The setScissorRect() method of the GPURenderPassEncoder interface sets the scissor rectangle used during the rasterization stage. After transformation into viewport coordinates any fragments that fall outside the scissor rectangle will be discarded.

x

A number representing the minimum X value of the scissor rectangle, in pixels.

y

A number representing the minimum Y value of the scissor rectangle, in pixels.

width

A number representing the width of the scissor rectangle, in pixels.

height

A number representing the height of the scissor rectangle, in pixels.

None (Undefined).

The following criteria must be met when calling setViewport(), otherwise a GPUValidationError is generated and the GPURenderPassEncoder becomes invalid:

• x + width is less than or equal to the width of the render pass's render attachments (see note below).
• y + height is less than or equal to the height of the render pass's render attachments (see note below).

In a typical canvas render, the following could be used to discard any rendering outside of the top-left quarter of the canvas:

passEncoder.setScissorRect(0, 0, canvas.width / 2, canvas.height / 2);

• The WebGPU API