[Fix, Test] (MG_Util, MG_Backend/DirectGLES): transform feedback captured nothing at all from an interface block

This commit is contained in:
2026-08-12 07:38:50 -04:00
parent ea4819a21d
commit 21159caf31
8 changed files with 1028 additions and 2 deletions
+1
View File
@@ -279,6 +279,7 @@ set(SOURCE_FILES
MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/DemoteFloat64Pass.cpp
MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/LowerDrawParametersPass.cpp
MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/PackDoubleVertexInputsPass.cpp
MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/FlattenXfbInterfaceBlocksPass.cpp
MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/SplitArrayVertexInputsPass.cpp
MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/RebaseInstanceIndexPass.cpp
MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/ZeroBaseVertexPass.cpp
+51 -2
View File
@@ -4427,6 +4427,21 @@ namespace MobileGL::MG_Backend::DirectGLES {
}
auto& shaderSpirvs = stateProgramObject->GetGeneratedSpirv();
// Blocks a transform-feedback capture request names a member of ("StageData" of
// "StageData.attrib[0]"). The Adreno ES driver accepts such a request, links, and
// then captures nothing at all for it, so those blocks - and ONLY those - get
// flattened into per-member variables below, in EVERY stage, so a producer and its
// consumer keep matching. gl_PerVertex members ("gl_Position") carry no block
// prefix and so never enter this set.
std::set<String> xfbCaptureBlockNames;
for (const auto& xfbVarying : stateProgramObject->GetTransformFeedbackVaryings()) {
const SizeT dot = xfbVarying.name.find('.');
if (dot != String::npos && dot > 0) {
xfbCaptureBlockNames.insert(xfbVarying.name.substr(0, dot));
}
}
std::set<String> flattenedXfbBlockNames;
for (int index = 0; index < attachedShaders.size(); ++index) {
auto& shader = attachedShaders[index];
GLenum glShaderType = MG_Util::ConvertShaderStageToGLEnum(shader->GetShaderStage());
@@ -4484,6 +4499,25 @@ namespace MobileGL::MG_Backend::DirectGLES {
effectiveSpirv = &splitArrayInputSpirv;
}
// Adopt the rewritten module only when THIS stage actually had one of the
// blocks - the optimizer hands back a re-serialised copy either way, and taking
// that copy for a module it did not rewrite is not free (it cost the
// create-indirect retrace 0.15 SSIM when the array-input split first missed
// this gate). The report has to be per stage, not cumulative: a fragment shader
// consuming the same block reports a name the vertex stage already reported,
// and its own rewrite must still be taken or the two stages stop matching.
Vector<unsigned int> flattenedXfbSpirv;
std::set<String> stageFlattenedXfbBlockNames;
if (!xfbCaptureBlockNames.empty() &&
MG_Util::ShaderTranspiler::ShaderCompiler::FlattenXfbInterfaceBlocksForEssl(
*effectiveSpirv, xfbCaptureBlockNames, stageFlattenedXfbBlockNames,
flattenedXfbSpirv) &&
!flattenedXfbSpirv.empty() && !stageFlattenedXfbBlockNames.empty()) {
effectiveSpirv = &flattenedXfbSpirv;
flattenedXfbBlockNames.insert(stageFlattenedXfbBlockNames.begin(),
stageFlattenedXfbBlockNames.end());
}
// ESSL stage-matches uniform blocks by member precision, but SPIRV-Cross prints
// a RelaxedPrecision member as explicit "mediump" in the vertex stage and as
// UNQUALIFIED (mediump-by-default) in the fragment stage; after
@@ -4692,8 +4726,23 @@ namespace MobileGL::MG_Backend::DirectGLES {
const auto& xfbVaryings = stateProgramObject->GetTransformFeedbackVaryings();
Vector<const GLchar*> xfbNames;
xfbNames.reserve(xfbVaryings.size());
for (const auto& xfbVarying : xfbVaryings) {
xfbNames.push_back(xfbVarying.name.c_str());
// A block this build flattened no longer HAS the member the application asked
// for; it has the variable that replaced it. Everything else - including a
// member of a block that was left alone - keeps the application's spelling.
// Storage first, pointers after: xfbNames holds pointers into these strings.
Vector<String> rewrittenXfbNames(xfbVaryings.size());
for (SizeT nameIndex = 0; nameIndex < xfbVaryings.size(); ++nameIndex) {
String flatName;
if (!flattenedXfbBlockNames.empty() &&
MG_Util::ShaderTranspiler::ShaderCompiler::RewriteXfbCaptureNameForFlattenedBlock(
xfbVaryings[nameIndex].name, flattenedXfbBlockNames, flatName)) {
rewrittenXfbNames[nameIndex] = std::move(flatName);
} else {
rewrittenXfbNames[nameIndex] = xfbVaryings[nameIndex].name;
}
}
for (const auto& xfbName : rewrittenXfbNames) {
xfbNames.push_back(xfbName.c_str());
}
MGLOG_D("Declaring %zu transform feedback varyings on program %u", xfbNames.size(),
m_backendProgramId);
@@ -4,6 +4,7 @@ add_executable(
SpirvPassTest
SpirvPassTest.cpp
DemoteFloat64Test.cpp
FlattenXfbInterfaceBlocksTest.cpp
)
target_include_directories(SpirvPassTest PRIVATE
@@ -0,0 +1,226 @@
// MobileGL - MobileGL/MG_Test/ShaderTranspiler/FlattenXfbInterfaceBlocksTest.cpp
// Copyright (c) 2025-2026 MobileGL-Dev
// Licensed under the GNU Lesser General Public License v3.0:
// https://www.gnu.org/licenses/gpl-3.0.txt
// https://www.gnu.org/licenses/lgpl-3.0.txt
// SPDX-License-Identifier: LGPL-3.0-only
// End of Source File Header
#include <gtest/gtest.h>
#include <set>
#include <string>
#include <vector>
#include "Includes.h"
#include "Init.h"
#include <MG_Util/ShaderTranspiler/ShaderCompiler.h>
#include <MG_Util/ShaderTranspiler/SpvcSession.h>
#include <MG_Util/ShaderTranspiler/Types.h>
#include <spirv-tools/libspirv.hpp>
using namespace MobileGL;
using MobileGL::MG_Util::ShaderTranspiler::SessionUsageBit;
using MobileGL::MG_Util::ShaderTranspiler::ShaderCompiler;
using MobileGL::MG_Util::ShaderTranspiler::SpvcSession;
namespace {
Vector<Uint32> CompileToSpirv(GLenum stage, const String& source) {
using namespace MG_Util::ShaderTranspiler;
ShaderAttrib shaderAttrib{.shaderType = stage, .sourceStr = source};
auto shaderResult = ShaderCompiler::CompileShader(shaderAttrib);
EXPECT_TRUE(shaderResult) << (shaderResult ? String{} : shaderResult.error().log);
if (!shaderResult) return {};
ProgramAttrib programAttrib{.shaders = {shaderResult.value()}};
auto programResult = ShaderCompiler::LinkProgram(programAttrib);
EXPECT_TRUE(programResult) << (programResult ? String{} : programResult.error().log);
if (!programResult) return {};
ProgramBinaryAttrib binaryAttrib{.shaderTypes = {stage}, .program = *programResult.value()};
auto binaryResult = ShaderCompiler::GetSpirvBinaryFromProgram(binaryAttrib);
EXPECT_TRUE(binaryResult) << (binaryResult ? String{} : binaryResult.error().log);
if (!binaryResult || binaryResult->empty()) return {};
return binaryResult->front();
}
String Disassemble(const Vector<Uint32>& spirv) {
spvtools::SpirvTools tools(SPV_ENV_VULKAN_1_1);
String text;
tools.Disassemble(spirv, &text);
return text;
}
String Transpile(const Vector<Uint32>& spirv) {
SpvcSession session(spirv, SessionUsageBit::Transpile);
auto essl = ShaderCompiler::DecompileShader(session);
EXPECT_TRUE(essl) << (essl ? String{} : essl.error().log);
return essl ? essl.value() : String{};
}
// The KHR-GL43.vertex_attrib_binding.basic-input capture program's output side, verbatim:
// a 16-element vec4 array inside a named output block, which is what the capture list
// addresses member by member ("StageData.attrib[0]" ... "StageData.attrib[15]").
const char* kCaptureVertexSource = R"(#version 430 core
layout(location = 0) in vec4 vs_in_attrib;
out StageData {
vec4 attrib[16];
} vs_out;
void main() {
for (int i = 0; i < 16; ++i) {
vs_out.attrib[i] = vs_in_attrib;
}
}
)";
// Mixed member widths, so a member that claims the wrong number of locations moves every
// member after it.
// 440, because a location on the BLOCK is ARB_enhanced_layouts.
const char* kMixedBlockVertexSource = R"(#version 440 core
layout(location = 0) in vec4 vs_in_attrib;
layout(location = 0) out StageData {
vec4 first;
vec2 second;
mat4 third;
vec4 fourth;
} vs_out;
void main() {
vs_out.first = vs_in_attrib;
vs_out.second = vs_in_attrib.xy;
vs_out.third = mat4(vs_in_attrib.x);
vs_out.fourth = vs_in_attrib;
}
)";
} // namespace
class FlattenXfbInterfaceBlocksTest : public ::testing::Test {
protected:
void SetUp() override {
MobileGL::Initialize();
ShaderCompiler::SetSpirvValidationEnabled(true);
m_validationFailuresAtStart = ShaderCompiler::SpirvValidationFailureCount();
}
void TearDown() override {
EXPECT_EQ(ShaderCompiler::SpirvValidationFailureCount(), m_validationFailuresAtStart)
<< "the flattened module did not survive spirv-val";
}
Uint64 m_validationFailuresAtStart = 0;
};
TEST_F(FlattenXfbInterfaceBlocksTest, FlattensACapturedBlockIntoOneVariablePerMember) {
const Vector<Uint32> input = CompileToSpirv(GL_VERTEX_SHADER, kCaptureVertexSource);
ASSERT_FALSE(input.empty());
std::set<String> flattened;
Vector<Uint32> output;
ASSERT_TRUE(ShaderCompiler::FlattenXfbInterfaceBlocksForEssl(input, {"StageData"}, flattened, output));
ASSERT_FALSE(output.empty());
EXPECT_EQ(flattened, (std::set<String>{"StageData"}));
const String dis = Disassemble(output);
spvtools::SpirvTools tools(SPV_ENV_VULKAN_1_1);
ASSERT_TRUE(tools.Validate(output)) << dis;
EXPECT_NE(dis.find("StageData_attrib"), String::npos) << dis;
// The block itself must have stopped being an interface variable, or the driver would see
// both spellings of the same data.
EXPECT_NE(dis.find("Private"), String::npos) << dis;
}
// The declaration is the point of the whole exercise: the emitted ESSL has to declare a plain
// output ARRAY, not an interface block, because that is the shape the Adreno driver can capture.
// SPIR-V validation does NOT catch the difference - leaving the struct's Block decoration on the
// demoted shadow produced a module that validated and emitted `StageData vs_out;` next to a block
// declaration the driver rejected with a bare "'vs_out' : syntax error".
TEST_F(FlattenXfbInterfaceBlocksTest, TheEmittedDeclarationIsAPlainArrayNotABlock) {
const Vector<Uint32> input = CompileToSpirv(GL_VERTEX_SHADER, kCaptureVertexSource);
ASSERT_FALSE(input.empty());
// Negative control: untouched, the block is emitted AS a block.
const String before = Transpile(input);
EXPECT_NE(before.find("out StageData"), String::npos) << before;
EXPECT_EQ(before.find("StageData_attrib"), String::npos) << before;
std::set<String> flattened;
Vector<Uint32> output;
ASSERT_TRUE(ShaderCompiler::FlattenXfbInterfaceBlocksForEssl(input, {"StageData"}, flattened, output));
const String after = Transpile(output);
EXPECT_NE(after.find("StageData_attrib[16]"), String::npos) << after;
EXPECT_EQ(after.find("out StageData"), String::npos)
<< "the block must not still be declared as an output block:\n"
<< after;
}
// GL 4.6 core 11.1.2.1: consecutive members take consecutive locations, and a member takes as
// many as its type needs. Getting a span wrong silently moves every member after it.
TEST_F(FlattenXfbInterfaceBlocksTest, GivesEachMemberItsOwnConsecutiveLocations) {
const Vector<Uint32> input = CompileToSpirv(GL_VERTEX_SHADER, kMixedBlockVertexSource);
ASSERT_FALSE(input.empty());
std::set<String> flattened;
Vector<Uint32> output;
ASSERT_TRUE(ShaderCompiler::FlattenXfbInterfaceBlocksForEssl(input, {"StageData"}, flattened, output));
ASSERT_FALSE(output.empty());
const String dis = Disassemble(output);
spvtools::SpirvTools tools(SPV_ENV_VULKAN_1_1);
ASSERT_TRUE(tools.Validate(output)) << dis;
EXPECT_NE(dis.find("OpDecorate %StageData_first Location 0"), String::npos) << dis;
EXPECT_NE(dis.find("OpDecorate %StageData_second Location 1"), String::npos) << dis;
EXPECT_NE(dis.find("OpDecorate %StageData_third Location 2"), String::npos) << dis;
// mat4 takes four, so the member after it starts at 2 + 4.
EXPECT_NE(dis.find("OpDecorate %StageData_fourth Location 6"), String::npos) << dis;
}
// Nothing captures this block, so nothing may touch it: a shader that merely HAS an output
// block must reach the driver exactly as it was.
TEST_F(FlattenXfbInterfaceBlocksTest, LeavesABlockNoCaptureNamesAlone) {
const Vector<Uint32> input = CompileToSpirv(GL_VERTEX_SHADER, kCaptureVertexSource);
ASSERT_FALSE(input.empty());
std::set<String> flattened;
Vector<Uint32> output;
ASSERT_TRUE(
ShaderCompiler::FlattenXfbInterfaceBlocksForEssl(input, {"SomeOtherBlock"}, flattened, output));
EXPECT_TRUE(flattened.empty());
const String after = Transpile(output);
EXPECT_NE(after.find("out StageData"), String::npos) << after;
EXPECT_EQ(after.find("StageData_attrib"), String::npos) << after;
}
// An empty request must not even run the optimizer: every program without transform feedback
// takes this path on every build.
TEST_F(FlattenXfbInterfaceBlocksTest, DeclinesAnEmptyRequestWithoutRewriting) {
const Vector<Uint32> input = CompileToSpirv(GL_VERTEX_SHADER, kCaptureVertexSource);
ASSERT_FALSE(input.empty());
std::set<String> flattened;
Vector<Uint32> output;
EXPECT_FALSE(ShaderCompiler::FlattenXfbInterfaceBlocksForEssl(input, {}, flattened, output));
EXPECT_TRUE(flattened.empty());
EXPECT_TRUE(output.empty());
}
// The capture list has to follow the declaration exactly, and only for blocks that were
// actually rewritten - a member of a block left alone keeps the application's spelling, and so
// does a name with no block prefix at all (gl_Position, a plain varying).
TEST_F(FlattenXfbInterfaceBlocksTest, RewritesOnlyTheCaptureNamesOfFlattenedBlocks) {
String rewritten;
EXPECT_TRUE(ShaderCompiler::RewriteXfbCaptureNameForFlattenedBlock("StageData.attrib[0]", {"StageData"},
rewritten));
EXPECT_EQ(rewritten, "StageData_attrib[0]");
EXPECT_TRUE(
ShaderCompiler::RewriteXfbCaptureNameForFlattenedBlock("StageData.attrib", {"StageData"}, rewritten));
EXPECT_EQ(rewritten, "StageData_attrib");
EXPECT_FALSE(
ShaderCompiler::RewriteXfbCaptureNameForFlattenedBlock("Other.member", {"StageData"}, rewritten));
EXPECT_FALSE(ShaderCompiler::RewriteXfbCaptureNameForFlattenedBlock("gl_Position", {"StageData"}, rewritten));
EXPECT_FALSE(ShaderCompiler::RewriteXfbCaptureNameForFlattenedBlock("vColor", {"StageData"}, rewritten));
EXPECT_FALSE(ShaderCompiler::RewriteXfbCaptureNameForFlattenedBlock(".leading", {"StageData"}, rewritten));
}
@@ -21,6 +21,7 @@
#include "SpirvPasses/DemoteFloat64Pass.h"
#include "SpirvPasses/LowerDrawParametersPass.h"
#include "SpirvPasses/PackDoubleVertexInputsPass.h"
#include "SpirvPasses/FlattenXfbInterfaceBlocksPass.h"
#include "SpirvPasses/SplitArrayVertexInputsPass.h"
#include "SpirvPasses/RebaseInstanceIndexPass.h"
#include "SpirvPasses/ZeroBaseVertexPass.h"
@@ -684,6 +685,26 @@ namespace MobileGL {
outputBinary);
}
bool ShaderCompiler::FlattenXfbInterfaceBlocksForEssl(const Vector<Uint32>& inputBinary,
const std::set<String>& blockNames,
std::set<String>& flattenedBlockNames,
Vector<uint32_t>& outputBinary) {
using namespace spvtools;
if (blockNames.empty()) return false;
Optimizer optimizer(SPV_ENV_VULKAN_1_1);
optimizer.RegisterPass(FlattenXfbInterfaceBlocksPass::CreateFlattenXfbInterfaceBlocksPass(
blockNames, &flattenedBlockNames));
return RunOptimizerChecked("FlattenXfbInterfaceBlocksForEssl", optimizer, inputBinary,
outputBinary);
}
bool ShaderCompiler::RewriteXfbCaptureNameForFlattenedBlock(
const String& captureName, const std::set<String>& flattenedBlockNames, String& outName) {
return FlattenXfbInterfaceBlocksPass::RewriteCaptureName(captureName, flattenedBlockNames,
outName);
}
bool ShaderCompiler::PackDoubleVertexInputsForVulkan(const Vector<Uint32>& inputBinary,
Vector<uint32_t>& outputBinary) {
using namespace spvtools;
@@ -12,6 +12,8 @@
#include "glslang/TVarEntryInfo.h"
#include "glslang/TMglGlslIoResolver.h"
#include <set>
namespace MobileGL {
namespace MG_Util {
namespace ShaderTranspiler {
@@ -34,6 +36,23 @@ namespace MobileGL {
// driver. Only for the DirectGLES transpile path.
static bool SplitArrayVertexInputsForEssl(const Vector<Uint32>& inputBinary,
Vector<uint32_t>& outputBinary);
// Replaces the named interface BLOCKS with one variable per member, named
// "<Block>_<member>", shadowing the block itself so the body is untouched. The
// Adreno ES driver silently captures NOTHING for a transform-feedback varying
// named as a block member, so a capture list that names one has to be respelled
// - and the declaration with it. `flattenedBlockNames` reports which blocks
// this stage actually rewrote, which is what the capture list must follow.
// Only for the DirectGLES transpile path.
static bool FlattenXfbInterfaceBlocksForEssl(const Vector<Uint32>& inputBinary,
const std::set<String>& blockNames,
std::set<String>& flattenedBlockNames,
Vector<uint32_t>& outputBinary);
// The capture request "StageData.attrib[0]" as the pass above renamed it,
// "StageData_attrib[0]", or false when it does not name a member of a block
// that was flattened.
static bool RewriteXfbCaptureNameForFlattenedBlock(const String& captureName,
const std::set<String>& flattenedBlockNames,
String& outName);
// Drops RelaxedPrecision member decorations from uniform-block structs so
// SPIRV-Cross prints the same (highp) member precision in every stage; ES
// drivers reject cross-stage uniform blocks whose member precisions differ.
@@ -0,0 +1,636 @@
// MobileGL - MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/FlattenXfbInterfaceBlocksPass.cpp
// Copyright (c) 2025-2026 MobileGL-Dev
// Licensed under the GNU Lesser General Public License v3.0:
// https://www.gnu.org/licenses/gpl-3.0.txt
// https://www.gnu.org/licenses/lgpl-3.0.txt
// SPDX-License-Identifier: LGPL-3.0-only
// End of Source File Header
#include "FlattenXfbInterfaceBlocksPass.h"
#include "spirv.hpp"
#include "source/opt/def_use_manager.h"
#include "source/opt/instruction.h"
#include "source/opt/ir_context.h"
#include "source/opt/module.h"
#include "source/opt/types.h"
#include "source/util/make_unique.h"
#include "source/util/string_utils.h"
#include <memory>
#include <unordered_set>
#include <vector>
namespace MobileGL {
namespace MG_Util {
namespace ShaderTranspiler {
namespace {
using spvtools::opt::IRContext;
using spvtools::opt::Instruction;
using spvtools::opt::Operand;
namespace analysis = spvtools::opt::analysis;
// Decorations that describe how ONE member is interpolated or stored, and
// therefore have to travel from the block member to the variable that replaces
// it. Location is handled separately (it is computed per member); everything
// else about a block - Block itself, member Offsets, builtin decorations - is
// about the aggregate and stays behind on the shadow.
Bool IsMemberDecorationToCarry(spv::Decoration decoration) {
switch (decoration) {
case spv::Decoration::RelaxedPrecision:
case spv::Decoration::Flat:
case spv::Decoration::NoPerspective:
case spv::Decoration::Centroid:
case spv::Decoration::Sample:
case spv::Decoration::Invariant:
case spv::Decoration::Patch:
return true;
default:
return false;
}
}
// Decorations that say something about a member's placement WITHIN the block's
// location, which a free-standing variable cannot express the same way. Rather
// than move a member to a place the consumer will not look for it, decline.
Bool IsMemberDecorationThatBlocksFlattening(spv::Decoration decoration) {
switch (decoration) {
case spv::Decoration::Component:
case spv::Decoration::XfbBuffer:
case spv::Decoration::XfbStride:
case spv::Decoration::Stream:
return true;
default:
return false;
}
}
// Every name the module already spells, so a synthesised "<Block>_<member>" that
// would collide with one declines instead of emitting two declarations of the
// same identifier (which the driver rejects, taking the whole program with it).
std::unordered_set<String> CollectNames(IRContext& irContext) {
std::unordered_set<String> names;
for (auto& debugInst : irContext.debugs2()) {
if (debugInst.opcode() != spv::Op::OpName) continue;
names.insert(debugInst.GetInOperand(1).AsString());
}
return names;
}
// Locations one value of `type` occupies (GL 4.6 core 11.1.2.1 / 15.2): a
// matrix takes one per column, a double-precision vector wider than two takes
// two, an array takes its element's span once per element. 0 means "this pass
// cannot place it", which declines the whole block rather than guessing.
Uint32 LocationSpan(const analysis::Type* type) {
if (type == nullptr) return 0;
if (type->AsFloat() != nullptr || type->AsInteger() != nullptr ||
type->AsBool() != nullptr) {
return 1u;
}
if (const auto* vector = type->AsVector()) {
const auto* element = vector->element_type();
if (element->AsFloat() == nullptr && element->AsInteger() == nullptr &&
element->AsBool() == nullptr) {
return 0;
}
const auto* elementFloat = element->AsFloat();
const Bool is64Bit = elementFloat != nullptr && elementFloat->width() == 64;
return (is64Bit && vector->element_count() > 2) ? 2u : 1u;
}
if (const auto* matrix = type->AsMatrix()) {
const Uint32 columnSpan = LocationSpan(matrix->element_type());
return columnSpan == 0 ? 0 : columnSpan * matrix->element_count();
}
if (const auto* array = type->AsArray()) {
const Uint32 elementSpan = LocationSpan(array->element_type());
if (elementSpan == 0) return 0;
// A runtime array has no span; a vertex-stage interface never has one.
if (!array->length_info().words.empty() &&
array->length_info().words[0] !=
static_cast<Uint32>(analysis::Array::LengthInfo::kConstant)) {
return 0;
}
// words[0] is the tag, words[1..] the constant value; only a
// single-word length can be an array size here.
if (array->length_info().words.size() != 2) return 0;
const Uint32 count = array->length_info().words[1];
return count == 0 ? 0 : elementSpan * count;
}
// Structs (a nested block member) carry their own layout rules and are not
// worth guessing at: declining leaves the module exactly as it was.
return 0;
}
// The Location a variable carries, or false when it carries none.
Bool FindLocationDecoration(IRContext& irContext, Uint32 variableId, Uint32& outLocation) {
for (auto& annotation : irContext.annotations()) {
if (annotation.opcode() != spv::Op::OpDecorate) continue;
if (annotation.GetSingleWordInOperand(0) != variableId) continue;
if (static_cast<spv::Decoration>(annotation.GetSingleWordInOperand(1)) !=
spv::Decoration::Location) {
continue;
}
outLocation = annotation.GetSingleWordInOperand(2);
return true;
}
return false;
}
// The Location decorating member `member` of struct type `typeId`, if any.
Bool FindMemberLocationDecoration(IRContext& irContext, Uint32 typeId, Uint32 member,
Uint32& outLocation) {
for (auto& annotation : irContext.annotations()) {
if (annotation.opcode() != spv::Op::OpMemberDecorate) continue;
if (annotation.GetSingleWordInOperand(0) != typeId) continue;
if (annotation.GetSingleWordInOperand(1) != member) continue;
if (static_cast<spv::Decoration>(annotation.GetSingleWordInOperand(2)) !=
spv::Decoration::Location) {
continue;
}
outLocation = annotation.GetSingleWordInOperand(3);
return true;
}
return false;
}
String FindName(IRContext& irContext, Uint32 id) {
for (auto& debugInst : irContext.debugs2()) {
if (debugInst.opcode() != spv::Op::OpName) continue;
if (debugInst.GetSingleWordInOperand(0) != id) continue;
return debugInst.GetInOperand(1).AsString();
}
return String();
}
String FindMemberName(IRContext& irContext, Uint32 typeId, Uint32 member) {
for (auto& debugInst : irContext.debugs2()) {
if (debugInst.opcode() != spv::Op::OpMemberName) continue;
if (debugInst.GetSingleWordInOperand(0) != typeId) continue;
if (debugInst.GetSingleWordInOperand(1) != member) continue;
return debugInst.GetInOperand(2).AsString();
}
return String();
}
} // namespace
Bool FlattenXfbInterfaceBlocksPass::RewriteCaptureName(const String& captureName,
const std::set<String>& flattenedBlockNames,
String& outName) {
const SizeT dot = captureName.find('.');
if (dot == String::npos || dot == 0) return false;
const String blockName = captureName.substr(0, dot);
if (flattenedBlockNames.find(blockName) == flattenedBlockNames.end()) return false;
outName = blockName + "_" + captureName.substr(dot + 1);
return true;
}
spvtools::opt::Pass::Status FlattenXfbInterfaceBlocksPass::Process() {
if (m_blockNames.empty()) return Status::SuccessWithoutChange;
auto* irContext = context();
auto entryPoints = irContext->module()->entry_points();
if (entryPoints.begin() == entryPoints.end()) return Status::SuccessWithoutChange;
Instruction* entryPoint = &*entryPoints.begin();
// A stage whose outputs are published somewhere other than the end of the entry
// point cannot take the shadow-and-copy-out shape: a geometry shader's outputs
// are captured by every OpEmitVertex, and a tessellation control shader's are
// per-invocation slots of an arrayed interface. Copying at OpReturn would
// publish once, at the end, which is silently the wrong data rather than a
// failure - so those stages keep their blocks and the capture keeps its
// spelling.
const auto executionModel =
static_cast<spv::ExecutionModel>(entryPoint->GetSingleWordInOperand(0));
if (executionModel == spv::ExecutionModel::Geometry ||
executionModel == spv::ExecutionModel::TessellationControl) {
MGLOG_I("FlattenXfbInterfaceBlocksPass: execution model %u publishes outputs outside "
"the entry point's return; leaving its blocks declared as blocks",
static_cast<Uint32>(executionModel));
return Status::SuccessWithoutChange;
}
auto* defUseMgr = irContext->get_def_use_mgr();
auto* typeMgr = irContext->get_type_mgr();
struct Member {
Uint32 typeId = 0;
Uint32 interfacePointerTypeId = 0;
Uint32 privatePointerTypeId = 0;
Uint32 variableId = 0;
Uint32 location = 0;
Bool hasLocation = false;
String name;
};
struct Target {
Instruction* variable = nullptr;
Uint32 structTypeId = 0;
Uint32 privatePointerTypeId = 0;
spv::StorageClass storageClass = spv::StorageClass::Output;
String blockName;
std::vector<Member> members;
};
std::vector<Target> targets;
const std::unordered_set<String> existingNames = CollectNames(*irContext);
for (Instruction& inst : irContext->types_values()) {
if (inst.opcode() != spv::Op::OpVariable) continue;
const auto storageClass =
static_cast<spv::StorageClass>(inst.GetSingleWordInOperand(0));
if (storageClass != spv::StorageClass::Input &&
storageClass != spv::StorageClass::Output) {
continue;
}
Instruction* pointerType = defUseMgr->GetDef(inst.type_id());
if (pointerType == nullptr) continue;
const Uint32 pointeeTypeId = pointerType->GetSingleWordInOperand(1);
const analysis::Type* pointeeType = typeMgr->GetType(pointeeTypeId);
const auto* structType = pointeeType != nullptr ? pointeeType->AsStruct() : nullptr;
if (structType == nullptr) continue;
const String blockName = FindName(*irContext, pointeeTypeId);
if (blockName.empty() ||
m_blockNames.find(blockName) == m_blockNames.end()) {
continue;
}
Target target;
target.variable = &inst;
target.structTypeId = pointeeTypeId;
target.storageClass = storageClass;
target.blockName = blockName;
Uint32 blockLocation = 0;
const Bool hasBlockLocation =
FindLocationDecoration(*irContext, inst.result_id(), blockLocation);
Bool usable = true;
for (auto& annotation : irContext->annotations()) {
if (annotation.opcode() != spv::Op::OpMemberDecorate) continue;
if (annotation.GetSingleWordInOperand(0) != pointeeTypeId) continue;
if (IsMemberDecorationThatBlocksFlattening(
static_cast<spv::Decoration>(annotation.GetSingleWordInOperand(2)))) {
usable = false;
break;
}
}
Uint32 runningLocation = blockLocation;
const auto& memberTypes = structType->element_types();
for (Uint32 memberIndex = 0; usable && memberIndex < memberTypes.size(); ++memberIndex) {
Member member;
member.typeId = typeMgr->GetId(memberTypes[memberIndex]);
member.name = FindMemberName(*irContext, pointeeTypeId, memberIndex);
if (member.typeId == 0 || member.name.empty() ||
existingNames.count(blockName + "_" + member.name) != 0) {
usable = false;
break;
}
const Uint32 span = LocationSpan(memberTypes[memberIndex]);
if (span == 0) {
usable = false;
break;
}
Uint32 memberLocation = 0;
if (FindMemberLocationDecoration(*irContext, pointeeTypeId, memberIndex,
memberLocation)) {
member.location = memberLocation;
member.hasLocation = true;
} else if (hasBlockLocation) {
member.location = runningLocation;
member.hasLocation = true;
}
runningLocation += span;
target.members.push_back(member);
}
if (!usable || target.members.empty()) {
MGLOG_I("FlattenXfbInterfaceBlocksPass: block '%s' has a member this pass cannot "
"place; leaving it declared as a block",
blockName.c_str());
continue;
}
targets.push_back(std::move(target));
}
if (targets.empty()) return Status::SuccessWithoutChange;
// The entry point's first block, past the leading OpVariable run SPIR-V
// requires to stay at the top of a function. Resolved BEFORE anything is
// mutated: a decline after the rewrite has started would leave a half-converted
// module behind, and the optimizer serialises whatever the module holds
// regardless of the status this returns.
const Uint32 entryFunctionId = entryPoint->GetSingleWordInOperand(1);
spvtools::opt::Function* entryFunction = nullptr;
for (auto& function : *irContext->module()) {
if (function.result_id() == entryFunctionId) {
entryFunction = &function;
break;
}
}
if (entryFunction == nullptr || entryFunction->begin() == entryFunction->end()) {
return Status::SuccessWithoutChange;
}
{
auto& probeBlock = *entryFunction->begin();
auto probe = probeBlock.begin();
while (probe != probeBlock.end() && probe->opcode() == spv::Op::OpVariable) ++probe;
if (probe == probeBlock.end()) return Status::SuccessWithoutChange;
}
// Demoting the block changes the STORAGE CLASS of every pointer derived from it,
// and a derived pointer's own result type still says Input/Output - which is an
// invalid module ("the result pointer storage class and base pointer storage
// class in OpAccessChain do not match") that spirv-val rejects and a driver may
// silently miscompile. Collected before anything is mutated so an unsupported
// use can still decline the whole rewrite rather than leave the module broken.
std::unordered_set<Uint32> derivedPointers;
for (const auto& target : targets) {
derivedPointers.insert(target.variable->result_id());
}
std::vector<Instruction*> pointersToRetype;
for (auto& function : *irContext->module()) {
for (auto& block : function) {
for (auto& inst : block) {
const spv::Op opcode = inst.opcode();
const Bool indexes = opcode == spv::Op::OpAccessChain ||
opcode == spv::Op::OpInBoundsAccessChain ||
opcode == spv::Op::OpCopyObject;
if (indexes) {
if (inst.NumInOperands() > 0 &&
derivedPointers.count(inst.GetSingleWordInOperand(0)) != 0) {
derivedPointers.insert(inst.result_id());
pointersToRetype.push_back(&inst);
}
continue;
}
// Reads and writes are exactly what a shadowed block is for; the
// pointer they use does not change shape.
if (opcode == spv::Op::OpLoad || opcode == spv::Op::OpStore) continue;
for (Uint32 i = 0; i < inst.NumInOperands(); ++i) {
const Operand& operand = inst.GetInOperand(i);
if (operand.type != SPV_OPERAND_TYPE_ID || operand.words.size() != 1) {
continue;
}
if (derivedPointers.count(operand.words[0]) == 0) continue;
MGLOG_I("FlattenXfbInterfaceBlocksPass: interface block %%%u reaches a "
"SPIR-V opcode %u that this pass cannot follow; leaving it "
"declared as a block",
operand.words[0], static_cast<Uint32>(opcode));
return Status::SuccessWithoutChange;
}
}
}
}
// Every type this pass names has to exist before the variables that name it.
for (auto& target : targets) {
target.privatePointerTypeId =
typeMgr->FindPointerToType(target.structTypeId, spv::StorageClass::Private);
for (auto& member : target.members) {
member.interfacePointerTypeId =
typeMgr->FindPointerToType(member.typeId, target.storageClass);
member.privatePointerTypeId =
typeMgr->FindPointerToType(member.typeId, spv::StorageClass::Private);
}
}
std::vector<Operand> interfaceOperands;
for (Uint32 i = 0; i < entryPoint->NumInOperands(); ++i) {
interfaceOperands.push_back(entryPoint->GetInOperand(i));
}
std::unordered_set<Uint32> strippedBlockStructTypes;
for (auto& target : targets) {
Instruction* variable = target.variable;
const Uint32 oldVariableId = variable->result_id();
std::vector<std::unique_ptr<Instruction>> newDecorations;
std::vector<std::unique_ptr<Instruction>> newNames;
for (auto& member : target.members) {
member.variableId = irContext->TakeNextId();
irContext->AddGlobalValue(spvtools::MakeUnique<Instruction>(
irContext, spv::Op::OpVariable, member.interfacePointerTypeId, member.variableId,
std::initializer_list<Operand>{
{SPV_OPERAND_TYPE_STORAGE_CLASS,
{static_cast<Uint32>(target.storageClass)}}}));
// The name IS the contract: it is what the rewritten capture request
// asks the driver for, and what makes the producer and consumer of a
// flattened block still match each other by name.
const String flatName = target.blockName + "_" + member.name;
std::vector<Operand> nameOperands;
nameOperands.push_back({SPV_OPERAND_TYPE_ID, {member.variableId}});
nameOperands.push_back(
{SPV_OPERAND_TYPE_LITERAL_STRING,
spvtools::utils::MakeVector(flatName)});
newNames.push_back(spvtools::MakeUnique<Instruction>(irContext, spv::Op::OpName, 0, 0,
nameOperands));
if (member.hasLocation) {
newDecorations.push_back(spvtools::MakeUnique<Instruction>(
irContext, spv::Op::OpDecorate, 0, 0,
std::initializer_list<Operand>{
{SPV_OPERAND_TYPE_ID, {member.variableId}},
{SPV_OPERAND_TYPE_DECORATION,
{static_cast<Uint32>(spv::Decoration::Location)}},
{SPV_OPERAND_TYPE_LITERAL_INTEGER, {member.location}}}));
}
}
// Member decorations that describe the member (not the aggregate) move to
// the variable that now carries it.
for (auto& annotation : irContext->annotations()) {
if (annotation.opcode() != spv::Op::OpMemberDecorate) continue;
if (annotation.GetSingleWordInOperand(0) != target.structTypeId) continue;
const Uint32 memberIndex = annotation.GetSingleWordInOperand(1);
if (memberIndex >= target.members.size()) continue;
const auto decoration =
static_cast<spv::Decoration>(annotation.GetSingleWordInOperand(2));
if (!IsMemberDecorationToCarry(decoration)) continue;
std::vector<Operand> operands;
operands.push_back({SPV_OPERAND_TYPE_ID, {target.members[memberIndex].variableId}});
for (Uint32 i = 2; i < annotation.NumInOperands(); ++i) {
operands.push_back(annotation.GetInOperand(i));
}
newDecorations.push_back(
spvtools::MakeUnique<Instruction>(irContext, spv::Op::OpDecorate, 0, 0, operands));
}
// The block's own Location described where its members start and means
// nothing on a Private shadow; leaving it would also make SPIRV-Cross print
// a location for a variable that no longer has an interface.
std::vector<Instruction*> deadDecorations;
// A struct type shared by two flattened variables would otherwise have its
// Block decoration killed twice - and the second kill is a use-after-free,
// not a no-op.
const Bool structTypeAlreadyStripped =
strippedBlockStructTypes.count(target.structTypeId) != 0;
strippedBlockStructTypes.insert(target.structTypeId);
for (auto& annotation : irContext->annotations()) {
if (annotation.opcode() != spv::Op::OpDecorate) continue;
const Uint32 target0 = annotation.GetSingleWordInOperand(0);
if (target0 == oldVariableId) {
deadDecorations.push_back(&annotation);
continue;
}
if (structTypeAlreadyStripped) continue;
// The struct type stops being an interface block the moment its only
// interface variable becomes a Private shadow, and SPIRV-Cross prints a
// Block-decorated struct as a BLOCK declaration - `out StageData {...}
// vs_out;` for a variable that is no longer an output, which is not
// ESSL and which the driver rejects with a bare syntax error on the
// instance name. A block name is unique per stage, so nothing else can
// still need this decoration.
if (target0 == target.structTypeId &&
static_cast<spv::Decoration>(annotation.GetSingleWordInOperand(1)) ==
spv::Decoration::Block) {
deadDecorations.push_back(&annotation);
}
}
for (auto* annotation : deadDecorations) {
irContext->KillInst(annotation);
}
for (auto& decoration : newDecorations) {
irContext->AddAnnotationInst(std::move(decoration));
}
for (auto& debugName : newNames) {
irContext->AddDebug2Inst(std::move(debugName));
}
// Demote the block to a Private shadow. Every OpAccessChain and OpStore the
// body already performs on it stays valid and keeps its types; only the
// storage class changed, and Private is the one storage class a pointer of
// any shape may live in.
variable->SetResultType(target.privatePointerTypeId);
variable->SetInOperand(0, {static_cast<Uint32>(spv::StorageClass::Private)});
variable->RemoveFromList();
irContext->AddGlobalValue(std::unique_ptr<Instruction>(variable));
// SPIR-V 1.3 lists only Input/Output in the entry-point interface, and the
// block is neither any more: it is replaced in place by its members.
std::vector<Operand> rebuilt;
for (Uint32 i = 0; i < interfaceOperands.size(); ++i) {
const Operand& operand = interfaceOperands[i];
if (i >= 3 && operand.type == SPV_OPERAND_TYPE_ID && operand.words.size() == 1 &&
operand.words[0] == oldVariableId) {
for (const auto& member : target.members) {
rebuilt.push_back({SPV_OPERAND_TYPE_ID, {member.variableId}});
}
continue;
}
rebuilt.push_back(operand);
}
interfaceOperands = std::move(rebuilt);
}
entryPoint->SetInOperands(std::move(interfaceOperands));
// Index constants for the copy access chains. Appended after the variables
// above, which is legal: nothing declared before them names them, and the only
// instructions that do are the ones inserted into the function body below.
auto* constMgr = irContext->get_constant_mgr();
std::vector<Uint32> memberIndexConstants;
Uint32 maxMembers = 0;
for (const auto& target : targets) {
maxMembers = std::max(maxMembers, static_cast<Uint32>(target.members.size()));
}
memberIndexConstants.resize(maxMembers, 0);
for (Uint32 index = 0; index < maxMembers; ++index) {
memberIndexConstants[index] = constMgr->GetUIntConstId(index);
}
// Input: seed the shadow once, before any code that reads it. Output: publish
// it at every exit, after all the code that writes it.
auto& entryBlock = *entryFunction->begin();
auto insertPoint = entryBlock.begin();
while (insertPoint != entryBlock.end() && insertPoint->opcode() == spv::Op::OpVariable) {
++insertPoint;
}
if (insertPoint == entryBlock.end()) return Status::SuccessWithoutChange;
for (const auto& target : targets) {
if (target.storageClass != spv::StorageClass::Input) continue;
for (Uint32 memberIndex = 0; memberIndex < target.members.size(); ++memberIndex) {
const auto& member = target.members[memberIndex];
const Uint32 loadedId = irContext->TakeNextId();
const Uint32 memberPointerId = irContext->TakeNextId();
insertPoint = insertPoint.InsertBefore(spvtools::MakeUnique<Instruction>(
irContext, spv::Op::OpLoad, member.typeId, loadedId,
std::initializer_list<Operand>{{SPV_OPERAND_TYPE_ID, {member.variableId}}}));
++insertPoint;
insertPoint = insertPoint.InsertBefore(spvtools::MakeUnique<Instruction>(
irContext, spv::Op::OpAccessChain, member.privatePointerTypeId, memberPointerId,
std::initializer_list<Operand>{
{SPV_OPERAND_TYPE_ID, {target.variable->result_id()}},
{SPV_OPERAND_TYPE_ID, {memberIndexConstants[memberIndex]}}}));
++insertPoint;
insertPoint = insertPoint.InsertBefore(spvtools::MakeUnique<Instruction>(
irContext, spv::Op::OpStore, 0, 0,
std::initializer_list<Operand>{{SPV_OPERAND_TYPE_ID, {memberPointerId}},
{SPV_OPERAND_TYPE_ID, {loadedId}}}));
++insertPoint;
}
}
// EVERY return, not just the last block: a shader with an early `return` would
// otherwise publish nothing on that path.
std::vector<Instruction*> returns;
for (auto& block : *entryFunction) {
Instruction* terminator = block.terminator();
if (terminator != nullptr && terminator->opcode() == spv::Op::OpReturn) {
returns.push_back(terminator);
}
}
for (Instruction* returnInst : returns) {
for (const auto& target : targets) {
if (target.storageClass != spv::StorageClass::Output) continue;
for (Uint32 memberIndex = 0; memberIndex < target.members.size(); ++memberIndex) {
const auto& member = target.members[memberIndex];
const Uint32 memberPointerId = irContext->TakeNextId();
const Uint32 loadedId = irContext->TakeNextId();
returnInst->InsertBefore(spvtools::MakeUnique<Instruction>(
irContext, spv::Op::OpAccessChain, member.privatePointerTypeId,
memberPointerId,
std::initializer_list<Operand>{
{SPV_OPERAND_TYPE_ID, {target.variable->result_id()}},
{SPV_OPERAND_TYPE_ID, {memberIndexConstants[memberIndex]}}}));
returnInst->InsertBefore(spvtools::MakeUnique<Instruction>(
irContext, spv::Op::OpLoad, member.typeId, loadedId,
std::initializer_list<Operand>{{SPV_OPERAND_TYPE_ID, {memberPointerId}}}));
returnInst->InsertBefore(spvtools::MakeUnique<Instruction>(
irContext, spv::Op::OpStore, 0, 0,
std::initializer_list<Operand>{{SPV_OPERAND_TYPE_ID, {member.variableId}},
{SPV_OPERAND_TYPE_ID, {loadedId}}}));
}
}
}
// Retype the derived pointers collected above. Done last, so the pointer types it
// appends land after the variables.
for (Instruction* pointer : pointersToRetype) {
Instruction* resultType = defUseMgr->GetDef(pointer->type_id());
if (resultType == nullptr || resultType->opcode() != spv::Op::OpTypePointer) continue;
if (static_cast<spv::StorageClass>(resultType->GetSingleWordInOperand(0)) ==
spv::StorageClass::Private) {
continue;
}
pointer->SetResultType(typeMgr->FindPointerToType(resultType->GetSingleWordInOperand(1),
spv::StorageClass::Private));
}
if (m_flattenedBlockNames != nullptr) {
for (const auto& target : targets) {
m_flattenedBlockNames->insert(target.blockName);
}
}
irContext->InvalidateAnalysesExceptFor(IRContext::kAnalysisNone);
return Status::SuccessWithChange;
}
spvtools::Optimizer::PassToken FlattenXfbInterfaceBlocksPass::CreateFlattenXfbInterfaceBlocksPass(
const std::set<String>& blockNames, std::set<String>* flattenedBlockNames) {
return spvtools::Optimizer::PassToken(
MakeUnique<FlattenXfbInterfaceBlocksPass>(blockNames, flattenedBlockNames));
}
} // namespace ShaderTranspiler
} // namespace MG_Util
} // namespace MobileGL
@@ -0,0 +1,73 @@
// MobileGL - MobileGL/MG_Util/ShaderTranspiler/SpirvPasses/FlattenXfbInterfaceBlocksPass.h
// Copyright (c) 2025-2026 MobileGL-Dev
// Licensed under the GNU Lesser General Public License v3.0:
// https://www.gnu.org/licenses/gpl-3.0.txt
// https://www.gnu.org/licenses/lgpl-3.0.txt
// SPDX-License-Identifier: LGPL-3.0-only
// End of Source File Header
#pragma once
#include "source/opt/pass.h"
#include "spirv-tools/optimizer.hpp"
#include <Includes.h>
#include <set>
namespace MobileGL {
namespace MG_Util {
namespace ShaderTranspiler {
// Replaces a named interface BLOCK whose members transform feedback captures with
// one free-standing variable per member, named "<BlockName>_<MemberName>", and
// demotes the block itself to a Private shadow that the entry point copies into
// (Input) or out of (Output). The block's own body code is untouched: every
// OpAccessChain into it - dynamically indexed ones included - keeps working
// against the shadow.
//
// WHY. The Adreno ES driver accepts "BlockName.member" in
// glTransformFeedbackVaryings, links, and reports the names straight back from
// glGetTransformFeedbackVarying - and then captures NONE of them: the recorded
// stream holds gl_Position in slot 0 and leaves the rest of every vertex's record
// untouched. Proven on an Adreno 830 by writing a recognisable gl_Position into
// the KHR-GL43.vertex_attrib_binding.basic-input capture program: the value landed
// in the slot that had asked for StageData.attrib[0]. The same program with the
// block flattened into a plain output array captures every member correctly, which
// is what this pass produces. Requesting the members under the ESSL instance-name
// spelling ("vs_out.attrib[0]") instead makes the driver fail the link outright, so
// the capture list cannot be spelled around the defect - only the declaration can.
//
// The rename is deterministic and derived only from names that GLSL interface
// matching already requires both sides of a stage boundary to agree on (block name
// and member names), so running this pass over EVERY stage of a program with the
// same block set keeps a producer and its consumer matched.
//
// DirectGLES only: Vulkan captures by xfb_offset, never by name.
class FlattenXfbInterfaceBlocksPass : public spvtools::opt::Pass {
public:
// `blockNames` are block TYPE names, i.e. the "StageData" of
// "StageData.attrib[0]". `flattenedBlockNames` receives the subset this pass
// actually rewrote, so the caller can rename exactly those capture requests
// and leave the rest spelled as the application wrote them.
FlattenXfbInterfaceBlocksPass(const std::set<String>& blockNames,
std::set<String>* flattenedBlockNames)
: m_blockNames(blockNames), m_flattenedBlockNames(flattenedBlockNames) {}
const char* name() const override { return "mobilegl-flatten-xfb-interface-blocks"; }
Status Process() override;
// The member of `blockName` spelled by a capture request, as this pass names
// it: "StageData.attrib[0]" -> "StageData_attrib[0]". Returns false when the
// name does not address a member of a flattened block.
static Bool RewriteCaptureName(const String& captureName, const std::set<String>& flattenedBlockNames,
String& outName);
static spvtools::Optimizer::PassToken CreateFlattenXfbInterfaceBlocksPass(
const std::set<String>& blockNames, std::set<String>* flattenedBlockNames);
private:
std::set<String> m_blockNames;
std::set<String>* m_flattenedBlockNames = nullptr;
};
} // namespace ShaderTranspiler
} // namespace MG_Util
} // namespace MobileGL