javascript - IndexSizeError on drawImage on IE on ARM -

i'm drawing stuff in winrt webview.

the same call draws on x86 , x64 builds, on arm build i'm getting indexsizeerror.

the call in question pdf.js , looks like:

  ctx.drawimage(imgtopaint, 0, 0, paintwidth, paintheight,                             0, -height, width, height); 

inspecting values in js debugger gives following values:

imgtopaint.width == 2132 imgtopaint.height == 2527 paintwidth == 2132 paintheight == 2527 width == 4264 height == 5053 ctx.canvas.width == 1126 ctx.canvas.height == 1467 

according spec, indexsizeerror thrown when of sw or sh (paintwidth , paintheight, respectively) 0, not case here.

what causing this, , can try diagnose properly?

i've confirmed arguments have same values on x86 , x64 builds.

rewriting draw call series of smaller draw calls makes error go away, image isn't drawn correctly on arm builds while drawn correctly on x64 , x86:

ctx.drawimage(imgtopaint, 0, 0, paintwidth/2, paintheight/2,     0, -height, width/2, height/2); ctx.drawimage(imgtopaint, paintwidth/2, 0, paintwidth/2, paintheight/2,     width/2, -height, width/2, height/2); ... 

this suggests me indexsizeerror being thrown in response running out of graphics memory. how might confirm this?