ObjectGeometry Class Reference

Geometry of an object. More...

#include <objects_geometry.h>

Inheritance diagram for ObjectGeometry:

Public Member Functions
	ObjectGeometry ()
	Construct an ObjectGeometry.
virtual	~ObjectGeometry ()
	Destructor.
virtual void	create_box2d_shape (b2BodyId body_id, b2ShapeDef &shape_def)=0
	Create Box2D shape based on this geometry.
b2ShapeId	get_shape_id () const
	Return Box2D shape_id.
virtual std::vector< std::vector< bool > >	export_geometry_grid (size_t num_bins_x, size_t num_bins_y, float bin_width, float bin_height, float obj_x, float obj_y) const =0
	Exports a boolean 2D grid showing which bins are covered by the geometry.
virtual void	render (SDL_Renderer *renderer, b2WorldId world_id, float x, float y, float theta, uint8_t r, uint8_t g, uint8_t b, uint8_t alpha=255) const =0
	Renders the object on the given SDL renderer.
virtual BoundingDisk	compute_bounding_disk () const =0
	Computes the bounding disk that completely encloses the geometry.
virtual BoundingBox	compute_bounding_box () const =0
	Computes the axis-aligned bounding box that completely encloses the geometry.
virtual float	get_distance_to (b2Vec2 orig, b2Vec2 point) const
	Compute the distance from a given point to the geometry.
virtual arena_polygons_t	generate_contours (std::size_t points_per_contour=0, b2Vec2 position={0.0f, 0.0f}) const =0
	Return one or more polygonal contours that approximate / represent this geometry.

Protected Attributes
bool	shape_created = false
b2ShapeId	shape_id
	Box2D shape identifier.

Detailed Description

Geometry of an object.

Constructor & Destructor Documentation

ObjectGeometry()

ObjectGeometry::ObjectGeometry ( )

inline

Construct an ObjectGeometry.

~ObjectGeometry()

ObjectGeometry::~ObjectGeometry ( )

virtual

Destructor.

Member Function Documentation

compute_bounding_box()

virtual BoundingBox ObjectGeometry::compute_bounding_box ( ) const

pure virtual

Computes the axis-aligned bounding box that completely encloses the geometry.

Returns

A BoundingBox with top-left corner (x,y) and width and height.

Implemented in ArenaGeometry, DiskGeometry, GlobalGeometry, RectangleGeometry, and TriangleGeometry.

compute_bounding_disk()

virtual BoundingDisk ObjectGeometry::compute_bounding_disk ( ) const

pure virtual

Computes the bounding disk that completely encloses the geometry.

Returns

A BoundingDisk with center (x,y) and radius.

Implemented in ArenaGeometry, DiskGeometry, GlobalGeometry, RectangleGeometry, and TriangleGeometry.

create_box2d_shape()

virtual void ObjectGeometry::create_box2d_shape ( b2BodyId body_id, b2ShapeDef & shape_def )

pure virtual

Create Box2D shape based on this geometry.

Implemented in ArenaGeometry, DiskGeometry, GlobalGeometry, RectangleGeometry, and TriangleGeometry.

export_geometry_grid()

virtual std::vector< std::vector< bool > > ObjectGeometry::export_geometry_grid ( size_t num_bins_x, size_t num_bins_y, float bin_width, float bin_height, float obj_x, float obj_y ) const

pure virtual

Exports a boolean 2D grid showing which bins are covered by the geometry.

Parameters

num_bins_x	Number of bins along the X-axis.
num_bins_y	Number of bins along the Y-axis.
bin_width	Width (size) of each bin.
bin_height	Height (size) of each bin.
obj_x	The x-coordinate of the object (geometry center).
obj_y	The y-coordinate of the object (geometry center).

Returns

A 2D vector of booleans. True in a given cell indicates that the geometry covers that bin.

Implemented in DiskGeometry, GlobalGeometry, RectangleGeometry, and TriangleGeometry.

generate_contours()

virtual arena_polygons_t ObjectGeometry::generate_contours ( std::size_t points_per_contour = 0, b2Vec2 position = {0.0f, 0.0f} ) const

pure virtual

Return one or more polygonal contours that approximate / represent this geometry.

Parameters

points_per_contour

Desired number of vertices for each contour (a rectangle has one contour, a disk has one, an arena may have many – one per wall).

Returns

arena_polygons_t A vector of closed polygons (counter‑clockwise, last vertex different from the first – the caller may close the loop if needed).

Implemented in ArenaGeometry, DiskGeometry, GlobalGeometry, RectangleGeometry, and TriangleGeometry.

get_distance_to()

float ObjectGeometry::get_distance_to ( b2Vec2 orig, b2Vec2 point ) const

virtual

Compute the distance from a given point to the geometry.

Reimplemented in ArenaGeometry, and GlobalGeometry.

get_shape_id()

b2ShapeId ObjectGeometry::get_shape_id ( ) const

inline

Return Box2D shape_id.

render()

virtual void ObjectGeometry::render ( SDL_Renderer * renderer, b2WorldId world_id, float x, float y, float theta, uint8_t r, uint8_t g, uint8_t b, uint8_t alpha = 255 ) const

pure virtual

Renders the object on the given SDL renderer.

Parameters

renderer	Pointer to the SDL_Renderer.
world_id	The Box2D world identifier (unused in rendering).
x	X coordinate
y	Y coordinate
r	Red color component
g	Green color component
b	Blue color component
alpha	Alpha color component

Implemented in ArenaGeometry, DiskGeometry, GlobalGeometry, RectangleGeometry, and TriangleGeometry.

Member Data Documentation

shape_created

bool ObjectGeometry::shape_created = false

protected

shape_id

b2ShapeId ObjectGeometry::shape_id

protected

Box2D shape identifier.

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

• src/pogosim/objects_geometry.h
• src/pogosim/objects_geometry.cpp