ludus::graphics::renderer::SelectionOutlineRenderer¶

Class

Draws the silhouette outline of one selected triangle mesh over an image, entirely on the GPU.

The outline is found in screen space instead of from the mesh's edges. The selected mesh is rasterized once into a one-channel coverage mask, with no depth test so that another object in front does not hide the outline. A second pass over the mesh's projected bounds then strokes the boundary of that mask: every pixel within half a stroke width of a boundary between covered and uncovered pixels takes the stroke colour. Only the outer contour of the projected mesh, and the contour of any hole in it, is stroked; edges inside the projected area are not part of the mask boundary.

The cost per frame is one rasterization of the mesh's triangles plus a bounded neighbourhood search per pixel near the mesh, and does not grow with an adjacency build or per-frame CPU work on the mesh. Selecting a mesh uploads its positions and indices once, in SetMesh.

It uses the portable raster profile only, a vertex/index buffer pair, instance rows, one sampled texture and premultiplied blending, so it runs on every RHI backend including the browser backends.

All members run on the RHI owner thread, between frames, except Draw, which records into an open frame. The device must outlive this object.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

#include <ludus/graphics/renderer/selection_outline.hpp>

class ludus::graphics::renderer::SelectionOutlineRenderer final

Static fields¶

MAX_STROKE_WIDTH_PIXELS¶

static constexpr foundation::float32 ludus::graphics::renderer::SelectionOutlineRenderer::MAX_STROKE_WIDTH_PIXELS = 16

Largest stroke width, in physical pixels, bounding the per-pixel search.

Related types: foundation::float32

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

Methods¶

SelectionOutlineRenderer¶

ludus::graphics::renderer::SelectionOutlineRenderer::SelectionOutlineRenderer() noexcept

Construct without allocation or device access.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

~SelectionOutlineRenderer¶

ludus::graphics::renderer::SelectionOutlineRenderer::~SelectionOutlineRenderer()

Release logical GPU ownership; RHI retires accepted uses.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

Initialize¶

rhi::RasterStatus ludus::graphics::renderer::SelectionOutlineRenderer::Initialize(rhi::DeviceHandle device, const rhi::RasterShaderDescription &maskVertex, const rhi::RasterShaderDescription &maskFragment, const rhi::RasterShaderDescription &edgeVertex, const rhi::RasterShaderDescription &edgeFragment) noexcept

Create the fixed shaders, layouts, sampler and pipelines.

Parameter	Description
`device`	Ready device with the portable raster profile.
`maskVertex`	Vertex stage of renderer_selection_mask.
`maskFragment`	Fragment stage of renderer_selection_mask.
`edgeVertex`	Vertex stage of renderer_selection_outline.
`edgeFragment`	Fragment stage of renderer_selection_outline.

Returns

Ready or Pending once owned (poll Poll until Ready); InvalidDescription when a stage does not have the expected interface; InvalidState when already initialized. Failure requires Reset before retry.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

Poll¶

rhi::RasterStatus ludus::graphics::renderer::SelectionOutlineRenderer::Poll() noexcept

Advance asynchronous setup between frames, without waiting.

Related types: rhi::RasterStatus

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

Reset¶

void ludus::graphics::renderer::SelectionOutlineRenderer::Reset() noexcept

Drop the mesh, prepared versions and fixed resources, between frames.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

IsReady¶

bool ludus::graphics::renderer::SelectionOutlineRenderer::IsReady() const noexcept

Whether Initialize and its asynchronous setup have completed.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

SetMesh¶

rhi::RasterStatus ludus::graphics::renderer::SelectionOutlineRenderer::SetMesh(foundation::BorrowedView< const foundation::math::Vector3 > positionsMesh, foundation::BorrowedView< const foundation::uint32 > indices) noexcept

Upload the mesh to outline, replacing any earlier one. The arrays are copied before return; the caller may release them at once. Existing prepared versions stay valid and draw the new mesh.

Parameter	Description
`positionsMesh`	Finite mesh-local positions.
`indices`	Triangle-list indices into positionsMesh: a positive multiple of three, each below the position count.

Returns

Ready or Pending (poll GetMeshStatus); NotReady before Initialize completes; InvalidDescription for an empty, non-finite or out-of-range mesh; CapacityExceeded or OutOfMemory when the RHI refuses the size. Failure preserves the previous mesh.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

ClearMesh¶

void ludus::graphics::renderer::SelectionOutlineRenderer::ClearMesh() noexcept

Forget the mesh. Prepared versions then draw nothing.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

GetMeshStatus¶

rhi::RasterStatus ludus::graphics::renderer::SelectionOutlineRenderer::GetMeshStatus() noexcept

Readiness of the mesh buffers: Ready, Pending, or NotReady when no mesh is set.

Related types: rhi::RasterStatus

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

Prepare¶

rhi::RasterStatus ludus::graphics::renderer::SelectionOutlineRenderer::Prepare(const SelectionOutlineView &view, PreparedSelectionOutline &outPrepared) noexcept

Create the per-frame data of an outline of the current mesh. Creating a version is cheap (one small buffer), so a caller prepares one per distinct view. At most four versions exist at once.

Parameter	Description
`view`	Matrix, target extent and strokes.
`outPrepared`	Null on entry; receives the version on Ready or Pending.

Returns

Ready or Pending (poll GetStatus); NotReady before Initialize completes or without a mesh; InvalidDescription for a non-finite matrix, an empty extent or invalid strokes; CapacityExceeded when four versions are in use; InvalidState when outPrepared is not null. Failure preserves outPrepared.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

GetStatus¶

rhi::RasterStatus ludus::graphics::renderer::SelectionOutlineRenderer::GetStatus(PreparedSelectionOutline prepared) noexcept

Poll the version's buffers and the mesh until all are ready to draw. Draw requires Ready.

Related types: rhi::RasterStatus · PreparedSelectionOutline

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

Draw¶

rhi::RasterStatus ludus::graphics::renderer::SelectionOutlineRenderer::Draw(PreparedSelectionOutline prepared, const rhi::RasterPassDescription &description) noexcept

Draw the outline over an already initialized target. Records two passes into the open frame: the mask, then the strokes over description's target. The target keeps its contents; only pixels near the silhouette change. A mesh entirely outside the target draws nothing and records no pass.

Parameter	Description
`prepared`	A version whose GetStatus returned Ready, prepared for exactly this target extent.
`description`	Target and optional viewport/scissor. Color is the acquired surface when null, otherwise an RGBA8 linear attachment. Load, store and depth members are replaced.

Returns

Ready; InvalidHandle for a stale version; InvalidState when the extent changed or the mesh was replaced by an empty one; Unsupported for another target format; or the RHI failure that stopped recording.

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp

Release¶

rhi::RasterStatus ludus::graphics::renderer::SelectionOutlineRenderer::Release(PreparedSelectionOutline &inoutPrepared) noexcept

Clear owned identity; submitted resources retire only after RHI completion.

Related types: rhi::RasterStatus · PreparedSelectionOutline

Declared in modules/graphics/renderer/include/ludus/graphics/renderer/selection_outline.hpp