HTML 5 Canvas Library

LQCanvas Library Method

Short Description: Select 3D Canvas Size for Low Quality Mode

Signature: taccgl.LQCanvas (x,y,w,h)
Class: taccgl Class

Sets position and size of the low quality 3D canvas. If taccgl™ detects that the animation is running slowly, it tries to reduce the size of the 3D canvas. Reducing the size of the canvas will speed up animations because less pixels need to be calculated and displayed. This usually works quite well, but on the other hand the animation will play only on a part of the screen / window.

If there are no performance problems taccgl™ will always run full screen / window. If performance gets worse, it first tries to use the portion selected with NQCanvas or NQCanvas and if that is not sufficent the portion selected with LQCanvas or LQCanvas is used.

Using LQCanvas a rectangular portion of the screen/window can be seleted on that a slow animation will play. x,y give the pixel coordinates and w,h width and height. All coordinates refer to pixel coordinates within the complete displayed document. If (due to scrolling) the selected portion is not completely visible it is moved to the visible part.

LQCanvas can be called while an animation is running, e.g. in an onscroll event handler, to adapt the visible portion to the scroll position.

WebGL™ is a trademark of the Khronos Group Inc.

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