src/dawn_native/CopyTextureForBrowserHelper.cpp - dawn - Git at Google

 // Copyright 2020 The Dawn Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 #include "dawn_native/CopyTextureForBrowserHelper.h"

 #include "dawn_native/BindGroup.h"
 #include "dawn_native/BindGroupLayout.h"
 #include "dawn_native/Buffer.h"
 #include "dawn_native/CommandBuffer.h"
 #include "dawn_native/CommandEncoder.h"
 #include "dawn_native/CommandValidation.h"
 #include "dawn_native/Device.h"
 #include "dawn_native/InternalPipelineStore.h"
 #include "dawn_native/Queue.h"
 #include "dawn_native/RenderPassEncoder.h"
 #include "dawn_native/RenderPipeline.h"
 #include "dawn_native/Sampler.h"
 #include "dawn_native/Texture.h"

 #include <unordered_set>

 namespace dawn_native {
     namespace {
         // TODO(shaobo.yan@intel.com) : Support premultiplay-alpha, flipY.
         static const char sCopyTextureForBrowserVertex[] = R"(
             [[block]] struct Uniforms {
                 [[offset(0)]] u_scale : vec2<f32>;
                 [[offset(8)]] u_offset : vec2<f32>;
             };
             const texcoord : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
                 vec2<f32>(-0.5, 0.0),
                 vec2<f32>( 1.5, 0.0),
                 vec2<f32>( 0.5, 2.0));
             [[location(0)]] var<out> v_texcoord: vec2<f32>;
             [[builtin(position)]] var<out> Position : vec4<f32>;
             [[builtin(vertex_idx)]] var<in> VertexIndex : u32;
             [[binding(0), set(0)]] var<uniform> uniforms : Uniforms;
             [[stage(vertex)]] fn main() -> void {
                 Position = vec4<f32>((texcoord[VertexIndex] * 2.0 - vec2<f32>(1.0, 1.0)), 0.0, 1.0);

                 # Texture coordinate takes top-left as origin point. We need to map the
                 # texture to triangle carefully.
                 v_texcoord = (texcoord[VertexIndex] * vec2<f32>(1.0, -1.0) + vec2<f32>(0.0, 1.0)) *
                     uniforms.u_scale + uniforms.u_offset;
             }
         )";

         static const char sPassthrough2D4ChannelFrag[] = R"(
             [[binding(1), set(0)]] var<uniform_constant> mySampler: sampler;
             [[binding(2), set(0)]] var<uniform_constant> myTexture: texture_sampled_2d<f32>;
             [[location(0)]] var<in> v_texcoord : vec2<f32>;
             [[location(0)]] var<out> rgbaColor : vec4<f32>;
             [[stage(fragment)]] fn main() -> void {
                 # Clamp the texcoord and discard the out-of-bound pixels.
                 var clampedTexcoord : vec2<f32> =
                     clamp(v_texcoord, vec2<f32>(0.0, 0.0), vec2<f32>(1.0, 1.0));
                 if (all(clampedTexcoord == v_texcoord)) {
                     rgbaColor = textureSample(myTexture, mySampler, v_texcoord);
                 }
             }
         )";

         // TODO(shaobo.yan@intel.com): Expand supported texture formats
         MaybeError ValidateCopyTextureFormatConversion(const wgpu::TextureFormat srcFormat,
                                                        const wgpu::TextureFormat dstFormat) {
             switch (srcFormat) {
                 case wgpu::TextureFormat::RGBA8Unorm:
                     break;
                 default:
                     return DAWN_VALIDATION_ERROR(
                         "Unsupported src texture format for CopyTextureForBrowser.");
             }

             switch (dstFormat) {
                 case wgpu::TextureFormat::RGBA8Unorm:
                     break;
                 default:
                     return DAWN_VALIDATION_ERROR(
                         "Unsupported dst texture format for CopyTextureForBrowser.");
             }

             return {};
         }

         MaybeError ValidateCopyTextureForBrowserOptions(
             const CopyTextureForBrowserOptions* options) {
             if (options->nextInChain != nullptr) {
                 return DAWN_VALIDATION_ERROR(
                     "CopyTextureForBrowserOptions: nextInChain must be nullptr");
             }

             return {};
         }

         RenderPipelineBase* GetOrCreateCopyTextureForBrowserPipeline(DeviceBase* device) {
             InternalPipelineStore* store = device->GetInternalPipelineStore();

             if (store->copyTextureForBrowserPipeline == nullptr) {
                 // Create vertex shader module if not cached before.
                 if (store->copyTextureForBrowserVS == nullptr) {
                     ShaderModuleDescriptor descriptor;
                     ShaderModuleWGSLDescriptor wgslDesc;
                     wgslDesc.source = sCopyTextureForBrowserVertex;
                     descriptor.nextInChain = reinterpret_cast<ChainedStruct*>(&wgslDesc);

                     store->copyTextureForBrowserVS =
                         AcquireRef(device->CreateShaderModule(&descriptor));
                 }

                 ShaderModuleBase* vertexModule = store->copyTextureForBrowserVS.Get();

                 // Create fragment shader module if not cached before.
                 if (store->copyTextureForBrowserFS == nullptr) {
                     ShaderModuleDescriptor descriptor;
                     ShaderModuleWGSLDescriptor wgslDesc;
                     wgslDesc.source = sPassthrough2D4ChannelFrag;
                     descriptor.nextInChain = reinterpret_cast<ChainedStruct*>(&wgslDesc);
                     store->copyTextureForBrowserFS =
                         AcquireRef(device->CreateShaderModule(&descriptor));
                 }

                 ShaderModuleBase* fragmentModule = store->copyTextureForBrowserFS.Get();

                 // Prepare vertex stage.
                 ProgrammableStageDescriptor vertexStage = {};
                 vertexStage.module = vertexModule;
                 vertexStage.entryPoint = "main";

                 // Prepare frgament stage.
                 ProgrammableStageDescriptor fragmentStage = {};
                 fragmentStage.module = fragmentModule;
                 fragmentStage.entryPoint = "main";

                 // Prepare color state.
                 ColorStateDescriptor colorState = {};
                 colorState.format = wgpu::TextureFormat::RGBA8Unorm;

                 // Create RenderPipeline.
                 RenderPipelineDescriptor renderPipelineDesc = {};

                 // Generate the layout based on shader modules.
                 renderPipelineDesc.layout = nullptr;

                 renderPipelineDesc.vertexStage = vertexStage;
                 renderPipelineDesc.fragmentStage = &fragmentStage;

                 renderPipelineDesc.primitiveTopology = wgpu::PrimitiveTopology::TriangleList;

                 renderPipelineDesc.colorStateCount = 1;
                 renderPipelineDesc.colorStates = &colorState;

                 store->copyTextureForBrowserPipeline =
                     AcquireRef(device->CreateRenderPipeline(&renderPipelineDesc));
             }

             return store->copyTextureForBrowserPipeline.Get();
         }

     }  // anonymous namespace

     MaybeError ValidateCopyTextureForBrowser(DeviceBase* device,
                                              const TextureCopyView* source,
                                              const TextureCopyView* destination,
                                              const Extent3D* copySize,
                                              const CopyTextureForBrowserOptions* options) {
         DAWN_TRY(device->ValidateObject(source->texture));
         DAWN_TRY(device->ValidateObject(destination->texture));

         DAWN_TRY(ValidateTextureCopyView(device, *source, *copySize));
         DAWN_TRY(ValidateTextureCopyView(device, *destination, *copySize));

         DAWN_TRY(ValidateTextureToTextureCopyRestrictions(*source, *destination, *copySize));

         DAWN_TRY(ValidateTextureCopyRange(*source, *copySize));
         DAWN_TRY(ValidateTextureCopyRange(*destination, *copySize));

         DAWN_TRY(ValidateCanUseAs(source->texture, wgpu::TextureUsage::CopySrc));
         DAWN_TRY(ValidateCanUseAs(destination->texture, wgpu::TextureUsage::CopyDst));

         DAWN_TRY(ValidateCopyTextureFormatConversion(source->texture->GetFormat().format,
                                                      destination->texture->GetFormat().format));

         DAWN_TRY(ValidateCopyTextureForBrowserOptions(options));

         // TODO(shaobo.yan@intel.com): Support the simplest case for now that source and destination
         // texture has the same size and do full texture blit. Will address sub texture blit in
         // future and remove these validations.
         if (source->origin.x != 0 || source->origin.y != 0 || source->origin.z != 0 ||
             destination->origin.x != 0 || destination->origin.y != 0 ||
             destination->origin.z != 0 || source->mipLevel != 0 || destination->mipLevel != 0 ||
             source->texture->GetWidth() != destination->texture->GetWidth() ||
             source->texture->GetHeight() != destination->texture->GetHeight()) {
             return DAWN_VALIDATION_ERROR("Cannot support sub blit now.");
         }

         return {};
     }

     MaybeError DoCopyTextureForBrowser(DeviceBase* device,
                                        const TextureCopyView* source,
                                        const TextureCopyView* destination,
                                        const Extent3D* copySize,
                                        const CopyTextureForBrowserOptions* options) {
         // TODO(shaobo.yan@intel.com): In D3D12 and Vulkan, compatible texture format can directly
         // copy to each other. This can be a potential fast path.
         RenderPipelineBase* pipeline = GetOrCreateCopyTextureForBrowserPipeline(device);

         // Prepare bind group layout.
         Ref<BindGroupLayoutBase> layout = AcquireRef(pipeline->GetBindGroupLayout(0));

         // Prepare bind group descriptor
         BindGroupEntry bindGroupEntries[3] = {};
         BindGroupDescriptor bgDesc = {};
         bgDesc.layout = layout.Get();
         bgDesc.entryCount = 3;
         bgDesc.entries = bindGroupEntries;

         // Prepare binding 0 resource: uniform buffer.
         float uniformData[] = {
             1.0, 1.0,  // scale
             0.0, 0.0   // offset
         };

         // Handle flipY.
         if (options && options->flipY) {
             uniformData[1] *= -1.0;
             uniformData[3] += 1.0;
         }

         BufferDescriptor uniformDesc = {};
         uniformDesc.usage = wgpu::BufferUsage::CopyDst | wgpu::BufferUsage::Uniform;
         uniformDesc.size = sizeof(uniformData);
         Ref<BufferBase> uniformBuffer = AcquireRef(device->CreateBuffer(&uniformDesc));

         device->GetDefaultQueue()->WriteBuffer(uniformBuffer.Get(), 0, uniformData,
                                                sizeof(uniformData));

         // Prepare binding 1 resource: sampler
         // Use default configuration, filterMode set to Nearest for min and mag.
         SamplerDescriptor samplerDesc = {};
         Ref<SamplerBase> sampler = AcquireRef(device->CreateSampler(&samplerDesc));

         // Prepare binding 2 resource: sampled texture
         TextureViewDescriptor srcTextureViewDesc = {};
         srcTextureViewDesc.baseMipLevel = source->mipLevel;
         srcTextureViewDesc.mipLevelCount = 1;
         Ref<TextureViewBase> srcTextureView =
             AcquireRef(source->texture->CreateView(&srcTextureViewDesc));

         // Set bind group entries.
         bindGroupEntries[0].binding = 0;
         bindGroupEntries[0].buffer = uniformBuffer.Get();
         bindGroupEntries[0].size = sizeof(uniformData);
         bindGroupEntries[1].binding = 1;
         bindGroupEntries[1].sampler = sampler.Get();
         bindGroupEntries[2].binding = 2;
         bindGroupEntries[2].textureView = srcTextureView.Get();

         // Create bind group after all binding entries are set.
         Ref<BindGroupBase> bindGroup = AcquireRef(device->CreateBindGroup(&bgDesc));

         // Create command encoder.
         CommandEncoderDescriptor encoderDesc = {};
         Ref<CommandEncoder> encoder = AcquireRef(device->CreateCommandEncoder(&encoderDesc));

         // Prepare dst texture view as color Attachment.
         TextureViewDescriptor dstTextureViewDesc;
         dstTextureViewDesc.baseMipLevel = destination->mipLevel;
         dstTextureViewDesc.mipLevelCount = 1;
         Ref<TextureViewBase> dstView =
             AcquireRef(destination->texture->CreateView(&dstTextureViewDesc));

         // Prepare render pass color attachment descriptor.
         RenderPassColorAttachmentDescriptor colorAttachmentDesc;
         colorAttachmentDesc.attachment = dstView.Get();
         colorAttachmentDesc.loadOp = wgpu::LoadOp::Load;
         colorAttachmentDesc.storeOp = wgpu::StoreOp::Store;
         colorAttachmentDesc.clearColor = {0.0, 0.0, 0.0, 1.0};

         // Create render pass.
         RenderPassDescriptor renderPassDesc;
         renderPassDesc.colorAttachmentCount = 1;
         renderPassDesc.colorAttachments = &colorAttachmentDesc;
         Ref<RenderPassEncoder> passEncoder = AcquireRef(encoder->BeginRenderPass(&renderPassDesc));

         // Start pipeline  and encode commands to complete
         // the copy from src texture to dst texture with transformation.
         passEncoder->SetPipeline(pipeline);
         passEncoder->SetBindGroup(0, bindGroup.Get());
         passEncoder->Draw(3);
         passEncoder->EndPass();

         // Finsh encoding.
         Ref<CommandBufferBase> commandBuffer = AcquireRef(encoder->Finish());
         CommandBufferBase* submitCommandBuffer = commandBuffer.Get();

         // Submit command buffer.
         Ref<QueueBase> queue = AcquireRef(device->GetDefaultQueue());
         queue->Submit(1, &submitCommandBuffer);

         return {};
     }

 }  // namespace dawn_native
	// Copyright 2020 The Dawn Authors
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	#include "dawn_native/CopyTextureForBrowserHelper.h"

	#include "dawn_native/BindGroup.h"
	#include "dawn_native/BindGroupLayout.h"
	#include "dawn_native/Buffer.h"
	#include "dawn_native/CommandBuffer.h"
	#include "dawn_native/CommandEncoder.h"
	#include "dawn_native/CommandValidation.h"
	#include "dawn_native/Device.h"
	#include "dawn_native/InternalPipelineStore.h"
	#include "dawn_native/Queue.h"
	#include "dawn_native/RenderPassEncoder.h"
	#include "dawn_native/RenderPipeline.h"
	#include "dawn_native/Sampler.h"
	#include "dawn_native/Texture.h"

	#include <unordered_set>

	namespace dawn_native {
	namespace {
	// TODO(shaobo.yan@intel.com) : Support premultiplay-alpha, flipY.
	static const char sCopyTextureForBrowserVertex[] = R"(
	[[block]] struct Uniforms {
	[[offset(0)]] u_scale : vec2<f32>;
	[[offset(8)]] u_offset : vec2<f32>;
	};
	const texcoord : array<vec2<f32>, 3> = array<vec2<f32>, 3>(
	vec2<f32>(-0.5, 0.0),
	vec2<f32>( 1.5, 0.0),
	vec2<f32>( 0.5, 2.0));
	[[location(0)]] var<out> v_texcoord: vec2<f32>;
	[[builtin(position)]] var<out> Position : vec4<f32>;
	[[builtin(vertex_idx)]] var<in> VertexIndex : u32;
	[[binding(0), set(0)]] var<uniform> uniforms : Uniforms;
	[[stage(vertex)]] fn main() -> void {
	Position = vec4<f32>((texcoord[VertexIndex] * 2.0 - vec2<f32>(1.0, 1.0)), 0.0, 1.0);

	# Texture coordinate takes top-left as origin point. We need to map the
	# texture to triangle carefully.
	v_texcoord = (texcoord[VertexIndex] * vec2<f32>(1.0, -1.0) + vec2<f32>(0.0, 1.0)) *
	uniforms.u_scale + uniforms.u_offset;
	}
	)";

	static const char sPassthrough2D4ChannelFrag[] = R"(
	[[binding(1), set(0)]] var<uniform_constant> mySampler: sampler;
	[[binding(2), set(0)]] var<uniform_constant> myTexture: texture_sampled_2d<f32>;
	[[location(0)]] var<in> v_texcoord : vec2<f32>;
	[[location(0)]] var<out> rgbaColor : vec4<f32>;
	[[stage(fragment)]] fn main() -> void {
	# Clamp the texcoord and discard the out-of-bound pixels.
	var clampedTexcoord : vec2<f32> =
	clamp(v_texcoord, vec2<f32>(0.0, 0.0), vec2<f32>(1.0, 1.0));
	if (all(clampedTexcoord == v_texcoord)) {
	rgbaColor = textureSample(myTexture, mySampler, v_texcoord);
	}
	}
	)";

	// TODO(shaobo.yan@intel.com): Expand supported texture formats
	MaybeError ValidateCopyTextureFormatConversion(const wgpu::TextureFormat srcFormat,
	const wgpu::TextureFormat dstFormat) {
	switch (srcFormat) {
	case wgpu::TextureFormat::RGBA8Unorm:
	break;
	default:
	return DAWN_VALIDATION_ERROR(
	"Unsupported src texture format for CopyTextureForBrowser.");
	}

	switch (dstFormat) {
	case wgpu::TextureFormat::RGBA8Unorm:
	break;
	default:
	return DAWN_VALIDATION_ERROR(
	"Unsupported dst texture format for CopyTextureForBrowser.");
	}

	return {};
	}

	MaybeError ValidateCopyTextureForBrowserOptions(
	const CopyTextureForBrowserOptions* options) {
	if (options->nextInChain != nullptr) {
	return DAWN_VALIDATION_ERROR(
	"CopyTextureForBrowserOptions: nextInChain must be nullptr");
	}

	return {};
	}

	RenderPipelineBase* GetOrCreateCopyTextureForBrowserPipeline(DeviceBase* device) {
	InternalPipelineStore* store = device->GetInternalPipelineStore();

	if (store->copyTextureForBrowserPipeline == nullptr) {
	// Create vertex shader module if not cached before.
	if (store->copyTextureForBrowserVS == nullptr) {
	ShaderModuleDescriptor descriptor;
	ShaderModuleWGSLDescriptor wgslDesc;
	wgslDesc.source = sCopyTextureForBrowserVertex;
	descriptor.nextInChain = reinterpret_cast<ChainedStruct*>(&wgslDesc);

	store->copyTextureForBrowserVS =
	AcquireRef(device->CreateShaderModule(&descriptor));
	}

	ShaderModuleBase* vertexModule = store->copyTextureForBrowserVS.Get();

	// Create fragment shader module if not cached before.
	if (store->copyTextureForBrowserFS == nullptr) {
	ShaderModuleDescriptor descriptor;
	ShaderModuleWGSLDescriptor wgslDesc;
	wgslDesc.source = sPassthrough2D4ChannelFrag;
	descriptor.nextInChain = reinterpret_cast<ChainedStruct*>(&wgslDesc);
	store->copyTextureForBrowserFS =
	AcquireRef(device->CreateShaderModule(&descriptor));
	}

	ShaderModuleBase* fragmentModule = store->copyTextureForBrowserFS.Get();

	// Prepare vertex stage.
	ProgrammableStageDescriptor vertexStage = {};
	vertexStage.module = vertexModule;
	vertexStage.entryPoint = "main";

	// Prepare frgament stage.
	ProgrammableStageDescriptor fragmentStage = {};
	fragmentStage.module = fragmentModule;
	fragmentStage.entryPoint = "main";

	// Prepare color state.
	ColorStateDescriptor colorState = {};
	colorState.format = wgpu::TextureFormat::RGBA8Unorm;

	// Create RenderPipeline.
	RenderPipelineDescriptor renderPipelineDesc = {};

	// Generate the layout based on shader modules.
	renderPipelineDesc.layout = nullptr;

	renderPipelineDesc.vertexStage = vertexStage;
	renderPipelineDesc.fragmentStage = &fragmentStage;

	renderPipelineDesc.primitiveTopology = wgpu::PrimitiveTopology::TriangleList;

	renderPipelineDesc.colorStateCount = 1;
	renderPipelineDesc.colorStates = &colorState;

	store->copyTextureForBrowserPipeline =
	AcquireRef(device->CreateRenderPipeline(&renderPipelineDesc));
	}

	return store->copyTextureForBrowserPipeline.Get();
	}

	} // anonymous namespace

	MaybeError ValidateCopyTextureForBrowser(DeviceBase* device,
	const TextureCopyView* source,
	const TextureCopyView* destination,
	const Extent3D* copySize,
	const CopyTextureForBrowserOptions* options) {
	DAWN_TRY(device->ValidateObject(source->texture));
	DAWN_TRY(device->ValidateObject(destination->texture));

	DAWN_TRY(ValidateTextureCopyView(device, source, copySize));
	DAWN_TRY(ValidateTextureCopyView(device, destination, copySize));

	DAWN_TRY(ValidateTextureToTextureCopyRestrictions(source, destination, *copySize));

	DAWN_TRY(ValidateTextureCopyRange(source, copySize));
	DAWN_TRY(ValidateTextureCopyRange(destination, copySize));

	DAWN_TRY(ValidateCanUseAs(source->texture, wgpu::TextureUsage::CopySrc));
	DAWN_TRY(ValidateCanUseAs(destination->texture, wgpu::TextureUsage::CopyDst));

	DAWN_TRY(ValidateCopyTextureFormatConversion(source->texture->GetFormat().format,
	destination->texture->GetFormat().format));

	DAWN_TRY(ValidateCopyTextureForBrowserOptions(options));

	// TODO(shaobo.yan@intel.com): Support the simplest case for now that source and destination
	// texture has the same size and do full texture blit. Will address sub texture blit in
	// future and remove these validations.
	if (source->origin.x != 0 \|\| source->origin.y != 0 \|\| source->origin.z != 0 \|\|
	destination->origin.x != 0 \|\| destination->origin.y != 0 \|\|
	destination->origin.z != 0 \|\| source->mipLevel != 0 \|\| destination->mipLevel != 0 \|\|
	source->texture->GetWidth() != destination->texture->GetWidth() \|\|
	source->texture->GetHeight() != destination->texture->GetHeight()) {
	return DAWN_VALIDATION_ERROR("Cannot support sub blit now.");
	}

	return {};
	}

	MaybeError DoCopyTextureForBrowser(DeviceBase* device,
	const TextureCopyView* source,
	const TextureCopyView* destination,
	const Extent3D* copySize,
	const CopyTextureForBrowserOptions* options) {
	// TODO(shaobo.yan@intel.com): In D3D12 and Vulkan, compatible texture format can directly
	// copy to each other. This can be a potential fast path.
	RenderPipelineBase* pipeline = GetOrCreateCopyTextureForBrowserPipeline(device);

	// Prepare bind group layout.
	Ref<BindGroupLayoutBase> layout = AcquireRef(pipeline->GetBindGroupLayout(0));

	// Prepare bind group descriptor
	BindGroupEntry bindGroupEntries[3] = {};
	BindGroupDescriptor bgDesc = {};
	bgDesc.layout = layout.Get();
	bgDesc.entryCount = 3;
	bgDesc.entries = bindGroupEntries;

	// Prepare binding 0 resource: uniform buffer.
	float uniformData[] = {
	1.0, 1.0, // scale
	0.0, 0.0 // offset
	};

	// Handle flipY.
	if (options && options->flipY) {
	uniformData[1] *= -1.0;
	uniformData[3] += 1.0;
	}

	BufferDescriptor uniformDesc = {};
	uniformDesc.usage = wgpu::BufferUsage::CopyDst \| wgpu::BufferUsage::Uniform;
	uniformDesc.size = sizeof(uniformData);
	Ref<BufferBase> uniformBuffer = AcquireRef(device->CreateBuffer(&uniformDesc));

	device->GetDefaultQueue()->WriteBuffer(uniformBuffer.Get(), 0, uniformData,
	sizeof(uniformData));

	// Prepare binding 1 resource: sampler
	// Use default configuration, filterMode set to Nearest for min and mag.
	SamplerDescriptor samplerDesc = {};
	Ref<SamplerBase> sampler = AcquireRef(device->CreateSampler(&samplerDesc));

	// Prepare binding 2 resource: sampled texture
	TextureViewDescriptor srcTextureViewDesc = {};
	srcTextureViewDesc.baseMipLevel = source->mipLevel;
	srcTextureViewDesc.mipLevelCount = 1;
	Ref<TextureViewBase> srcTextureView =
	AcquireRef(source->texture->CreateView(&srcTextureViewDesc));

	// Set bind group entries.
	bindGroupEntries[0].binding = 0;
	bindGroupEntries[0].buffer = uniformBuffer.Get();
	bindGroupEntries[0].size = sizeof(uniformData);
	bindGroupEntries[1].binding = 1;
	bindGroupEntries[1].sampler = sampler.Get();
	bindGroupEntries[2].binding = 2;
	bindGroupEntries[2].textureView = srcTextureView.Get();

	// Create bind group after all binding entries are set.
	Ref<BindGroupBase> bindGroup = AcquireRef(device->CreateBindGroup(&bgDesc));

	// Create command encoder.
	CommandEncoderDescriptor encoderDesc = {};
	Ref<CommandEncoder> encoder = AcquireRef(device->CreateCommandEncoder(&encoderDesc));

	// Prepare dst texture view as color Attachment.
	TextureViewDescriptor dstTextureViewDesc;
	dstTextureViewDesc.baseMipLevel = destination->mipLevel;
	dstTextureViewDesc.mipLevelCount = 1;
	Ref<TextureViewBase> dstView =
	AcquireRef(destination->texture->CreateView(&dstTextureViewDesc));

	// Prepare render pass color attachment descriptor.
	RenderPassColorAttachmentDescriptor colorAttachmentDesc;
	colorAttachmentDesc.attachment = dstView.Get();
	colorAttachmentDesc.loadOp = wgpu::LoadOp::Load;
	colorAttachmentDesc.storeOp = wgpu::StoreOp::Store;
	colorAttachmentDesc.clearColor = {0.0, 0.0, 0.0, 1.0};

	// Create render pass.
	RenderPassDescriptor renderPassDesc;
	renderPassDesc.colorAttachmentCount = 1;
	renderPassDesc.colorAttachments = &colorAttachmentDesc;
	Ref<RenderPassEncoder> passEncoder = AcquireRef(encoder->BeginRenderPass(&renderPassDesc));

	// Start pipeline and encode commands to complete
	// the copy from src texture to dst texture with transformation.
	passEncoder->SetPipeline(pipeline);
	passEncoder->SetBindGroup(0, bindGroup.Get());
	passEncoder->Draw(3);
	passEncoder->EndPass();

	// Finsh encoding.
	Ref<CommandBufferBase> commandBuffer = AcquireRef(encoder->Finish());
	CommandBufferBase* submitCommandBuffer = commandBuffer.Get();

	// Submit command buffer.
	Ref<QueueBase> queue = AcquireRef(device->GetDefaultQueue());
	queue->Submit(1, &submitCommandBuffer);

	return {};
	}

	} // namespace dawn_native