Struct ShadowSystem

ClassList > ShadowSystem

Owns per-light GPU resources, shadow maps, and shadow computation. More...

• #include <ShadowSystem.h>

Classes

Type	Name
struct	AreaStruct GPU layout for area light data.
struct	PointStruct GPU layout for point light data.
struct	PolyStruct GPU layout for polygonal light header data.
struct	PolyVertStruct GPU layout for polygonal light vertex data.
struct	SceneInfo Light count statistics for current scene.
struct	SpotStruct GPU layout for spot light data.
struct	SunStruct GPU layout for sun/directional light data.

Public Attributes

Type	Name
StorageBuffer	area_buffer GPU buffer for area light data.
std::vector< AreaStruct >	area_list List of area lights for GPU upload.
UniformBuffer	info GPU buffer for SceneInfo metadata.
StorageBuffer	point_buffer GPU buffer for point light data.
std::vector< PointStruct >	point_list List of point lights for GPU upload.
StorageBuffer	poly_buffer GPU buffer for polygonal light header data.
std::vector< PolyStruct >	poly_list List of polygonal light headers for GPU upload.
std::vector< PolyVertStruct >	poly_verts List of polygonal light vertices for GPU upload.
StorageBuffer	poly_verts_buffer GPU buffer for polygonal light vertex data.
std::unordered_map< int, glm::mat4 >	proj_matrices Per-light projection matrices for shadow rendering.
std::unordered_map< int, Texture >	shadow_cache Processed shadow cache per light (light ID -> texture)
std::unordered_map< int, Texture >	shadow_maps Raw per-light shadow map textures (depth / moment)
StorageBuffer	spot_buffer GPU buffer for spot light data.
std::vector< SpotStruct >	spot_list List of spot lights for GPU upload.
StorageBuffer	sun_buffer GPU buffer for sun light data.
std::vector< SunStruct >	sun_list List of sun lights for GPU upload.

Public Static Attributes

Type	Name
const GLuint	Sizeof_Area = sizeof([**AreaStruct**](structShadowSystem_1_1AreaStruct.md)) Size of AreaStruct in bytes.
const GLuint	Sizeof_Point = sizeof([**PointStruct**](structShadowSystem_1_1PointStruct.md)) Size of PointStruct in bytes.
const GLuint	Sizeof_Poly = sizeof([**PolyStruct**](structShadowSystem_1_1PolyStruct.md)) Size of PolyStruct in bytes.
const GLuint	Sizeof_PolyVert = sizeof([**PolyVertStruct**](structShadowSystem_1_1PolyVertStruct.md)) Size of PolyVertStruct in bytes.
const GLuint	Sizeof_Spot = sizeof([**SpotStruct**](structShadowSystem_1_1SpotStruct.md)) Size of SpotStruct in bytes.
const GLuint	Sizeof_Sun = sizeof([**SunStruct**](structShadowSystem_1_1SunStruct.md)) Size of SunStruct in bytes.
constexpr int	shadow_slot = {31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16} Texture slots for shadow maps (GL_TEXTURE16-31)

Public Functions

Type	Name
void	Bind () const Binds all light buffers to shader binding points.
void	BindShadowMap () const Binds all shadow map textures to shader slots.
void	BindShadowMapBuffer (Light * light, Texture & shadow_map) Binds the shadow map framebuffer for a light, targeting its shadow map texture.
void	BindShadowMapShader (Light * light, const glm::mat4 & proj) Binds the shadow map generation shader and sets per-light uniforms.
void	BindTargetTrans (Light * light, const glm::mat4 & _trans) Sets the model matrix uniform for a shadow-casting object.
void	ConstructSAT (Light * light, const RenderConfigs * config) Constructs Summed Area Table (SAT) for soft shadows.
SceneInfo	GetSceneInfo () const Returns light count statistics for current scene.
GLuint	GetSlotOffset (LightType _type) const Returns shadow map slot offset for a given light type.
GLsizei	GetTotalCount () const Returns total number of lights across all types.
void	Init () Initializes GPU buffers.
void	InitShadowMap (Light * light, bool using_moment_shadow) Initializes the raw shadow map texture for a single light.
void	ParseLightData (const std::unordered_map< int, std::shared_ptr< Light > > & light_list, bool using_moment_shadow=false) Parses basic lights (point, sun, spot, area) into GPU buffers.
void	ParsePolygonLightData (const std::unordered_map< int, std::shared_ptr< PolygonLight > > & poly_light_list) Parses polygonal lights into GPU buffers.
void	Resize (GLuint _w, GLuint _h) Resizes all cached shadow maps.
	ShadowSystem () Constructs an empty ShadowSystem .
void	Update (int frame, RenderConfigs * config) Updates shadow maps for the current frame.
void	UpdateLight (Light * light) Updates a single light's GPU data.
void	UpdateProjMatrix (Light * light) Computes and stores the projection matrix for a light.
	~ShadowSystem () Destroys the ShadowSystem and releases GPU resources.

Public Static Functions

Type	Name
void	EnableShadowMap () Initializes static shadow map framebuffers and shaders.

Detailed Description

ShadowSystem aggregates all lights in the scene and packs them into typed storage buffers (SSBO) for efficient GPU access. It also owns the per-light shadow map textures and projection matrices that were previously held by Light.

GPU Layout: * PointStruct: Point lights (position, color, power, radius, shadow flag) * SunStruct: Directional sun lights (direction, projection matrix) * SpotStruct: Spot lights (position, direction, cone angles) * AreaStruct: Rectangular area lights (transform, aspect ratio) * PolyStruct + PolyVertStruct: Polygonal area lights (vertex list)

Shadow Map Management: * Owns shadow map textures per-light (raw depth / moment maps) * Owns projection matrices per-light * Handles shadow map resizing on viewport changes * Binds shadow maps to dedicated texture slots (16-31)

Note:

All structs use explicit alignment (alignas) to match GLSL std140/std430 layout.

Note:

Thread-safety: Not thread-safe. Access from main thread only.

Public Attributes Documentation

variable area_buffer

GPU buffer for area light data.

StorageBuffer ShadowSystem::area_buffer;

---

variable area_list

List of area lights for GPU upload.

std::vector<AreaStruct> ShadowSystem::area_list;

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variable info

GPU buffer for SceneInfo metadata.

UniformBuffer ShadowSystem::info;

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variable point_buffer

GPU buffer for point light data.

StorageBuffer ShadowSystem::point_buffer;

---

variable point_list

List of point lights for GPU upload.

std::vector<PointStruct> ShadowSystem::point_list;

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variable poly_buffer

GPU buffer for polygonal light header data.

StorageBuffer ShadowSystem::poly_buffer;

---

variable poly_list

List of polygonal light headers for GPU upload.

std::vector<PolyStruct> ShadowSystem::poly_list;

---

variable poly_verts

List of polygonal light vertices for GPU upload.

std::vector<PolyVertStruct> ShadowSystem::poly_verts;

---

variable poly_verts_buffer

GPU buffer for polygonal light vertex data.

StorageBuffer ShadowSystem::poly_verts_buffer;

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variable proj_matrices

Per-light projection matrices for shadow rendering.

std::unordered_map<int, glm::mat4> ShadowSystem::proj_matrices;

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variable shadow_cache

Processed shadow cache per light (light ID -> texture)

std::unordered_map<int, Texture> ShadowSystem::shadow_cache;

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variable shadow_maps

Raw per-light shadow map textures (depth / moment)

std::unordered_map<int, Texture> ShadowSystem::shadow_maps;

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variable spot_buffer

GPU buffer for spot light data.

StorageBuffer ShadowSystem::spot_buffer;

---

variable spot_list

List of spot lights for GPU upload.

std::vector<SpotStruct> ShadowSystem::spot_list;

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variable sun_buffer

GPU buffer for sun light data.

StorageBuffer ShadowSystem::sun_buffer;

---

variable sun_list

List of sun lights for GPU upload.

std::vector<SunStruct> ShadowSystem::sun_list;

---

Public Static Attributes Documentation

variable Sizeof_Area

Size of AreaStruct in bytes.

const GLuint ShadowSystem::Sizeof_Area;

---

variable Sizeof_Point

Size of PointStruct in bytes.

const GLuint ShadowSystem::Sizeof_Point;

---

variable Sizeof_Poly

Size of PolyStruct in bytes.

const GLuint ShadowSystem::Sizeof_Poly;

---

variable Sizeof_PolyVert

Size of PolyVertStruct in bytes.

const GLuint ShadowSystem::Sizeof_PolyVert;

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variable Sizeof_Spot

Size of SpotStruct in bytes.

const GLuint ShadowSystem::Sizeof_Spot;

---

variable Sizeof_Sun

Size of SunStruct in bytes.

const GLuint ShadowSystem::Sizeof_Sun;

---

variable shadow_slot

Texture slots for shadow maps (GL_TEXTURE16-31)

constexpr int ShadowSystem::shadow_slot[16];

---

Public Functions Documentation

function Bind

Binds all light buffers to shader binding points.

void ShadowSystem::Bind () const

Note:

Called before rendering to make light data accessible to shaders.

---

function BindShadowMap

Binds all shadow map textures to shader slots.

void ShadowSystem::BindShadowMap () const

Note:

Binds cached shadow maps to slots 16-31 for shader sampling.

---

function BindShadowMapBuffer

Binds the shadow map framebuffer for a light, targeting its shadow map texture.

void ShadowSystem::BindShadowMapBuffer (
    Light * light,
    Texture & shadow_map
) 

Parameters:

• light Light whose shadow map framebuffer to bind
• shadow_map Shadow map texture to use as render target

---

function BindShadowMapShader

Binds the shadow map generation shader and sets per-light uniforms.

void ShadowSystem::BindShadowMapShader (
    Light * light,
    const glm::mat4 & proj
) 

Parameters:

• light Light providing position, direction, and type-specific parameters
• proj Light-space projection matrix for this light

---

function BindTargetTrans

Sets the model matrix uniform for a shadow-casting object.

void ShadowSystem::BindTargetTrans (
    Light * light,
    const glm::mat4 & _trans
) 

Parameters:

• light Light whose shadow shader is currently bound
• _trans Model matrix of the geometry to render into the shadow map

---

function ConstructSAT

Constructs Summed Area Table (SAT) for soft shadows.

void ShadowSystem::ConstructSAT (
    Light * light,
    const RenderConfigs * config
) 

Parameters:

• light Light whose shadow map should be processed
• config Render configuration specifying shadow quality

Note:

SAT enables efficient variable-size blur for soft shadow filtering.

---

function GetSceneInfo

Returns light count statistics for current scene.

SceneInfo ShadowSystem::GetSceneInfo () const

Returns:

SceneInfo struct with counts per light type

---

function GetSlotOffset

Returns shadow map slot offset for a given light type.

GLuint ShadowSystem::GetSlotOffset (
    LightType _type
) const

Parameters:

• _type Light type (POINTLIGHT, SUNLIGHT, etc.)

Returns:

Starting texture slot index for this light type

---

function GetTotalCount

Returns total number of lights across all types.

GLsizei ShadowSystem::GetTotalCount () const

Returns:

Sum of all light counts (point + sun + spot + area + poly)

---

function Init

Initializes GPU buffers.

void ShadowSystem::Init () 

Note:

Must be called after OpenGL context creation.

---

function InitShadowMap

Initializes the raw shadow map texture for a single light.

void ShadowSystem::InitShadowMap (
    Light * light,
    bool using_moment_shadow
) 

Parameters:

• light Light to initialize shadow map for
• using_moment_shadow Use moment-based (HDR) format instead of depth

Note:

Allocates GPU texture based on light type (2D for sun/spot, cubemap for point).

---

function ParseLightData

Parses basic lights (point, sun, spot, area) into GPU buffers.

void ShadowSystem::ParseLightData (
    const std::unordered_map< int, std::shared_ptr< Light > > & light_list,
    bool using_moment_shadow=false
) 

Parameters:

• light_list Map of light ID to Light shared_ptr
• using_moment_shadow Initialize shadow maps with moment-based (HDR) format

Note:

Populates point_list, sun_list, spot_list, area_list and uploads to GPU.

Note:

Also initializes shadow_maps and proj_matrices for each light.

---

function ParsePolygonLightData

Parses polygonal lights into GPU buffers.

void ShadowSystem::ParsePolygonLightData (
    const std::unordered_map< int, std::shared_ptr< PolygonLight > > & poly_light_list
) 

Parameters:

• poly_light_list Map of polygon light ID to PolygonLight shared_ptr

Note:

Populates poly_list and poly_verts, then uploads to GPU.

---

function Resize

Resizes all cached shadow maps.

void ShadowSystem::Resize (
    GLuint _w,
    GLuint _h
) 

Parameters:

• _w New shadow map width
• _h New shadow map height

Note:

Called on viewport resize to match shadow map resolution.

---

function ShadowSystem

Constructs an empty ShadowSystem .

ShadowSystem::ShadowSystem () 

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function Update

Updates shadow maps for the current frame.

void ShadowSystem::Update (
    int frame,
    RenderConfigs * config
) 

Parameters:

• frame Current frame number
• config Render configuration for shadow quality

Note:

Manages per-light shadow cache updates and format changes.

---

function UpdateLight

Updates a single light's GPU data.

void ShadowSystem::UpdateLight (
    Light * light
) 

Parameters:

• light Pointer to modified Light object

Note:

Incrementally updates GPU buffer without full re-upload.

---

function UpdateProjMatrix

Computes and stores the projection matrix for a light.

void ShadowSystem::UpdateProjMatrix (
    Light * light
) 

Parameters:

• light Light whose projection matrix should be updated

Note:

Result is stored in proj_matrices keyed by light ID.

---

function ~ShadowSystem

Destroys the ShadowSystem and releases GPU resources.

ShadowSystem::~ShadowSystem () 

---

Public Static Functions Documentation

function EnableShadowMap

Initializes static shadow map framebuffers and shaders.

static void ShadowSystem::EnableShadowMap () 

Note:

Must be called once after OpenGL context creation, before rendering any shadows.

---

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The documentation for this class was generated from the following file src/render/ShadowSystem.h