- From: Ian Hickson via cvs-syncmail <cvsmail@w3.org>
- Date: Tue, 07 Dec 2010 20:57:01 +0000
- To: public-html-commits@w3.org
Update of /sources/public/html5/2dcontext In directory hutz:/tmp/cvs-serv18687 Modified Files: Overview.html Log Message: <canvas> drawImage() and pattern filtering issue (whatwg r5708) Index: Overview.html =================================================================== RCS file: /sources/public/html5/2dcontext/Overview.html,v retrieving revision 1.91 retrieving revision 1.92 diff -u -d -r1.91 -r1.92 --- Overview.html 29 Nov 2010 22:56:56 -0000 1.91 +++ Overview.html 7 Dec 2010 20:56:59 -0000 1.92 @@ -1368,6 +1368,17 @@ stroking or filling effect requires that they be drawn, and are affected by the current transformation matrix.</p> + <p>If the original image data is a bitmap image, the value painted + at a point in the area of the repetitions is computed by filtering + the original image data. The user agent may use any filtering + algorithm (for example bilinear interpolation or nearest-neighbor). + When the filtering algorithm requires a pixel value from outside the + original image data, it must instead use the value from wrapping the + pixel's coordinates to the original image's dimensions. (That is, + the filter uses 'repeat' behavior, regardless of the value of + <var title="">repetition</var>.) + <!-- drawImage() has a similar paragraph with different rules --> + <p>When the <code title="dom-context-2d-createPattern"><a href="#dom-context-2d-createpattern">createPattern()</a></code> method is passed an animated image as its <var title="">image</var> argument, the user agent must use the poster frame of the animation, @@ -2773,10 +2784,6 @@ arguments is zero, the implementation must raise an <code>INDEX_SIZE_ERR</code> exception.</p> - <p>Pixels of the source rectangle that are not entirely within the - source image must be treated as transparent black.</p> <!-- see - CORE-32111 http://krijnhoetmer.nl/irc-logs/whatwg/20100818#l-737 --> - <p>The destination rectangle is the rectangle whose corners are the four points (<var title="">dx</var>, <var title="">dy</var>), (<span title=""><var title="">dx</var>+<var title="">dw</var></span>, <var title="">dy</var>), (<span title=""><var title="">dx</var>+<var title="">dw</var></span>, <span title=""><var title="">dy</var>+<var title="">dh</var></span>), (<var title="">dx</var>, <span title=""><var title="">dy</var>+<var title="">dh</var></span>).</p> @@ -2803,6 +2810,19 @@ back onto the canvas, so it is possible to copy parts of a canvas onto overlapping parts of itself.</p> + <p>If the original image data is a bitmap image, the value painted + at a point in the destination rectangle is computed by filtering the + original image data. The user agent may use any filtering algorithm + (for example bilinear interpolation or nearest-neighbor). When the + filtering algorithm requires a pixel value from outside the original + image data, it must instead use the value from the nearest edge + pixel. (That is, the filter uses 'clamp-to-edge' behavior.)</p> + <!-- see CORE-32111 and: + http://krijnhoetmer.nl/irc-logs/whatwg/20100818#l-737 + http://www.w3.org/Bugs/Public/show_bug.cgi?id=10799#c11 + --> + <!-- createPattern() has a similar paragraph with different rules --> + <p>When the <code title="dom-context-2d-drawImage"><a href="#dom-context-2d-drawimage">drawImage()</a></code> method is passed an animated image as its <var title="">image</var> argument, the user agent must use the poster frame of the animation,
Received on Tuesday, 7 December 2010 20:57:04 UTC