GPURenderPassEncoder: drawIndexed() method

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The drawIndexed() method of the GPURenderPassEncoder interface draws indexed primitives based on the vertex and index buffers provided by setVertexBuffer() and setIndexBuffer().

Syntax

js
drawIndexed(indexCount)
drawIndexed(indexCount, instanceCount)
drawIndexed(indexCount, instanceCount, firstIndex)
drawIndexed(indexCount, instanceCount, firstIndex, baseVertex)
drawIndexed(indexCount, instanceCount, firstIndex, baseVertex, firstInstance)

Parameters

indexCount

A number defining the number of indices to draw.

instanceCount Optional

A number defining the number of instances to draw. If omitted, instanceCount defaults to 1.

firstIndex Optional

A number defining the offset into the index buffer, in indices, to begin drawing from. If omitted, firstIndex defaults to 0.

baseVertex Optional

A number added to each index value before indexing into the vertex buffers. If omitted, baseVertex defaults to 0.

firstInstance Optional

A number defining the first instance to draw. If omitted, firstInstance defaults to 0.

Return value

None (undefined).

Examples

In the WebGPU Samples Shadow Mapping example, drawIndexed() is used in two separate render passes in each animation frame, one to populate the shadow buffer and one to draw the primary view of the scene. Study the example code listing for the full context.

js
// …

const commandEncoder = device.createCommandEncoder();
{
  const shadowPass = commandEncoder.beginRenderPass(shadowPassDescriptor);
  shadowPass.setPipeline(shadowPipeline);
  shadowPass.setBindGroup(0, sceneBindGroupForShadow);
  shadowPass.setBindGroup(1, modelBindGroup);
  shadowPass.setVertexBuffer(0, vertexBuffer);
  shadowPass.setIndexBuffer(indexBuffer, "uint16");
  shadowPass.drawIndexed(indexCount);

  shadowPass.end();
}
{
  const renderPass = commandEncoder.beginRenderPass(renderPassDescriptor);
  renderPass.setPipeline(pipeline);
  renderPass.setBindGroup(0, sceneBindGroupForRender);
  renderPass.setBindGroup(1, modelBindGroup);
  renderPass.setVertexBuffer(0, vertexBuffer);
  renderPass.setIndexBuffer(indexBuffer, "uint16");
  renderPass.drawIndexed(indexCount);

  renderPass.end();
}

// …

Specifications

See also