Your own geometry

gpu is client.gpu() — script-owned vertex formats, meshes, pipelines and draw calls. Vertex positions are relative to the camera, the buffers are freed while the script is off, and every type on this page is API 2.

val format = gpu.format(VertexAttribute.floats(3), VertexAttribute.color())
val mesh = gpu.indexedMesh(format)
val pipeline = gpu.pipeline(myShader, DrawMode.TRIANGLES, BlendMode.ALPHA, DepthMode.TEST)
val pass = gpu.renderType(pipeline, mesh)

on<Render3DEvent> { event ->
    val verts = mesh.verts()
    val base = verts.putVec3(0f, 0f, 0f).putColor(Colors.RED).next()
    verts.putVec3(1f, 0f, 0f).putColor(Colors.GREEN).next()
    verts.putVec3(0f, 1f, 0f).putColor(Colors.BLUE).next()
    mesh.idx()?.putTriangle(base, base + 1, base + 2)

    myShader.setMat4("u_view", event.viewMatrix())
    myShader.setMat4("u_projection", event.projectionMatrix())
    pass.draw()
}

#The factory

Every method throws IllegalStateException once the script session is closed. Meshes, pipelines and render types are tracked resources; formats are not.

#The vertex format

#AttributeType

#The format itself

Attributes map to the shader's layout(location = N) inputs in declaration order; nothing checks that what you write matches the format.

#Writing vertices

The GL buffer is created on first use, and that first write must happen on the render thread. draw() uploads both writers and empties them, so each frame writes its geometry from scratch.

#The vertex writer

#Indices

#The pipeline

#DrawMode

#BlendMode

#DepthMode

#Drawing

No built-in uniforms are supplied, unlike Render.shader: u_view, u_projection and anything else are yours to set before the call. Both calls draw nothing while the mesh is empty or the shader failed to compile.

#Limits

The exception each limit throws: Sandbox and limits.