When I constructed my test canvas to measure the vertical extent of a
text string for ALIGN_VCENTRE, I forgot to ensure that the 'width'
variable was an integer, as a result of which the loop over canvas
pixels kept trying to use fractional array indices and returning
undefined :-)
[originally from svn r10196]
// Find the width of the string
var ctx1 = onscreen_canvas.getContext('2d');
ctx1.font = font;
- var width = ctx1.measureText(midpoint_test_str).width;
+ var width = (ctx1.measureText(midpoint_test_str).width + 1) | 0;
// Construct a test canvas of appropriate size, initialise it to
// black, and draw the string on it in white