IInstancedDrawable Interface Reference

Interface for objects that support GPU instanced rendering. More...

#include <IDrawable.h>

Inheritance diagram for IInstancedDrawable:

Collaboration diagram for IInstancedDrawable:

Public Member Functions
virtual glm::mat4	getModelMatrix () const =0
	Gets the model transformation matrix for this instance.
virtual Rendering::InstanceData	getInstanceData () const
	Gets the complete per-instance data for GPU upload.
Public Member Functions inherited from IDrawable
virtual	~IDrawable ()=default
	Virtual destructor for proper cleanup of derived classes.
virtual Shader *	getShader () const =0
	Gets the shader used to render this object.
virtual Mesh *	getMesh () const =0
	Gets the mesh geometry for this object.
virtual uint32_t	getObjectID () const =0
	Gets the unique identifier for this object.

Detailed Description

Interface for objects that support GPU instanced rendering.

Objects implementing this interface can be efficiently batched and rendered together when they share the same mesh and shader. The Scene groups compatible objects and renders them in a single instanced draw call, significantly reducing CPU overhead and draw call count.

This is the preferred rendering path for most scene objects (SceneObject, etc.) as it provides optimal performance for large numbers of similar objects.

Note

The default getInstanceData() implementation provides basic transform and ID data. Override for custom per-instance attributes (e.g., color).

Example usage:

class SceneObject : public IInstancedDrawable {
    glm::mat4 getModelMatrix() const override {
        return computeTransformMatrix();
    }
};

See also

Scene::draw()

Mesh::drawInstanced()

Rendering::InstanceData

Definition at line 111 of file IDrawable.h.

Member Function Documentation

getInstanceData()

virtual Rendering::InstanceData IInstancedDrawable::getInstanceData ( ) const

inlinevirtual

Gets the complete per-instance data for GPU upload.

Constructs an InstanceData structure containing the model matrix, object ID, and any additional per-instance attributes. This data is uploaded to the GPU's instance buffer for instanced rendering.

The default implementation provides model matrix and object ID. Override to add custom attributes (e.g., per-instance color).

Returns

InstanceData structure for this object.

Note

The InstanceData layout must match the vertex attribute setup in Mesh::setupInstanceAttributes().

See also

Rendering::InstanceData

Mesh::drawInstanced()

Implemented in SceneObject.

Definition at line 145 of file IDrawable.h.

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getModelMatrix()

virtual glm::mat4 IInstancedDrawable::getModelMatrix ( ) const

pure virtual

Gets the model transformation matrix for this instance.

The model matrix transforms vertices from model space to render space. World-space drawables should subtract SceneObject::getRenderOrigin() before uploading instance data. Simulation, picking, and serialization must keep using world-space transforms.

Returns

The 4x4 model transformation matrix.

Note

This is called once per frame during batch preparation.

Implemented in SceneObject.

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

• src/graphics/core/IDrawable.h