src/tests/end2end/SamplerFilterAnisotropicTests.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 <cmath>

 #include "tests/DawnTest.h"

 #include "common/Assert.h"
 #include "common/Constants.h"
 #include "utils/ComboRenderPipelineDescriptor.h"
 #include "utils/WGPUHelpers.h"

 constexpr static unsigned int kRTSize = 16;

 namespace {
     // MipLevel colors, ordering from base level to high level
     // each mipmap of the texture is having a different color
     // so we can check if the sampler anisotropic filtering is fetching
     // from the correct miplevel
     const std::array<RGBA8, 3> colors = {RGBA8::kRed, RGBA8::kGreen, RGBA8::kBlue};
 }  // namespace

 class SamplerFilterAnisotropicTest : public DawnTest {
   protected:
     void SetUp() override {
         DawnTest::SetUp();
         mRenderPass = utils::CreateBasicRenderPass(device, kRTSize, kRTSize);

         wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
             [[block]] struct Uniforms {
                 matrix : mat4x4<f32>;
             };

             struct VertexIn {
                 [[location(0)]] position : vec4<f32>;
                 [[location(1)]] uv : vec2<f32>;
             };

             [[group(0), binding(2)]] var<uniform> uniforms : Uniforms;

             struct VertexOut {
                 [[location(0)]] uv : vec2<f32>;
                 [[builtin(position)]] position : vec4<f32>;
             };

             [[stage(vertex)]]
             fn main(input : VertexIn) -> VertexOut {
                 var output : VertexOut;
                 output.uv = input.uv;
                 output.position = uniforms.matrix * input.position;
                 return output;
             }
         )");
         wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
             [[group(0), binding(0)]] var sampler0 : sampler;
             [[group(0), binding(1)]] var texture0 : texture_2d<f32>;

             struct FragmentIn {
                 [[location(0)]] uv: vec2<f32>;
                 [[builtin(position)]] fragCoord : vec4<f32>;
             };

             [[stage(fragment)]]
             fn main(input : FragmentIn) -> [[location(0)]] vec4<f32> {
                 return textureSample(texture0, sampler0, input.uv);
             })");

         utils::ComboRenderPipelineDescriptor pipelineDescriptor;
         pipelineDescriptor.vertex.module = vsModule;
         pipelineDescriptor.cFragment.module = fsModule;
         pipelineDescriptor.cBuffers[0].attributeCount = 2;
         pipelineDescriptor.cAttributes[0].format = wgpu::VertexFormat::Float32x4;
         pipelineDescriptor.cAttributes[1].shaderLocation = 1;
         pipelineDescriptor.cAttributes[1].offset = 4 * sizeof(float);
         pipelineDescriptor.cAttributes[1].format = wgpu::VertexFormat::Float32x2;
         pipelineDescriptor.vertex.bufferCount = 1;
         pipelineDescriptor.cBuffers[0].arrayStride = 6 * sizeof(float);
         pipelineDescriptor.cTargets[0].format = mRenderPass.colorFormat;

         mPipeline = device.CreateRenderPipeline(&pipelineDescriptor);
         mBindGroupLayout = mPipeline.GetBindGroupLayout(0);

         InitTexture();
     }

     void InitTexture() {
         const uint32_t mipLevelCount = colors.size();

         const uint32_t textureWidthLevel0 = 1 << (mipLevelCount - 1);
         const uint32_t textureHeightLevel0 = 1 << (mipLevelCount - 1);

         wgpu::TextureDescriptor descriptor;
         descriptor.dimension = wgpu::TextureDimension::e2D;
         descriptor.size.width = textureWidthLevel0;
         descriptor.size.height = textureHeightLevel0;
         descriptor.size.depthOrArrayLayers = 1;
         descriptor.sampleCount = 1;
         descriptor.format = wgpu::TextureFormat::RGBA8Unorm;
         descriptor.mipLevelCount = mipLevelCount;
         descriptor.usage = wgpu::TextureUsage::CopyDst | wgpu::TextureUsage::TextureBinding;
         wgpu::Texture texture = device.CreateTexture(&descriptor);

         const uint32_t rowPixels = kTextureBytesPerRowAlignment / sizeof(RGBA8);

         wgpu::CommandEncoder encoder = device.CreateCommandEncoder();

         // Populate each mip level with a different color
         for (uint32_t level = 0; level < mipLevelCount; ++level) {
             const uint32_t texWidth = textureWidthLevel0 >> level;
             const uint32_t texHeight = textureHeightLevel0 >> level;

             const RGBA8 color = colors[level];

             std::vector<RGBA8> data(rowPixels * texHeight, color);
             wgpu::Buffer stagingBuffer = utils::CreateBufferFromData(
                 device, data.data(), data.size() * sizeof(RGBA8), wgpu::BufferUsage::CopySrc);
             wgpu::ImageCopyBuffer imageCopyBuffer =
                 utils::CreateImageCopyBuffer(stagingBuffer, 0, kTextureBytesPerRowAlignment);
             wgpu::ImageCopyTexture imageCopyTexture =
                 utils::CreateImageCopyTexture(texture, level, {0, 0, 0});
             wgpu::Extent3D copySize = {texWidth, texHeight, 1};
             encoder.CopyBufferToTexture(&imageCopyBuffer, &imageCopyTexture, &copySize);
         }
         wgpu::CommandBuffer copy = encoder.Finish();
         queue.Submit(1, &copy);

         mTextureView = texture.CreateView();
     }

     // void TestFilterAnisotropic(const FilterAnisotropicTestCase& testCase) {
     void TestFilterAnisotropic(const uint16_t maxAnisotropy) {
         wgpu::Sampler sampler;
         {
             wgpu::SamplerDescriptor descriptor = {};
             descriptor.minFilter = wgpu::FilterMode::Linear;
             descriptor.magFilter = wgpu::FilterMode::Linear;
             descriptor.mipmapFilter = wgpu::FilterMode::Linear;
             descriptor.maxAnisotropy = maxAnisotropy;
             sampler = device.CreateSampler(&descriptor);
         }

         // The transform matrix gives us a slanted plane
         // Tweaking happens at: https://jsfiddle.net/t8k7c95o/5/
         // You can get an idea of what the test looks like at the url rendered by webgl
         std::array<float, 16> transform = {-1.7320507764816284,
                                            1.8322050568049563e-16,
                                            -6.176817699518044e-17,
                                            -6.170640314703498e-17,
                                            -2.1211504944260596e-16,
                                            -1.496108889579773,
                                            0.5043753981590271,
                                            0.5038710236549377,
                                            0,
                                            -43.63650894165039,
                                            -43.232173919677734,
                                            -43.18894577026367,
                                            0,
                                            21.693578720092773,
                                            21.789791107177734,
                                            21.86800193786621};
         wgpu::Buffer transformBuffer = utils::CreateBufferFromData(
             device, transform.data(), sizeof(transform), wgpu::BufferUsage::Uniform);

         wgpu::BindGroup bindGroup = utils::MakeBindGroup(
             device, mBindGroupLayout,
             {{0, sampler}, {1, mTextureView}, {2, transformBuffer, 0, sizeof(transform)}});

         // The plane is scaled on z axis in the transform matrix
         // so uv here is also scaled
         // vertex attribute layout:
         // position : vec4, uv : vec2
         const float vertexData[] = {
             -0.5, 0.5, -0.5, 1, 0, 0,  0.5, 0.5, -0.5, 1, 1, 0, -0.5, 0.5, 0.5, 1, 0, 50,
             -0.5, 0.5, 0.5,  1, 0, 50, 0.5, 0.5, -0.5, 1, 1, 0, 0.5,  0.5, 0.5, 1, 1, 50,
         };
         wgpu::Buffer vertexBuffer = utils::CreateBufferFromData(
             device, vertexData, sizeof(vertexData), wgpu::BufferUsage::Vertex);

         wgpu::CommandEncoder encoder = device.CreateCommandEncoder();
         {
             wgpu::RenderPassEncoder pass = encoder.BeginRenderPass(&mRenderPass.renderPassInfo);
             pass.SetPipeline(mPipeline);
             pass.SetBindGroup(0, bindGroup);
             pass.SetVertexBuffer(0, vertexBuffer);
             pass.Draw(6);
             pass.EndPass();
         }

         wgpu::CommandBuffer commands = encoder.Finish();
         queue.Submit(1, &commands);

         // https://jsfiddle.net/t8k7c95o/5/
         // (x, y) -> (8, [0,15)) full readpixels result on Win10 Nvidia D3D12 GPU
         // maxAnisotropy: 1
         //  0 - 00 00 00
         //  1 - 00 00 ff
         //  2 - 00 00 ff
         //  3 - 00 00 ff
         //  4 - 00 f9 06
         //  5 - 00 f9 06
         //  6 - f2 0d 00
         //  7 - f2 0d 00
         //  8 - ff 00 00
         //  9 - ff 00 00
         // 10 - ff 00 00
         // 11 - ff 00 00
         // 12 - ff 00 00
         // 13 - ff 00 00
         // 14 - ff 00 00
         // 15 - ff 00 00

         // maxAnisotropy: 2
         //  0 - 00 00 00
         //  1 - 00 00 ff
         //  2 - 00 7e 81
         //  3 - 00 7e 81
         //  4 - ff 00 00
         //  5 - ff 00 00
         //  6 - ff 00 00
         //  7 - ff 00 00
         //  8 - ff 00 00
         //  9 - ff 00 00
         // 10 - ff 00 00
         // 11 - ff 00 00
         // 12 - ff 00 00
         // 13 - ff 00 00
         // 14 - ff 00 00
         // 15 - ff 00 00

         // maxAnisotropy: 16
         //  0 - 00 00 00
         //  1 - 00 00 ff
         //  2 - dd 22 00
         //  3 - dd 22 00
         //  4 - ff 00 00
         //  5 - ff 00 00
         //  6 - ff 00 00
         //  7 - ff 00 00
         //  8 - ff 00 00
         //  9 - ff 00 00
         // 10 - ff 00 00
         // 11 - ff 00 00
         // 12 - ff 00 00
         // 13 - ff 00 00
         // 14 - ff 00 00
         // 15 - ff 00 00

         if (maxAnisotropy >= 16) {
             EXPECT_PIXEL_RGBA8_BETWEEN(colors[0], colors[1], mRenderPass.color, 8, 2);
             EXPECT_PIXEL_RGBA8_EQ(colors[0], mRenderPass.color, 8, 6);
         } else if (maxAnisotropy == 2) {
             EXPECT_PIXEL_RGBA8_BETWEEN(colors[1], colors[2], mRenderPass.color, 8, 2);
             EXPECT_PIXEL_RGBA8_EQ(colors[0], mRenderPass.color, 8, 6);
         } else if (maxAnisotropy <= 1) {
             EXPECT_PIXEL_RGBA8_EQ(colors[2], mRenderPass.color, 8, 2);
             EXPECT_PIXEL_RGBA8_BETWEEN(colors[0], colors[1], mRenderPass.color, 8, 6);
         }
     }

     utils::BasicRenderPass mRenderPass;
     wgpu::BindGroupLayout mBindGroupLayout;
     wgpu::RenderPipeline mPipeline;
     wgpu::TextureView mTextureView;
 };

 TEST_P(SamplerFilterAnisotropicTest, SlantedPlaneMipmap) {
     // TODO(crbug.com/dawn/740): Test output is wrong with D3D12 + WARP.
     DAWN_SUPPRESS_TEST_IF(IsD3D12() && IsWARP());

     DAWN_SUPPRESS_TEST_IF(IsOpenGL() || IsOpenGLES());
     const uint16_t maxAnisotropyLists[] = {1, 2, 16, 128};
     for (uint16_t t : maxAnisotropyLists) {
         TestFilterAnisotropic(t);
     }
 }

 DAWN_INSTANTIATE_TEST(SamplerFilterAnisotropicTest,
                       D3D12Backend(),
                       MetalBackend(),
                       OpenGLBackend(),
                       OpenGLESBackend(),
                       VulkanBackend());
	// 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 <cmath>

	#include "tests/DawnTest.h"

	#include "common/Assert.h"
	#include "common/Constants.h"
	#include "utils/ComboRenderPipelineDescriptor.h"
	#include "utils/WGPUHelpers.h"

	constexpr static unsigned int kRTSize = 16;

	namespace {
	// MipLevel colors, ordering from base level to high level
	// each mipmap of the texture is having a different color
	// so we can check if the sampler anisotropic filtering is fetching
	// from the correct miplevel
	const std::array<RGBA8, 3> colors = {RGBA8::kRed, RGBA8::kGreen, RGBA8::kBlue};
	} // namespace

	class SamplerFilterAnisotropicTest : public DawnTest {
	protected:
	void SetUp() override {
	DawnTest::SetUp();
	mRenderPass = utils::CreateBasicRenderPass(device, kRTSize, kRTSize);

	wgpu::ShaderModule vsModule = utils::CreateShaderModule(device, R"(
	[[block]] struct Uniforms {
	matrix : mat4x4<f32>;
	};

	struct VertexIn {
	[[location(0)]] position : vec4<f32>;
	[[location(1)]] uv : vec2<f32>;
	};

	[[group(0), binding(2)]] var<uniform> uniforms : Uniforms;

	struct VertexOut {
	[[location(0)]] uv : vec2<f32>;
	[[builtin(position)]] position : vec4<f32>;
	};

	[[stage(vertex)]]
	fn main(input : VertexIn) -> VertexOut {
	var output : VertexOut;
	output.uv = input.uv;
	output.position = uniforms.matrix * input.position;
	return output;
	}
	)");
	wgpu::ShaderModule fsModule = utils::CreateShaderModule(device, R"(
	[[group(0), binding(0)]] var sampler0 : sampler;
	[[group(0), binding(1)]] var texture0 : texture_2d<f32>;

	struct FragmentIn {
	[[location(0)]] uv: vec2<f32>;
	[[builtin(position)]] fragCoord : vec4<f32>;
	};

	[[stage(fragment)]]
	fn main(input : FragmentIn) -> [[location(0)]] vec4<f32> {
	return textureSample(texture0, sampler0, input.uv);
	})");

	utils::ComboRenderPipelineDescriptor pipelineDescriptor;
	pipelineDescriptor.vertex.module = vsModule;
	pipelineDescriptor.cFragment.module = fsModule;
	pipelineDescriptor.cBuffers[0].attributeCount = 2;
	pipelineDescriptor.cAttributes[0].format = wgpu::VertexFormat::Float32x4;
	pipelineDescriptor.cAttributes[1].shaderLocation = 1;
	pipelineDescriptor.cAttributes[1].offset = 4 * sizeof(float);
	pipelineDescriptor.cAttributes[1].format = wgpu::VertexFormat::Float32x2;
	pipelineDescriptor.vertex.bufferCount = 1;
	pipelineDescriptor.cBuffers[0].arrayStride = 6 * sizeof(float);
	pipelineDescriptor.cTargets[0].format = mRenderPass.colorFormat;

	mPipeline = device.CreateRenderPipeline(&pipelineDescriptor);
	mBindGroupLayout = mPipeline.GetBindGroupLayout(0);

	InitTexture();
	}

	void InitTexture() {
	const uint32_t mipLevelCount = colors.size();

	const uint32_t textureWidthLevel0 = 1 << (mipLevelCount - 1);
	const uint32_t textureHeightLevel0 = 1 << (mipLevelCount - 1);

	wgpu::TextureDescriptor descriptor;
	descriptor.dimension = wgpu::TextureDimension::e2D;
	descriptor.size.width = textureWidthLevel0;
	descriptor.size.height = textureHeightLevel0;
	descriptor.size.depthOrArrayLayers = 1;
	descriptor.sampleCount = 1;
	descriptor.format = wgpu::TextureFormat::RGBA8Unorm;
	descriptor.mipLevelCount = mipLevelCount;
	descriptor.usage = wgpu::TextureUsage::CopyDst \| wgpu::TextureUsage::TextureBinding;
	wgpu::Texture texture = device.CreateTexture(&descriptor);

	const uint32_t rowPixels = kTextureBytesPerRowAlignment / sizeof(RGBA8);

	wgpu::CommandEncoder encoder = device.CreateCommandEncoder();

	// Populate each mip level with a different color
	for (uint32_t level = 0; level < mipLevelCount; ++level) {
	const uint32_t texWidth = textureWidthLevel0 >> level;
	const uint32_t texHeight = textureHeightLevel0 >> level;

	const RGBA8 color = colors[level];

	std::vector<RGBA8> data(rowPixels * texHeight, color);
	wgpu::Buffer stagingBuffer = utils::CreateBufferFromData(
	device, data.data(), data.size() * sizeof(RGBA8), wgpu::BufferUsage::CopySrc);
	wgpu::ImageCopyBuffer imageCopyBuffer =
	utils::CreateImageCopyBuffer(stagingBuffer, 0, kTextureBytesPerRowAlignment);
	wgpu::ImageCopyTexture imageCopyTexture =
	utils::CreateImageCopyTexture(texture, level, {0, 0, 0});
	wgpu::Extent3D copySize = {texWidth, texHeight, 1};
	encoder.CopyBufferToTexture(&imageCopyBuffer, &imageCopyTexture, &copySize);
	}
	wgpu::CommandBuffer copy = encoder.Finish();
	queue.Submit(1, &copy);

	mTextureView = texture.CreateView();
	}

	// void TestFilterAnisotropic(const FilterAnisotropicTestCase& testCase) {
	void TestFilterAnisotropic(const uint16_t maxAnisotropy) {
	wgpu::Sampler sampler;
	{
	wgpu::SamplerDescriptor descriptor = {};
	descriptor.minFilter = wgpu::FilterMode::Linear;
	descriptor.magFilter = wgpu::FilterMode::Linear;
	descriptor.mipmapFilter = wgpu::FilterMode::Linear;
	descriptor.maxAnisotropy = maxAnisotropy;
	sampler = device.CreateSampler(&descriptor);
	}

	// The transform matrix gives us a slanted plane
	// Tweaking happens at: https://jsfiddle.net/t8k7c95o/5/
	// You can get an idea of what the test looks like at the url rendered by webgl
	std::array<float, 16> transform = {-1.7320507764816284,
	1.8322050568049563e-16,
	-6.176817699518044e-17,
	-6.170640314703498e-17,
	-2.1211504944260596e-16,
	-1.496108889579773,
	0.5043753981590271,
	0.5038710236549377,
	0,
	-43.63650894165039,
	-43.232173919677734,
	-43.18894577026367,
	0,
	21.693578720092773,
	21.789791107177734,
	21.86800193786621};
	wgpu::Buffer transformBuffer = utils::CreateBufferFromData(
	device, transform.data(), sizeof(transform), wgpu::BufferUsage::Uniform);

	wgpu::BindGroup bindGroup = utils::MakeBindGroup(
	device, mBindGroupLayout,
	{{0, sampler}, {1, mTextureView}, {2, transformBuffer, 0, sizeof(transform)}});

	// The plane is scaled on z axis in the transform matrix
	// so uv here is also scaled
	// vertex attribute layout:
	// position : vec4, uv : vec2
	const float vertexData[] = {
	-0.5, 0.5, -0.5, 1, 0, 0, 0.5, 0.5, -0.5, 1, 1, 0, -0.5, 0.5, 0.5, 1, 0, 50,
	-0.5, 0.5, 0.5, 1, 0, 50, 0.5, 0.5, -0.5, 1, 1, 0, 0.5, 0.5, 0.5, 1, 1, 50,
	};
	wgpu::Buffer vertexBuffer = utils::CreateBufferFromData(
	device, vertexData, sizeof(vertexData), wgpu::BufferUsage::Vertex);

	wgpu::CommandEncoder encoder = device.CreateCommandEncoder();
	{
	wgpu::RenderPassEncoder pass = encoder.BeginRenderPass(&mRenderPass.renderPassInfo);
	pass.SetPipeline(mPipeline);
	pass.SetBindGroup(0, bindGroup);
	pass.SetVertexBuffer(0, vertexBuffer);
	pass.Draw(6);
	pass.EndPass();
	}

	wgpu::CommandBuffer commands = encoder.Finish();
	queue.Submit(1, &commands);

	// https://jsfiddle.net/t8k7c95o/5/
	// (x, y) -> (8, [0,15)) full readpixels result on Win10 Nvidia D3D12 GPU
	// maxAnisotropy: 1
	// 0 - 00 00 00
	// 1 - 00 00 ff
	// 2 - 00 00 ff
	// 3 - 00 00 ff
	// 4 - 00 f9 06
	// 5 - 00 f9 06
	// 6 - f2 0d 00
	// 7 - f2 0d 00
	// 8 - ff 00 00
	// 9 - ff 00 00
	// 10 - ff 00 00
	// 11 - ff 00 00
	// 12 - ff 00 00
	// 13 - ff 00 00
	// 14 - ff 00 00
	// 15 - ff 00 00

	// maxAnisotropy: 2
	// 0 - 00 00 00
	// 1 - 00 00 ff
	// 2 - 00 7e 81
	// 3 - 00 7e 81
	// 4 - ff 00 00
	// 5 - ff 00 00
	// 6 - ff 00 00
	// 7 - ff 00 00
	// 8 - ff 00 00
	// 9 - ff 00 00
	// 10 - ff 00 00
	// 11 - ff 00 00
	// 12 - ff 00 00
	// 13 - ff 00 00
	// 14 - ff 00 00
	// 15 - ff 00 00

	// maxAnisotropy: 16
	// 0 - 00 00 00
	// 1 - 00 00 ff
	// 2 - dd 22 00
	// 3 - dd 22 00
	// 4 - ff 00 00
	// 5 - ff 00 00
	// 6 - ff 00 00
	// 7 - ff 00 00
	// 8 - ff 00 00
	// 9 - ff 00 00
	// 10 - ff 00 00
	// 11 - ff 00 00
	// 12 - ff 00 00
	// 13 - ff 00 00
	// 14 - ff 00 00
	// 15 - ff 00 00

	if (maxAnisotropy >= 16) {
	EXPECT_PIXEL_RGBA8_BETWEEN(colors[0], colors[1], mRenderPass.color, 8, 2);
	EXPECT_PIXEL_RGBA8_EQ(colors[0], mRenderPass.color, 8, 6);
	} else if (maxAnisotropy == 2) {
	EXPECT_PIXEL_RGBA8_BETWEEN(colors[1], colors[2], mRenderPass.color, 8, 2);
	EXPECT_PIXEL_RGBA8_EQ(colors[0], mRenderPass.color, 8, 6);
	} else if (maxAnisotropy <= 1) {
	EXPECT_PIXEL_RGBA8_EQ(colors[2], mRenderPass.color, 8, 2);
	EXPECT_PIXEL_RGBA8_BETWEEN(colors[0], colors[1], mRenderPass.color, 8, 6);
	}
	}

	utils::BasicRenderPass mRenderPass;
	wgpu::BindGroupLayout mBindGroupLayout;
	wgpu::RenderPipeline mPipeline;
	wgpu::TextureView mTextureView;
	};

	TEST_P(SamplerFilterAnisotropicTest, SlantedPlaneMipmap) {
	// TODO(crbug.com/dawn/740): Test output is wrong with D3D12 + WARP.
	DAWN_SUPPRESS_TEST_IF(IsD3D12() && IsWARP());

	DAWN_SUPPRESS_TEST_IF(IsOpenGL() \|\| IsOpenGLES());
	const uint16_t maxAnisotropyLists[] = {1, 2, 16, 128};
	for (uint16_t t : maxAnisotropyLists) {
	TestFilterAnisotropic(t);
	}
	}

	DAWN_INSTANTIATE_TEST(SamplerFilterAnisotropicTest,
	D3D12Backend(),
	MetalBackend(),
	OpenGLBackend(),
	OpenGLESBackend(),
	VulkanBackend());