1. Web
  2. Web APIs
  3. GPURenderBundleEncoder
  4. drawIndexedIndirect()

GPURenderBundleEncoder: drawIndexedIndirect() method

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is available in Web Workers.

The drawIndexedIndirect() method of the GPURenderBundleEncoder interface draws indexed primitives using parameters read from a GPUBuffer.

Note: This method is functionally identical to its equivalent on GPURenderPassEncoder — drawIndexedIndirect().

Syntax

js
drawIndexedIndirect(indirectBuffer, indirectOffset)

Parameters

indirectBuffer

A GPUBuffer containing the indexCount, instanceCount, firstIndex, baseVertex, and firstInstance values needed to carry out the drawing operation. The buffer must contain a tightly packed block of five 32-bit unsigned integer values representing the values (20 bytes total), given in the same order as the arguments for GPURenderBundleEncoder.drawIndexed(). So for example:

js
const uint32 = new Uint32Array(5); uint32[0] = 3; // The indexCount value uint32[1] = 1; // The instanceCount value uint32[2] = 0; // The firstIndex value uint32[3] = 0; // The baseVertex value uint32[4] = 0; // The firstInstance value // Write values into a GPUBuffer device.queue.writeBuffer(buffer, 0, uint32, 0, uint32.length);

Note: The indirect-first-instance feature needs to be enabled for non-zero firstInstance values to be used. If the indirect-first-instance feature is not enabled and firstInstance is not zero, the drawIndexedIndirect() call will be treated as a no-op.

indirectOffset

The offset, in bytes, into indirectBuffer where the value data begins.

Return value

None (Undefined).

Validation

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

  • indirectBuffer's GPUBuffer.usage contains the GPUBufferUsage.INDIRECT flag.
  • indirectOffset + the total size specified by the value parameters in the indirectBuffer is less than or equal to the indirectBuffer's GPUBuffer.size.
  • indirectOffset is a multiple of 4.

Examples

js
// … // Create GPURenderBundleEncoder const bundleEncoder = device.createRenderBundleEncoder(descriptor); // Set pipeline and vertex buffer bundleEncoder.setPipeline(renderPipeline); bundleEncoder.setVertexBuffer(0, vertexBuffer); bundleEncoder.setIndexBuffer(indexBuffer, "uint16"); // Create drawIndexedIndirect values const uint32 = new Uint32Array(5); uint32[0] = 3; uint32[1] = 1; uint32[2] = 0; uint32[3] = 0; uint32[4] = 0; // Create a GPUBuffer and write the draw values into it const drawValues = device.createBuffer({ size: 20, usage: GPUBufferUsage.COPY_DST | GPUBufferUsage.INDIRECT, }); device.queue.writeBuffer(drawValues, 0, uint32, 0, uint32.length); // Draw the vertices bundleEncoder.drawIndexedIndirect(drawValues, 0); // End the bundle recording const renderBundle = bundleEncoder.finish(); // …

Specifications

Specification
WebGPU
# dom-gpurendercommandsmixin-drawindexedindirect

Browser compatibility

See also

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