KTech::Collider Struct Reference

2D physical space for Objects. More...

#include <collider.hpp>

Public Member Functions
void	Simple (UPoint size, uint8_t type, Point relativePosition=Point(0, 0))
	Construct a simple Collider (filled rectangle).
void	Write (const std::vector< std::string > &stringVector, uint8_t type, Point relativePosition=Point(0, 0))
	Construct a complex Collider (2D bitmap).
void	ByTextureCharacter (const Texture &texture, uint8_t type, char excludedCharacter=' ')
	Construct a Collider based on a Texture's character values.
void	ByTextureBackground (const Texture &texture, uint8_t type, uint8_t alphaThreshold=0)
	Construct a Collider based on a Texture's background values.
void	ByTextureForeground (const Texture &texture, uint8_t type, uint8_t alphaThreshold=0)
	Construct a Collider based on a Texture's foreground values.
auto	operator() (size_t x, size_t y) const -> bool
	Get a value from the 2D bitmap by-value (complex Colliders only).

Public Attributes
bool	m_active = true
	Activation status: true means enabled. false means disabled, and will be ignored in Object movement processing.
bool	m_simple
	true means simple, false means complex.
uint8_t	m_type
	Collider type, which determines collision results based on Collision::colliderTypes.
Point	m_rPos
	Relative position to the parent Object.
UPoint	m_size
	Rectangle size (used in both simple and complex forms).
std::vector< bool >	m_c
	1D vector of the 2D bitmap (used only in complex form).

Detailed Description

2D physical space for Objects.

Objects have a vector of these Colliders (Object::m_colliders), which represents their physical space. Colliders are used to process Object movement in Collision::MoveObject().

Similarly to Texture, there are 2 forms of Colliders: "simple" and "complex".

• Simple colliders are just efficient filled rectangles, which take the least amount of processing and memory. So, you should prefer using simple Colliders.
• Complex colliders are 2D bitmaps of bools which allow them to hold a detailed shape (in contrary to a filled rectangle). This makes them the least efficient in terms of processing and memory. So, minimize your use of complex Colliders to when you need such detailed shapes.

Colliders also have a "type", which you can define yourself (or first learn about) in Collision::colliderTypes.

See also

Collision::colliderTypes

Member Function Documentation

ByTextureBackground()

void KTech::Collider::ByTextureBackground	(	const Texture &	texture,
		uint8_t	type,
		uint8_t	alphaThreshold = 0 )

Construct a Collider based on a Texture's background values.

Parameters

texture	The base Texture.
type	Collider type, as defiend in Collision::colliderTypes.
alphaThreshold	Cells with background alpha => this value will be turned on.

ByTextureCharacter()

void KTech::Collider::ByTextureCharacter	(	const Texture &	texture,
		uint8_t	type,
		char	excludedCharacter = ' ' )

Construct a Collider based on a Texture's character values.

Parameters

texture	The base Texture.
type	Collider type, as defiend in Collision::colliderTypes.
excludedCharacter	Cells with this character will not be turned on.

ByTextureForeground()

void KTech::Collider::ByTextureForeground	(	const Texture &	texture,
		uint8_t	type,
		uint8_t	alphaThreshold = 0 )

Construct a Collider based on a Texture's foreground values.

Parameters

texture	The base Texture.
type	Collider type, as defiend in Collision::colliderTypes.
alphaThreshold	Cells with foreground alpha => this value will be turned on.

operator()()

auto KTech::Collider::operator() ( size_t x, size_t y ) const -> bool

nodiscard

Get a value from the 2D bitmap by-value (complex Colliders only).

Useful if you don't want to convert the 2D position to the corresponding index in the bitmap vector (Collider::m_c).

Parameters

x	X axis.
y	Y axis.

Returns

The value of the 2D bitmap at the given location, by-value (not by-reference!)

Simple()

void KTech::Collider::Simple	(	UPoint	size,
		uint8_t	type,
		Point	relativePosition = Point(0, 0) )

Construct a simple Collider (filled rectangle).

Parameters

size	Rectangle size.
type	Collider type, as defiend in Collision::colliderTypes.
relativePosition	Relative position to the parent Object.

Write()

void KTech::Collider::Write	(	const std::vector< std::string > &	stringVector,
		uint8_t	type,
		Point	relativePosition = Point(0, 0) )

Construct a complex Collider (2D bitmap).

Parameters

stringVector	The 2D bitmap representation in a vector of std::strings. If a character is a space (' '), the collider will not exist in the corresponding part of the resulting bitmap. Otherwise, the collider will exist there.
type	Collider type, as defiend in Collision::colliderTypes.
relativePosition	Relative position to the parent Object.

Example:

Collider::Write(
    {
        " # ",
        "###",
        "# #"
    }, 1, Point(0, 0)
);

Will construct a Collider that corresponds to the Texture:

Texture::Write(
    {
        " O ",
        "/|\\",
        "/ \\"
    }, RGBA( 255, 255, 0, 255 ), RGBAColors::transparent, Point(0, 0)
);

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

• ktech/world/collider.hpp
• ktech/world/collider.cpp