, y)

Set point to fill color.

[Source]

     # File lib/RMagick.rb, line 440
440:     def point(x, y)
441:         primitive "point #{x},#{y}"
442:     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 446
446:     def pointsize(points)
447:         primitive "font-size #{points}"
448:     end

polygon(*points)

Draw a polygon

[Source]

     # File lib/RMagick.rb, line 452
452:     def polygon(*points)
453:         if points.length == 0
454:             Kernel.raise ArgumentError, "no points specified"
455:         elsif points.length % 2 != 0
456:             Kernel.raise ArgumentError, "odd number of points specified"
457:         end
458:         primitive "polygon " + points.join(',')
459:     end

polyline(*points)

Draw a polyline

[Source]

     # File lib/RMagick.rb, line 462
462:     def polyline(*points)
463:         if points.length == 0
464:             Kernel.raise ArgumentError, "no points specified"
465:         elsif points.length % 2 != 0
466:             Kernel.raise ArgumentError, "odd number of points specified"
467:         end
468:         primitive "polyline " + points.join(',')
469:     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 477
477:     def pop(*what)
478:         if what.length == 0
479:             primitive "pop graphic-context"
480:         else
481:             # to_s allows a Symbol to be used instead of a String
482:             primitive "pop " + what.map {|w| w.to_s}.join(' ')
483:         end
484:     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 491
491:     def push(*what)
492:         if what.length == 0
493:             primitive "push graphic-context"
494:         else
495:             # to_s allows a Symbol to be used instead of a String
496:             primitive "push " + what.map {|w| w.to_s}.join(' ')
497:         end
498:     end

rectangle(upper_left_x, upper_left_y, lower_right_x, lower_right_y)

Draw a rectangle

[Source]

     # File lib/RMagick.rb, line 501
501:     def rectangle(upper_left_x, upper_left_y, lower_right_x, lower_right_y)
502:         primitive "rectangle " + sprintf("%g,%g %g,%g",
503:                 upper_left_x, upper_left_y, lower_right_x, lower_right_y)
504:     end

rotate(angle)

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

[Source]

     # File lib/RMagick.rb, line 507
507:     def rotate(angle)
508:         primitive "rotate #{angle}"
509:     end

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

Draw a rectangle with rounded corners

[Source]

     # File lib/RMagick.rb, line 512
512:     def roundrectangle(center_x, center_y, width, height, corner_width, corner_height)
513:         primitive "roundrectangle " + sprintf("%g,%g,%g,%g,%g,%g",
514:             center_x, center_y, width, height, corner_width, corner_height)
515:     end

scale(x, y)

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

[Source]

     # File lib/RMagick.rb, line 518
518:     def scale(x, y)
519:         primitive "scale #{x},#{y}"
520:     end

skewx(angle)

[Source]

     # File lib/RMagick.rb, line 522
522:     def skewx(angle)
523:         primitive "skewX #{angle}"
524:     end

skewy(angle)

[Source]

     # File lib/RMagick.rb, line 526
526:     def skewy(angle)
527:         primitive "skewY #{angle}"
528:     end

stroke(colorspec)

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

[Source]

     # File lib/RMagick.rb, line 531
531:     def stroke(colorspec)
532:         primitive "stroke #{enquote(colorspec)}"
533:     end

stroke_antialias(bool)

Specify if stroke should be antialiased or not

[Source]

     # File lib/RMagick.rb, line 538
538:     def stroke_antialias(bool)
539:         bool = bool ? '1' : '0'
540:         primitive "stroke-antialias #{bool}"
541:     end

stroke_color(colorspec)

Alias for stroke

stroke_dasharray(*list)

Specify a stroke dash pattern

[Source]

     # File lib/RMagick.rb, line 544
544:     def stroke_dasharray(*list)
545:         if list.length == 0
546:             primitive "stroke-dasharray none"
547:         else
548:             list.each { |x|
549:                 if x <= 0 then
550:                     Kernel.raise ArgumentError, "dash array elements must be > 0 (#{x} given)"
551:                 end
552:             }
553:             primitive "stroke-dasharray #{list.join(',')}"
554:         end
555:     end

stroke_dashoffset(value=0)

Specify the initial offset in the dash pattern

[Source]

     # File lib/RMagick.rb, line 558
558:     def stroke_dashoffset(value=0)
559:         primitive "stroke-dashoffset #{value}"
560:     end

stroke_linecap(value)

[Source]

     # File lib/RMagick.rb, line 562
562:     def stroke_linecap(value)
563:         if ( not ["butt", "round", "square"].include?(value.downcase) )
564:             Kernel.raise ArgumentError, "Unknown linecap type: #{value}"
565:         end
566:         primitive "stroke-linecap #{value}"
567:     end

stroke_linejoin(value)

[Source]

     # File lib/RMagick.rb, line 569
569:     def stroke_linejoin(value)
570:         if ( not ["round", "miter", "bevel"].include?(value.downcase) )
571:             Kernel.raise ArgumentError, "Unknown linejoin type: #{value}"
572:         end
573:         primitive "stroke-linejoin #{value}"
574:     end

stroke_miterlimit(value)

[Source]

     # File lib/RMagick.rb, line 576
576:     def stroke_miterlimit(value)
577:         if (value < 1)
578:             Kernel.raise ArgumentError, "miterlimit must be >= 1"
579:         end
580:         primitive "stroke-miterlimit #{value}"
581:     end

stroke_opacity(value)

Specify opacity of stroke drawing color

 (use "xx%" to indicate percentage)

[Source]

     # File lib/RMagick.rb, line 585
585:     def stroke_opacity(value)
586:         primitive "stroke-opacity #{value}"
587:     end

stroke_pattern(colorspec)

Alias for stroke

stroke_width(pixels)

Specify stroke (outline) width in pixels.

[Source]

     # File lib/RMagick.rb, line 590
590:     def stroke_width(pixels)
591:         primitive "stroke-width #{pixels}"
592:     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 595
595:     def text(x, y, text)
596:         if text.to_s.empty?
597:             Kernel.raise ArgumentError, "missing text argument"
598:         end
599:         if text.length > 2 && /\A(?:\"[^\"]+\"|\'[^\']+\'|\{[^\}]+\})\z/.match(text)
600:             ; # text already quoted
601:         elsif !text['\'']
602:             text = '\''+text+'\''
603:         elsif !text['"']
604:             text = '"'+text+'"'
605:         elsif !(text['{'] || text['}'])
606:             text = '{'+text+'}'
607:         else
608:             # escape existing braces, surround with braces
609:             text = '{' +  text.gsub(/[}]/) { |b| '\\' + b } + '}'
610:         end
611:         primitive "text #{x},#{y} #{text}"
612:     end

text_align(alignment)

Specify text alignment relative to a given point

[Source]

     # File lib/RMagick.rb, line 615
615:     def text_align(alignment)
616:         if ( not ALIGN_TYPE_NAMES.has_key?(alignment.to_i) )
617:             Kernel.raise ArgumentError, "Unknown alignment constant: #{alignment}"
618:         end
619:         primitive "text-align #{ALIGN_TYPE_NAMES[alignment.to_i]}"
620:     end

text_anchor(anchor)

SVG-compatible version of text_align

[Source]

     # File lib/RMagick.rb, line 623
623:     def text_anchor(anchor)
624:         if ( not ANCHOR_TYPE_NAMES.has_key?(anchor.to_i) )
625:             Kernel.raise ArgumentError, "Unknown anchor constant: #{anchor}"
626:         end
627:         primitive "text-anchor #{ANCHOR_TYPE_NAMES[anchor.to_i]}"
628:     end

text_antialias(boolean)

Specify if rendered text is to be antialiased.

[Source]

     # File lib/RMagick.rb, line 631
631:     def text_antialias(boolean)
632:         boolean = boolean ? '1' : '0'
633:         primitive "text-antialias #{boolean}"
634:     end

text_undercolor(color)

Specify color underneath text

[Source]

     # File lib/RMagick.rb, line 637
637:     def text_undercolor(color)
638:         primitive "text-undercolor #{enquote(color)}"
639:     end

translate(x, y)

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

[Source]

     # File lib/RMagick.rb, line 643
643:     def translate(x, y)
644:         primitive "translate #{x},#{y}"
645:     end

Private Instance methods

enquote(str)

[Source]

     # File lib/RMagick.rb, line 199
199:     def enquote(str)
200:         if str.length > 2 && /\A(?:\"[^\"]+\"|\'[^\']+\'|\{[^\}]+\})\z/.match(str)
201:             return str
202:         else
203:             return '"' + str + '"'
204:         end
205:     end

Methods

Constants

Public Instance methods

Private Instance methods