com.bonzaiengine.camera

Class PerspectiveProjection

java.lang.Object

com.bonzaiengine.camera.PerspectiveProjection

public final class PerspectiveProjection
extends java.lang.Object

Perspective projection matrix as describe with OpenGL fovY, ratio, near and far parameters.

Constructor Summary

Constructors

Constructor and Description
PerspectiveProjection(float fovYInDegrees, float ratio, float zNear, float zFar)

Method Summary

Modifier and Type	Method and Description
void	adjust(ICamera view, IBoundable boundable, float zNearRatio, float minZNear, float zFarRatio, float maxZFar)
float	depthToZ(float depth)
Vec2	getFarPlaneSize() Calculate the back frustum face dimension, according to those formulas: height = 2 * zFar * tan(fovY/2) width = height * aspectRatio
float	getFovXInDegrees()
float	getFovXInRadians()
float	getFovYInDegrees()
float	getFovYInRadians()
Mat4x4	getMatrix()
Vec2	getNearPlaneSize() Calculate the front frustum face dimension, according to those formulas: height = 2 * zNear * tan(fovY/2) width = height * aspectRatio
float	getPlaneDepthFromHeight(float h) Calculate the distance of a face, laying on the xy plane, according to those formulas: dist = h / ( 2 * tan(fovY/2) )
float	getPlaneDepthFromWidth(float w) Calculate the distance of a face, laying on the xy plane, according to those formulas: dist = zNear / aspect * w / ( 2 * tan(fovY/2) )
Vec2	getPlaneSize(float z) Calculate the face (laying on the xy plane) dimension, according to those formulas: height = 2 * z * tan(fovY/2) width = height * aspectRatio
float	getRatio()
float	getZFar()
float	getZNear()
float	getZoom() Simulate a camera zooming
Vec2	projectionPoint(Vec2 dst, float zFaceDist, Vec2 point, float zProjectionFaceDist)
Vec3	projectionPoint(Vec3 dst, Vec3 point, float zProjectionFaceDist)
boolean	projectSphereInNDC(Rectangle dst, Vec3 center, float r) Project Sphere in Normal Device Coordinates Reference: http://article.gmane.org/gmane.games.devel.algorithms/21697
void	set(float fovYInDegrees, float ratio, float zNear, float zFar)
void	set(PerspectiveProjection src)
void	setFovY(float fovY) Fov Y in degrees
void	setRatio(float ratio)
void	setZFar(float zFar)
void	setZNear(float zNear)
void	setZoom(float zoom) Simulate a camera zooming

Methods inherited from class java.lang.Object

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

Constructor Detail

PerspectiveProjection

public PerspectiveProjection(float fovYInDegrees,
                             float ratio,
                             float zNear,
                             float zFar)

Parameters:

fovY - angle in degree

ratio -

zNear -

zFar -

Method Detail

set

public void set(PerspectiveProjection src)

set

public final void set(float fovYInDegrees,
                      float ratio,
                      float zNear,
                      float zFar)

Parameters:

fovY - angle in degree

ratio -

zNear -

zFar -

getRatio

public final float getRatio()

getZNear

public final float getZNear()

getZFar

public final float getZFar()

getZoom

public final float getZoom()

Simulate a camera zooming

setFovY

public final void setFovY(float fovY)

Fov Y in degrees

setRatio

public final void setRatio(float ratio)

setZNear

public final void setZNear(float zNear)

setZFar

public final void setZFar(float zFar)

setZoom

public final void setZoom(float zoom)

Simulate a camera zooming

getFovYInDegrees

public final float getFovYInDegrees()

Returns:

fovY angle in degrees.

getFovYInRadians

public final float getFovYInRadians()

Returns:

fovY angle in radians.

getFovXInDegrees

public final float getFovXInDegrees()

Returns:

fovX angle in degrees.

getFovXInRadians

public final float getFovXInRadians()

Returns:

fovX angle in radians.

getNearPlaneSize

public final Vec2 getNearPlaneSize()

Calculate the front frustum face dimension, according to those formulas:
height = 2 * zNear * tan(fovY/2)
width = height * aspectRatio

getFarPlaneSize

public final Vec2 getFarPlaneSize()

Calculate the back frustum face dimension, according to those formulas:
height = 2 * zFar * tan(fovY/2)
width = height * aspectRatio

getPlaneSize

public final Vec2 getPlaneSize(float z)

Calculate the face (laying on the xy plane) dimension, according to those formulas:
height = 2 * z * tan(fovY/2)
width = height * aspectRatio

Parameters:

z - distance of the face, on the xy plane, from the viewing volume 'origin'.
It is a positive value.

getPlaneDepthFromHeight

public final float getPlaneDepthFromHeight(float h)

Calculate the distance of a face, laying on the xy plane, according to those formulas:
dist = h / ( 2 * tan(fovY/2) )

Parameters:

h - the height of the face

getPlaneDepthFromWidth

public final float getPlaneDepthFromWidth(float w)

Calculate the distance of a face, laying on the xy plane, according to those formulas:
dist = zNear / aspect * w / ( 2 * tan(fovY/2) )

Parameters:

w - the width of the face

projectionPoint

public final Vec2 projectionPoint(Vec2 dst,
                                  float zFaceDist,
                                  Vec2 point,
                                  float zProjectionFaceDist)

projectionPoint

public final Vec3 projectionPoint(Vec3 dst,
                                  Vec3 point,
                                  float zProjectionFaceDist)

projectSphereInNDC

public final boolean projectSphereInNDC(Rectangle dst,
                                        Vec3 center,
                                        float r)

Project Sphere in Normal Device Coordinates
Reference: http://article.gmane.org/gmane.games.devel.algorithms/21697

Parameters:

center - center of the sphere in modelview coordinates

r - radius of the sphere

dst - destination Area to store area (x1, x2, y1, y2) in NDC coordinates

Returns:

true if the sphere is inside the frustum, false with no set anything into dst

depthToZ

public final float depthToZ(float depth)

Parameters:

depth - in window coordinate, meaning ranges [0;1]

Returns:

z value in eye coordinate system
At depth = 0, return getZNear(). At depth = 1, returns getZFar()

adjust

public final void adjust(ICamera view,
                         IBoundable boundable,
                         float zNearRatio,
                         float minZNear,
                         float zFarRatio,
                         float maxZFar)

Parameters:

view - view (camera) matrix

boundable - scene volume

zNearRatio -

minZNear -

zFarRatio -

maxZFar -

getMatrix

public Mat4x4 getMatrix()

Returns:

the projection matrix.