DirectGLES keeps the requested eglSwapInterval in a process global on purpose (a surface re-created mid-session re-applies it), and every server process used to serve one session. The in-process display server serves the next session in the same process, which then silently inherited the previous client's interval. The server backend's destruction under a transport now calls DirectGLES::ForgetRequestedSwapInterval() beside DropEveryTwinForEndedServerSession (split build only; the pull build is unchanged, G1).
- P-1: MGPCaps is DynamicBackendParameters by inclusion (plan B section 4.4.1), but that struct carried MaxComputeWorkGroupInvocations and no per-axis GL_MAX_COMPUTE_WORK_GROUP_COUNT / GL_MAX_COMPUTE_WORK_GROUP_SIZE - the six numbers that ARE the backend-owned indexed answers surviving the getter retirement (GL_Getter.cpp and CompileEnv.cpp ask GLFunctionsTable::GetIntegeri_v for exactly these, DirectVulkan answers them from VkPhysicalDeviceLimits), so the interface had a hole where its only genuine indexed carrier should be. DynamicBackendParameters now has MaxComputeWorkGroupCount[3] / MaxComputeWorkGroupSize[3] with the GL 4.3 minimums as the no-backend defaults; DirectGLES fills them from glGetIntegeri_v inside the loader's bracketed probe run (GLESCapabilities carries them, logged with the other limits) and DirectVulkan from maxComputeWorkGroupCount / maxComputeWorkGroupSize through the loader's SaturateToInt like every other limit. Raw driver answers, as the invocations limit is: the frontend floors them at the shared MIN_COMPUTE_WORK_GROUP_* minimums itself.
- The GetIntegeri_v table path is untouched, as is GL_Getter and CompileEnv behaviour: retiring the getter in favour of the caps is P0.5, and this only makes sure the caps have what P0.5 needs.
- PipeCalls.def's footer no longer claims that "only GL_COMPUTE_WORK_GROUP_SIZE is a real backend answer and it lives in MGPCaps": the six limits live in MGPCaps, and GL_COMPUTE_WORK_GROUP_SIZE is a frontend link artifact (ProgramObject::GetComputeLocalSize, what GL_Program.cpp answers from), which AdvertisedLimitsScenario.ComputeLocalSizeComesFromTheLinkedProgram already pins. The MGPCaps size assertion is a composition of sizeof(DynamicBackendParameters) and follows the struct.
- AdvertisedLimitsScenario.ComputeWorkGroupLimitsAreTheCapsBlocksAnswer pins, on both lanes: answerability, the GL 4.3 floors, vector/indexed agreement, INVALID_VALUE past axis 2, and - through the new Harness/BackendCapsPeek translation unit, which is the one place the module looks past the GL API - that max(caps, minimum) equals the live glGetIntegeri_v answer axis by axis. Shown live by halving each backend's caps copy: both lanes fail with "MGPCaps carries 512 but glGetIntegeri_v answers 1024". On Android the module links the shipping .so (hidden visibility), so the peek returns false there and only the GL-visible half runs. ComputeWorkGroupCapabilities.TakesEveryAxisFromTheIndexedQuery in BackendLoaderTest pins the DirectGLES loader half against the fake driver, per axis and above the initialisers.
- Verified: AdvertisedLimitsScenario 20/20 on DirectGLES and DirectVulkan (llvmpipe / lavapipe), BackendLoaderTest green.
- GLFunctionsTable had three entries that are frontend queries wearing a
backend interface (plan B v2 §2.1(a)): GetIntegeri_v, GetInteger64i_v and
GetProgramiv. Two of them have NO caller at all - `grep -o
'gBackendFunctionsTable\.GL\.[A-Za-z_0-9]*'` outside MG_Backend/ lists 69
distinct entries and neither GetInteger64i_v nor GetProgramiv is among them -
so both table slots, both backends' implementations and both registrations are
deleted here. This is plan B §11 P0's first "strictly no-op free win".
- Nothing was moved into MG_Impl, because MG_Impl already answers all of it.
glGetInteger64i_v is served by GL_Getter.cpp:1240-1314, which handles the
indexed buffer queries itself and derives every other pname from its own
GetIntegeri_v ("Handing the leftovers straight to the backend instead made
glGetInteger64i_v disagree with glGetIntegeri_v on the very same pname").
glGetProgramiv is served by GL_Program.cpp, whose GL_COMPUTE_WORK_GROUP_SIZE
arm (:928-946) reads ProgramObject::GetComputeLocalSize - a link artifact of
the program the APPLICATION wrote, which is the only program in the
application's namespace. §4.7.1 class B.
- GetIntegeri_v stays, but only for what a backend genuinely owns. Its pure
frontend arms were unreachable: GL_Getter::GetIntegeri_v answers
GL_SHADER_STORAGE_BUFFER_{BINDING,START,SIZE} through
TryDecodeIndexedBufferQuery (:991-1029) and the six GL_IMAGE_BINDING_* pnames
at :1115-1153, and returns before touching the table. That left 9 dead cases
in DirectGLES.cpp and 9 in DirectVulkan.cpp - the plan's "15" undercounts the
two files separately. What still arrives is GL_MAX_COMPUTE_WORK_GROUP_COUNT /
_SIZE (GL_Getter.cpp:1161-1177, and MG_Util/ShaderTranspiler/CompileEnv.cpp
:134-138 asks the table directly), so DirectVulkan keeps exactly those two and
DirectGLES becomes a plain driver passthrough.
- The dead arms were also WRONG, which is why deleting rather than reconciling
them is the strict no-op: they clamped a bound range's size to the buffer's
current storage, while the frontend reports the size glBindBufferRange was
asked for verbatim (GL 4.6 core tables 23.4/23.5 - the clamp answered 0 for
KHR-GL43.shader_storage_buffer_object.basic-binding's shape). Had a later
refactor made the table the answer, the regression would have been silent.
- ProgramResourceCache::computeWorkGroupSize and the spirv-reflect entry-point
loop that filled it go with DirectVulkan's GetProgramiv; nothing else read it.
- Three cases added to AdvertisedLimitsScenario pin what the frontend answers,
on both lanes: the indexed SSBO binding/start/size on the 32- and 64-bit
widths INCLUDING a shrink of the store underneath the binding (the arm that
actually separates verbatim from clamped), the six image-unit pnames on both
widths, and the compute local size plus the INVALID_OPERATION a program with
no compute stage must give.
- Both new gates were shown to go red for their reason: making
GL_COMPUTE_WORK_GROUP_SIZE answer a defaulted (1,1,1) fails
ComputeLocalSizeComesFromTheLinkedProgram on both lanes, and re-introducing
the deleted store clamp in GL_Getter fails
IndexedBufferBindingsAreReportedVerbatimOnBothWidths on both lanes.
- Tested: cmake --build build-linux -j 24 (clean); ctest -L unit -j 12 ->
1382/1382 passed; ctest -R AdvertisedLimits -> 18/18 passed (6 pre-existing +
3 new, x DirectGLES and DirectVulkan).
Complementary Reimagined would not load through Espryt on Mali: Iris got
GL_FRAMEBUFFER_UNSUPPORTED building its composite framebuffer, because
colortex1 is RGB8_SNORM and colortex2 is RGB16F - three-channel formats
that no real ES driver can render to (EXT_render_snorm covers R/RG/RGBA
only, and the float extensions exclude the RGB forms). The frontend's
probe cache diagnosed this correctly and then had nothing to offer: the
NoThreeChannelRenderTarget widening machinery existed but was gated to
multisample targets alone. llvmpipe turns out to refuse most of the same
attachments - CI retrace stayed green only because a replay never
branches on glCheckFramebufferStatus - so this was never a desktop-vs-
device split, just an unlit path.
The widening now applies to every color-attachable image, renderbuffers
included, riding the driver-probe branch so the native format is still
tried first and substituted only on refusal. One ThreeChannelWidening
table owns the widened (internalformat, format, type) triple per source
format - the previous per-case branches disagreed with each other and
could emit an unuploadable (RGBA16F, GL_RGB, GL_BYTE) combination or
widen into another three-channel format the driver refuses just the
same. Uploads repack three-component client data to four with the
format's own one in the alpha channel (127 is not 1 for RGB8I - the
integer arms carry integer ones); readback drops the synthetic alpha,
derived from the actual image being read, not the bound framebuffer,
so glGetTexImage through a scratch FBO cannot be confused by an
unrelated widened attachment.
Stored alpha on a widened attachment is now an invariant 1.0 rather
than an accident: the color-mask sync clears the alpha bit per draw
buffer (glColorMaski for MRT mixes), and clears route through
glClearBufferfv with alpha substituted on widened slots only -
scissored clears inherit the discipline for free, integer color
buffers keep their explicit integer-clear path, and glGet still
answers the application's own mask. GL_DST_ALPHA blending, blits and
readback therefore all see 1.0 without further interception.
DriverPost grows the rows this bug earned: EXT_color_buffer_float
detection (previously unreferenced anywhere) with a FAIL row when
absent, the missing EXT_render_snorm row, and a three-channel-
attachment row that reports one representative per widening class -
graded so a half-float-only driver warns about the 32-bit float gap
instead of being declared unsupported.
Gates: 606/606 unit at default and with the async kill switch; full
retrace, both backends - the complementary fixtures now run with the
widening ACTIVE on llvmpipe and pass with a slightly better SSIM than
before; ext caselist DirectGLES holds 3914/4867 with zero set drift
while 54 cases move from NotSupported to genuinely passing; on the
Mali-G77 device, Complementary Reimagined builds its pipeline and
renders in-world through Espryt (md5-verified build), BSL still green.
A new ThreeChannelAttachmentScenario pins the frontend answer -
COMPLETE where it used to say UNSUPPORTED - on the real driver.
Wave 2 of the advertised-extension conformance campaign.
PROGRAM INTERFACE QUERIES (the load-bearing piece). glGetProgramInterfaceiv
and the five glGetProgramResource* entry points were answered by the
BACKENDS - Espryt asked the real driver about SPIRV-Cross-generated ESSL
whose namespace is not the GL one (default-block uniforms live in
MGL_GLOBAL_UBO there), and Magma kept a second, partial reflection that
hardcoded types and diverged from the frontend. Both are now deleted; a new
frontend resource-model layer (ProgramInterface.{h,cpp}) answers every
interface - uniforms, uniform blocks, atomic-counter buffers (recovered
from glslang's synthesized gl_AtomicCounterBlock_<binding> lowering),
buffer variables, shader-storage blocks (classified by TType storage
qualifier since glslang reflects them as uniform blocks), program inputs/
outputs (built-ins' layoutLocationEnd sentinel mapped to -1), and
transform-feedback varyings including the gl_NextBuffer/gl_SkipComponentsN
pseudo-varyings - from the glslang reflection the frontend already trusts
for glGetActiveUniform. Name/index round-tripping, the "[0]" array
spelling, and the GL 4.6 table 7.2 prop/error matrix live in the new layer
only; GetActiveUniform*/GetActiveAttrib* are untouched.
glShaderStorageBlockBinding now takes the interface-layer index (the one
GetProgramResourceIndex returns, with a range check it never had), records
the binding on the program keyed by block NAME - the one coordinate all
three index spaces agree on - and delegates by name across the backend
boundary. Both backends reseed the recorded bindings on their own program
rebuilds, so an unrelated resync can no longer silently revert a rebound
block, and GL_BUFFER_BINDING reports the live binding, not the declared
one. The Espryt delegate applies only to an already-synced twin and can no
longer trigger SyncToBackend from a getter; the sync path's GL query
out-params are initialized and clamped (a load-dependent stack-garbage
Vector size crash caught by the gate, reproduced 3/50 pre-fix, 100/100
post-fix under saturating load).
ESPRYT RENDER-STATE SHADOW RESET (rides along because it shares
DirectGLES.cpp): the render-state shadow is file-static and survives
MobileGL context switches, so GL_FRAMEBUFFER_SRGB (and the whole synced-cap
class) leaked between contexts - the cross-test leakage class the CTS maps
have carried for a week. MakeCurrent now invalidates the shadow like it
already invalidates the program/FBO/buffer caches, and the resync resolves
a never-set scissor box to the current surface instead of pushing the
(0,0,0,0) sentinel verbatim (which scissored everything away - caught by
the retrace gate, bisected to the exact field via a bitmask probe, and
fixed by resolving like the viewport path rather than reverting).
Frontend riders exposed by the layer: glGetUniformLocation resolves
arrays-of-arrays element addressing ("a[2][1]"); transform-feedback capture
accepts element-addressed varying names ("b[1]") and snapshots the request
verbatim for the interface (Magma's decorate pass logs loudly that element
capture is unimplemented there - follow-up).
KNOWN GAPS, documented in code and tests: the 6 subroutines-* cases
(glslang refuses subroutine for SPIR-V; wave 3), the 5 separate-programs-*
cases (glslang's pipe-I/O reflection cannot see a separable non-vertex
stage's own inputs; needs stage-aware output validation first), and
uniform-block-types' per-instance stage masks (not derivable from the
reflection).
Gate: 593/593 unit at default and kill-switch, x10 each, plus the SSB race
case 100/100 under 20-way CPU load; ext caselist Espryt 77.87% -> 80.42%,
Magma 77.58% -> 79.39% (+212 fixed, 0 newly broken); program_interface_query
2/43 -> 31/43 unique on Espryt, 9/43 -> 31/43 on Magma, backends now
byte-identical; KHR-GL45.direct_state_access 370/371 + 371/371 with the 4
sRGB leak victims recovered in cross-test ordering; KHR-GL33 held at
9884/9886; full 39x2 CI retrace with zero wave-attributable failures (the
3 failing newly-added fixtures are bit-identical on the pristine baseline).
Gated on the configuration flag on purpose: the string is the one change a
retrace can never cover (Iris/Sodium pipeline their submissions differently
once they see it), so the kill switch has to withdraw the app-visible
behaviour along with the threading.
Whether a backend can attach a single layer of a texture to a framebuffer was one
Bool, so it could only give the most conservative answer any target needed.
DirectVulkan therefore declined every layer of every target and
direct_state_access.framebuffers_texture_layer_attachment failed with 542
messages across four targets.
The three ways a GL layer maps onto Vulkan are independent capabilities, so the
flag becomes a per-TextureTarget mask. A 2D or 2D multisample array layer IS a
VkImage array layer and needed nothing but the gate opened. A cube map array is
one 2D image with arrayLayers = 6 * cubeCount and CUBE_COMPATIBLE, which is a
shape VkTextureManager simply did not have - it is declined softly when the depth
is not a whole number of cubes or the level is not square, because that function's
Bool return exists for unrepresentable shapes and asserting there would abort on
ordinary input, GL_PROXY_TEXTURE_CUBE_MAP_ARRAY above all. A 3D texture's layer is
a z slice, which needs a 2D-array-compatible image and a per-slice clear, because
vkCmdClearColorImage cannot address a subset of a 3D image's slices - a render
pass whose only content is its LOAD_OP_CLEAR can, since its attachment is a 2D
view over that one slice.
VK_IMAGE_CREATE_2D_ARRAY_COMPATIBLE_BIT is asked for per format and withdrawn per
format, mirroring the MUTABLE_FORMAT pattern already in this file: the capability
is per format+usage, so a single global probe answers a different question than
the one the frontend goes on to ask. Losing it costs per-slice attachment for that
format; failing creation would lose the texture.
Three things found on the way that are not the headline:
glFramebufferTextureLayer, the non-DSA twin, had no gate at all and additionally
refused cube map arrays that GL 4.5 requires it to accept. GL 4.6 core 9.2.8 makes
the two entry points equivalent, so they now decline in the same places - leaving
one ungated is what let an unrepresentable attachment reach the renderer.
ComputeFullMipLevelCount takes max(x, y, z), and for every array shape z is the
layer count rather than a mip-able axis, so a 4x4 array with 192 layers asked for
six mip levels on an image whose legal maximum is three
(VUID-VkImageCreateInfo-mipLevels-00958). Only the image's own extent can bound
it. lavapipe had been letting that through.
A layered GL clear queues layerCount = depth, which is illegal for a
VK_IMAGE_TYPE_3D image (VUID-vkCmdClearColorImage-baseArrayLayer-01472 pins it to
0/1, read as the whole mip level) and the old code passed it straight through.
Takes framebuffers_texture_layer_attachment green on DirectVulkan, so the whole
direct_state_access suite is 371/371 there; Espryt stays 370/371, the remaining
case being the fp64 one it declines by design.
Known and deliberately not fixed here, with a FIXME at the site:
KHR-GL44/45/46.geometry_shader.layered_framebuffer.clear_call_support now fails on
DirectVulkan - a layered clear of a 3D texture reads back zeros. Those cases exist
only in the GL44+ lists, above the 4.0 this backend reports. An A/B of a 6935-case
subset (cube map array, texture storage, framebuffer, 3D, the full DSA suite and
the GL33 texture group) is otherwise clean on both backends: 16 cases fixed and
none broken on Espryt, 15 fixed and those 2 broken on Magma, and zero difference
anywhere at GL 4.0 or below. The FIXME records which causes were already ruled out
by bisection so the next reader does not repeat them.
glVertexAttribLFormat validated its arguments and then refused unconditionally
with "64-bit vertex attributes are not supported", so
direct_state_access.vertex_arrays_attribute_format failed every GL_DOUBLE
subcase on both backends - the format never landed, the draw fetched whatever
the attribute held before, and the captured values came back as reinterpreted
garbage.
The attribute is now real state. IsLong is its own bit rather than being
inferred from Float64, because glVertexAttribFormat(GL_DOUBLE) also reads
doubles - it just asks for them converted to float - so the type alone cannot
tell the two apart. It participates in the format comparison, so an L-format
call over a plain one still bumps the version, and glVertexAttribPointer clears
it inside the mutation block so the clear and the bump stay atomic.
GL_VERTEX_ATTRIB_ARRAY_LONG stops being hardcoded false, and the pname is now
accepted by the attribute queries at all.
Support is detected, never assumed. SupportsFloat64VertexAttributes comes from
VkPhysicalDeviceFeatures::shaderFloat64 on DirectVulkan and is false on
DirectGLES - not a driver question there and never will be, since ES has no
GL_DOUBLE vertex format and ESSL has no fp64 type to consume one with. A backend
without it declines in the entry point, with the GL error and a log line naming
the reason, rather than accepting state no draw could honour. Both cases get a
DriverPost row so the loss is named at startup instead of at draw setup.
On DirectVulkan the attribute deliberately does not use VK_FORMAT_R64*_SFLOAT:
those are optional and lavapipe advertises zero features for all four of them.
It is fetched as its 32-bit word pair (R32G32_UINT / R32G32B32A32_UINT) and
bitcast back to double in the shader by a new SPIR-V pass, which is bit-exact
and needs no format capability at all. The pass re-declares the input as uvec2 /
uvec4, demotes the original variable to a Private global and seeds it once at
the top of the entry point, so every existing load keeps its id and its double
type and no other instruction is rewritten. Both halves branch on nothing but
"is this attribute long", so they cannot disagree - and if the pass ever fails,
the assertion fires rather than letting a UINT format sit under a double input.
The pointer types are all created before any variable that names them and the
demoted variable is moved after them, since the types-and-variables section may
not forward-reference a type.
dvec3/dvec4 are declined rather than fetched wrong: six or eight uint32
components have no single VkFormat, and GL spreads such an input over two
attribute locations, which the location-per-index model here does not express.
Fixes vertex_arrays_attribute_format on Magma (369/371). On Espryt it stays
failing, now as a detected and explained decline rather than a blanket refusal.
NamedFramebufferTextureLayer declined every attachment but layer zero, on both
backends. That was right for DirectVulkan, which maps a GL layer onto a Vulkan
array layer with no notion of a 3D depth slice, but wrong for DirectGLES:
SyncAttachmentObject already routes a layered upload target to
glFramebufferTextureLayer with the attachment's layer passed straight through,
and array storage already carries the real layer count into glTexStorage3D. The
one backend that could render to the layer was being told it could not.
The decision now lives in a DynamicBackendParameters flag, so it is the backend
that answers rather than the entry point guessing. DirectGLES sets it when the
driver resolved glFramebufferTextureLayer; DirectVulkan leaves it false until
VkRenderPassManager tells a depth slice from an array layer.
framebuffers_texture_layer_attachment's colour checks now pass on Espryt for 3D,
2D array and 2D multisample array textures - the case still fails there on cube
map arrays, which DirectGLES gives no storage at all, and on the depth and
stencil halves. No case changes on DirectVulkan, which keeps the old behaviour.
Both backends stopped their advertised version list at V_OpenGL33, so an
application - or the CTS - asking what MobileGL supports was told 3.3 even
though the 4.0 entry points and the KHR-GL40 suite already pass on both.
Adding V_OpenGL40 lets that work be reached through the ordinary version query
instead of only through the individual ARB extension strings.
SamplerParameters defaulted compareFunc to ALWAYS, but GL 4.6 core table 23.18
and GLES 3.2 table 21.16 both say the initial value is LEQUAL - for sampler
objects and for the sampler state a texture object carries alike. Every freshly
created texture and sampler therefore answered GL_ALWAYS to
glGetTextureParameteriv(GL_TEXTURE_COMPARE_FUNC).
The Vulkan backend had been papering over it: ResolveCompareFunc substituted
LESS_EQUAL whenever a depth texture was sampled in compare mode and the func
still read ALWAYS, which fixed the rendering but also made an explicitly
requested GL_ALWAYS unreachable. With the default corrected that special case is
both unnecessary and wrong, so it is gone and the compare op is taken straight
from the sampler.
Takes direct_state_access.textures_defaults from failing to passing on both
backends.
glClearNamedFramebufferiv and glClearNamedFramebufferuiv were stubs, so a clear through
them was silently dropped and the attachment kept whatever it held. Their float siblings
were already implemented, which is what made the gap look like a rendering bug rather than
a missing entry point.
Which buffers they accept is narrower than glClearNamedFramebufferfv and differs between
the two: signed values clear COLOR or STENCIL, unsigned only COLOR (GL 4.6 core 17.4.3.1).
Only the colour buffer is indexed, so a stencil clear naming any drawbuffer other than 0 is
INVALID_VALUE rather than merely ignored, and anything else is INVALID_ENUM. Resolving the
framebuffer by name goes through the same helper the float forms use, which is what reports
INVALID_OPERATION for a name that is neither zero nor an existing framebuffer.
Both backends express them the way they already express the float forms: DirectGLES binds
the named framebuffer and forwards to glClearBuffer*, Magma queues the payload against the
named framebuffer rather than the bound one.
direct_state_access.framebuffers_clear_errors passes on both backends, and
framebuffers_clear passes on Espryt. Magma still fails that one, for a separate reason on
the materialization side rather than in these entry points.
glTexBufferRange, glTextureBuffer and glTextureBufferRange were all stubs, so a
buffer texture could only ever be attached through glTexBuffer -- by binding, and
always to the whole buffer.
Give the buffer texture the window it is supposed to address. The non-range forms
record it as offset 0 with a whole-buffer sentinel rather than the size the buffer
happens to have, so a later respecify keeps being followed instead of freezing the
texture at yesterday's size. All four entry points now share one attach path,
differing only in how they name the texture: by binding for the target forms, by
name for the DSA ones.
Both backends honour the window: DirectVulkan offsets and clamps the buffer view,
DirectGLES uses glTexBufferRange when the texture names a sub-range and keeps
plain glTexBuffer for the whole-buffer case, which also works on a driver without
the range entry point.
GL_TEXTURE_BUFFER_OFFSET_ALIGNMENT reported 0 with a comment explaining that the
range entry points were stubbed. It now reports what the device actually requires
-- minTexelBufferOffsetAlignment on Vulkan, the driver's own value on GLES -- and
the range entry points enforce it. Zero was never a legal answer; the minimum is
1, and an application that trusted it would have built unaligned offsets.
GL_PATCH_VERTICES decides how many vertices one tessellation patch consumes, and
glPatchParameteri was a stub - so the value stayed at the driver's default of 3 no
matter what the application asked for. KHR-GL40.texture_gather.gather-tesselation-shader
sets it to 1 and then draws a single patch: with the request dropped the draw had too
few vertices for one patch, produced nothing at all, and the case read back the clear
colour.
The value is context state on both sides and ES 3.2 spells the entry point exactly the
same way, so it is stored in the render state (where glGetIntegerv(GL_PATCH_VERTICES)
now finds it) and forwarded. Validation needs the real bound, so GL_MAX_PATCH_VERTICES
and GL_MAX_TESS_GEN_LEVEL are probed off the host driver alongside the other limits and
answered from there too; the defaults are the GL 4.0 core minimums.
KHR-GL40.texture_gather is now 75/75.
glProgramParameteri is not core before GL 4.1, so in the 4.0 context the CTS runs it
only exists through GL_ARB_get_program_binary or GL_ARB_separate_shader_objects.
MobileGL advertised neither, so dEQP's loader left the entry point null - and
KHR-GL40.api.coverage, which registers glProgramParameteri from GL 3.2 upwards, called
straight through the null pointer and took the process down.
GL_NUM_PROGRAM_BINARY_FORMATS was already 0, and the extension explicitly allows an
implementation to support no binary format at all; that is the honest state of things
here, since a MobileGL program is a glslang link plus a per-backend translation with no
serialised form. So the extension is advertised for what it really provides:
glProgramParameteri stores GL_PROGRAM_BINARY_RETRIEVABLE_HINT (reported back by
glGetProgramiv alongside a GL_PROGRAM_BINARY_LENGTH of zero), glGetProgramBinary is the
INVALID_OPERATION the spec requires when that length is zero, and glProgramBinary
rejects every format with INVALID_ENUM and leaves the program's LINK_STATUS false.
Applications that ask for a binary get the documented "no formats" answer and fall
back, which is what they already had to do - only now they can ask.
GL 4.0 folds ARB_transform_feedback2 and _3 into core, and neither existed:
glGenTransformFeedbacks, glBindTransformFeedback, glDeleteTransformFeedbacks,
glIsTransformFeedback, glPause/ResumeTransformFeedback, the whole
glDrawTransformFeedback family and glBegin/EndQueryIndexed were all stubs, and
gl_NextBuffer / gl_SkipComponents1..4 failed the link as "not an output of the vertex
stage". Seven KHR-GL40.transform_feedback* cases failed on it, three of them by
leaving a capture open at deinit and taking the process down.
Objects. The capture state and the indexed GL_TRANSFORM_FEEDBACK_BUFFER bindings are
object state, but the context keeps one live copy of both, which is what every
existing reader - each backend's per-draw sync, the drawing and getter paths - is
written against. Rather than teach all of them about objects, a bind saves the live
copy into the outgoing object and restores the incoming one's. Object 0 is the
default object and needs no seeding; operator[] materialises the rest on first touch.
Pause. A paused span captures nothing, and three rules key off that: a draw is exempt
from the capture primitive-mode match, it feeds PRIMITIVES_GENERATED but not
TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN, and glUseProgram is allowed again (that last
one was already refused for an active capture, correctly for GL 3.3, which has no
pause).
glDrawTransformFeedback replays the vertices the object captured in its last completed
span, recorded at End. "Has a completed span" is tracked separately from that count,
because a completed empty span draws nothing while an object that never ended one is
INVALID_OPERATION. Drawing from the object whose capture is currently open is
deliberately allowed - feeding a result straight into the next span is the point of
KHR-GL40.transform_feedback.draw_xfb_feedbackk_test.
DirectGLES gets a real driver object per frontend object. That is the only reason the
default one would not do: several objects can be paused at once, and a paused span
lives inside the driver's object. The deferred driver-side Begin (still needed - ES
wants the program current and the buffers bound) now also has to be held back while
the span is paused, or a pause taken before the first draw would open the span on that
draw and subject it to the primitive-mode rule it is exempt from.
Special names. gl_NextBuffer and gl_SkipComponents<n> are consumed during varying
resolution and never become varyings of their own, so they only move where the
following ones land - and stay out of the name list the backend declares on its own
driver. ES cannot express the resulting layout at all: it packs every captured varying
into one gap-free record. So when the layout has holes or spans several buffers,
DirectGLES captures into a scratch buffer bound in place of the application's, and
End distributes the records to the offsets GL asked for. Only the bytes a varying
occupies are written, which is exactly what makes the holes keep the contents the
application left there - the property KHR-GL40.transform_feedback3.skip_components
checks.
glBegin/EndQueryIndexed and glGetQueryIndexediv differ from the plain forms only in the
vertex stream they address, so they validate the index and forward. GL_MAX_VERTEX_STREAMS
stays at 1: multi-stream capture needs ARB_gpu_shader5 stream qualifiers that no ES
driver implements, and the CTS cases that need more than one stream check the limit and
skip.
KHR-GL40.transform_feedback, transform_feedback2 and transform_feedback3: 38/38.
glGetIntegerv(GL_MIN_PROGRAM_TEXTURE_GATHER_OFFSET) and its GL_MAX_ counterpart fell
through to the default arm of the getter and raised GL_INVALID_ENUM, leaving the
caller's variable untouched - KHR-GL40.texture_gather.api-enums read back the
uninitialised 32764 that happened to be on its stack and failed on the error alone.
Both are core state from GL 4.0 (table 23.53) and from ES 3.1 (table 20.40), so the
value is simply the host driver's, probed alongside the other limits in
FillInGLESCapabilities and carried to the getter through DynamicBackendParameters.
The probe result is widened to the -8/+7 core minimums rather than trusted blindly:
a driver that leaves the out-parameter alone (no ES 3.1, or an enum it ignores) would
otherwise hand us a range narrower than GL 4.0 requires MobileGL to advertise, and
the shaders the CTS builds assume the guaranteed range regardless.
GL_RGB16_SNORM widened to GL_RGBA16F to stay renderable as multisample storage, and
a half float's 11-bit mantissa cannot hold a 16-bit signed-normalized channel:
KHR-GL33.texture_swizzle's blue channel came back several units of 32767 away from
the value the reference computes, well outside its one-unit tolerance.
GL_EXT_render_snorm makes the signed-normalized formats colour-renderable on ES, so
widen to GL_RGBA16_SNORM instead wherever it and EXT_texture_norm16 are both
present, and only fall back to the half float otherwise. Threaded through as its own
normalize option so the capability probe and the runtime pick the same format, the
way every other driver-dependent substitution here is decided.