[Mesa-dev] [PATCH 15/30] i965/miptree: Add new entrypoints for resolve management

[Chad Versace]

On Fri 26 May 2017, Jason Ekstrand wrote:
> This commit adds a new unified interface for doing resolves.  The basic
> format is that, prior to any surface access such as texturing or
> rendering, you call intel_miptree_prepare_access.  If the surface was
> written, you call intel_miptree_finish_write.  These two functions take
> parameters which tell them whether or not auxiliary compression and fast
> clears are supported on the surface.  Later commits will add wrappers
> around these two functions for texturing, rendering, etc.
> ---
>  src/mesa/drivers/dri/i965/intel_mipmap_tree.c | 156 +++++++++++++++++++++++++-
>  src/mesa/drivers/dri/i965/intel_mipmap_tree.h |  80 +++++++++++++
>  2 files changed, 232 insertions(+), 4 deletions(-)


> +void
> +intel_miptree_prepare_access(struct brw_context *brw,
> +                             struct intel_mipmap_tree *mt,
> +                             uint32_t start_level, uint32_t num_levels,
> +                             uint32_t start_layer, uint32_t num_layers,
> +                             bool aux_supported, bool fast_clear_supported)

This parameter list seems a good place to pass in a bool that indicates
the miptree data can be invalidated before access. For example, before
a full, non-scissored clear or before mapping with
GL_MAP_INVALIDATE_RANGE_BIT. That info would let us avoid unneeded aux
ops.

But, of course, such a change doesn't belong in this patch, or perhaps
even in this patch series. I just wanted to suggest a future
improvement.