1 /*------------------------------------------------------------------------
2 * OpenGL Conformance Tests
3 * ------------------------
4 *
5 * Copyright (c) 2017-2019 The Khronos Group Inc.
6 * Copyright (c) 2017 Codeplay Software Ltd.
7 * Copyright (c) 2019 NVIDIA Corporation.
8 *
9 * Licensed under the Apache License, Version 2.0 (the "License");
10 * you may not use this file except in compliance with the License.
11 * You may obtain a copy of the License at
12 *
13 * http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS,
17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
20 *
21 */ /*!
22 * \file
23 * \brief Subgroups Tests
24 */ /*--------------------------------------------------------------------*/
25
26 #include "glcSubgroupsShapeTests.hpp"
27 #include "glcSubgroupsTestsUtils.hpp"
28
29 #include <string>
30 #include <vector>
31
32 using namespace tcu;
33 using namespace std;
34
35 namespace glc
36 {
37 namespace subgroups
38 {
39 namespace
40 {
checkVertexPipelineStages(std::vector<const void * > datas,deUint32 width,deUint32)41 static bool checkVertexPipelineStages(std::vector<const void*> datas,
42 deUint32 width, deUint32)
43 {
44 return glc::subgroups::check(datas, width, 1);
45 }
46
checkComputeStage(std::vector<const void * > datas,const deUint32 numWorkgroups[3],const deUint32 localSize[3],deUint32)47 static bool checkComputeStage(std::vector<const void*> datas,
48 const deUint32 numWorkgroups[3], const deUint32 localSize[3],
49 deUint32)
50 {
51 return glc::subgroups::checkCompute(datas, numWorkgroups, localSize, 1);
52 }
53
54 enum OpType
55 {
56 OPTYPE_CLUSTERED = 0,
57 OPTYPE_QUAD,
58 OPTYPE_LAST
59 };
60
getOpTypeName(int opType)61 std::string getOpTypeName(int opType)
62 {
63 switch (opType)
64 {
65 default:
66 DE_FATAL("Unsupported op type");
67 return "";
68 case OPTYPE_CLUSTERED:
69 return "clustered";
70 case OPTYPE_QUAD:
71 return "quad";
72 }
73 }
74
75 struct CaseDefinition
76 {
77 int opType;
78 ShaderStageFlags shaderStage;
79 };
80
initFrameBufferPrograms(SourceCollections & programCollection,CaseDefinition caseDef)81 void initFrameBufferPrograms (SourceCollections& programCollection, CaseDefinition caseDef)
82 {
83 std::ostringstream bdy;
84 std::string extension = (OPTYPE_CLUSTERED == caseDef.opType) ?
85 "#extension GL_KHR_shader_subgroup_clustered: enable\n" :
86 "#extension GL_KHR_shader_subgroup_quad: enable\n";
87
88 subgroups::setFragmentShaderFrameBuffer(programCollection);
89
90 if (SHADER_STAGE_VERTEX_BIT != caseDef.shaderStage)
91 subgroups::setVertexShaderFrameBuffer(programCollection);
92
93 extension += "#extension GL_KHR_shader_subgroup_ballot: enable\n";
94
95 bdy << " uint tempResult = 0x1u;\n"
96 << " uvec4 mask = subgroupBallot(true);\n";
97
98 if (OPTYPE_CLUSTERED == caseDef.opType)
99 {
100 for (deUint32 i = 1; i <= subgroups::maxSupportedSubgroupSize(); i *= 2)
101 {
102 bdy << " if (gl_SubgroupSize >= " << i << "u)\n"
103 << " {\n"
104 << " uvec4 contribution = uvec4(0);\n"
105 << " uint modID = gl_SubgroupInvocationID % 32u;\n"
106 << " switch (gl_SubgroupInvocationID / 32u)\n"
107 << " {\n"
108 << " case 0u: contribution.x = 1u << modID; break;\n"
109 << " case 1u: contribution.y = 1u << modID; break;\n"
110 << " case 2u: contribution.z = 1u << modID; break;\n"
111 << " case 3u: contribution.w = 1u << modID; break;\n"
112 << " }\n"
113 << " uvec4 result = subgroupClusteredOr(contribution, " << i << "u);\n"
114 << " uint rootID = gl_SubgroupInvocationID & ~(" << i - 1 << "u);\n"
115 << " for (uint i = 0u; i < " << i << "u; i++)\n"
116 << " {\n"
117 << " uint nextID = rootID + i;\n"
118 << " if (subgroupBallotBitExtract(mask, nextID) ^^ subgroupBallotBitExtract(result, nextID))\n"
119 << " {\n"
120 << " tempResult = 0u;\n"
121 << " }\n"
122 << " }\n"
123 << " }\n";
124 }
125 }
126 else
127 {
128 bdy << " uint cluster[4] =\n"
129 << " uint[](\n"
130 << " subgroupQuadBroadcast(gl_SubgroupInvocationID, 0u),\n"
131 << " subgroupQuadBroadcast(gl_SubgroupInvocationID, 1u),\n"
132 << " subgroupQuadBroadcast(gl_SubgroupInvocationID, 2u),\n"
133 << " subgroupQuadBroadcast(gl_SubgroupInvocationID, 3u)\n"
134 << " );\n"
135 << " uint rootID = gl_SubgroupInvocationID & ~0x3u;\n"
136 << " for (uint i = 0u; i < 4u; i++)\n"
137 << " {\n"
138 << " uint nextID = rootID + i;\n"
139 << " if (subgroupBallotBitExtract(mask, nextID) && (cluster[i] != nextID))\n"
140 << " {\n"
141 << " tempResult = mask.x;\n"
142 << " }\n"
143 << " }\n";
144 }
145
146 if (SHADER_STAGE_VERTEX_BIT == caseDef.shaderStage)
147 {
148 std::ostringstream vertexSrc;
149 vertexSrc << "${VERSION_DECL}\n"
150 << extension
151 << "layout(location = 0) in highp vec4 in_position;\n"
152 << "layout(location = 0) out float result;\n"
153 << "\n"
154 << "void main (void)\n"
155 << "{\n"
156 << bdy.str()
157 << " result = float(tempResult);\n"
158 << " gl_Position = in_position;\n"
159 << " gl_PointSize = 1.0f;\n"
160 << "}\n";
161 programCollection.add("vert") << glu::VertexSource(vertexSrc.str());
162 }
163 else if (SHADER_STAGE_GEOMETRY_BIT == caseDef.shaderStage)
164 {
165 std::ostringstream geometry;
166
167 geometry << "${VERSION_DECL}\n"
168 << extension
169 << "layout(points) in;\n"
170 << "layout(points, max_vertices = 1) out;\n"
171 << "layout(location = 0) out float out_color;\n"
172 << "\n"
173 << "void main (void)\n"
174 << "{\n"
175 << bdy.str()
176 << " out_color = float(tempResult);\n"
177 << " gl_Position = gl_in[0].gl_Position;\n"
178 << " EmitVertex();\n"
179 << " EndPrimitive();\n"
180 << "}\n";
181
182 programCollection.add("geometry") << glu::GeometrySource(geometry.str());
183 }
184 else if (SHADER_STAGE_TESS_CONTROL_BIT == caseDef.shaderStage)
185 {
186 std::ostringstream controlSource;
187
188 controlSource << "${VERSION_DECL}\n"
189 << extension
190 << "layout(vertices = 2) out;\n"
191 << "layout(location = 0) out float out_color[];\n"
192 << "\n"
193 << "void main (void)\n"
194 << "{\n"
195 << " if (gl_InvocationID == 0)\n"
196 <<" {\n"
197 << " gl_TessLevelOuter[0] = 1.0f;\n"
198 << " gl_TessLevelOuter[1] = 1.0f;\n"
199 << " }\n"
200 << bdy.str()
201 << " out_color[gl_InvocationID] = float(tempResult);\n"
202 << " gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position;\n"
203 << "}\n";
204
205 programCollection.add("tesc") << glu::TessellationControlSource(controlSource.str());
206 subgroups::setTesEvalShaderFrameBuffer(programCollection);
207 }
208 else if (SHADER_STAGE_TESS_EVALUATION_BIT == caseDef.shaderStage)
209 {
210 std::ostringstream evaluationSource;
211
212 evaluationSource << "${VERSION_DECL}\n"
213 << extension
214 << "layout(isolines, equal_spacing, ccw) in;\n"
215 << "layout(location = 0) out float out_color;\n"
216 << "void main (void)\n"
217 << "{\n"
218 << bdy.str()
219 << " out_color = float(tempResult);\n"
220 << " gl_Position = mix(gl_in[0].gl_Position, gl_in[1].gl_Position, gl_TessCoord.x);\n"
221 << "}\n";
222
223 subgroups::setTesCtrlShaderFrameBuffer(programCollection);
224 programCollection.add("tese") << glu::TessellationEvaluationSource(evaluationSource.str());
225 }
226 else
227 {
228 DE_FATAL("Unsupported shader stage");
229 }
230 }
231
initPrograms(SourceCollections & programCollection,CaseDefinition caseDef)232 void initPrograms(SourceCollections& programCollection, CaseDefinition caseDef)
233 {
234 std::string extension = (OPTYPE_CLUSTERED == caseDef.opType) ?
235 "#extension GL_KHR_shader_subgroup_clustered: enable\n" :
236 "#extension GL_KHR_shader_subgroup_quad: enable\n";
237
238 extension += "#extension GL_KHR_shader_subgroup_ballot: enable\n";
239
240 std::ostringstream bdy;
241
242 bdy << " uint tempResult = 0x1u;\n"
243 << " uvec4 mask = subgroupBallot(true);\n";
244
245 if (OPTYPE_CLUSTERED == caseDef.opType)
246 {
247 for (deUint32 i = 1; i <= subgroups::maxSupportedSubgroupSize(); i *= 2)
248 {
249 bdy << " if (gl_SubgroupSize >= " << i << "u)\n"
250 << " {\n"
251 << " uvec4 contribution = uvec4(0);\n"
252 << " uint modID = gl_SubgroupInvocationID % 32u;\n"
253 << " switch (gl_SubgroupInvocationID / 32u)\n"
254 << " {\n"
255 << " case 0u: contribution.x = 1u << modID; break;\n"
256 << " case 1u: contribution.y = 1u << modID; break;\n"
257 << " case 2u: contribution.z = 1u << modID; break;\n"
258 << " case 3u: contribution.w = 1u << modID; break;\n"
259 << " }\n"
260 << " uvec4 result = subgroupClusteredOr(contribution, " << i << "u);\n"
261 << " uint rootID = gl_SubgroupInvocationID & ~(" << i - 1 << "u);\n"
262 << " for (uint i = 0u; i < " << i << "u; i++)\n"
263 << " {\n"
264 << " uint nextID = rootID + i;\n"
265 << " if (subgroupBallotBitExtract(mask, nextID) ^^ subgroupBallotBitExtract(result, nextID))\n"
266 << " {\n"
267 << " tempResult = 0u;\n"
268 << " }\n"
269 << " }\n"
270 << " }\n";
271 }
272 }
273 else
274 {
275 bdy << " uint cluster[4] =\n"
276 << " uint[](\n"
277 << " subgroupQuadBroadcast(gl_SubgroupInvocationID, 0u),\n"
278 << " subgroupQuadBroadcast(gl_SubgroupInvocationID, 1u),\n"
279 << " subgroupQuadBroadcast(gl_SubgroupInvocationID, 2u),\n"
280 << " subgroupQuadBroadcast(gl_SubgroupInvocationID, 3u)\n"
281 << " );\n"
282 << " uint rootID = gl_SubgroupInvocationID & ~0x3u;\n"
283 << " for (uint i = 0u; i < 4u; i++)\n"
284 << " {\n"
285 << " uint nextID = rootID + i;\n"
286 << " if (subgroupBallotBitExtract(mask, nextID) && (cluster[i] != nextID))\n"
287 << " {\n"
288 << " tempResult = mask.x;\n"
289 << " }\n"
290 << " }\n";
291 }
292
293 if (SHADER_STAGE_COMPUTE_BIT == caseDef.shaderStage)
294 {
295 std::ostringstream src;
296
297 src << "${VERSION_DECL}\n"
298 << extension
299 << "layout (${LOCAL_SIZE_X}, ${LOCAL_SIZE_Y}, ${LOCAL_SIZE_Z}) in;\n"
300 << "layout(binding = 0, std430) buffer Buffer0\n"
301 << "{\n"
302 << " uint result[];\n"
303 << "};\n"
304 << "\n"
305 << "void main (void)\n"
306 << "{\n"
307 << " uvec3 globalSize = gl_NumWorkGroups * gl_WorkGroupSize;\n"
308 << " highp uint offset = globalSize.x * ((globalSize.y * "
309 "gl_GlobalInvocationID.z) + gl_GlobalInvocationID.y) + "
310 "gl_GlobalInvocationID.x;\n"
311 << bdy.str()
312 << " result[offset] = tempResult;\n"
313 << "}\n";
314
315 programCollection.add("comp") << glu::ComputeSource(src.str());
316 }
317 else
318 {
319 {
320 const string vertex =
321 "${VERSION_DECL}\n"
322 + extension +
323 "layout(binding = 0, std430) buffer Buffer0\n"
324 "{\n"
325 " uint result[];\n"
326 "} b0;\n"
327 "\n"
328 "void main (void)\n"
329 "{\n"
330 + bdy.str() +
331 " b0.result[gl_VertexID] = tempResult;\n"
332 " float pixelSize = 2.0f/1024.0f;\n"
333 " float pixelPosition = pixelSize/2.0f - 1.0f;\n"
334 " gl_Position = vec4(float(gl_VertexID) * pixelSize + pixelPosition, 0.0f, 0.0f, 1.0f);\n"
335 "}\n";
336
337 programCollection.add("vert") << glu::VertexSource(vertex);
338 }
339
340 {
341 const string tesc =
342 "${VERSION_DECL}\n"
343 + extension +
344 "layout(vertices=1) out;\n"
345 "layout(binding = 1, std430) buffer Buffer1\n"
346 "{\n"
347 " uint result[];\n"
348 "} b1;\n"
349 "\n"
350 "void main (void)\n"
351 "{\n"
352 + bdy.str() +
353 " b1.result[gl_PrimitiveID] = 1u;\n"
354 " if (gl_InvocationID == 0)\n"
355 " {\n"
356 " gl_TessLevelOuter[0] = 1.0f;\n"
357 " gl_TessLevelOuter[1] = 1.0f;\n"
358 " }\n"
359 " gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position;\n"
360 "}\n";
361
362 programCollection.add("tesc") << glu::TessellationControlSource(tesc);
363 }
364
365 {
366 const string tese =
367 "${VERSION_DECL}\n"
368 + extension +
369 "layout(isolines) in;\n"
370 "layout(binding = 2, std430) buffer Buffer2\n"
371 "{\n"
372 " uint result[];\n"
373 "} b2;\n"
374 "\n"
375 "void main (void)\n"
376 "{\n"
377 + bdy.str() +
378 " b2.result[gl_PrimitiveID * 2 + int(gl_TessCoord.x + 0.5)] = 1u;\n"
379 " float pixelSize = 2.0f/1024.0f;\n"
380 " gl_Position = gl_in[0].gl_Position + gl_TessCoord.x * pixelSize / 2.0f;\n"
381 "}\n";
382
383 programCollection.add("tese") << glu::TessellationEvaluationSource(tese);
384 }
385
386 {
387 const string geometry =
388 // version added by addGeometryShadersFromTemplate
389 extension +
390 "layout(${TOPOLOGY}) in;\n"
391 "layout(points, max_vertices = 1) out;\n"
392 "layout(binding = 3, std430) buffer Buffer3\n"
393 "{\n"
394 " uint result[];\n"
395 "} b3;\n"
396 "\n"
397 "void main (void)\n"
398 "{\n"
399 + bdy.str() +
400 " b3.result[gl_PrimitiveIDIn] = tempResult;\n"
401 " gl_Position = gl_in[0].gl_Position;\n"
402 " EmitVertex();\n"
403 " EndPrimitive();\n"
404 "}\n";
405
406 subgroups::addGeometryShadersFromTemplate(geometry, programCollection);
407 }
408
409 {
410 const string fragment =
411 "${VERSION_DECL}\n"
412 + extension +
413 "precision highp int;\n"
414 "layout(location = 0) out uint result;\n"
415 "void main (void)\n"
416 "{\n"
417 + bdy.str() +
418 " result = tempResult;\n"
419 "}\n";
420
421 programCollection.add("fragment") << glu::FragmentSource(fragment);
422 }
423 subgroups::addNoSubgroupShader(programCollection);
424 }
425 }
426
supportedCheck(Context & context,CaseDefinition caseDef)427 void supportedCheck (Context& context, CaseDefinition caseDef)
428 {
429 if (!subgroups::isSubgroupSupported(context))
430 TCU_THROW(NotSupportedError, "Subgroup operations are not supported");
431
432 if (!subgroups::isSubgroupFeatureSupportedForDevice(context, SUBGROUP_FEATURE_BALLOT_BIT))
433 {
434 TCU_THROW(NotSupportedError, "Device does not support subgroup ballot operations");
435 }
436
437 if (OPTYPE_CLUSTERED == caseDef.opType)
438 {
439 if (!subgroups::isSubgroupFeatureSupportedForDevice(context, SUBGROUP_FEATURE_CLUSTERED_BIT))
440 {
441 TCU_THROW(NotSupportedError, "Subgroup shape tests require that clustered operations are supported!");
442 }
443 }
444
445 if (OPTYPE_QUAD == caseDef.opType)
446 {
447 if (!subgroups::isSubgroupFeatureSupportedForDevice(context, SUBGROUP_FEATURE_QUAD_BIT))
448 {
449 TCU_THROW(NotSupportedError, "Subgroup shape tests require that quad operations are supported!");
450 }
451 }
452 }
453
noSSBOtest(Context & context,const CaseDefinition caseDef)454 tcu::TestStatus noSSBOtest (Context& context, const CaseDefinition caseDef)
455 {
456 if (!subgroups::areSubgroupOperationsSupportedForStage(
457 context, caseDef.shaderStage))
458 {
459 if (subgroups::areSubgroupOperationsRequiredForStage(
460 caseDef.shaderStage))
461 {
462 return tcu::TestStatus::fail(
463 "Shader stage " +
464 subgroups::getShaderStageName(caseDef.shaderStage) +
465 " is required to support subgroup operations!");
466 }
467 else
468 {
469 TCU_THROW(NotSupportedError, "Device does not support subgroup operations for this stage");
470 }
471 }
472
473 if (SHADER_STAGE_VERTEX_BIT == caseDef.shaderStage)
474 return subgroups::makeVertexFrameBufferTest(context, FORMAT_R32_UINT, DE_NULL, 0, checkVertexPipelineStages);
475 else if (SHADER_STAGE_GEOMETRY_BIT == caseDef.shaderStage)
476 return subgroups::makeGeometryFrameBufferTest(context, FORMAT_R32_UINT, DE_NULL, 0, checkVertexPipelineStages);
477 else if (SHADER_STAGE_TESS_CONTROL_BIT == caseDef.shaderStage)
478 return subgroups::makeTessellationEvaluationFrameBufferTest(context, FORMAT_R32_UINT, DE_NULL, 0, checkVertexPipelineStages, SHADER_STAGE_TESS_CONTROL_BIT);
479 else if (SHADER_STAGE_TESS_EVALUATION_BIT == caseDef.shaderStage)
480 return subgroups::makeTessellationEvaluationFrameBufferTest(context, FORMAT_R32_UINT, DE_NULL, 0, checkVertexPipelineStages, SHADER_STAGE_TESS_EVALUATION_BIT);
481 else
482 TCU_THROW(InternalError, "Unhandled shader stage");
483 }
484
485
test(Context & context,const CaseDefinition caseDef)486 tcu::TestStatus test(Context& context, const CaseDefinition caseDef)
487 {
488 if (!subgroups::isSubgroupFeatureSupportedForDevice(context, SUBGROUP_FEATURE_BASIC_BIT))
489 {
490 return tcu::TestStatus::fail(
491 "Subgroup feature " +
492 subgroups::getSubgroupFeatureName(SUBGROUP_FEATURE_BASIC_BIT) +
493 " is a required capability!");
494 }
495
496 if (SHADER_STAGE_COMPUTE_BIT == caseDef.shaderStage)
497 {
498 if (!subgroups::areSubgroupOperationsSupportedForStage(context, caseDef.shaderStage))
499 {
500 return tcu::TestStatus::fail(
501 "Shader stage " +
502 subgroups::getShaderStageName(caseDef.shaderStage) +
503 " is required to support subgroup operations!");
504 }
505 return subgroups::makeComputeTest(context, FORMAT_R32_UINT, DE_NULL, 0, checkComputeStage);
506 }
507 else
508 {
509 int supportedStages = context.getDeqpContext().getContextInfo().getInt(GL_SUBGROUP_SUPPORTED_STAGES_KHR);
510
511 ShaderStageFlags stages = (ShaderStageFlags)(caseDef.shaderStage & supportedStages);
512
513 if (SHADER_STAGE_FRAGMENT_BIT != stages && !subgroups::isVertexSSBOSupportedForDevice(context))
514 {
515 if ( (stages & SHADER_STAGE_FRAGMENT_BIT) == 0)
516 TCU_THROW(NotSupportedError, "Device does not support vertex stage SSBO writes");
517 else
518 stages = SHADER_STAGE_FRAGMENT_BIT;
519 }
520
521 if ((ShaderStageFlags)0u == stages)
522 TCU_THROW(NotSupportedError, "Subgroup operations are not supported for any graphic shader");
523
524 return subgroups::allStages(context, FORMAT_R32_UINT, DE_NULL, 0, checkVertexPipelineStages, stages);
525 }
526 }
527 }
528
createSubgroupsShapeTests(deqp::Context & testCtx)529 deqp::TestCaseGroup* createSubgroupsShapeTests(deqp::Context& testCtx)
530 {
531 de::MovePtr<deqp::TestCaseGroup> graphicGroup(new deqp::TestCaseGroup(
532 testCtx, "graphics", "Subgroup shape category tests: graphics"));
533 de::MovePtr<deqp::TestCaseGroup> computeGroup(new deqp::TestCaseGroup(
534 testCtx, "compute", "Subgroup shape category tests: compute"));
535 de::MovePtr<deqp::TestCaseGroup> framebufferGroup(new deqp::TestCaseGroup(
536 testCtx, "framebuffer", "Subgroup shape category tests: framebuffer"));
537
538 const ShaderStageFlags stages[] =
539 {
540 SHADER_STAGE_VERTEX_BIT,
541 SHADER_STAGE_TESS_EVALUATION_BIT,
542 SHADER_STAGE_TESS_CONTROL_BIT,
543 SHADER_STAGE_GEOMETRY_BIT,
544 };
545
546 for (int opTypeIndex = 0; opTypeIndex < OPTYPE_LAST; ++opTypeIndex)
547 {
548 const std::string op = de::toLower(getOpTypeName(opTypeIndex));
549
550 {
551 const CaseDefinition caseDef = {opTypeIndex, SHADER_STAGE_COMPUTE_BIT};
552 SubgroupFactory<CaseDefinition>::addFunctionCaseWithPrograms(computeGroup.get(), op, "", supportedCheck, initPrograms, test, caseDef);
553
554 }
555
556 {
557 const CaseDefinition caseDef =
558 {
559 opTypeIndex,
560 SHADER_STAGE_ALL_GRAPHICS
561 };
562 SubgroupFactory<CaseDefinition>::addFunctionCaseWithPrograms(graphicGroup.get(),
563 op, "",
564 supportedCheck, initPrograms, test, caseDef);
565 }
566
567 for (int stageIndex = 0; stageIndex < DE_LENGTH_OF_ARRAY(stages); ++stageIndex)
568 {
569 const CaseDefinition caseDef = {opTypeIndex, stages[stageIndex]};
570 SubgroupFactory<CaseDefinition>::addFunctionCaseWithPrograms(framebufferGroup.get(),op + "_" + getShaderStageName(caseDef.shaderStage), "",
571 supportedCheck, initFrameBufferPrograms, noSSBOtest, caseDef);
572 }
573 }
574
575 de::MovePtr<deqp::TestCaseGroup> group(new deqp::TestCaseGroup(
576 testCtx, "shape", "Subgroup shape category tests"));
577
578 group->addChild(graphicGroup.release());
579 group->addChild(computeGroup.release());
580 group->addChild(framebufferGroup.release());
581
582 return group.release();
583 }
584
585 } // subgroups
586 } // glc
587