src/gpu/vk/GrVkUniformHandler.cpp - skia - Git at Google


            
            /*

            
            * Copyright 2016 Google Inc.

            
            *

            
            * Use of this source code is governed by a BSD-style license that can be

            
            * found in the LICENSE file.

            
            */


            #include "GrVkUniformHandler.h"

            
            #include "glsl/GrGLSLProgramBuilder.h"


            // To determine whether a current offset is aligned, we can just 'and' the lowest bits with the

            
            // alignment mask. A value of 0 means aligned, any other value is how many bytes past alignment we

            
            // are. This works since all alignments are powers of 2. The mask is always (alignment - 1).

            
            // This alignment mask will give correct alignments for using the std430 block layout. If you want

            
            // the std140 alignment, you can use this, but then make sure if you have an array type it is

            
            // aligned to 16 bytes (i.e. has mask of 0xF).

            
            uint32_t grsltype_to_alignment_mask(GrSLType type) {

            
                SkASSERT(GrSLTypeIsFloatType(type));

            
                static const uint32_t kAlignmentMask[] = {

            
                    0x0, // kVoid_GrSLType, should never return this

            
                    0x3, // kFloat_GrSLType

            
                    0x7, // kVec2f_GrSLType

            
                    0xF, // kVec3f_GrSLType

            
                    0xF, // kVec4f_GrSLType

            
                    0x7, // kMat22f_GrSLType

            
                    0xF, // kMat33f_GrSLType

            
                    0xF, // kMat44f_GrSLType

            
                    0x0, // Sampler2D_GrSLType, should never return this

            
                    0x0, // SamplerExternal_GrSLType, should never return this

            
                    0x0, // Sampler2DRect_GrSLType, should never return this

            
                    0x0, // SamplerBuffer_GrSLType, should never return this

            
                    0x0, // kBool_GrSLType

            
                    0x7, // kInt_GrSLType

            
                    0x7, // kUint_GrSLType

            
                    0x0, // Texture2D_GrSLType, should never return this

            
                    0x0, // Sampler_GrSLType, should never return this

            
                };

            
                GR_STATIC_ASSERT(0 == kVoid_GrSLType);

            
                GR_STATIC_ASSERT(1 == kFloat_GrSLType);

            
                GR_STATIC_ASSERT(2 == kVec2f_GrSLType);

            
                GR_STATIC_ASSERT(3 == kVec3f_GrSLType);

            
                GR_STATIC_ASSERT(4 == kVec4f_GrSLType);

            
                GR_STATIC_ASSERT(5 == kMat22f_GrSLType);

            
                GR_STATIC_ASSERT(6 == kMat33f_GrSLType);

            
                GR_STATIC_ASSERT(7 == kMat44f_GrSLType);

            
                GR_STATIC_ASSERT(8 == kTexture2DSampler_GrSLType);

            
                GR_STATIC_ASSERT(9 == kTextureExternalSampler_GrSLType);

            
                GR_STATIC_ASSERT(10 == kTexture2DRectSampler_GrSLType);

            
                GR_STATIC_ASSERT(11 == kTextureBufferSampler_GrSLType);

            
                GR_STATIC_ASSERT(12 == kBool_GrSLType);

            
                GR_STATIC_ASSERT(13 == kInt_GrSLType);

            
                GR_STATIC_ASSERT(14 == kUint_GrSLType);

            
                GR_STATIC_ASSERT(15 == kTexture2D_GrSLType);

            
                GR_STATIC_ASSERT(16 == kSampler_GrSLType);

            
                GR_STATIC_ASSERT(SK_ARRAY_COUNT(kAlignmentMask) == kGrSLTypeCount);

            
                return kAlignmentMask[type];

            
            }


            /** Returns the size in bytes taken up in vulkanbuffers for floating point GrSLTypes.

            
                For non floating point type returns 0. Currently this reflects the std140 alignment

            
                so a mat22 takes up 8 floats. */

            
            static inline uint32_t grsltype_to_vk_size(GrSLType type) {

            
                SkASSERT(GrSLTypeIsFloatType(type));

            
                static const uint32_t kSizes[] = {

            
                    0,                        // kVoid_GrSLType

            
                    sizeof(float),            // kFloat_GrSLType

            
                    2 * sizeof(float),        // kVec2f_GrSLType

            
                    3 * sizeof(float),        // kVec3f_GrSLType

            
                    4 * sizeof(float),        // kVec4f_GrSLType

            
                    8 * sizeof(float),        // kMat22f_GrSLType. TODO: this will be 4 * szof(float) on std430.

            
                    12 * sizeof(float),       // kMat33f_GrSLType

            
                    16 * sizeof(float),       // kMat44f_GrSLType

            
                    0,                        // kTexture2DSampler_GrSLType

            
                    0,                        // kTextureExternalSampler_GrSLType

            
                    0,                        // kTexture2DRectSampler_GrSLType

            
                    0,                        // kTextureBufferSampler_GrSLType

            
                    1,                        // kBool_GrSLType

            
                    4,                        // kInt_GrSLType

            
                    4,                        // kUint_GrSLType

            
                    0,                        // kTexture2D_GrSLType

            
                    0,                        // kSampler_GrSLType

            
                };

            
                return kSizes[type];


                GR_STATIC_ASSERT(0 == kVoid_GrSLType);

            
                GR_STATIC_ASSERT(1 == kFloat_GrSLType);

            
                GR_STATIC_ASSERT(2 == kVec2f_GrSLType);

            
                GR_STATIC_ASSERT(3 == kVec3f_GrSLType);

            
                GR_STATIC_ASSERT(4 == kVec4f_GrSLType);

            
                GR_STATIC_ASSERT(5 == kMat22f_GrSLType);

            
                GR_STATIC_ASSERT(6 == kMat33f_GrSLType);

            
                GR_STATIC_ASSERT(7 == kMat44f_GrSLType);

            
                GR_STATIC_ASSERT(8 == kTexture2DSampler_GrSLType);

            
                GR_STATIC_ASSERT(9 == kTextureExternalSampler_GrSLType);

            
                GR_STATIC_ASSERT(10 == kTexture2DRectSampler_GrSLType);

            
                GR_STATIC_ASSERT(11 == kTextureBufferSampler_GrSLType);

            
                GR_STATIC_ASSERT(12 == kBool_GrSLType);

            
                GR_STATIC_ASSERT(13 == kInt_GrSLType);

            
                GR_STATIC_ASSERT(14 == kUint_GrSLType);

            
                GR_STATIC_ASSERT(15 == kTexture2D_GrSLType);

            
                GR_STATIC_ASSERT(16 == kSampler_GrSLType);

            
                GR_STATIC_ASSERT(SK_ARRAY_COUNT(kSizes) == kGrSLTypeCount);

            
            }


            // Given the current offset into the ubo, calculate the offset for the uniform we're trying to add

            
            // taking into consideration all alignment requirements. The uniformOffset is set to the offset for

            
            // the new uniform, and currentOffset is updated to be the offset to the end of the new uniform.

            
            void get_ubo_aligned_offset(uint32_t* uniformOffset,

            
                                        uint32_t* currentOffset,

            
                                        GrSLType type,

            
                                        int arrayCount) {

            
                uint32_t alignmentMask = grsltype_to_alignment_mask(type);

            
                // We want to use the std140 layout here, so we must make arrays align to 16 bytes.

            
                if (arrayCount || type == kMat22f_GrSLType) {

            
                    alignmentMask = 0xF;

            
                }

            
                uint32_t offsetDiff = *currentOffset & alignmentMask;

            
                if (offsetDiff != 0) {

            
                    offsetDiff = alignmentMask - offsetDiff + 1;

            
                }

            
                *uniformOffset = *currentOffset + offsetDiff;

            
                SkASSERT(sizeof(float) == 4);

            
                if (arrayCount) {

            
                    uint32_t elementSize = SkTMax<uint32_t>(16, grsltype_to_vk_size(type));

            
                    SkASSERT(0 == (elementSize & 0xF));

            
                    *currentOffset = *uniformOffset + elementSize * arrayCount;

            
                } else {

            
                    *currentOffset = *uniformOffset + grsltype_to_vk_size(type);

            
                }

            
            }


            GrGLSLUniformHandler::UniformHandle GrVkUniformHandler::internalAddUniformArray(

            
                                                                                        uint32_t visibility,

            
                                                                                        GrSLType type,

            
                                                                                        GrSLPrecision precision,

            
                                                                                        const char* name,

            
                                                                                        bool mangleName,

            
                                                                                        int arrayCount,

            
                                                                                        const char** outName) {

            
                SkASSERT(name && strlen(name));

            
                SkDEBUGCODE(static const uint32_t kVisibilityMask = kVertex_GrShaderFlag|kFragment_GrShaderFlag);

            
                SkASSERT(0 == (~kVisibilityMask & visibility));

            
                SkASSERT(0 != visibility);

            
                SkASSERT(kDefault_GrSLPrecision == precision || GrSLTypeIsFloatType(type));

            
                GrSLTypeIsFloatType(type);


                UniformInfo& uni = fUniforms.push_back();

            
                uni.fVariable.setType(type);

            
                // TODO this is a bit hacky, lets think of a better way.  Basically we need to be able to use

            
                // the uniform view matrix name in the GP, and the GP is immutable so it has to tell the PB

            
                // exactly what name it wants to use for the uniform view matrix.  If we prefix anythings, then

            
                // the names will mismatch.  I think the correct solution is to have all GPs which need the

            
                // uniform view matrix, they should upload the view matrix in their setData along with regular

            
                // uniforms.

            
                char prefix = 'u';

            
                if ('u' == name[0]) {

            
                    prefix = '\0';

            
                }

            
                fProgramBuilder->nameVariable(uni.fVariable.accessName(), prefix, name, mangleName);

            
                uni.fVariable.setArrayCount(arrayCount);

            
                // For now asserting the the visibility is either only vertex or only fragment

            
                SkASSERT(kVertex_GrShaderFlag == visibility || kFragment_GrShaderFlag == visibility);

            
                uni.fVisibility = visibility;

            
                uni.fVariable.setPrecision(precision);

            
                // When outputing the GLSL, only the outer uniform block will get the Uniform modifier. Thus

            
                // we set the modifier to none for all uniforms declared inside the block.

            
                uni.fVariable.setTypeModifier(GrGLSLShaderVar::kNone_TypeModifier);


                uint32_t* currentOffset = kVertex_GrShaderFlag == visibility ? &fCurrentVertexUBOOffset

            
                                                                               : &fCurrentFragmentUBOOffset;

            
                get_ubo_aligned_offset(&uni.fUBOffset, currentOffset, type, arrayCount);


                if (outName) {

            
                    *outName = uni.fVariable.c_str();

            
                }


                return GrGLSLUniformHandler::UniformHandle(fUniforms.count() - 1);

            
            }


            GrGLSLUniformHandler::SamplerHandle GrVkUniformHandler::internalAddSampler(uint32_t visibility,

            
                                                                                       GrPixelConfig config,

            
                                                                                       GrSLType type,

            
                                                                                       GrSLPrecision precision,

            
                                                                                       const char* name) {

            
                SkASSERT(name && strlen(name));

            
                SkDEBUGCODE(static const uint32_t kVisMask = kVertex_GrShaderFlag | kFragment_GrShaderFlag);

            
                SkASSERT(0 == (~kVisMask & visibility));

            
                SkASSERT(0 != visibility);

            
                SkString mangleName;

            
                char prefix = 'u';

            
                fProgramBuilder->nameVariable(&mangleName, prefix, name, true);

            
                fSamplers.emplace_back(visibility, config, type, precision, mangleName.c_str(),

            
                                       (uint32_t)fSamplers.count(), kSamplerDescSet);

            
                return GrGLSLUniformHandler::SamplerHandle(fSamplers.count() - 1);

            
            }


            void GrVkUniformHandler::appendUniformDecls(GrShaderFlags visibility, SkString* out) const {

            
                SkASSERT(kVertex_GrShaderFlag == visibility || kFragment_GrShaderFlag == visibility);


                for (int i = 0; i < fSamplers.count(); ++i) {

            
                    const GrVkGLSLSampler& sampler = fSamplers[i];

            
                    SkASSERT(sampler.type() == kTexture2DSampler_GrSLType);

            
                    if (visibility == sampler.visibility()) {

            
                        sampler.fShaderVar.appendDecl(fProgramBuilder->glslCaps(), out);

            
                        out->append(";\n");

            
                    }

            
                }


                SkString uniformsString;

            
                for (int i = 0; i < fUniforms.count(); ++i) {

            
                    const UniformInfo& localUniform = fUniforms[i];

            
                    if (visibility == localUniform.fVisibility) {

            
                        if (GrSLTypeIsFloatType(localUniform.fVariable.getType())) {

            
                            localUniform.fVariable.appendDecl(fProgramBuilder->glslCaps(), &uniformsString);

            
                            uniformsString.append(";\n");

            
                        }

            
                    }

            
                }

            
                if (!uniformsString.isEmpty()) {

            
                    uint32_t uniformBinding = (visibility == kVertex_GrShaderFlag) ? kVertexBinding

            
                                                                                   : kFragBinding;

            
                    const char* stage = (visibility == kVertex_GrShaderFlag) ? "vertex" : "fragment";

            
                    out->appendf("layout (set=%d, binding=%d) uniform %sUniformBuffer\n{\n",

            
                                 kUniformBufferDescSet, uniformBinding, stage);

            
                    out->appendf("%s\n};\n", uniformsString.c_str());

            
                }

            
            }
	/*
	* Copyright 2016 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "GrVkUniformHandler.h"
	#include "glsl/GrGLSLProgramBuilder.h"

	// To determine whether a current offset is aligned, we can just 'and' the lowest bits with the
	// alignment mask. A value of 0 means aligned, any other value is how many bytes past alignment we
	// are. This works since all alignments are powers of 2. The mask is always (alignment - 1).
	// This alignment mask will give correct alignments for using the std430 block layout. If you want
	// the std140 alignment, you can use this, but then make sure if you have an array type it is
	// aligned to 16 bytes (i.e. has mask of 0xF).
	uint32_t grsltype_to_alignment_mask(GrSLType type) {
	SkASSERT(GrSLTypeIsFloatType(type));
	static const uint32_t kAlignmentMask[] = {
	0x0, // kVoid_GrSLType, should never return this
	0x3, // kFloat_GrSLType
	0x7, // kVec2f_GrSLType
	0xF, // kVec3f_GrSLType
	0xF, // kVec4f_GrSLType
	0x7, // kMat22f_GrSLType
	0xF, // kMat33f_GrSLType
	0xF, // kMat44f_GrSLType
	0x0, // Sampler2D_GrSLType, should never return this
	0x0, // SamplerExternal_GrSLType, should never return this
	0x0, // Sampler2DRect_GrSLType, should never return this
	0x0, // SamplerBuffer_GrSLType, should never return this
	0x0, // kBool_GrSLType
	0x7, // kInt_GrSLType
	0x7, // kUint_GrSLType
	0x0, // Texture2D_GrSLType, should never return this
	0x0, // Sampler_GrSLType, should never return this
	};
	GR_STATIC_ASSERT(0 == kVoid_GrSLType);
	GR_STATIC_ASSERT(1 == kFloat_GrSLType);
	GR_STATIC_ASSERT(2 == kVec2f_GrSLType);
	GR_STATIC_ASSERT(3 == kVec3f_GrSLType);
	GR_STATIC_ASSERT(4 == kVec4f_GrSLType);
	GR_STATIC_ASSERT(5 == kMat22f_GrSLType);
	GR_STATIC_ASSERT(6 == kMat33f_GrSLType);
	GR_STATIC_ASSERT(7 == kMat44f_GrSLType);
	GR_STATIC_ASSERT(8 == kTexture2DSampler_GrSLType);
	GR_STATIC_ASSERT(9 == kTextureExternalSampler_GrSLType);
	GR_STATIC_ASSERT(10 == kTexture2DRectSampler_GrSLType);
	GR_STATIC_ASSERT(11 == kTextureBufferSampler_GrSLType);
	GR_STATIC_ASSERT(12 == kBool_GrSLType);
	GR_STATIC_ASSERT(13 == kInt_GrSLType);
	GR_STATIC_ASSERT(14 == kUint_GrSLType);
	GR_STATIC_ASSERT(15 == kTexture2D_GrSLType);
	GR_STATIC_ASSERT(16 == kSampler_GrSLType);
	GR_STATIC_ASSERT(SK_ARRAY_COUNT(kAlignmentMask) == kGrSLTypeCount);
	return kAlignmentMask[type];
	}

	/** Returns the size in bytes taken up in vulkanbuffers for floating point GrSLTypes.
	For non floating point type returns 0. Currently this reflects the std140 alignment
	so a mat22 takes up 8 floats. */
	static inline uint32_t grsltype_to_vk_size(GrSLType type) {
	SkASSERT(GrSLTypeIsFloatType(type));
	static const uint32_t kSizes[] = {
	0, // kVoid_GrSLType
	sizeof(float), // kFloat_GrSLType
	2 * sizeof(float), // kVec2f_GrSLType
	3 * sizeof(float), // kVec3f_GrSLType
	4 * sizeof(float), // kVec4f_GrSLType
	8 * sizeof(float), // kMat22f_GrSLType. TODO: this will be 4 * szof(float) on std430.
	12 * sizeof(float), // kMat33f_GrSLType
	16 * sizeof(float), // kMat44f_GrSLType
	0, // kTexture2DSampler_GrSLType
	0, // kTextureExternalSampler_GrSLType
	0, // kTexture2DRectSampler_GrSLType
	0, // kTextureBufferSampler_GrSLType
	1, // kBool_GrSLType
	4, // kInt_GrSLType
	4, // kUint_GrSLType
	0, // kTexture2D_GrSLType
	0, // kSampler_GrSLType
	};
	return kSizes[type];

	GR_STATIC_ASSERT(0 == kVoid_GrSLType);
	GR_STATIC_ASSERT(1 == kFloat_GrSLType);
	GR_STATIC_ASSERT(2 == kVec2f_GrSLType);
	GR_STATIC_ASSERT(3 == kVec3f_GrSLType);
	GR_STATIC_ASSERT(4 == kVec4f_GrSLType);
	GR_STATIC_ASSERT(5 == kMat22f_GrSLType);
	GR_STATIC_ASSERT(6 == kMat33f_GrSLType);
	GR_STATIC_ASSERT(7 == kMat44f_GrSLType);
	GR_STATIC_ASSERT(8 == kTexture2DSampler_GrSLType);
	GR_STATIC_ASSERT(9 == kTextureExternalSampler_GrSLType);
	GR_STATIC_ASSERT(10 == kTexture2DRectSampler_GrSLType);
	GR_STATIC_ASSERT(11 == kTextureBufferSampler_GrSLType);
	GR_STATIC_ASSERT(12 == kBool_GrSLType);
	GR_STATIC_ASSERT(13 == kInt_GrSLType);
	GR_STATIC_ASSERT(14 == kUint_GrSLType);
	GR_STATIC_ASSERT(15 == kTexture2D_GrSLType);
	GR_STATIC_ASSERT(16 == kSampler_GrSLType);
	GR_STATIC_ASSERT(SK_ARRAY_COUNT(kSizes) == kGrSLTypeCount);
	}


	// Given the current offset into the ubo, calculate the offset for the uniform we're trying to add
	// taking into consideration all alignment requirements. The uniformOffset is set to the offset for
	// the new uniform, and currentOffset is updated to be the offset to the end of the new uniform.
	void get_ubo_aligned_offset(uint32_t* uniformOffset,
	uint32_t* currentOffset,
	GrSLType type,
	int arrayCount) {
	uint32_t alignmentMask = grsltype_to_alignment_mask(type);
	// We want to use the std140 layout here, so we must make arrays align to 16 bytes.
	if (arrayCount \|\| type == kMat22f_GrSLType) {
	alignmentMask = 0xF;
	}
	uint32_t offsetDiff = *currentOffset & alignmentMask;
	if (offsetDiff != 0) {
	offsetDiff = alignmentMask - offsetDiff + 1;
	}
	uniformOffset = currentOffset + offsetDiff;
	SkASSERT(sizeof(float) == 4);
	if (arrayCount) {
	uint32_t elementSize = SkTMax<uint32_t>(16, grsltype_to_vk_size(type));
	SkASSERT(0 == (elementSize & 0xF));
	currentOffset = uniformOffset + elementSize * arrayCount;
	} else {
	currentOffset = uniformOffset + grsltype_to_vk_size(type);
	}
	}

	GrGLSLUniformHandler::UniformHandle GrVkUniformHandler::internalAddUniformArray(
	uint32_t visibility,
	GrSLType type,
	GrSLPrecision precision,
	const char* name,
	bool mangleName,
	int arrayCount,
	const char** outName) {
	SkASSERT(name && strlen(name));
	SkDEBUGCODE(static const uint32_t kVisibilityMask = kVertex_GrShaderFlag\|kFragment_GrShaderFlag);
	SkASSERT(0 == (~kVisibilityMask & visibility));
	SkASSERT(0 != visibility);
	SkASSERT(kDefault_GrSLPrecision == precision \|\| GrSLTypeIsFloatType(type));
	GrSLTypeIsFloatType(type);

	UniformInfo& uni = fUniforms.push_back();
	uni.fVariable.setType(type);
	// TODO this is a bit hacky, lets think of a better way. Basically we need to be able to use
	// the uniform view matrix name in the GP, and the GP is immutable so it has to tell the PB
	// exactly what name it wants to use for the uniform view matrix. If we prefix anythings, then
	// the names will mismatch. I think the correct solution is to have all GPs which need the
	// uniform view matrix, they should upload the view matrix in their setData along with regular
	// uniforms.
	char prefix = 'u';
	if ('u' == name[0]) {
	prefix = '\0';
	}
	fProgramBuilder->nameVariable(uni.fVariable.accessName(), prefix, name, mangleName);
	uni.fVariable.setArrayCount(arrayCount);
	// For now asserting the the visibility is either only vertex or only fragment
	SkASSERT(kVertex_GrShaderFlag == visibility \|\| kFragment_GrShaderFlag == visibility);
	uni.fVisibility = visibility;
	uni.fVariable.setPrecision(precision);
	// When outputing the GLSL, only the outer uniform block will get the Uniform modifier. Thus
	// we set the modifier to none for all uniforms declared inside the block.
	uni.fVariable.setTypeModifier(GrGLSLShaderVar::kNone_TypeModifier);

	uint32_t* currentOffset = kVertex_GrShaderFlag == visibility ? &fCurrentVertexUBOOffset
	: &fCurrentFragmentUBOOffset;
	get_ubo_aligned_offset(&uni.fUBOffset, currentOffset, type, arrayCount);

	if (outName) {
	*outName = uni.fVariable.c_str();
	}

	return GrGLSLUniformHandler::UniformHandle(fUniforms.count() - 1);
	}

	GrGLSLUniformHandler::SamplerHandle GrVkUniformHandler::internalAddSampler(uint32_t visibility,
	GrPixelConfig config,
	GrSLType type,
	GrSLPrecision precision,
	const char* name) {
	SkASSERT(name && strlen(name));
	SkDEBUGCODE(static const uint32_t kVisMask = kVertex_GrShaderFlag \| kFragment_GrShaderFlag);
	SkASSERT(0 == (~kVisMask & visibility));
	SkASSERT(0 != visibility);
	SkString mangleName;
	char prefix = 'u';
	fProgramBuilder->nameVariable(&mangleName, prefix, name, true);
	fSamplers.emplace_back(visibility, config, type, precision, mangleName.c_str(),
	(uint32_t)fSamplers.count(), kSamplerDescSet);
	return GrGLSLUniformHandler::SamplerHandle(fSamplers.count() - 1);
	}

	void GrVkUniformHandler::appendUniformDecls(GrShaderFlags visibility, SkString* out) const {
	SkASSERT(kVertex_GrShaderFlag == visibility \|\| kFragment_GrShaderFlag == visibility);

	for (int i = 0; i < fSamplers.count(); ++i) {
	const GrVkGLSLSampler& sampler = fSamplers[i];
	SkASSERT(sampler.type() == kTexture2DSampler_GrSLType);
	if (visibility == sampler.visibility()) {
	sampler.fShaderVar.appendDecl(fProgramBuilder->glslCaps(), out);
	out->append(";\n");
	}
	}

	SkString uniformsString;
	for (int i = 0; i < fUniforms.count(); ++i) {
	const UniformInfo& localUniform = fUniforms[i];
	if (visibility == localUniform.fVisibility) {
	if (GrSLTypeIsFloatType(localUniform.fVariable.getType())) {
	localUniform.fVariable.appendDecl(fProgramBuilder->glslCaps(), &uniformsString);
	uniformsString.append(";\n");
	}
	}
	}
	if (!uniformsString.isEmpty()) {
	uint32_t uniformBinding = (visibility == kVertex_GrShaderFlag) ? kVertexBinding
	: kFragBinding;
	const char* stage = (visibility == kVertex_GrShaderFlag) ? "vertex" : "fragment";
	out->appendf("layout (set=%d, binding=%d) uniform %sUniformBuffer\n{\n",
	kUniformBufferDescSet, uniformBinding, stage);
	out->appendf("%s\n};\n", uniformsString.c_str());
	}
	}