Below are listed the problems that were found to occur with various browser versions. Most of the rendering bugs are no longer visible in Canvex due to workarounds or other changes in the code.

Firefox 1.5+

• Bug #346927: errors drawing transparent PNGs. Causes sprites to be drawn incorrectly on Linux.
• Horrid memory leaks. Seems fixed in Firefox 2.0 (?)

Firefox 2.0+

• Bug #344830: cannot call getElementById on UI SVG element. Causes UI initialisation to fail. Fixed in beta 2.
• Bug #346421: sometimes causes screen to go almost entirely black, when looking in a direction where the last thing drawn is textured (not a floor or shaded wall).
• Bug #347458: sometimes causes screen to go partly black.
• Blurrier display than in 1.5 when canvas is rendered at 320x240 then stretched to 640x480: 1.5 duplicates pixels, 2.0 uses some filtering.
• Faster than 1.5.

Firefox 3.0 (trunk)

• Blurrier display than in 2.0 with resized canvas – each pixel is spread out in both directions. (Bug? or intentional feature, to avoid the 1-pixel offset caused by only spreading pixels in one direction?)
• Black lines between adjacently-drawn texture tiles.
• Faster than 2.0. (Except when there's a performance regression somewhere. The code is very unstable, so problems should be expected.)

Opera 9.00

• Appears to send exactly the same keyCode in keydown handlers for the . and delete keys. It matches Mozilla's KeyEvent.DOM_VK_DELETE, so we just allow DOM_VK_DELETE as strafe-right. (Key handling seems completely non-standard across browsers, and it's not their fault because there isn't any sufficiently useful standard.)

Internet Explorer 6, 7

• Uh... Various problems.

Compatibility philosophy

Canvex attempts to follow the relevant standards such that it would work in a perfectly compliant web browser. (If it fails to do so, that should be considered a bug and preferably reported (email)). Since browsers do not implement the standards perfectly, Canvex tries to use a subset that works correctly in them all. Browser detection is used only to set the default options to maximise performance, since different browsers prefer different ways of implementing the same effect. Some proprietary extensions (e.g. opera-2dgame) are used when available, but never required or expected.