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GPURenderPassEncoder: draw() method

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The draw() method of the GPURenderPassEncoder interface draws primitives based on the vertex buffers provided by setVertexBuffer().

Syntax

draw(vertexCount)
draw(vertexCount, instanceCount)
draw(vertexCount, instanceCount, firstVertex)
draw(vertexCount, instanceCount, firstVertex, firstInstance)

Parameters

vertexCount: A number defining the number of vertices to draw.
instanceCount Optional: A number defining the number of instances to draw. If omitted, instanceCount defaults to 1.
firstVertex Optional: A number defining the offset into the vertex buffers, in vertices, to begin drawing from. If omitted, firstVertex 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 our basic render demo, several commands are recorded via a GPUCommandEncoder. Most of these commands originate from the GPURenderPassEncoder created via GPUCommandEncoder.beginRenderPass(). draw() is used to specify that three vertices should be drawn to create our triangle.

// ...

const renderPipeline = device.createRenderPipeline(pipelineDescriptor);

// Create GPUCommandEncoder to issue commands to the GPU
// Note: render pass descriptor, command encoder, etc. are destroyed after use, fresh one needed for each frame.
const commandEncoder = device.createCommandEncoder();

// Create GPURenderPassDescriptor to tell WebGPU which texture to draw into, then initiate render pass
const renderPassDescriptor = {
  colorAttachments: [
    {
      clearValue: clearColor,
      loadOp: "clear",
      storeOp: "store",
      view: context.getCurrentTexture().createView(),
    },
  ],
};

const passEncoder = commandEncoder.beginRenderPass(renderPassDescriptor);

// Draw the triangle
passEncoder.setPipeline(renderPipeline);
passEncoder.setVertexBuffer(0, vertexBuffer);
passEncoder.draw(3);

// End the render pass
passEncoder.end();

// End frame by passing array of command buffers to command queue for execution
device.queue.submit([commandEncoder.finish()]);

// ...

Specifications

Specification
WebGPU # dom-gpurendercommandsmixin-draw

Browser compatibility