GPURenderPassEncoder: setViewport() method

{{APIRef("WebGPU API")}}{{SecureContext_Header}}{{AvailableInWorkers}}

The setViewport() method of the {{domxref("GPURenderPassEncoder")}} interface sets the viewport used during the rasterization stage to linearly map from normalized device coordinates to viewport coordinates.

Syntax

setViewport(x, y, width, height, minDepth, maxDepth)

Parameters

• x
  • : A number representing the minimum X value of the viewport, in pixels.
• y
  • : A number representing the minimum Y value of the viewport, in pixels.
• width
  • : A number representing the width of the viewport, in pixels.
• height
  • : A number representing the height of the viewport, in pixels.
• minDepth
  • : A number representing the minimum depth value of the viewport.
• maxDepth
  • : A number representing the maximum depth value of the viewport.

[!NOTE] If a setViewport() call is not made, the default values are (0, 0, attachment width, attachment height, 0, 1) for each render pass.

Return value

None ({{jsxref("Undefined")}}).

Validation

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

• x, y, width, and height are all greater than or equal to 0.
• 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).
• minDepth and maxDepth are both inside the range 0.0–1.0 inclusive.
• minDepth is less than maxDepth.

[!NOTE] See the color and depth/stencil attachments specified in the descriptor of {{domxref("GPUCommandEncoder.beginRenderPass()")}}; the width and height are based on that of the {{domxref("GPUTexture")}} that their views originate from.

Examples

Basic snippet

In a typical canvas render, the following could be used to halve the width and height of the rendered graphics:

passEncoder.setViewport(0, 0, canvas.width / 2, canvas.height / 2, 0, 1);

In context

In the WebGPU Samples reversedZ example, setViewport is used several times to set the viewport for the different render passes. Study the example code listing for the full context.

For example:

// …

colorPass.setViewport(
  (canvas.width * m) / 2,
  0,
  canvas.width / 2,
  canvas.height,
  0,
  1,
);

// …

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• The WebGPU API