Qt RHI-based 3-D renderer managing scene objects, lighting, camera, and render pipeline for brain visualization. More...

#include <brainrenderer.h>

Classes
struct	SceneData
	Aggregated GPU resources and render state for the 3-D brain visualization scene. More...
struct	Impl

Public Types
using	ShaderMode = ::ShaderMode

Public Member Functions
	BrainRenderer ()
	~BrainRenderer ()
void	initialize (QRhi rhi, QRhiRenderPassDescriptor rp, int sampleCount)
void	ensureRenderTargets (QRhi rhi, QRhiTexture colorTex, const QSize &pixelSize)
QRhiRenderTarget *	rtClear () const
QRhiRenderTarget *	rtPreserve () const
void	beginFrame (QRhiCommandBuffer *cb)
void	beginPreservingPass (QRhiCommandBuffer *cb)
void	updateSceneUniforms (QRhi *rhi, const SceneData &data)
void	renderSurface (QRhiCommandBuffer cb, QRhi rhi, const SceneData &data, BrainSurface *surface, ShaderMode mode)
int	prepareSurfaceDraw (QRhiResourceUpdateBatch u, const SceneData &data, BrainSurface surface)
void	issueSurfaceDraw (QRhiCommandBuffer cb, BrainSurface surface, ShaderMode mode, int uniformOffset)
void	prepareMergedSurfaces (QRhi rhi, QRhiResourceUpdateBatch u, const QVector< BrainSurface * > &surfaces, const QString &groupName=QStringLiteral("default"))
void	invalidateMergedGroup (const QString &groupName=QStringLiteral("default"))
bool	hasMergedContent (const QString &groupName) const
void	drawMergedSurfaces (QRhiCommandBuffer cb, QRhi rhi, const SceneData &data, ShaderMode mode, const QString &groupName=QStringLiteral("default"))
void	renderDipoles (QRhiCommandBuffer cb, QRhi rhi, const SceneData &data, DipoleObject *dipoles)
void	renderNetwork (QRhiCommandBuffer cb, QRhi rhi, const SceneData &data, NetworkObject *network)
void	prepareVideoOverlay (QRhi rhi, QRhiResourceUpdateBatch u, DISP3DLIB::VideoOverlay *overlay)
void	renderVideoOverlay (QRhiCommandBuffer cb, QRhi rhi, const SceneData &data, DISP3DLIB::VideoOverlay *overlay)
void	renderVideoOverlayOnSurface (QRhiCommandBuffer cb, QRhi rhi, const SceneData &data, DISP3DLIB::VideoOverlay overlay, BrainSurface surface)
void	prepareSlice (QRhi rhi, QRhiResourceUpdateBatch u, DISP3DLIB::SliceObject *slice, int slotIndex)
int	prepareSliceDraw (QRhiResourceUpdateBatch *u, const SceneData &data, int slotIndex)
void	issueSliceDraw (QRhiCommandBuffer *cb, int slotIndex, int uniformOffset)
void	endPass (QRhiCommandBuffer *cb)

Static Public Attributes
static constexpr ShaderMode	Standard = ::Standard
static constexpr ShaderMode	Holographic = ::Holographic
static constexpr ShaderMode	Anatomical = ::Anatomical
static constexpr ShaderMode	Dipole = ::Dipole
static constexpr ShaderMode	XRay = ::XRay
static constexpr ShaderMode	ShowNormals = ::ShowNormals

Detailed Description

Qt RHI-based 3-D renderer managing scene objects, lighting, camera, and render pipeline for brain visualization.

BrainRenderer handles the low-level RHI rendering logic, managing pipelines, shaders, and draw calls for brain surfaces.

Definition at line 69 of file brainrenderer.h.

Member Typedef Documentation

◆ ShaderMode

using BrainRenderer::ShaderMode = ::ShaderMode

Definition at line 86 of file brainrenderer.h.

Constructor & Destructor Documentation

◆ BrainRenderer()

BrainRenderer::BrainRenderer ( )

Default Constructor

Definition at line 208 of file brainrenderer.cpp.

◆ ~BrainRenderer()

BrainRenderer::~BrainRenderer ( )

default

Destructor

Member Function Documentation

◆ beginFrame()

void BrainRenderer::beginFrame ( QRhiCommandBuffer * cb )

Begin the first render pass of a frame. Clears color and depth.

Parameters

[in] cb Command buffer to record to.

Definition at line 425 of file brainrenderer.cpp.

◆ beginPreservingPass()

void BrainRenderer::beginPreservingPass ( QRhiCommandBuffer * cb )

Begin an additional render pass that preserves previous output. Uses the internal preserving render target (m_rtPreserve).

Parameters

[in] cb Command buffer.

Definition at line 447 of file brainrenderer.cpp.

◆ drawMergedSurfaces()

void BrainRenderer::drawMergedSurfaces	(	QRhiCommandBuffer *	cb,
		QRhi *	rhi,
		const SceneData &	data,
		ShaderMode	mode,
		const QString &	groupName = QStringLiteral("default") )

Draw previously prepared merged surfaces in a single drawIndexed. Call between beginFrame()/beginPreservingPass() and endPass().

Parameters

[in]	cb	Command buffer.
[in]	rhi	QRhi pointer.
[in]	data	Scene uniforms.
[in]	mode	Shader mode.

Definition at line 1714 of file brainrenderer.cpp.

◆ endPass()

void BrainRenderer::endPass ( QRhiCommandBuffer * cb )

End any render pass (clearing or preserving).

Parameters

[in] cb Command buffer.

Definition at line 459 of file brainrenderer.cpp.

◆ ensureRenderTargets()

void BrainRenderer::ensureRenderTargets	(	QRhi *	rhi,
		QRhiTexture *	colorTex,
		const QSize &	pixelSize )

Create the dual render-target pair for multi-pass rendering.

Both render targets share the same color texture and depth-stencil buffer but differ in their load/store flags:

m_rtClear: clears color+depth on beginPass (first pass)
m_rtPreserve: preserves previous output (passes 2+)

Qt bakes these flags into native resources at create() time, so calling setFlags() dynamically does NOT work (especially on WebGL). This is the validated pattern from test_wasm_multi_pass.

Parameters

[in]	rhi	QRhi instance.
[in]	colorTex	Color texture (owned by QRhiWidget or caller).
[in]	pixelSize	Render target dimensions.

Definition at line 378 of file brainrenderer.cpp.

◆ hasMergedContent()

bool BrainRenderer::hasMergedContent ( const QString & groupName ) const

Check if a merged group has drawable geometry (indexCount > 0). Use before beginPreservingPass() to avoid empty render passes which can clear the framebuffer on some WebGL implementations.

Parameters

[in] groupName Category name to check.

Returns: true if the group exists and has indices to draw.

Definition at line 1706 of file brainrenderer.cpp.

◆ initialize()

void BrainRenderer::initialize	(	QRhi *	rhi,
		QRhiRenderPassDescriptor *	rp,
		int	sampleCount )

Initialize resources (shaders, pipelines) for the given RHI and render pass. Ensures pipelines for all supported modes are created.

Parameters

[in]	rhi	Pointer to QRhi instance.
[in]	rp	Render pass descriptor.
[in]	sampleCount	MSAA sample count.

Definition at line 219 of file brainrenderer.cpp.

◆ invalidateMergedGroup()

void BrainRenderer::invalidateMergedGroup ( const QString & groupName = QStringLiteral("default") )

Mark a merged group as dirty so it is rebuilt on the next prepareMergedSurfaces call. Call when surfaces are added/removed or visibility changes.

Parameters

[in] groupName Category name to invalidate.

Definition at line 1696 of file brainrenderer.cpp.

◆ issueSliceDraw()

void BrainRenderer::issueSliceDraw	(	QRhiCommandBuffer *	cb,
		int	slotIndex,
		int	uniformOffset )

Issue draw commands for a prepared MRI slice.

Call after cb->resourceUpdate() has been submitted with the batch from prepareSliceDraw(). Does not create resource batches.

Parameters

[in]	cb	Command buffer (must be inside a render pass).
[in]	slotIndex	Slot index matching the prepareSliceDraw call.
[in]	uniformOffset	Offset returned by prepareSliceDraw().

Definition at line 1215 of file brainrenderer.cpp.

◆ issueSurfaceDraw()

void BrainRenderer::issueSurfaceDraw	(	QRhiCommandBuffer *	cb,
		BrainSurface *	surface,
		ShaderMode	mode,
		int	uniformOffset )

Issue draw commands for a surface using a pre-computed uniform offset.

Call after cb->resourceUpdate() has been submitted with the batch from prepareSurfaceDraw(). Does not create resource batches or modify viewport/scissor state.

Parameters

[in]	cb	Command buffer.
[in]	surface	Pointer to surface to draw.
[in]	mode	Shader mode.
[in]	uniformOffset	Offset returned by prepareSurfaceDraw().

Definition at line 1363 of file brainrenderer.cpp.

◆ prepareMergedSurfaces()

void BrainRenderer::prepareMergedSurfaces	(	QRhi *	rhi,
		QRhiResourceUpdateBatch *	u,
		const QVector< BrainSurface * > &	surfaces,
		const QString &	groupName = QStringLiteral("default") )

Prepare merged brain surface geometry for single-drawIndexed rendering. Call BEFORE beginFrame() with a pre-upload resource batch.

Uses dirty-flag caching: geometry is only rebuilt when the surface list changes (add/remove/visibility toggle). Per-vertex color updates (STC animation) only re-upload the color channel.

Parameters

[in]	rhi	QRhi pointer.
[in]	u	Resource update batch (pre-render uploads).
[in]	surfaces	Brain surfaces to merge.
[in]	groupName	Category name (e.g. "brain", "bem", "srcsp").

Definition at line 1542 of file brainrenderer.cpp.

◆ prepareSlice()

void BrainRenderer::prepareSlice	(	QRhi *	rhi,
		QRhiResourceUpdateBatch *	u,
		DISP3DLIB::SliceObject *	slice,
		int	slotIndex )

Prepare MRI slice GPU resources and upload texture data.

Must be called before a render pass starts. Creates the slice pipeline lazily on first use and uploads the slice texture.

Parameters

[in]	rhi	QRhi pointer.
[in]	u	Resource update batch owned by the caller.
[in]	slice	Pointer to SliceObject; ignored when null.
[in]	slotIndex	Slot index (0=axial, 1=coronal, 2=sagittal).

Definition at line 995 of file brainrenderer.cpp.

◆ prepareSliceDraw()

int BrainRenderer::prepareSliceDraw	(	QRhiResourceUpdateBatch *	u,
		const SceneData &	data,
		int	slotIndex )

Upload uniform data for an MRI slice into a shared resource batch.

Call once per visible slice, then submit the batch with cb->resourceUpdate(), and finally call issueSliceDraw() for each slice.

Parameters

[in]	u	Shared resource update batch.
[in]	data	Scene uniforms (MVP, camera position).
[in]	slotIndex	Slot index (0=axial, 1=coronal, 2=sagittal).

Returns: Uniform buffer offset for this draw, or -1 on failure.

Definition at line 1167 of file brainrenderer.cpp.

◆ prepareSurfaceDraw()

int BrainRenderer::prepareSurfaceDraw	(	QRhiResourceUpdateBatch *	u,
		const SceneData &	data,
		BrainSurface *	surface )

Upload uniform data for a surface into a shared resource batch.

This is the batched equivalent of the first half of renderSurface(). Call once per surface, then submit the batch with cb->resourceUpdate(), and finally call issueSurfaceDraw() for each surface.

Parameters

[in]	u	Shared resource update batch.
[in]	data	Scene uniforms (MVP, light, etc).
[in]	surface	Pointer to surface.

Returns: Uniform buffer offset for this draw, or -1 on failure.

Definition at line 1319 of file brainrenderer.cpp.

◆ prepareVideoOverlay()

void BrainRenderer::prepareVideoOverlay	(	QRhi *	rhi,
		QRhiResourceUpdateBatch *	u,
		DISP3DLIB::VideoOverlay *	overlay )

Prepare live video overlay GPU resources and upload the latest frame.

Must be called before a render pass starts. Texture uploads require a blit encoder on Metal and must not be recorded while a render encoder is active.

Parameters

[in]	rhi	QRhi pointer.
[in]	u	Resource update batch owned by the caller.
[in]	overlay	Pointer to VideoOverlay; ignored when null/disabled.

Definition at line 468 of file brainrenderer.cpp.

◆ renderDipoles()

void BrainRenderer::renderDipoles	(	QRhiCommandBuffer *	cb,
		QRhi *	rhi,
		const SceneData &	data,
		DipoleObject *	dipoles )

Render dipoles using instanced rendering.

Parameters

[in]	cb	Command buffer.
[in]	rhi	QRhi pointer.
[in]	data	Scene uniforms.
[in]	dipoles	Pointer to DipoleObject.

Definition at line 1391 of file brainrenderer.cpp.

◆ renderNetwork()

void BrainRenderer::renderNetwork	(	QRhiCommandBuffer *	cb,
		QRhi *	rhi,
		const SceneData &	data,
		NetworkObject *	network )

Render a connectivity network using instanced rendering. Renders both node spheres and edge cylinders as two draw calls.

Parameters

[in]	cb	Command buffer.
[in]	rhi	QRhi pointer.
[in]	data	Scene uniforms.
[in]	network	Pointer to NetworkObject.

Definition at line 1449 of file brainrenderer.cpp.

◆ renderSurface()

void BrainRenderer::renderSurface	(	QRhiCommandBuffer *	cb,
		QRhi *	rhi,
		const SceneData &	data,
		BrainSurface *	surface,
		ShaderMode	mode )

Render a single surface. Must be called between beginFrame/beginPreservingPass and endPass.

Parameters

[in]	cb	Command buffer.
[in]	rhi	QRhi pointer.
[in]	data	Scene uniforms (MVP, light, etc).
[in]	surface	Pointer to surface to draw.
[in]	mode	Shader mode to use for this surface.

Definition at line 1235 of file brainrenderer.cpp.

◆ renderVideoOverlay()

void BrainRenderer::renderVideoOverlay	(	QRhiCommandBuffer *	cb,
		QRhi *	rhi,
		const SceneData &	data,
		DISP3DLIB::VideoOverlay *	overlay )

Render a live video overlay as a camera-facing textured quad. Always drawn last (depth test disabled) so the cut-out sits on top of the head surface at the current focus position.

Parameters

[in]	cb	Command buffer (must be inside a render pass).
[in]	rhi	QRhi pointer.
[in]	data	Scene uniforms (MVP, camera position).
[in]	overlay	Pointer to VideoOverlay; ignored when null/disabled.

Definition at line 783 of file brainrenderer.cpp.

◆ renderVideoOverlayOnSurface()

void BrainRenderer::renderVideoOverlayOnSurface	(	QRhiCommandBuffer *	cb,
		QRhi *	rhi,
		const SceneData &	data,
		DISP3DLIB::VideoOverlay *	overlay,
		BrainSurface *	surface )

Render a live video overlay projected onto an existing surface mesh.

Parameters

[in]	cb	Command buffer (must be inside a render pass).
[in]	rhi	QRhi pointer.
[in]	data	Scene uniforms (MVP, camera position).
[in]	overlay	Pointer to VideoOverlay; ignored when null/disabled.
[in]	surface	Target surface mesh (typically scalp/head).

Definition at line 876 of file brainrenderer.cpp.

◆ rtClear()

QRhiRenderTarget * BrainRenderer::rtClear ( ) const

Returns: The clearing render target (pass 1).

Definition at line 413 of file brainrenderer.cpp.

◆ rtPreserve()

QRhiRenderTarget * BrainRenderer::rtPreserve ( ) const

Returns: The preserving render target (passes 2+).

Definition at line 418 of file brainrenderer.cpp.

◆ updateSceneUniforms()

void BrainRenderer::updateSceneUniforms	(	QRhi *	rhi,
		const SceneData &	data )

Set uniforms that are shared for the entire frame.

Parameters

[in] data Scene uniforms (MVP, light, etc).

Definition at line 440 of file brainrenderer.cpp.

Member Data Documentation

◆ Anatomical

ShaderMode BrainRenderer::Anatomical = ::Anatomical

staticconstexpr

Definition at line 89 of file brainrenderer.h.

◆ Dipole

ShaderMode BrainRenderer::Dipole = ::Dipole

staticconstexpr

Definition at line 90 of file brainrenderer.h.

◆ Holographic

ShaderMode BrainRenderer::Holographic = ::Holographic

staticconstexpr

Definition at line 88 of file brainrenderer.h.

◆ ShowNormals

ShaderMode BrainRenderer::ShowNormals = ::ShowNormals

staticconstexpr

Definition at line 92 of file brainrenderer.h.

◆ Standard

ShaderMode BrainRenderer::Standard = ::Standard

staticconstexpr

Definition at line 87 of file brainrenderer.h.

◆ XRay

ShaderMode BrainRenderer::XRay = ::XRay

staticconstexpr

Definition at line 91 of file brainrenderer.h.

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

src/libraries/disp3D/view/brainrenderer.h
src/libraries/disp3D/view/brainrenderer.cpp

Classes

Public Types

Public Member Functions

Static Public Attributes

Detailed Description

Member Typedef Documentation

◆ ShaderMode

Constructor & Destructor Documentation

◆ BrainRenderer()

◆ ~BrainRenderer()

Member Function Documentation

◆ beginFrame()

◆ beginPreservingPass()

◆ drawMergedSurfaces()

◆ endPass()

◆ ensureRenderTargets()

◆ hasMergedContent()

◆ initialize()

◆ invalidateMergedGroup()

◆ issueSliceDraw()

◆ issueSurfaceDraw()

◆ prepareMergedSurfaces()

◆ prepareSlice()

◆ prepareSliceDraw()

◆ prepareSurfaceDraw()

◆ prepareVideoOverlay()

◆ renderDipoles()

◆ renderNetwork()

◆ renderSurface()

◆ renderVideoOverlay()

◆ renderVideoOverlayOnSurface()

◆ rtClear()

◆ rtPreserve()

◆ updateSceneUniforms()

Member Data Documentation

◆ Anatomical

◆ Dipole

◆ Holographic

◆ ShowNormals

◆ Standard

◆ XRay