draw: add support for later transform feedback extensions

This adds support to draw for the new features of transform feedback.

a) fix count_from_stream_output, using max_index+1 for now but it looks
like it should be valid as its derived from the vertex elements/vbo.

b) fix striding and dst offsets in output buffers - was just wrong before.

c) fix crash if tfb is suspended (so.num_targets == 0)

This also enables the new features on softpipe. It should be possible
to enable them on llvmpipe as well after this commit, but would need
to schedule piglit runs.

Signed-off-by: Dave Airlie <airlied@redhat.com>
draw/llvmpipe: fix transform feedback position + enable other extensions

This builds on the previous draw/softpipe patch.

So llvmpipe does streamout calls after clip/viewport stages,
but we have the pre-clip position stored for later use, so
when we are doing transform feedback, and its the position vertex
grab the vertex from the stored pre clip position.

The perfect fix is too probably add a codegen transform feedback
stage in between shader and clip stages, but this is good enough
for now.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
swrast: make _mesa_get_texel_fetch_func() static

Not called from any other file.
swrast: merge get_texel_fetch_func() and set_fetch_functions()

No real need for separate functions anymore.
mesa: add compressed_fetch_func typedef

This is a first step in removing the swrast-related code in core
Mesa's texture compression files.
mesa: add new texel fetch code for dxt formats
mesa: add new texel fetch code for fxt formats
mesa: add new texel fetch code for rgtc formats
mesa: add new texel fetch code for etc formats
mesa: added _mesa_get_compressed_fetch_func()
mesa: reimplement _mesa_decompress_image() using new tex fetch code
swrast: use new core Mesa compressed texel fetch functions
mesa: remove old swrast-based compressed texel fetch code
mesa: minor indentation fixes in texcompress_etc.c
android: build fix for libmesa_glsl_utils

hash_table.c compilation requires ralloc.h include path

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>
glsl/lower_clip_distance: Update symbol table.

This patch modifies the clip distance lowering pass so that the new
symbol it generates (glClipDistanceMESA) is added to the shader's
symbol table.

This will allow a later patch to modify the linker so that it finds
transform feedback varyings using the symbol table rather than having
to iterate through all the declarations in the shader.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
glsl/linker: Always invalidate shader ins/outs, even in corner cases.

Previously, link_invalidate_variable_locations() was only called
during assign_attribute_or_color_locations() and
assign_varying_locations().  This meant that in the corner case when
there was only a vertex shader, and varyings were being captured by
transform feedback, link_invalidate_variable_locations() wasn't being
called for the varyings.

This patch migrates the calls to link_invalidate_variable_locations()
to link_shaders(), so that they will be called in all circumstances.
In addition, it modifies the call semantics so that
link_invalidate_variable_locations() need only be called once per
shader stage (rather than once for inputs and once for outputs).

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
glsl/linker: Make separate ir_variable field to mean "unmatched".

Previously, the linker used a value of -1 in ir_variable::location to
denote a generic input or output of the shader that had not yet been
matched up to a variable in another pipeline stage.

This patch introduces a new ir_variable field,
is_unmatched_generic_inout, for that purpose.

In future patches, this will allow us to separate the process of
matching varyings between shader stages from the processes of
assigning locations to those varying.  That will in turn pave the way
for packing varyings.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
glsl: Create a field to store fractional varying locations.

Currently, the location of each varying is recorded in ir_variable as
a multiple of the size of a vec4.  In order to pack varyings, we need
to be able to record, e.g. that a vec2 is stored in the second half of
a varying slot rather than the first half.

This patch introduces a field ir_variable::location_frac, which
represents the offset within a vec4 where a varying's value is stored.
Varyings that are not subject to packing will always have a
location_frac value of zero.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
glsl/linker: Defer recording transform feedback locations.

This patch subdivides the loop that assigns varying locations into two
phases: one phase to match up varyings between shader stages (and
assign them varying locations), and a second phase to record the
varying assignments for use by transform feedback.

This paves the way for varying packing, which will require us to
further subdivide the first phase.

In addition, it lets us avoid a clumsy O(n^2) algorithm, since we can
now record the locations of all transform feedback varyings in a
single pass through the tfeedback_decls array, rather than have to
iterate through the array after assigning each varying.

Reviewed-by: Eric Anholt <eric@anholt.net>