RenderPassFactory Class

Factory for constructing `RenderPass` objects from scene snapshots. More...

Declaration

class helios::rendering::RenderPassFactory { ... }

Public Member Functions Index

RenderPass	buildRenderPass (const helios::scene::Snapshot &snapshot) const
	Builds a `RenderPass` from a given `Snapshot`. More...
void	populateRenderQueue (const helios::scene::Snapshot &snapshot, helios::rendering::RenderQueue &renderQueue) const
	Populates an existing `RenderQueue` with render commands based on a `Snapshot`. More...
void	makeRenderCommand (const helios::scene::SnapshotItem &snapshotItem, helios::rendering::RenderQueue &renderQueue) const noexcept
	Emits render commands from a `SnapshotItem` to the render queue. More...

Public Static Functions Index

static RenderPassFactory &	getInstance ()
	Returns the singleton instance of `RenderPassFactory`. More...

Protected Static Attributes Index

static const helios::util::log::Logger &	logger_ = ...
	Shared logger instance for all RenderPassFactory objects. More...

Description

Factory for constructing `RenderPass` objects from scene snapshots.

`RenderPassFactory` transforms high-level scene data (`Snapshot` and `SnapshotItem`) into low-level rendering commands suitable for the rendering device. It creates `RenderPass` objects with populated `RenderQueue`s and configured frame uniforms.

## Responsibilities

• Build `RenderPass` objects from `Snapshot` data.
• Populate `RenderQueue` with `MeshRenderCommand` and `TextRenderCommand` objects.
• Configure frame-level uniforms (view/projection matrices).

## Usage

```cpp auto& factory = RenderPassFactory::getInstance(); auto snapshot = sceneGraph.createSnapshot(viewport); auto renderPass = factory.buildRenderPass(snapshot);

device.beginRenderPass(renderPass); device.doRender(renderPass); device.endRenderPass(renderPass); ```

info

This class implements a singleton pattern. In the future, the conversion of high-level scene data into lower-level rendering commands might be realized with strategies and/or separate factories.

See Also

RenderPass

See Also

Snapshot

See Also

SnapshotItem

See Also

RenderQueue

Definition at line 61 of file RenderPassFactory.ixx.

Public Member Functions

buildRenderPass()

RenderPass helios::rendering::RenderPassFactory::buildRenderPass (const helios::scene::Snapshot & snapshot)

inline nodiscard

Builds a `RenderPass` from a given `Snapshot`.

This method orchestrates the creation of a `RenderQueue` and populates it with render commands derived from the `SnapshotItem`s within the snapshot. It also sets up frame-specific uniform values (view and projection matrices) for the `RenderPass`.

Parameters

snapshot

A const reference to the snapshot containing the scene data for which the `RenderPass` is to be built.

Returns

A fully constructed `RenderPass` object containing the render queue and frame-specific uniforms.

See Also

populateRenderQueue()

Definition at line 99 of file RenderPassFactory.ixx.

99 [[nodiscard]] RenderPass buildRenderPass(const helios::scene::Snapshot& snapshot) const {

100

101 auto renderQueue = RenderQueue();

102

103 populateRenderQueue(snapshot, renderQueue);

104

105 const auto& projectionMatrix = snapshot.projectionMatrix();

106 const auto& viewMatrix = snapshot.viewMatrix();

107

108 auto frameUniformValues = helios::rendering::shader::UniformValueMap();

109 frameUniformValues.set(helios::rendering::shader::UniformSemantics::ProjectionMatrix, projectionMatrix);

110 frameUniformValues.set(helios::rendering::shader::UniformSemantics::ViewMatrix, viewMatrix);

111

112 return RenderPass(

113 &snapshot.viewport(),

114 std::move(renderQueue),

115 frameUniformValues

116 );

117 }

References populateRenderQueue, helios::rendering::shader::ProjectionMatrix, helios::scene::Snapshot::projectionMatrix, helios::rendering::shader::ViewMatrix, helios::scene::Snapshot::viewMatrix and helios::scene::Snapshot::viewport.

Referenced by helios::engine::modules::scene::systems::SceneRenderingSystem::update.

makeRenderCommand()

void helios::rendering::RenderPassFactory::makeRenderCommand (const helios::scene::SnapshotItem & snapshotItem, helios::rendering::RenderQueue & renderQueue)

inline noexcept

Emits render commands from a `SnapshotItem` to the render queue.

This method extracts necessary data from the `SnapshotItem`, sets up the object uniform values (e.g., model matrix), and delegates to the `Renderable` to emit its render commands to the queue.

Parameters

snapshotItem	A const reference to the `SnapshotItem` from which to create render commands.
renderQueue	A reference to the `RenderQueue` to emit commands to.

info

If the `Renderable` pointer in the `SnapshotItem` is `nullptr`, a warning is logged and no commands are emitted.

Definition at line 158 of file RenderPassFactory.ixx.

158 void makeRenderCommand(

159 const helios::scene::SnapshotItem& snapshotItem,

160 helios::rendering::RenderQueue& renderQueue) const noexcept {

161

162 const auto* renderable = snapshotItem.renderable();

163

164 if (renderable == nullptr) {

165 logger_.warn("Renderable no longer available");

166 return;

167 }

168

169 auto objectUniformValues = helios::rendering::shader::UniformValueMap();

170 auto materialUniformValues = helios::rendering::shader::UniformValueMap();

171 objectUniformValues.set(

172 helios::rendering::shader::UniformSemantics::ModelMatrix,

173 snapshotItem.worldMatrix()

174 );

175

176 renderable->emit(

177 renderQueue,

178 objectUniformValues,

179 materialUniformValues

180 );

181

182 }

References logger_ and helios::rendering::shader::ModelMatrix.

Referenced by populateRenderQueue.

populateRenderQueue()

void helios::rendering::RenderPassFactory::populateRenderQueue (const helios::scene::Snapshot & snapshot, helios::rendering::RenderQueue & renderQueue)

inline

Populates an existing `RenderQueue` with render commands based on a `Snapshot`.

This method clears the specified `RenderQueue` before adding new commands. Each `SnapshotItem` in the snapshot is processed via `makeRenderCommand()`.

Parameters

snapshot	A const reference to the `Snapshot` providing scene data.
renderQueue	A reference to the `RenderQueue` to be filled. This queue will be cleared before new commands are added.

See Also

makeRenderCommand()

Definition at line 131 of file RenderPassFactory.ixx.

131 void populateRenderQueue(

132 const helios::scene::Snapshot& snapshot, helios::rendering::RenderQueue& renderQueue) const {

133

134 // clear the queue

135 renderQueue.clear();

136

137 auto snapshotItems = snapshot.snapshotItems();

138

139 for (const auto& item : snapshotItems) {

140 makeRenderCommand(item, renderQueue);

141 }

142 }

References helios::rendering::RenderQueue::clear, makeRenderCommand and helios::scene::Snapshot::snapshotItems.

Referenced by buildRenderPass.

Public Static Functions

getInstance()

RenderPassFactory & helios::rendering::RenderPassFactory::getInstance ()

inline static

Returns the singleton instance of `RenderPassFactory`.

Returns

A reference to the single `RenderPassFactory` instance.

Definition at line 77 of file RenderPassFactory.ixx.

77 static RenderPassFactory& getInstance() {

78 static RenderPassFactory instance;

79

80 return instance;

81 }

Referenced by helios::engine::modules::scene::systems::SceneRenderingSystem::update.

Protected Static Attributes

logger_

const helios::util::log::Logger& helios::rendering::RenderPassFactory::logger_

protected static

Shared logger instance for all RenderPassFactory objects.

Initialiser

= helios::util::log::LogManager::loggerForScope( HELIOS_LOG_SCOPE )

Definition at line 67 of file RenderPassFactory.ixx.

67 inline static const helios::util::log::Logger& logger_ = helios::util::log::LogManager::loggerForScope(

Referenced by makeRenderCommand.

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The documentation for this class was generated from the following file:

• RenderPassFactory.ixx

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