Use instancing to generate two triangles for each destination layer and use a geometry shader to route the layer index.
v2:- directly write layer in VS if supported by the driver (Marek Olšák)
c99f2fe st/mesa: implement PBO upload for multiple layers
src/mesa/state_tracker/st_cb_texture.c | 159 ++++++++++++++++++++++++++++----
src/mesa/state_tracker/st_context.h | 3 +
2 files changed, 143 insertions(+), 19 deletions(-)
Upstream: cgit.freedesktop.org