Commit Graph

115 Commits

Author SHA1 Message Date
Ilia Mirkin
73f53c097a glsl: record number of components used in each slot for varying packing
Instead of packing varyings into vec4's, keep track of how many
components each slot uses and create varyings with matching types. This
ensures that we don't end up using more components than the orginal
shader, which is especially important for geometry shader output limits.

This comes up for NVIDIA hw, where the limit is 1024 output components
for a GS, and the hardware complains *loudly* if you even think about
going over.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
2016-11-09 20:26:48 -05:00
Ilia Mirkin
885c788017 glsl: fix slot_end calculations and simplify reserved_slots check
The previous code was confused about whether slot_end was inclusive or
exclusive. Make it so that it is inclusive consistently, and use it for
setting the new location. This also avoids discrepancies in how
num_components is calculated vs the more manual approach taken for the
former reserved_slots check.

Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
2016-11-09 20:25:15 -05:00
Timothy Arceri
29c174a3e5 Revert "glsl: move xfb BufferStride into gl_transform_feedback_info"
This reverts commit f5a6aab403.

This broke some tests. It seems gl_transform_feedback_info gets memset
to 0 so we were losing the values in BufferStride before we used them.
2016-09-24 10:17:26 +10:00
Timothy Arceri
f5a6aab403 glsl: move xfb BufferStride into gl_transform_feedback_info
It makes more sense to have this here where we store the other values
from xfb qualifiers. The struct it was previously part of is now only
used to store values that come from the api.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
2016-09-24 09:18:29 +10:00
Marek Olšák
ae0a4a1299 glsl: remove interpolateAt* instructions for demoted inputs
This fixes 8 fs-interpolateat* piglit crashes on radeonsi, because it can't
handle non-input operands in interpolateAt*.

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
2016-09-16 22:35:08 +02:00
Thomas Helland
f10cc9407b glsl: Convert link_varyings to the util hash table
Signed-off-by: Thomas Helland <thomashelland90@gmail.com>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
2016-09-12 10:48:35 +10:00
Kenneth Graunke
9c562956f9 glsl: Only force varyings to be flat when varying packing.
Varying packing would like to mark certain variables as flat.
This works as long as both sides of the interfaces are changed
accordingly.  However, with SSO, we disable varying packing on
the outermost stages.  We also disable varying packing for
certain tessellation stages.

With SSO, we operate on the producer and consumer separately.
Checks based on the consumer stage and variable are risky, and
can easily lead to altering one half of the interface between
stages, breaking SSO pipeline IO validation.

Just stop monkeying around with interpolation modes unless
required for varying packing.  There's no point.  This also
disables it in unsafe SSO cases.

Fixes CTS tests:
*.tessellation_shader.tessellation_control_to_tessellation_evaluation.gl_MaxPatchVertices_Position_PointSize

Also fixes Piglit's spec/oes_geometry_shader/sso_validation:
- user-defined-gs-input-not-in-block.shader_test
- user-defined-gs-input-in-block.shader_test

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2016-09-01 11:24:17 -07:00
Kenneth Graunke
f9f462936a glsl: Fix invariant matching in GLSL 4.30 and GLSL ES 1.00.
Old languages (GLSL <= 4.20 and GLSL ES 1.00) require "invariant"
to be specified on both inputs and outputs, and match when linking.

New languages only allow outputs to be qualified as "invariant"
and remove the "invariant must match" restriction when linking
varyings (because no input can have that qualifier).

Commit 426a50e208 introduced the new
behavior for ES 3.00.  It also removed the "must match" restriction
for ES 1.00 shaders, which I believe is incorrect.  This patch adds
that back, as well as making 4.30+ follow the new rules.

Thanks to Qiankun Miao for noticing this discrepancy.

Fixes a WebGL 2.0 conformance test when run in Chromium:
https://www.khronos.org/registry/webgl/sdk/tests/deqp/data/gles3/shaders/qualification_order.html?webglVersion=2

Cc: mesa-stable@lists.freedesktop.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96971
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
2016-08-11 23:56:53 -07:00
Timothy Arceri
29d70cc964 glsl: free hash tables earlier
These are only used by get_matching_input() which has been call
at this point so free the hash tables.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2016-07-28 08:05:04 +10:00
Timothy Arceri
91dde3ddca glsl: re-enable varying packing in GL4.4+
We can still do packing we just need to get the packing type from the consumer
rather than the producer.

Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97033
2016-07-22 10:21:08 +10:00
Kenneth Graunke
ac1181ffbe compiler: Rename INTERP_QUALIFIER_* to INTERP_MODE_*.
Likewise, rename the enum type to glsl_interp_mode.

Beyond the GLSL front-end, talking about "interpolation modes" seems
more natural than "interpolation qualifiers" - in the IR, we're removed
from how exactly the source language specifies how to interpolate an
input.  Also, SPIR-V calls these "decorations" rather than "qualifiers".

Generated by:
$ find . -regextype egrep -regex '.*\.(c|cpp|h)' -type f -exec sed -i \
  -e 's/INTERP_QUALIFIER_/INTERP_MODE_/g' \
  -e 's/glsl_interp_qualifier/glsl_interp_mode/g' {} \;

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Dave Airlie <airlied@redhat.com>
2016-07-17 19:26:48 -07:00
Ian Romanick
3119871bd9 glsl: Pack integer and double varyings as flat even if interpolation mode is none
v2: Also update varying_matches::compute_packing_class().  Suggested by
Timothy Arceri.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=96358
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Cc: "12.0" <mesa-stable@lists.freedesktop.org>
Cc: Gregory Hainaut <gregory.hainaut@gmail.com>
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
2016-07-05 16:58:27 -07:00
Timothy Arceri
1591e668e1 glsl/mesa: move duplicate shader fields into new struct gl_shader_info
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
2016-06-30 16:51:25 +10:00
Timothy Arceri
1fb8c6df88 glsl/mesa: split gl_shader in two
There are two distinctly different uses of this struct. The first
is to store GL shader objects. The second is to store information
about a shader stage thats been linked.

The two uses actually share few fields and there is clearly confusion
about their use. For example the linked shaders map one to one with
a program so can simply be destroyed along with the program. However
previously we were calling reference counting on the linked shaders.

We were also creating linked shaders with a name even though it
is always 0 and called the driver version of the _mesa_new_shader()
function unnecessarily for GL shader objects.

Acked-by: Iago Toral Quiroga <itoral@igalia.com>
2016-06-30 16:51:25 +10:00
Timothy Arceri
31dee99e05 mesa/glsl: stop using GL shader type internally
Instead use the internal gl_shader_stage enum everywhere. This
makes things more consistent and gets rid of unnecessary
conversions.

Ideally it would be nice to remove the Type field from gl_shader
altogether but currently it is used to differentiate between
gl_shader and gl_shader_program in the ShaderObjects hash table.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2016-06-16 10:45:35 +10:00
Timothy Arceri
30df78236c glsl: fix component overlap validation for doubles
This change makes sure to remove arrays when checking if type
is a double.

The check for the end of the first slot of a multi-slot double
is also fixed by bumping the check to 4 rather than 3.
Previously we were we not reserving the last component.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2016-06-12 21:56:32 +10:00
Timothy Arceri
ad3def919e glsl: fix max varyings count for ARB_enhanced_layouts
Since this extension allows more than one varying to share a single
location we can't just count the number of slots a varying takes and
add it to the total.

Instead we now reuse the reserved varyings bitfield to determine how
many slots are reserved for explicit locations instead.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2016-06-12 21:56:28 +10:00
Dave Airlie
2df46519e4 glsl/link_varyings: switch to 64bit check instead of double.
This is prep work for int64 support.

Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-06-09 07:37:43 +10:00
Dave Airlie
35616a9e0e glsl: use new interfaces for 64-bit checks.
This is just prep work for int64 support, changing
places where 64-bit matters no doubles.

Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-06-09 07:37:19 +10:00
Dave Airlie
1f66a4b689 glsl: for anonymous struct matching use without_array() (v3)
With tessellation shaders we can have cases where we have
arrays of anon structs, so make sure we match using without_array().

Fixes:
GL45-CTS.tessellation_shader.tessellation_control_to_tessellation_evaluation.gl_in

v2:
test lengths match as well (Ilia)
v3:
descend array lengths to check for matches as well (Ilia)

Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: "12.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-06-06 12:54:41 +10:00
Dave Airlie
1fe7bbb911 glsl/linker: fix multiple streams transform feedback.
e2791b38b4
mesa/program_interface_query: fix transform feedback varyings.

caused a regression in
GL45-CTS.gtf40.GL3Tests.transform_feedback3.transform_feedback3_multiple_streams
on radeonsi.

The problem was it was using the skip components varying to set
the stream id, when it should wait until a varying was written,
this just adds the varying checks in the right place.

Cc: "12.0" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-06-01 13:30:41 +10:00
Timothy Arceri
98d40b4d11 Revert "glsl: fix xfb_offset unsized array validation"
This reverts commit aac90ba292.

The commit caused a regression in:
piglit.spec.glsl-1_50.compiler.gs-input-nonarray-named-block.geom

Also the CTS test it was meant to fix seems like it may be bogus.

Cc: "12.0" <mesa-stable@lists.freedesktop.org>
2016-06-01 10:33:57 +10:00
Timothy Arceri
aac90ba292 glsl: fix xfb_offset unsized array validation
This partially fixes CTS test:
GL44-CTS.enhanced_layouts.xfb_get_program_resource_api

The test now fails at a tes evaluation shader with unsized output arrays.

The ARB_enhanced_layouts spec says:

   "It is a compile-time error to apply xfb_offset to the declaration of an
   unsized array."

So this seems like a bug in the CTS.

Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-05-30 15:11:47 +10:00
Dave Airlie
e2791b38b4 mesa/program_interface_query: fix transform feedback varyings.
The spec says gl_NextBuffer and gl_SkipComponents need to be
returned to userspace in the program interface queries.

We currently throw those away, this requires a complete piglit
run to make sure no drivers fallover due to the extra varyings.

This fixes:
GL45-CTS.program_interface_query.transform-feedback-built-in

Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-05-30 11:26:50 +10:00
Timothy Arceri
2d9308012c glsl: fix explicit location validation for doubles
Previously we would fail to find a match for the second half of a
dvec4 as 'i' would get incremented to 1 before we added the var to
the array at component 0.

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
2016-05-24 11:30:51 +10:00
Dave Airlie
61b6789252 glsl/linker: attempt to match anonymous structures at link
This is my attempt at fixing at least one of the UE4 bugs with GL4.3.

If we are doing intrastage matching and hit anonymous structs, then
we should do a record comparison instead of using the names.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=95005
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-05-19 08:16:50 +10:00
Ian Romanick
cf9220b11f glsl/linker: Fix trivial typos in comments
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
2016-05-18 10:53:34 -07:00
Ian Romanick
d2579728c9 glsl/linker: Fix some formatting to match current coding conventions
Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
2016-05-18 10:53:34 -07:00
Ian Romanick
02e4753777 glsl/linker: Silence unused parameter warning
The use of the parameter was removed in d6b92028.

glsl/link_varyings.cpp:1390:39: warning: unused parameter ‘separate_shader’ [-Wunused-parameter]
                                   bool separate_shader)
                                       ^

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
2016-05-18 10:53:34 -07:00
Timothy Arceri
4fb4fd0b6b glsl: make reserved_varying_slot() static
Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-05-17 15:06:39 +10:00
Timothy Arceri
1d752823af glsl: include per-patch varyings when generating reserved slot bitfield
Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-05-17 15:06:27 +10:00
Timothy Arceri
3f477f0ea5 glsl: remove remainings tabs in link_varyings.cpp
Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-05-17 15:06:16 +10:00
Timothy Arceri
6d5f7557fb glsl: fix location and component packing validation on patches
These varyings have a separate location domain from per-vertex varyings
and need to be handled separately.

Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-05-17 15:06:12 +10:00
Tobias Klausmann
d656736bbf glsl: Add arb_cull_distance support (v3)
v2: make too large array a compile error
v3: squash mesa/prog patch to avoid static compiler errors in bisect

Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
2016-05-14 08:28:08 +10:00
Tobias Klausmann
eb18fea707 mesa/main: Add support for GL_ARB_cull_distance (v2)
airlied:
v2: rename LowerClipDistance to LowerCombinedClipCullDistnace.
I don't think we want any other behaviour with any current hw.

Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-05-14 08:27:29 +10:00
Timothy Arceri
0d88b15f07 glsl: cross validate varyings with a component qualifier
This change checks for component overlap, including handling overlap of
locations and components by doubles. Previously there was no validation
for assigning explicit locations to a location used by the second half
of a double.

V3: simplify handling of doubles and fix double component aliasing
detection

V2: fix component matching for matricies

Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2016-05-01 23:13:10 +10:00
Timothy Arceri
72b5d00c9c glsl: fix cross validation for explicit locations on structs and arrays
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2016-04-22 20:59:57 +10:00
Kenneth Graunke
26c56e24e7 glsl: Don't remove XFB-only varyings.
Consider the case of linking a program with both a vertex and fragment
shader.  The VS may compute output varyings that are intended for
transform feedback, and not read by the fragment shader.

In this case, var->data.is_unmatched_generic_inout will be true,
but we still cannot eliminate the varyings.  We need to also check
!var->data.is_xfb_only.

Fixes failures in ES31-CTS.gpu_shader5.fma_precision_*, which happen
to use transform feedback in a way we apparently hadn't seen before.

Cc: mesa-stable@lists.freedesktop.org
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Timothy Arceri <timothy.arceri@collabora.com>
2016-04-10 19:03:06 -07:00
Jordan Justen
ef1b397b07 glsl: Don't require matching centroid qualifiers
Note: This patch appears to violate older OpenGL and OpenGLES specs.

The OpenGLES GLSL 3.1 and OpenGL GLSL 4.3 specifications both remove
the requirement for the output and input centroid qualifiers to match.

The deqp
dEQP-GLES3.functional.shaders.linkage.varying.rules.differing_interpolation_2
test wants the newer OpenGLES 3.1 specification behavior, even for
OpenGLES 3.0. This patch simply removes the checking in all cases.

The OpenGLES 3.0 conformance test suite doesn't appear to require the
older ("must match") spec behavior.

For reference, here are the relavent spec citations:

  The OpenGL 4.2 spec says: "the last active shader stage output
  variables and fragment shader input variables of the same name must
  match in type and qualification (other than out matching to in)"

  The OpenGL 4.3 spec says: "interpolation qualification (e.g., flat)
  and auxiliary qualification (e.g. centroid) may differ."

  The OpenGLES GLSL 3.00.4 specification says: "The output of the
  vertex shader and the input of the fragment shader form an
  interface. For this interface, vertex shader output variables and
  fragment shader input variables of the same name must match in type
  and qualification (other than precision and out matching to in)."

  The OpenGLES GLSL 3.10 Specification says: "interpolation
  qualification (e.g., flat) and auxiliary qualification (e.g.
  centroid) may differ"

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92743
Bugzilla: https://cvs.khronos.org/bugzilla/show_bug.cgi?id=7819
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
2016-04-01 18:06:19 -07:00
Timothy Arceri
c5704bb350 mesa: add query support for GL_TRANSFORM_FEEDBACK_BUFFER interface
Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:53:02 +11:00
Timothy Arceri
9e317271d7 mesa: add support to query GL_TRANSFORM_FEEDBACK_BUFFER_INDEX
Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:52:47 +11:00
Timothy Arceri
51142e7705 mesa: add support to query GL_OFFSET for GL_TRANSFORM_FEEDBACK_VARYING
Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:52:43 +11:00
Timothy Arceri
b77c909878 glsl: always enable transform feedback mode when xfb_stride defined
This enables in shader defined transform feedback mode even if the
only place xfb_stride is defined is on the global out.

We don't worry about xfb_buffer since Issue 22 c) in the spec says:

   "If the shader has an "xfb_buffer" qualifier identifying a buffer,
    but doesn't declare "xfb_offset" on anything associated with it,
    what happens?

    ...

    variables not qualified with "xfb_offset" are not captured, which
    makes the associated "xfb_buffer" qualifier irrelevant."

Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:52:34 +11:00
Timothy Arceri
c95e92b14d glsl: handle varyings that are not written to but have an xfb_offset
Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:52:29 +11:00
Timothy Arceri
a2fbc5ed44 glsl: reset current stream tracker
When we move to the next buffer we need to reset the stream
so that we don't generate an error message about streams not
matching.

Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:52:17 +11:00
Timothy Arceri
f2a3c87a00 glsl: generate link error when implicit stride is to large
This moves the check until after we have done the stride
calculation and applies it to the xfb_* qualifiers.

Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:52:11 +11:00
Timothy Arceri
2fab85aaea glsl: add xfb_stride link time validation
From the ARB_enhanced_layous spec:

   "It is a compile-time or link-time error to have any *xfb_offset*
    that overflows *xfb_stride*, whether stated on declarations before
    or after the *xfb_stride*, or in different compilation units.

    ...

    When no *xfb_stride* is specified for a buffer, the stride of a
    buffer will be the smallest needed to hold the variable placed at
    the highest offset, including any required padding."

Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:52:05 +11:00
Timothy Arceri
8120e869b1 glsl: validate global out xfb_stride qualifiers and set stride on empty buffers
Here we use the built-in validation in
ast_layout_expression::process_qualifier_constant() to check for mismatching
global out strides on buffers in a single shader.

From the ARB_enhanced_layouts spec:

   "While *xfb_stride* can be declared multiple times for the same buffer,
   it is a compile-time or link-time error to have different values
   specified for the stride for the same buffer."

For intrastage validation a new helper link_xfb_stride_layout_qualifiers()
is created. We also take this opportunity to make sure stride is at least
a multiple of 4, we will validate doubles at a later stage.

From the ARB_enhanced_layouts spec:

   "If the buffer is capturing any double-typed outputs, the stride must
   be a multiple of 8, otherwise it must be a multiple of 4, or a
   compile-time or link-time error results."

Finally we update store_tfeedback_info() to apply the strides to
LinkedTransformFeedback and update the buffers bitmask to mark any global
buffers with a stride as active. For example a shader with:

layout (xfb_buffer = 0, xfb_offset = 0)  out vec4 gs_fs;
layout (xfb_buffer = 1, xfb_stride = 64) out;

Is expected to have a buffer bound to both 0 and 1.

From the ARB_enhanced_layouts spec:

   "A binding point requires a bound buffer object if and only if its
   associated stride in the program object used for transform feedback
   primitive capture is non-zero."

Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:52:00 +11:00
Timothy Arceri
cf039a309a mesa: split transform feedback buffer into its own struct
This will be used in a following patch to implement interface
query support for TRANSFORM_FEEDBACK_BUFFER.

Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:51:52 +11:00
Timothy Arceri
258299d87a glsl: use bitmask of active xfb buffer indices
This allows us to print the correct binding point when not all
buffers declared in the shader are bound.

For example if we use a single buffer:

layout(xfb_buffer=2, offset=0) out vec4 v;

We now print '2' when the buffer is not bound rather than '0'.

Reviewed-by: Dave Airlie <airlied@redhat.com>
2016-03-31 12:51:47 +11:00