* 関連

[45] [CODE(HTMLe)@en[[[canvas]]]] も参照。

* 歴史

[1] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-08-03 07:21:00 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5226&to=5227>

[2] [CITE@en[Web Applications 1.0 r8132     Allow UAs to use algorithms other than nearest-neighbour when scaling images down.]]
( ([TIME[2013-08-07 05:30:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=8131&to=8132>

[3] [CITE@en-US-x-Hixie[HTML Canvas 2D Context]]
( ([TIME[2013-08-07 02:46:06 +09:00]] 版))
<http://www.w3.org/TR/2013/CR-2dcontext-20130806/>

[4] [CITE[''''''[''''''whatwg'''''']'''''' canvas 2d's ellipse]]
( ([TIME[2013-08-21 01:11:59 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-August/040524.html>

[5] [CITE[''''''[''''''whatwg'''''']'''''' Path API feedback]]
( ([TIME[2013-08-21 03:13:57 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-August/040523.html>

[6] [CITE[''''''[''''''whatwg'''''']'''''' 2D canvas feature proposal: text decoration]]
( ([TIME[2013-08-21 03:13:57 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-August/040521.html>

[7] [CITE[''''''[''''''whatwg'''''']'''''' Questions regarding Path object]]
( ([TIME[2013-08-21 03:13:57 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-August/040511.html>

[8] [CITE[''''''[''''''whatwg'''''']'''''' Blurry lines in 2D Canvas]]
( ([TIME[2013-09-05 23:33:46 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040707.html>

[9] [CITE@en[HTML Canvas 2D Context Extensions]]
( ([TIME[2011-12-16 12:39:56 +09:00]] 版))
<http://dev.w3.org/html5/canvas-extensions/>

[10] [CITE[''''''[''''''whatwg'''''']'''''' High-density canvases]]
( ([TIME[2013-09-10 00:07:53 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040735.html>

[11] [CITE[''''''[''''''whatwg'''''']'''''' Stroking algorithm in Canvas 2d]]
( ([TIME[2013-09-09 19:56:11 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040733.html>

[12] [CITE[''''''[''''''whatwg'''''']'''''' remove resetClip from the Canvas 2D spec]]
( ([TIME[2013-09-12 01:08:12 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040788.html>

[13] [CITE[IRC logs: freenode / #whatwg / 20130910]]
( ([TIME[2013-09-14 10:13:52 +09:00]] 版))
<http://krijnhoetmer.nl/irc-logs/whatwg/20130910#l-89>

[14] [CITE[IRC logs: freenode / #whatwg / 20130914]]
( ([TIME[2013-09-16 19:41:31 +09:00]] 版))
<http://krijnhoetmer.nl/irc-logs/whatwg/20130914>

[15] [CITE[''''''[''''''whatwg'''''']'''''' canvas 2d's ellipse]]
( ([TIME[2013-09-17 18:16:43 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040853.html>

[16] [CITE[''''''[''''''whatwg'''''']'''''' Canvas - Should setLineDash be a nullable sequence?]]
( ([TIME[2013-09-17 17:30:40 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040851.html>

[17] [CITE[''''''[''''''whatwg'''''']'''''' 2D canvas feature proposal: text decoration]]
( ([TIME[2013-09-27 22:35:37 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040908.html>

[18] [CITE[''''''[''''''whatwg'''''']'''''' canvas 2d's ellipse]]
( ([TIME[2013-09-27 22:35:37 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040857.html>

[19] [CITE[''''''[''''''whatwg'''''']'''''' Stroking algorithm in Canvas 2d]]
( ([TIME[2013-09-27 22:35:36 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040917.html>

[20] [CITE[''''''[''''''whatwg'''''']'''''' Adding 2D Canvas features]]
( ([TIME[2013-09-27 22:07:44 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040911.html>

[21] [CITE[''''''[''''''whatwg'''''']'''''' High-density canvases]]
( ([TIME[2013-09-27 22:35:36 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040914.html>

[22] [CITE[''''''[''''''whatwg'''''']'''''' Outline style to use for drawSystemFocusRing]]
( ([TIME[2013-10-01 00:42:44 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-September/040932.html>

[23] [CITE@en[Web Applications 1.0 r8225     Change how tracing a path works so that it's more similar to SVG, PDF, etc.]]
( ([TIME[2013-10-16 08:17:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=8224&to=8225>

[24] [CITE@en[Web Applications 1.0 r8227 Clarify rules for drawing focus rings]]
( ([TIME[2013-10-17 07:43:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=8226&to=8227>

[25] [CITE@en[Web Applications 1.0 r8227 Clarify rules for drawing focus rings]]
( ([TIME[2013-10-17 07:43:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=8226&to=8227>

[26] [CITE[''''''[''''''whatwg'''''']'''''' Drawing shapes on canvas and feedback thereon]]
( ([TIME[2013-11-25 23:55:40 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2013-November/041659.html>

[27] [CITE@en[Web Applications 1.0 r8397     Add a couple of ImageData() constructors, and (in order to make that feasible) drop all the HD stuff on <canvas>.]]
( ([TIME[2014-01-16 07:06:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=8396&to=8397>

[28] [CITE[''''''[''''''whatwg'''''']'''''' <canvas> feedback]]
( ([TIME[2014-04-29 23:36:07 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2014-April/254125.html>

[29] [CITE[''''''[''''''whatwg'''''']'''''' <canvas> feedback]]
( ([TIME[2014-04-29 23:36:07 +09:00]] 版))
<http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2014-April/254179.html>

[30] [CITE@en[HTML Standard Tracker]]
( ([TIME[2014-05-16 03:17:47 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=8628&to=8629>

[31] [CITE@en-US-x-Hixie[HTML Canvas 2D Context]]
( ([TIME[2014-05-20 22:49:46 +09:00]] 版))
<http://www.w3.org/TR/2014/WD-2dcontext-20140520/>

[32] [CITE@en[corbanbrook/webgl-2d]]
( ([TIME[2014-08-08 16:14:18 +09:00]] 版))
<https://github.com/corbanbrook/webgl-2d>

[33] [CITE@en-US-x-Hixie[HTML Canvas 2D Context]]
( ([TIME[2014-08-21 14:38:42 +09:00]] 版))
<http://www.w3.org/TR/2014/CR-2dcontext-20140821/>

[34] [CITE@en-US-x-Hixie[HTML Canvas 2D Context, Level 2]]
( ([TIME[2014-08-27 01:01:13 +09:00]] 版))
<http://www.w3.org/TR/2014/WD-2dcontext2-20140828/>

[35] [CITE@en[Web Applications 1.0 r8783     Fix IDL blocks due to my misunderstanding what 'optional' meant]]
( ([TIME[2014-09-18 07:43:00 +09:00]] 版))
<https://html5.org/r/8783>

[36] [CITE@en[Web Applications 1.0 r8813 Remove a note about a possible canvas change, since it hasn't happened for a few years now.]]
( ([TIME[2014-09-25 05:03:00 +09:00]] 版))
<https://html5.org/r/8813>

[37] [CITE@en[Bug 8794 – <canvas>: lineWidth = 'hairline']]
( ([TIME[2014-09-28 09:04:16 +09:00]] 版))
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=8794>

[38] [CITE@en[Bug 11739 – <canvas>: clearPath() that clears pixels the way clearRect() does, but using a path]]
( ([TIME[2014-09-28 09:05:42 +09:00]] 版))
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=11739>

[39] [CITE@en-US-x-Hixie[HTML Canvas 2D Context]]
( ([TIME[2015-05-15 00:43:14 +09:00]] 版))
<http://www.w3.org/TR/2015/WD-2dcontext-20150514/>

[40] [CITE@en-US-x-Hixie[HTML Canvas 2D Context]]
( ([TIME[2015-07-01 03:24:13 +09:00]] 版))
<http://www.w3.org/TR/2015/CR-2dcontext-20150702/>

[41] [CITE@en-US-x-Hixie[HTML Canvas 2D Context]]
([TIME[2015-09-24 12:46:31 +09:00]] 版)
<http://www.w3.org/TR/2015/PR-2dcontext-20150924/>

[42] [CITE@en-US-x-Hixie[HTML Canvas 2D Context]]
( ([TIME[2015-11-19 07:12:11 +09:00]] 版))
<http://www.w3.org/TR/2015/REC-2dcontext-20151119/>

[43] [CITE@en[''''''[''''''whatwg'''''']''''''  Splitting CanvasRenderingContext2D]]
([[Ian Kilpatrick]] 著, [TIME[2015-12-01 08:40:13 +09:00]] 版)
<https://lists.w3.org/Archives/Public/public-whatwg-archive/2015Nov/0020.html>

[44] [CITE@en[''''''[''''''css-paint-api'''''']'''''' Initial overview of what is in PaintRenderingContext2D. · w3c/css-houdini-drafts@08a4cf8]]
([TIME[2016-01-07 11:57:31 +09:00]] 版)
<https://github.com/w3c/css-houdini-drafts/commit/08a4cf853c27012222b7d28a8d639e08ca37a0e2>

[46] [CITE@en[Use enum for lineCap/lineJoin/textAlign/textBaseline/direction · whatwg/html@a4b9eef]]
([TIME[2016-02-14 00:55:45 +09:00]] 版)
<https://github.com/whatwg/html/commit/a4b9eef6ff40c394cf6ec9247ce6286795348f3f>

[47] [CITE@en[Remove CanvasProxy along with related concepts and complexities · whatwg/html@740634d]]
([TIME[2016-03-08 18:40:26 +09:00]] 版)
<https://github.com/whatwg/html/commit/740634d0f30a3b76e9da166ac2fa8835fcc073ab>

[48] [CITE[Here's the list of all the 2D Context API specs I could find at the W3C as of March 4th 2014]]
([TIME[2014-04-12 07:37:43 +09:00]] 版)
<http://damowmow.com/temp/canvas-specs>

[49] [CITE@en[Editorial: synchronize with the DOM Standard · whatwg/html@21c6ec7]]
([TIME[2016-03-20 18:14:36 +09:00]] 版)
<https://github.com/whatwg/html/commit/21c6ec77594eb89b836d4872222f5916910967fd>

[50] [CITE@en[21835 – <canvas>: Path object should have a way to add paths keeping only the union given a fill rule]]
([TIME[2016-04-22 17:56:16 +09:00]] 版)
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=21835>

[51] [CITE@en[18751 – <canvas>: a way to get the coordinate of the last point in a path]]
([TIME[2016-04-22 17:57:07 +09:00]] 版)
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=18751>

[52] [CITE@en[22703 – <canvas>: Masks]]
([TIME[2016-04-22 17:57:41 +09:00]] 版)
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=22703>

[53] [CITE@en[Fix "text preparation algorithm" to account for NaN]]
( ([[xidachen]]著, [TIME[2016-06-22 09:24:03 +09:00]]))
<https://github.com/whatwg/html/commit/c8afae01320a3b7161273105193b61cb2b9caf3c>

[54] [CITE@en[Revert behavior change of 2D context "currentColor" keyword]]
([[junov]]著, [TIME[2016-07-07 05:05:39 +09:00]])
<https://github.com/whatwg/html/commit/c836c70ccff790f82b8a22f3f1897b3bcdcbd870>

[55] [CITE@en[Remove unnecessary and unimplemented canvas tainting when painting text]]
([[domenic]]著, [TIME[2016-07-15 02:21:54 +09:00]])
<https://github.com/whatwg/html/commit/6c76b617d2b45326afea2625d174ce2fd5ab6423>

[56] [CITE@en[Disallow defining a custom element using HTMLElement or its subclasses]]
([[domenic]]著, [TIME[2016-06-16 17:09:53 +09:00]])
<https://github.com/whatwg/html/commit/69847259ecd9b3166b88e24ab2d5f6dd8bd59aec>

[57] [CITE@en[Fix incorrect reference to the 2D rendering context alpha flag]]
([[junov]]著, [TIME[2016-09-29 07:09:53 +09:00]])
<https://github.com/whatwg/html/commit/f9ac1ceb2b67d71f08579e10ebcaeb6725be2d12>

[58] [CITE@en[Inline the infinite/NaN argument handling in 2d canvas methods]]
([[zcorpan]]著, [TIME[2016-09-30 22:38:34 +09:00]])
<https://github.com/whatwg/html/commit/6f2c0e884e3a7974637514b04e62f7352b6e405d>

[59] [CITE@en[Work in progress on Web Platform re-charter; Service Workers WG  charter (Advance Notice)]]
([[Wendy Seltzer]]著, [TIME[2017-05-13 04:44:55 +09:00]])
<https://lists.w3.org/Archives/Public/public-new-work/2017May/0006.html>

[60] [CITE@en[22704 – <canvas>: Layers]]
([TIME[2017-07-23 13:18:27 +09:00]])
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=22704>

[61] [CITE@en[27993 – <canvas>: influence of computed style or bidi text direction on CanvasRenderingContext2D text rendering]]
([TIME[2017-07-23 14:18:55 +09:00]])
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=27993>

[62] [CITE@en[23516 – <canvas>: controlling whether text is anti-aliased]]
([TIME[2017-07-27 15:24:10 +09:00]])
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=23516>

[63] [CITE@en[Fix variable typos in canvas "trace a path" algorithm]]
([[earnubs]]著, [TIME[2017-12-15 06:27:00 +09:00]])
<https://github.com/whatwg/html/commit/4c84beec20b840ca3d956515008f94d4ab1924af>

[64] [CITE@en["The miter length is the distance from the point..." · Issue #3121 · whatwg/html]]
([TIME[2017-12-15 17:09:30 +09:00]])
<https://github.com/whatwg/html/issues/3121>

[65] [CITE@en[fix typos on style var in Canvas trace a path algo by earnubs · Pull Request #3288 · whatwg/html]]
([TIME[2017-12-15 17:09:54 +09:00]])
<https://github.com/whatwg/html/pull/3288>

[66] [CITE@en[Use Web IDL's new-ish interface mixins concept]]
([[romandev]]著, [TIME[2017-12-21 05:39:18 +09:00]])
<https://github.com/whatwg/html/commit/c8867a179c21134021dc3435e98c1b9c4542d794>

[67] [CITE@en[Editorial: define arc() and ellipse() in terms of shared steps]]
([[annevk]]著, [TIME[2018-01-13 02:32:01 +09:00]])
<https://github.com/whatwg/html/commit/af11308332a82f8bc548b3d52f701973575f205f>

[68] [CITE@en[Editorial: remove more obsolete canvas worker text]]
([[annevk]]著, [TIME[2018-01-22 23:28:08 +09:00]])
<https://github.com/whatwg/html/commit/471e869889d2fc2153b9483f388c7282fac29530>

[69] [CITE@en[Editorial: remove more obsolete canvas worker text by annevk · Pull Request #3381 · whatwg/html]]
([TIME[2018-01-24 12:44:30 +09:00]])
<https://github.com/whatwg/html/pull/3381>

[70] [CITE@en[Improve creation of 2D and ImageBitmap rendering contexts]]
([[annevk]]著, [TIME[2018-01-22 23:56:16 +09:00]])
<https://github.com/whatwg/html/commit/ad4ddd802e91da38f194a7d7df04157f739eb46b>

[71] [CITE@en[Improve creation of 2D and ImageBitmap rendering contexts by annevk · Pull Request #3382 · whatwg/html]]
([TIME[2018-01-24 12:45:11 +09:00]])
<https://github.com/whatwg/html/pull/3382>

[72] [CITE@en[Editorial: use "identity matrix" consistently]]
([[TimvdLippe]]著, [TIME[2018-03-14 13:20:39 +09:00]])
<https://github.com/whatwg/html/commit/6f9e3c05f30eaaa4da3a63bd7d7d990e3bb22c9d>

[73] [CITE@en[Replace "identity transform" with "identity matrix" · Issue #3426 · whatwg/html]]
([TIME[2018-03-15 17:31:26 +09:00]])
<https://github.com/whatwg/html/issues/3426>

[74] [CITE@en[Fix usage of "identity transform" to use "identity matrix" instead by TimvdLippe · Pull Request #3555 · whatwg/html]]
([TIME[2018-03-15 17:31:35 +09:00]])
<https://github.com/whatwg/html/pull/3555>

[75] [CITE@en[Memorandum of Understanding Between W3C and WHATWG]]
([TIME[2019-05-28 17:23:37 +09:00]])
<https://www.w3.org/2019/04/WHATWG-W3C-MOU.html>

[76] [CITE@en[Add getContextAttributes() to CanvasRenderingContext2D]]
([[yellowdoge]]著, [TIME[2019-01-05 09:01:40 +09:00]])
<https://github.com/whatwg/html/commit/206873adc7d6862545b56097db874d175e81d15a>

[77] [CITE@en[Add an optional desynchronized mode to 2D canvas]]
([[yellowdoge]]著, [TIME[2019-03-21 02:11:54 +09:00]])
<https://github.com/whatwg/html/commit/cf529a3291dc8a9b823048c12ed9020915a432b9>

[78] [CITE@en[Add lowLatency flag to CanvasRenderingContext2DSettings. by kenrussell · Pull Request #4234 · whatwg/html]]
([TIME[2019-07-24 20:34:55 +09:00]])
<https://github.com/whatwg/html/pull/4234>

[79] [CITE@en[Add a low latency mode for 2D/3D Canvas contexts · Issue #4087 · whatwg/html]]
([TIME[2019-07-24 20:36:53 +09:00]])
<https://github.com/whatwg/html/issues/4087>

[80] [CITE@en[Add lowLatency flag to CanvasRenderingContext2DSettings by yellowdoge · Pull Request #4360 · whatwg/html]]
([TIME[2019-07-24 20:37:38 +09:00]])
<https://github.com/whatwg/html/pull/4360>

[81] [CITE@en[Explain multiplied-out coordinates for canvas transforms]]
([[domenic]]著, [TIME[2019-05-14 23:28:36 +09:00]])
<https://github.com/whatwg/html/commit/3d150e83eb1ba4a95ab839b16cc29d7fffe60c97>

[82] [CITE@en[28333 – Show on example how a,b,c,d,e,f affect the point position]]
([TIME[2019-04-02 13:48:11 +09:00]])
<https://www.w3.org/Bugs/Public/show_bug.cgi?id=28333>

[83] [CITE@en[Add multiplied-out coordinates for canvas transforms by domenic · Pull Request #4473 · whatwg/html]]
([TIME[2019-12-06 16:55:32 +09:00]])
<https://github.com/whatwg/html/pull/4473>

[84] [CITE@en[fserb/canvas2D: Update Canvas 2D API]]
([TIME[2020-04-03 11:52:23 +09:00]])
<https://github.com/fserb/canvas2D>


[85] 
大量の [CODE[canvas]] を順に作成 → [CODE[beginPath()]] → [[パス]]の構築 → [CODE[closePath()]] → [CODE[fill()]] で描画したとき、
[CITE[Windows]] の [CITE[Chrome]]
で表示すると、描画内容が部分的に崩れたり、他の [CODE[canvas]] の内容が混ざって表示されたりすることがあります。
[CODE[fill()]] を2回呼ぶと正常に描画されます。前後に別個の描画を行うことだけでは解消されませんが、
単純に [CODE[beginPath]] から [CODE[fill]] までの全体を2回繰り返すのでも解消するので、
事情は少し複雑そうです。
それ以外の挙動は正常で軽快なので、[[メモリー]]不足ということでもなさそうです。
症状からみて [CITE[Chrome]] の描画エンジンの何らかの不具合のように思われます。
[TIME[2026-01-13T11:50:41.400Z]]