- From: Brian Birtles via GitHub <sysbot+gh@w3.org>
- Date: Tue, 23 Oct 2018 06:38:27 +0000
- To: public-css-archive@w3.org
birtles has just labeled a pull request from birtles for https://github.com/w3c/csswg-drafts as "css-transforms-2": == [css-transforms-2] Fix the check for product == 1.0 to include the case when product is -1 == This occurs in the following code: ``` if (product == 1.0) quaternionDst = quaternionA return theta = acos(dot) w = sin(t * theta) * 1 / sqrt(1 - product * product) ``` If `product` is -1.0 we'll end up doing division by zero when we calculate `w`. WebKit works around this by inverting the angle (effectively doing the same thing as taking the absolute value): https://github.com/WebKit/webkit/blob/425f9748af04b2c7e235cf3ff9396eecc23c0af5/Source/WebCore/platform/graphics/transforms/TransformationMatrix.cpp#L542-L548 Chromium takes the absolute value like this patch does: https://cs.chromium.org/chromium/src/third_party/blink/renderer/platform/transforms/transformation_matrix.cc?l=762&rcl=cd5181ecb173efdef4163f066c27bd136fca01d5 See https://github.com/w3c/csswg-drafts/pull/3235
Received on Tuesday, 23 October 2018 06:38:31 UTC