impeller/entity/geometry/point_field_geometry.cc - mirrors/engine - Git at Google

 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "impeller/entity/geometry/point_field_geometry.h"

 #include "impeller/renderer/command_buffer.h"

 namespace impeller {

 PointFieldGeometry::PointFieldGeometry(std::vector<Point> points,
                                        Scalar radius,
                                        bool round)
     : points_(std::move(points)), radius_(radius), round_(round) {}

 GeometryResult PointFieldGeometry::GetPositionBuffer(
     const ContentContext& renderer,
     const Entity& entity,
     RenderPass& pass) const {
   if (renderer.GetDeviceCapabilities().SupportsCompute()) {
     return GetPositionBufferGPU(renderer, entity, pass);
   }
   auto vtx_builder = GetPositionBufferCPU(renderer, entity, pass);
   if (!vtx_builder.has_value()) {
     return {};
   }

   auto& host_buffer = renderer.GetTransientsBuffer();
   return {
       .type = PrimitiveType::kTriangleStrip,
       .vertex_buffer = vtx_builder->CreateVertexBuffer(host_buffer),
       .transform = pass.GetOrthographicTransform() * entity.GetTransform(),
   };
 }

 GeometryResult PointFieldGeometry::GetPositionUVBuffer(
     Rect texture_coverage,
     Matrix effect_transform,
     const ContentContext& renderer,
     const Entity& entity,
     RenderPass& pass) const {
   if (renderer.GetDeviceCapabilities().SupportsCompute()) {
     return GetPositionBufferGPU(renderer, entity, pass, texture_coverage,
                                 effect_transform);
   }

   auto vtx_builder = GetPositionBufferCPU(renderer, entity, pass);
   if (!vtx_builder.has_value()) {
     return {};
   }
   auto uv_vtx_builder =
       ComputeUVGeometryCPU(vtx_builder.value(), {0, 0},
                            texture_coverage.GetSize(), effect_transform);

   auto& host_buffer = renderer.GetTransientsBuffer();
   return {
       .type = PrimitiveType::kTriangleStrip,
       .vertex_buffer = uv_vtx_builder.CreateVertexBuffer(host_buffer),
       .transform = pass.GetOrthographicTransform() * entity.GetTransform(),
   };
 }

 std::optional<VertexBufferBuilder<SolidFillVertexShader::PerVertexData>>
 PointFieldGeometry::GetPositionBufferCPU(const ContentContext& renderer,
                                          const Entity& entity,
                                          RenderPass& pass) const {
   if (radius_ < 0.0) {
     return std::nullopt;
   }
   auto transform = entity.GetTransform();
   auto determinant = transform.GetDeterminant();
   if (determinant == 0) {
     return std::nullopt;
   }

   Scalar min_size = 1.0f / sqrt(std::abs(determinant));
   Scalar radius = std::max(radius_, min_size);

   VertexBufferBuilder<SolidFillVertexShader::PerVertexData> vtx_builder;

   if (round_) {
     // Get triangulation relative to {0, 0} so we can translate it to each
     // point in turn.
     auto generator =
         renderer.GetTessellator()->FilledCircle(transform, {}, radius);
     FML_DCHECK(generator.GetTriangleType() == PrimitiveType::kTriangleStrip);
     std::vector<Point> circle_vertices;
     circle_vertices.reserve(generator.GetVertexCount());
     generator.GenerateVertices([&circle_vertices](const Point& p) {  //
       circle_vertices.push_back(p);
     });
     FML_DCHECK(circle_vertices.size() == generator.GetVertexCount());

     vtx_builder.Reserve((circle_vertices.size() + 2) * points_.size() - 2);
     for (auto& center : points_) {
       if (vtx_builder.HasVertices()) {
         vtx_builder.AppendVertex(vtx_builder.Last());
         vtx_builder.AppendVertex({center + circle_vertices[0]});
       }

       for (auto& vertex : circle_vertices) {
         vtx_builder.AppendVertex({center + vertex});
       }
     }
   } else {
     vtx_builder.Reserve(6 * points_.size() - 2);
     for (auto& point : points_) {
       auto first = Point(point.x - radius, point.y - radius);

       if (vtx_builder.HasVertices()) {
         vtx_builder.AppendVertex(vtx_builder.Last());
         vtx_builder.AppendVertex({first});
       }

       // Z pattern from UL -> UR -> LL -> LR
       vtx_builder.AppendVertex({first});
       vtx_builder.AppendVertex({{point.x + radius, point.y - radius}});
       vtx_builder.AppendVertex({{point.x - radius, point.y + radius}});
       vtx_builder.AppendVertex({{point.x + radius, point.y + radius}});
     }
   }

   return vtx_builder;
 }

 GeometryResult PointFieldGeometry::GetPositionBufferGPU(
     const ContentContext& renderer,
     const Entity& entity,
     RenderPass& pass,
     std::optional<Rect> texture_coverage,
     std::optional<Matrix> effect_transform) const {
   FML_DCHECK(renderer.GetDeviceCapabilities().SupportsCompute());
   if (radius_ < 0.0) {
     return {};
   }
   Scalar determinant = entity.GetTransform().GetDeterminant();
   if (determinant == 0) {
     return {};
   }

   Scalar min_size = 1.0f / sqrt(std::abs(determinant));
   Scalar radius = std::max(radius_, min_size);

   size_t vertices_per_geom = ComputeCircleDivisions(
       entity.GetTransform().GetMaxBasisLength() * radius, round_);

   size_t points_per_circle = 3 + (vertices_per_geom - 3) * 3;
   size_t total = points_per_circle * points_.size();

   std::shared_ptr<CommandBuffer> cmd_buffer =
       renderer.GetContext()->CreateCommandBuffer();
   std::shared_ptr<ComputePass> compute_pass = cmd_buffer->CreateComputePass();
   HostBuffer& host_buffer = renderer.GetTransientsBuffer();

   BufferView points_data =
       host_buffer.Emplace(points_.data(), points_.size() * sizeof(Point),
                           DefaultUniformAlignment());

   BufferView geometry_buffer =
       host_buffer.Emplace(nullptr, total * sizeof(Point), alignof(Point));

   BufferView output;
   {
     using PS = PointsComputeShader;

     compute_pass->SetPipeline(renderer.GetPointComputePipeline());
     compute_pass->SetCommandLabel("Points Geometry");

     PS::FrameInfo frame_info;
     frame_info.count = points_.size();
     frame_info.radius = round_ ? radius : radius * kSqrt2;
     frame_info.radian_start = round_ ? 0.0f : kPiOver4;
     frame_info.radian_step = k2Pi / vertices_per_geom;
     frame_info.points_per_circle = points_per_circle;
     frame_info.divisions_per_circle = vertices_per_geom;

     PS::BindFrameInfo(*compute_pass, host_buffer.EmplaceUniform(frame_info));
     PS::BindGeometryData(*compute_pass, geometry_buffer);
     PS::BindPointData(*compute_pass, points_data);

     if (!compute_pass->Compute(ISize(total, 1)).ok()) {
       return {};
     }
     output = geometry_buffer;
   }

   if (texture_coverage.has_value() && effect_transform.has_value()) {
     BufferView geometry_uv_buffer =
         host_buffer.Emplace(nullptr, total * sizeof(Vector4), alignof(Vector4));

     using UV = UvComputeShader;

     compute_pass->AddBufferMemoryBarrier();
     compute_pass->SetCommandLabel("UV Geometry");
     compute_pass->SetPipeline(renderer.GetUvComputePipeline());

     UV::FrameInfo frame_info;
     frame_info.count = total;
     frame_info.effect_transform = effect_transform.value();
     frame_info.texture_origin = {0, 0};
     frame_info.texture_size = Vector2(texture_coverage.value().GetSize());

     UV::BindFrameInfo(*compute_pass, host_buffer.EmplaceUniform(frame_info));
     UV::BindGeometryData(*compute_pass, geometry_buffer);
     UV::BindGeometryUVData(*compute_pass, geometry_uv_buffer);

     if (!compute_pass->Compute(ISize(total, 1)).ok()) {
       return {};
     }
     output = geometry_uv_buffer;
   }

   if (!compute_pass->EncodeCommands()) {
     return {};
   }
   renderer.RecordCommandBuffer(std::move(cmd_buffer));

   return {
       .type = PrimitiveType::kTriangle,
       .vertex_buffer = {.vertex_buffer = std::move(output),
                         .vertex_count = total,
                         .index_type = IndexType::kNone},
       .transform = pass.GetOrthographicTransform() * entity.GetTransform(),
   };
 }

 /// @brief Compute the number of vertices to divide each circle into.
 ///
 /// @return the number of vertices.
 size_t PointFieldGeometry::ComputeCircleDivisions(Scalar scaled_radius,
                                                   bool round) {
   if (!round) {
     return 4;
   }

   // Note: these values are approximated based on the values returned from
   // the decomposition of 4 cubics performed by Path::CreatePolyline.
   if (scaled_radius < 1.0) {
     return 4;
   }
   if (scaled_radius < 2.0) {
     return 8;
   }
   if (scaled_radius < 12.0) {
     return 24;
   }
   if (scaled_radius < 22.0) {
     return 34;
   }
   return std::min(scaled_radius, 140.0f);
 }

 // |Geometry|
 GeometryVertexType PointFieldGeometry::GetVertexType() const {
   return GeometryVertexType::kPosition;
 }

 // |Geometry|
 std::optional<Rect> PointFieldGeometry::GetCoverage(
     const Matrix& transform) const {
   if (points_.size() > 0) {
     // Doesn't use MakePointBounds as this isn't resilient to points that
     // all lie along the same axis.
     auto first = points_.begin();
     auto last = points_.end();
     auto left = first->x;
     auto top = first->y;
     auto right = first->x;
     auto bottom = first->y;
     for (auto it = first + 1; it < last; ++it) {
       left = std::min(left, it->x);
       top = std::min(top, it->y);
       right = std::max(right, it->x);
       bottom = std::max(bottom, it->y);
     }
     auto coverage = Rect::MakeLTRB(left - radius_, top - radius_,
                                    right + radius_, bottom + radius_);
     return coverage.TransformBounds(transform);
   }
   return std::nullopt;
 }

 }  // namespace impeller
	// Copyright 2013 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "impeller/entity/geometry/point_field_geometry.h"

	#include "impeller/renderer/command_buffer.h"

	namespace impeller {

	PointFieldGeometry::PointFieldGeometry(std::vector<Point> points,
	Scalar radius,
	bool round)
	: points_(std::move(points)), radius_(radius), round_(round) {}

	GeometryResult PointFieldGeometry::GetPositionBuffer(
	const ContentContext& renderer,
	const Entity& entity,
	RenderPass& pass) const {
	if (renderer.GetDeviceCapabilities().SupportsCompute()) {
	return GetPositionBufferGPU(renderer, entity, pass);
	}
	auto vtx_builder = GetPositionBufferCPU(renderer, entity, pass);
	if (!vtx_builder.has_value()) {
	return {};
	}

	auto& host_buffer = renderer.GetTransientsBuffer();
	return {
	.type = PrimitiveType::kTriangleStrip,
	.vertex_buffer = vtx_builder->CreateVertexBuffer(host_buffer),
	.transform = pass.GetOrthographicTransform() * entity.GetTransform(),
	};
	}

	GeometryResult PointFieldGeometry::GetPositionUVBuffer(
	Rect texture_coverage,
	Matrix effect_transform,
	const ContentContext& renderer,
	const Entity& entity,
	RenderPass& pass) const {
	if (renderer.GetDeviceCapabilities().SupportsCompute()) {
	return GetPositionBufferGPU(renderer, entity, pass, texture_coverage,
	effect_transform);
	}

	auto vtx_builder = GetPositionBufferCPU(renderer, entity, pass);
	if (!vtx_builder.has_value()) {
	return {};
	}
	auto uv_vtx_builder =
	ComputeUVGeometryCPU(vtx_builder.value(), {0, 0},
	texture_coverage.GetSize(), effect_transform);

	auto& host_buffer = renderer.GetTransientsBuffer();
	return {
	.type = PrimitiveType::kTriangleStrip,
	.vertex_buffer = uv_vtx_builder.CreateVertexBuffer(host_buffer),
	.transform = pass.GetOrthographicTransform() * entity.GetTransform(),
	};
	}

	std::optional<VertexBufferBuilder<SolidFillVertexShader::PerVertexData>>
	PointFieldGeometry::GetPositionBufferCPU(const ContentContext& renderer,
	const Entity& entity,
	RenderPass& pass) const {
	if (radius_ < 0.0) {
	return std::nullopt;
	}
	auto transform = entity.GetTransform();
	auto determinant = transform.GetDeterminant();
	if (determinant == 0) {
	return std::nullopt;
	}

	Scalar min_size = 1.0f / sqrt(std::abs(determinant));
	Scalar radius = std::max(radius_, min_size);

	VertexBufferBuilder<SolidFillVertexShader::PerVertexData> vtx_builder;

	if (round_) {
	// Get triangulation relative to {0, 0} so we can translate it to each
	// point in turn.
	auto generator =
	renderer.GetTessellator()->FilledCircle(transform, {}, radius);
	FML_DCHECK(generator.GetTriangleType() == PrimitiveType::kTriangleStrip);
	std::vector<Point> circle_vertices;
	circle_vertices.reserve(generator.GetVertexCount());
	generator.GenerateVertices([&circle_vertices](const Point& p) { //
	circle_vertices.push_back(p);
	});
	FML_DCHECK(circle_vertices.size() == generator.GetVertexCount());

	vtx_builder.Reserve((circle_vertices.size() + 2) * points_.size() - 2);
	for (auto& center : points_) {
	if (vtx_builder.HasVertices()) {
	vtx_builder.AppendVertex(vtx_builder.Last());
	vtx_builder.AppendVertex({center + circle_vertices[0]});
	}

	for (auto& vertex : circle_vertices) {
	vtx_builder.AppendVertex({center + vertex});
	}
	}
	} else {
	vtx_builder.Reserve(6 * points_.size() - 2);
	for (auto& point : points_) {
	auto first = Point(point.x - radius, point.y - radius);

	if (vtx_builder.HasVertices()) {
	vtx_builder.AppendVertex(vtx_builder.Last());
	vtx_builder.AppendVertex({first});
	}

	// Z pattern from UL -> UR -> LL -> LR
	vtx_builder.AppendVertex({first});
	vtx_builder.AppendVertex({{point.x + radius, point.y - radius}});
	vtx_builder.AppendVertex({{point.x - radius, point.y + radius}});
	vtx_builder.AppendVertex({{point.x + radius, point.y + radius}});
	}
	}

	return vtx_builder;
	}

	GeometryResult PointFieldGeometry::GetPositionBufferGPU(
	const ContentContext& renderer,
	const Entity& entity,
	RenderPass& pass,
	std::optional<Rect> texture_coverage,
	std::optional<Matrix> effect_transform) const {
	FML_DCHECK(renderer.GetDeviceCapabilities().SupportsCompute());
	if (radius_ < 0.0) {
	return {};
	}
	Scalar determinant = entity.GetTransform().GetDeterminant();
	if (determinant == 0) {
	return {};
	}

	Scalar min_size = 1.0f / sqrt(std::abs(determinant));
	Scalar radius = std::max(radius_, min_size);

	size_t vertices_per_geom = ComputeCircleDivisions(
	entity.GetTransform().GetMaxBasisLength() * radius, round_);

	size_t points_per_circle = 3 + (vertices_per_geom - 3) * 3;
	size_t total = points_per_circle * points_.size();

	std::shared_ptr<CommandBuffer> cmd_buffer =
	renderer.GetContext()->CreateCommandBuffer();
	std::shared_ptr<ComputePass> compute_pass = cmd_buffer->CreateComputePass();
	HostBuffer& host_buffer = renderer.GetTransientsBuffer();

	BufferView points_data =
	host_buffer.Emplace(points_.data(), points_.size() * sizeof(Point),
	DefaultUniformAlignment());

	BufferView geometry_buffer =
	host_buffer.Emplace(nullptr, total * sizeof(Point), alignof(Point));

	BufferView output;
	{
	using PS = PointsComputeShader;

	compute_pass->SetPipeline(renderer.GetPointComputePipeline());
	compute_pass->SetCommandLabel("Points Geometry");

	PS::FrameInfo frame_info;
	frame_info.count = points_.size();
	frame_info.radius = round_ ? radius : radius * kSqrt2;
	frame_info.radian_start = round_ ? 0.0f : kPiOver4;
	frame_info.radian_step = k2Pi / vertices_per_geom;
	frame_info.points_per_circle = points_per_circle;
	frame_info.divisions_per_circle = vertices_per_geom;

	PS::BindFrameInfo(*compute_pass, host_buffer.EmplaceUniform(frame_info));
	PS::BindGeometryData(*compute_pass, geometry_buffer);
	PS::BindPointData(*compute_pass, points_data);

	if (!compute_pass->Compute(ISize(total, 1)).ok()) {
	return {};
	}
	output = geometry_buffer;
	}

	if (texture_coverage.has_value() && effect_transform.has_value()) {
	BufferView geometry_uv_buffer =
	host_buffer.Emplace(nullptr, total * sizeof(Vector4), alignof(Vector4));

	using UV = UvComputeShader;

	compute_pass->AddBufferMemoryBarrier();
	compute_pass->SetCommandLabel("UV Geometry");
	compute_pass->SetPipeline(renderer.GetUvComputePipeline());

	UV::FrameInfo frame_info;
	frame_info.count = total;
	frame_info.effect_transform = effect_transform.value();
	frame_info.texture_origin = {0, 0};
	frame_info.texture_size = Vector2(texture_coverage.value().GetSize());

	UV::BindFrameInfo(*compute_pass, host_buffer.EmplaceUniform(frame_info));
	UV::BindGeometryData(*compute_pass, geometry_buffer);
	UV::BindGeometryUVData(*compute_pass, geometry_uv_buffer);

	if (!compute_pass->Compute(ISize(total, 1)).ok()) {
	return {};
	}
	output = geometry_uv_buffer;
	}

	if (!compute_pass->EncodeCommands()) {
	return {};
	}
	renderer.RecordCommandBuffer(std::move(cmd_buffer));

	return {
	.type = PrimitiveType::kTriangle,
	.vertex_buffer = {.vertex_buffer = std::move(output),
	.vertex_count = total,
	.index_type = IndexType::kNone},
	.transform = pass.GetOrthographicTransform() * entity.GetTransform(),
	};
	}

	/// @brief Compute the number of vertices to divide each circle into.
	///
	/// @return the number of vertices.
	size_t PointFieldGeometry::ComputeCircleDivisions(Scalar scaled_radius,
	bool round) {
	if (!round) {
	return 4;
	}

	// Note: these values are approximated based on the values returned from
	// the decomposition of 4 cubics performed by Path::CreatePolyline.
	if (scaled_radius < 1.0) {
	return 4;
	}
	if (scaled_radius < 2.0) {
	return 8;
	}
	if (scaled_radius < 12.0) {
	return 24;
	}
	if (scaled_radius < 22.0) {
	return 34;
	}
	return std::min(scaled_radius, 140.0f);
	}

	// \|Geometry\|
	GeometryVertexType PointFieldGeometry::GetVertexType() const {
	return GeometryVertexType::kPosition;
	}

	// \|Geometry\|
	std::optional<Rect> PointFieldGeometry::GetCoverage(
	const Matrix& transform) const {
	if (points_.size() > 0) {
	// Doesn't use MakePointBounds as this isn't resilient to points that
	// all lie along the same axis.
	auto first = points_.begin();
	auto last = points_.end();
	auto left = first->x;
	auto top = first->y;
	auto right = first->x;
	auto bottom = first->y;
	for (auto it = first + 1; it < last; ++it) {
	left = std::min(left, it->x);
	top = std::min(top, it->y);
	right = std::max(right, it->x);
	bottom = std::max(bottom, it->y);
	}
	auto coverage = Rect::MakeLTRB(left - radius_, top - radius_,
	right + radius_, bottom + radius_);
	return coverage.TransformBounds(transform);
	}
	return std::nullopt;
	}

	} // namespace impeller