com.io7m.r2.meshes.defaults

Class R2UnitSphere

java.lang.Object

com.io7m.r2.meshes.defaults.R2UnitSphere

All Implemented Interfaces:

com.io7m.jcanephora.core.JCGLResourceSizedType, com.io7m.jcanephora.core.JCGLResourceUsableType, R2DeletableType, R2UnitSphereType, R2UnitSphereUsableType

public final class R2UnitSphere
extends Object
implements R2UnitSphereType

The default implementation of the R2UnitSphereType interface.

Method Summary

Modifier and Type	Method and Description
com.io7m.jcanephora.core.JCGLArrayObjectUsableType	arrayObject()
void	delete(com.io7m.jcanephora.core.api.JCGLInterfaceGL33Type g) Delete the current object.
static double	getCircleArea(double r) Calculate the area of a circle with radius r.
com.io7m.junsigned.ranges.UnsignedRangeInclusiveL	getRange()
static double	getUVSphereApproximationArea(double r, int s) Calculate the area of an approximation of a circle with radius r constructed with s line segments.
static double	getUVSphereApproximationScaleFactor(double r, int s) Calculate the scale factor required to completely contain a circle of radius r inside an approximation with radius r constructed with s line segments.
static double	getUVSphereApproximationTriangleArea(double r, int s) Calculate the area of one of the triangles that make up an approximation of a circle with radius r constructed with s line segments.
static double	getUVSphereTriangleInteriorAngle(int s) A UV sphere approximates a real sphere by using a fixed number of vertical segments.
boolean	isDeleted()
static R2UnitSphereType	newUnitSphere8(com.io7m.jcanephora.core.api.JCGLInterfaceGL33Type g) Construct a new 8 segment unit sphere.

Methods inherited from class java.lang.Object

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

Method Detail

newUnitSphere8

public static R2UnitSphereType newUnitSphere8(com.io7m.jcanephora.core.api.JCGLInterfaceGL33Type g)

Construct a new 8 segment unit sphere.

Parameters:

g - An OpenGL interface

Returns:

A new unit sphere

getUVSphereTriangleInteriorAngle

public static double getUVSphereTriangleInteriorAngle(int s)

A UV sphere approximates a real sphere by using a fixed number of vertical segments. When using 8 segments, for example, the sphere looks like an octagon when viewed from above. This function returns the interior angle, in radians, of one of the triangles that make up the shape.

The following always holds: 2 * π = n * getUVSphereTriangleInteriorAngle(n)

Parameters:

s - The number of segments

Returns:

The interior angle of one of the resulting triangles

getUVSphereApproximationTriangleArea

public static double getUVSphereApproximationTriangleArea(double r,
                                                          int s)

Calculate the area of one of the triangles that make up an approximation of a circle with radius r constructed with s line segments.

Parameters:

r - The radius

s - The number of segments in the approximation

Returns:

The approximation area

getUVSphereApproximationScaleFactor

public static double getUVSphereApproximationScaleFactor(double r,
                                                         int s)

Calculate the scale factor required to completely contain a circle of radius r inside an approximation with radius r constructed with s line segments.

Parameters:

r - The radius

s - The number of segments in the approximation

Returns:

The approximation area

getUVSphereApproximationArea

public static double getUVSphereApproximationArea(double r,
                                                  int s)

Calculate the area of an approximation of a circle with radius r constructed with s line segments.

Parameters:

r - The radius

s - The number of segments in the approximation

Returns:

The approximation area

getCircleArea

public static double getCircleArea(double r)

Calculate the area of a circle with radius r.

Parameters:

r - The radius

Returns:

The circle area

delete

public void delete(com.io7m.jcanephora.core.api.JCGLInterfaceGL33Type g)
            throws R2Exception

Description copied from interface: R2DeletableType

Delete the current object.

Specified by:

delete in interface R2DeletableType

Parameters:

g - An OpenGL interface

Throws:

R2Exception - On errors

arrayObject

public com.io7m.jcanephora.core.JCGLArrayObjectUsableType arrayObject()

Specified by:

arrayObject in interface R2UnitSphereUsableType

Returns:

The array object for the sphere

getRange

public com.io7m.junsigned.ranges.UnsignedRangeInclusiveL getRange()

Specified by:

getRange in interface com.io7m.jcanephora.core.JCGLResourceSizedType

isDeleted

public boolean isDeleted()

Specified by:

isDeleted in interface com.io7m.jcanephora.core.JCGLResourceUsableType