HTMLCanvasElement: mozOpaque property
Deprecated
Avoid using this feature in new projects. This feature may be a candidate for removal from web standards or browsers.
Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.
The non-standard HTMLCanvasElement.mozOpaque property is
a boolean value reflecting the moz-opaque HTML
attribute of the <canvas> element. It lets the canvas know whether or
not translucency will be a factor. If the canvas knows there's no translucency, painting
performance can be optimized.
Note:
This has been standardized as setting the alpha option to
false when creating a drawing context with
HTMLCanvasElement.getContext(). Use of mozOpaque should be
avoided. Firefox will stop supporting it in the future.
Value
A boolean value.
Examples
Given this <canvas> element:
<canvas id="canvas" width="300" height="300" moz-opaque></canvas>
You can get or set the mozOpaque property. For example, you could
conditionally set it to true if mimeType === 'image/jpeg', or
similar, to gain performance in your application when translucency is not needed.
const canvas = document.getElementById("canvas");
console.log(canvas.mozOpaque); // true
// deactivate it
canvas.mozOpaque = false;
Specifications
Not part of any standard.
Browser compatibility
See also
HTMLCanvasElement: Interface used to define theHTMLCanvasElement.mozOpaquepropertymoz-opaque: HTML attribute of the<canvas>element- Optimizing your JavaScript game for Firefox OS