draw method

@override void draw({ int instanceCount = 1, })

Draws what is bound. Always indexed — there is no non-indexed path in this engine, which is why the debug overlay keeps an identity index sequence.

instanceCount draws the bound geometry that many times, with the vertex stage seeing an instance index and reading any attribute whose BufferLayout.stepMode is VertexStepMode.instance from a per-instance buffer. One means an ordinary draw and is the only value anything asked for before mesh particles.

The one count that belongs to the draw rather than to a binding. Every other count here travels with the thing it counts — vertices with the vertex buffer, indices with the index buffer — because that is where it is known. An instance count is not a property of any buffer: the same mesh and the same instance buffer can be drawn a hundred times or ten.

Zero draws nothing, which matters because the number usually comes from a live population: a particle system with nothing alive should not be a special case at every call site.

Implementation

@override
void draw({int instanceCount = 1}) =>
    commands.add(RecordedDraw(instanceCount: instanceCount));