1. override
void renderTriangleMesh(RenderState renderState, Int16List ixList, Float32List vxList, int color)

Source 

@override
void renderTriangleMesh(
    RenderState renderState,
    Int16List ixList, Float32List vxList, int color) {

  activateRenderProgram(renderProgramTriangle);
  activateBlendMode(renderState.globalBlendMode);
  renderProgramTriangle.renderTriangleMesh(renderState, ixList, vxList, color);
}