Package edu.cornell.gdiac.physics2

Class CapsuleObstacle

java.lang.Object

edu.cornell.gdiac.physics2.Obstacle

edu.cornell.gdiac.physics2.CapsuleObstacle

public class CapsuleObstacle
extends Obstacle

A capsule-shaped model to support collisions.

A capsule typically is a pill-like shape that fits inside of given rectangle (e.g. it has half circles at the ends of the longest side). If width < height, the capsule will be oriented vertically with the rounded portions at the top and bottom. Otherwise it will be oriented horizontally.

This class allows for the creation of half-capsules, simply by using the enumeration Capsule. The enumeration specifies which side should be rounded in case of a half-capsule. Half-capsules are sized so that the corresponding full capsule would fit in the bounding box.

Unless otherwise specified, the center of mass is the center of the capsule.

Field Summary

Fields

Modifier and Type	Field	Description
protected com.badlogic.gdx.math.Rectangle	center	Rectangle representation of capsule core for fast computation
protected com.badlogic.gdx.physics.box2d.CircleShape	end1	Shape information for the end cap
protected com.badlogic.gdx.physics.box2d.CircleShape	end2	Shape information for the end cap
protected com.badlogic.gdx.physics.box2d.PolygonShape	shape	Shape information for this box

Fields inherited from class edu.cornell.gdiac.physics2.Obstacle

body, bodyinfo, centroidCache, DEFAULT_UNITS, fixture, massdata, masseffect, outline, positionCache, transform, units, velocityCache

Constructor Summary

Constructors

Constructor	Description
CapsuleObstacle(float width, float height)	Creates a new box at the origin.
CapsuleObstacle(float x, float y, float width, float height)	Creates a new capsule object.
CapsuleObstacle(float x, float y, float width, float height, Capsule style)	Creates a new capsule object width the given style.

Method Summary

Modifier and Type	Method	Description
protected void	createFixtures()	Creates new fixtures for this body, defining the shape
com.badlogic.gdx.math.Vector2	getDimension()	Returns the dimensions of this capsule
float	getHeight()	Returns the capsule height
float	getSeamOffset()	Returns the seam offset of the core rectangle
Capsule	getStyle()	Returns the style of this capsule
float	getTolerance()	Returns the outline tolerance of this obstacle.
float	getWidth()	Returns the capsule width
protected void	releaseFixtures()	Releases the fixtures for this body, reseting the shape
void	setDensity(float value)	Sets the density of this body
void	setDimension(float width, float height)	Sets the dimensions of this capsule
void	setDimension(com.badlogic.gdx.math.Vector2 value)	Sets the dimensions of this capsule
void	setHeight(float value)	Sets the capsule height
void	setOrientation(Capsule value)	Sets the style of this capsule.
void	setSeamOffset(float value)	Sets the seam offset of the core rectangle
void	setTolerance(float tolerance)	Sets the outline tolerance of this obstacle.
void	setWidth(float value)	Sets the capsule width

Methods inherited from class edu.cornell.gdiac.physics2.Obstacle

activatePhysics, deactivatePhysics, draw, draw, draw, draw, getAngle, getAngularDamping, getAngularVelocity, getBody, getBodyType, getCentroid, getDensity, getFilterData, getFriction, getGravityScale, getInertia, getLinearDamping, getLinearVelocity, getMass, getName, getOutline, getPhysicsUnits, getPosition, getRestitution, getUserData, getVX, getVY, getX, getY, isActive, isAwake, isBullet, isDirty, isFixedRotation, isRemoved, isSensor, isSleepingAllowed, markDirty, markRemoved, resetMass, setActive, setAngle, setAngularDamping, setAngularVelocity, setAwake, setBodyState, setBodyType, setBullet, setCentroid, setFilterData, setFixedRotation, setFriction, setGravityScale, setInertia, setLinearDamping, setLinearVelocity, setMass, setName, setPhysicsUnits, setPosition, setPosition, setRestitution, setSensor, setSleepingAllowed, setUserData, setVX, setVY, setX, setY, update

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

shape

protected com.badlogic.gdx.physics.box2d.PolygonShape shape

Shape information for this box

end1

protected com.badlogic.gdx.physics.box2d.CircleShape end1

Shape information for the end cap

end2

protected com.badlogic.gdx.physics.box2d.CircleShape end2

Shape information for the end cap

center

protected com.badlogic.gdx.math.Rectangle center

Rectangle representation of capsule core for fast computation

Constructor Details

CapsuleObstacle

public CapsuleObstacle(float width,
 float height)

Creates a new box at the origin.

The orientation of the capsule will be a full capsule along the major axis. If width == height, it will be a degenerate capsule (e.g a circle).

The size is expressed in physics units NOT pixels. In order for drawing to work properly, you MUST call Obstacle.setPhysicsUnits(float).

Parameters:

width - The object width in physics units

height - The object width in physics units

CapsuleObstacle

public CapsuleObstacle(float x,
 float y,
 float width,
 float height)

Creates a new capsule object.

The orientation of the capsule will be a full capsule along the major axis. If width == height, it will be a degenerate capsule (e.g a circle).

The size is expressed in physics units NOT pixels. In order for drawing to work properly, you MUST call Obstacle.setPhysicsUnits(float).

Parameters:

x - Initial x position of the box center

y - Initial y position of the box center

width - The object width in physics units

height - The object width in physics units

CapsuleObstacle

public CapsuleObstacle(float x,
 float y,
 float width,
 float height,
 Capsule style)

Creates a new capsule object width the given style.

The size is expressed in physics units NOT pixels. In order for drawing to work properly, you MUST call Obstacle.setPhysicsUnits(float).

Parameters:

x - Initial x position of the box center

y - Initial y position of the box center

width - The object width in physics units

height - The object width in physics units

style - The capsule style

Method Details

getDimension

public com.badlogic.gdx.math.Vector2 getDimension()

Returns the dimensions of this capsule

This method does NOT return a reference to the dimension vector. Changes to this vector will not affect the shape. However, it returns the same vector each time its is called, and so cannot be used as an allocator.

Returns:

the dimensions of this capsule

setDimension

public void setDimension(com.badlogic.gdx.math.Vector2 value)

Sets the dimensions of this capsule

This method does not keep a reference to the parameter.

Parameters:

value - the dimensions of this capsule

setDimension

public void setDimension(float width,
 float height)

Sets the dimensions of this capsule

Parameters:

width - The width of this capsule

height - The height of this capsule

getWidth

public float getWidth()

Returns the capsule width

Returns:

the capsule width

setWidth

public void setWidth(float value)

Sets the capsule width

Parameters:

value - the capsule width

getHeight

public float getHeight()

Returns the capsule height

Returns:

the capsule height

setHeight

public void setHeight(float value)

Sets the capsule height

Parameters:

value - the capsule height

getStyle

public Capsule getStyle()

Returns the style of this capsule

Returns:

the style of this capsule

setOrientation

public void setOrientation(Capsule value)

Sets the style of this capsule.

Note that style only controls whether the capsule is full, half, or half-reverse . The actual orientation is determined by the longest axis.

Parameters:

value - the style of this capsule

getSeamOffset

public float getSeamOffset()

Returns the seam offset of the core rectangle

If the center rectangle is exactly the same size as the circle radius, you may get catching at the seems. To prevent this, you should make the center rectangle epsilon narrower so that everything rolls off the round shape. This parameter is that epsilon value.

Returns:

the seam offset of the core rectangle

setSeamOffset

public void setSeamOffset(float value)

Sets the seam offset of the core rectangle

If the center rectangle is exactly the same size as the circle radius, you may get catching at the seems. To prevent this, you should make the center rectangle epsilon narrower so that everything rolls off the round shape. This parameter is that epsilon value.

Parameters:

value - the seam offset of the core rectangle

getTolerance

public float getTolerance()

Returns the outline tolerance of this obstacle. In box2d, the ends of the capsule will be perfect circles. But we cannot draw perfect circles. As a result, the outline drawn in debug mode may not perfectly match the box2d fixtures. This value defines that drawing tolerance. Lower values mean the ends are more likely to be circular (default value is 0.05). This value only affects debugging. It has no affect on box2d.

Returns:

the outline tolerance of this obstacle.

setTolerance

public void setTolerance(float tolerance)

Sets the outline tolerance of this obstacle. In box2d, the ends of the capsule will be perfect circles. But we cannot draw perfect circles. As a result, the outline drawn in debug mode may not perfectly match the box2d fixtures. This value defines that drawing tolerance. Lower values mean the ends are more likely to be circular (default value is 0.05). This value only affects debugging. It has no affect on box2d.

Parameters:

tolerance - The outline tolerance of this obstacle.

setDensity

public void setDensity(float value)

Sets the density of this body

The density is typically measured in usually in kg/m^2. The density can be zero or positive. You should generally use similar densities for all your fixtures. This will improve stacking stability.

Overrides:

setDensity in class Obstacle

Parameters:

value - the density of this body

createFixtures

protected void createFixtures()

Creates new fixtures for this body, defining the shape

This is the primary method to override for custom physics objects

Specified by:

createFixtures in class Obstacle

releaseFixtures

protected void releaseFixtures()

Releases the fixtures for this body, reseting the shape

This is the primary method to override for custom physics objects

Specified by:

releaseFixtures in class Obstacle