The class for controlling the view camera: it's position, orientation field of view, projection matrix, etc. More...

#include <GLCamera.h>

Public Types
enum	CamEnum { ORTHO, PERSP }
	Determines the projection matrix of the 3D camera.

Public Member Functions
	GLCamera ()
	Default constructor.

	GLCamera (const Vector3 &p)
	Constructor for setting camera position. More...

	GLCamera (const Vector3 &p, const Vector3 &t)
	Constructor for setting camera position and target. More...

	GLCamera (const Vector3 &p, const Vector3 &t, const Vector3 &u)
	Constructor for setting camera position, target, and up vector. More...

void	setOrtho (float scaleFactor=1.f)
	Sets the camera to use an orthographic projection. More...

void	setPersp ()
	Sets the camera to use a perspective projection.

void	setActive ()
	Called the first time a camera is put into use. Failing to call this may lead to unexpected camera settings until the camera is manipulated.

Vector3	getPosition () const
	Return the position of the camera. More...

void	setPosition (const Vector3 &p)
	Set the camera position explicitly from a Vector3. More...

void	setPosition (float x, float y, float z)
	Set the camera position explicitly from three values. More...

Vector3	getTarget () const
	Return the position of the camera's view target. More...

void	setTarget (const Vector3 &p)
	Set the position of the camera's view target explicitly from a Vector3. More...

void	setTarget (float x, float y, float z)
	Set the position of the camera's view target explicitly from three values. More...

Vector3	getUp () const
	Return the orientation of the camera's up direction. More...

void	setUp (const Vector3 &u)
	Set the orientation of the camera's up vector from a Vector3. More...

void	setUp (float x, float y, float z)
	Set the orientation of the camera's up vector from three values. More...

void	setFOV (float fov)
	Sets the field of view of the camera – only applicable when using the perspective projection. More...

float	getFOV () const
	Returns the current horizontal field of view (in degrees).

void	setFarPlane (float fp)
	Sets the far plane distance. More...

float	getFarPlane () const
	Reports the camera's current far plane distance. More...

void	setNearPlane (float np)
	Sets the near plane distance. More...

float	getNearPlane () const
	Reports the camera's current near plane distance. More...

float	getOrthoScaleFactor () const
	Reports the orthographic scale factor for this camera. More...

void	setViewport (int w, int h, int left=0, int bottom=0)
	Sets the camera's viewport to a view with the given width and height dimensions. More...

void	setProjMat (int w, int h) const
	Create OpenGL commands. More...

void	setSelectMat (int *selectPoint) const
	Emits the appropriate OpenGL commands for setting up a selection context. More...

void	setGLView () const
	Emits the appropriate OpenGL commands for setting up the view for this camera.

void	viewXAxis (bool downPositive=true)
	Sets the camera to look along the world's x-axis. More...

void	viewYAxis (bool downPositive=true)
	Sets the camera to look along the world's y-axis. More...

void	viewZAxis (bool downPositive=true)
	Sets the camera to look along the world's z-axis. More...

void	pan (float angle)
	Causes the camera to "pan" the given angle. More...

void	tilt (float angle)
	Causes the camera to "tilt" the given angle. More...

void	truck (float amount)
	Causes the camera to "truck" the given amount. More...

void	crane (float amount)
	Causes the camera to "crane" the given amount. More...

void	dolly (float amount)
	Causes the camera to "dolly" in and out. More...

void	dollyPlane (float amount)
	Causes the camera to "dolly" along a plane. More...

void	zoom (float amount)
	Causes the camera to "zoom" toward its target. More...

void	orbitVerticalAxis (float angle)
	Causes the camera to rotate an axis, parallel with the world vertical axis centered on the camera's target. More...

void	orbitHorizontalAxis (float angle)
	Camera rotates, at distance, around target on axis parallel to camera's horizontal axis. More...

float	targetDistance () const
	Camera state. More...

Vector3	targetDir () const
	Returns the unit-length vector indicating direction FROM camera to TARGET. More...

Vector3	getActualUpDir () const
	Returns the ACTUAL up dir – as opposed to the desired up. More...

Vector3	getRightDir () const
	Returns the normalized vector representing the camera's horizontal axis pointing to right. More...

void	outputState () const
	Outputs the state of the camera to the console. More...

Detailed Description

The class for controlling the view camera: it's position, orientation field of view, projection matrix, etc.

Constructor & Destructor Documentation

Menge::SceneGraph::GLCamera::GLCamera ( const Vector3 & p )

Constructor for setting camera position.

Parameters

p	The position of the camera.

Menge::SceneGraph::GLCamera::GLCamera	(	const Vector3 &	p,
		const Vector3 &	t
	)

Constructor for setting camera position and target.

Parameters

p	The position of the camera.
t	The position of the camera's view target.

Menge::SceneGraph::GLCamera::GLCamera	(	const Vector3 &	p,
		const Vector3 &	t,
		const Vector3 &	u
	)

Constructor for setting camera position, target, and up vector.

Parameters

p	The position of the camera.
t	The position of the camera's view target.
u	the direction of the camera's up direction.

Member Function Documentation

void Menge::SceneGraph::GLCamera::crane ( float amount )

Causes the camera to "crane" the given amount.

A camera "cranes" by moving along its own vertical axis. This causes the camera to rise and lower in its view. The actual movement in the WORLD coordinate system depends on the camera's orientation.

Parameters

amount The amount to move. Postive values move the camera up and negative values move down.

void Menge::SceneGraph::GLCamera::dolly ( float amount )

Causes the camera to "dolly" in and out.

Dollying a camera moves it forward and backward in the camera's facing direction (i.e., moving in the direction of the target). The target moves with the camera.

Parameters

amount The amount to move. Positive values move forward and negative values move backward.

void Menge::SceneGraph::GLCamera::dollyPlane ( float amount )

Causes the camera to "dolly" along a plane.

In this case, the elevation (in world space) does not change. The camera moves parallel with the ground plane based on the projeciton of the camera's facing direction on that plane.

Parameters

amount The amount to move. Positive values move forward and negative values move backward.

Vector3 Menge::SceneGraph::GLCamera::getActualUpDir ( ) const

Returns the ACTUAL up dir – as opposed to the desired up.

Essentially, the cross product of the camera's horizontal direction with its facing direction.

Returns: Camera's current, local up vector in world space.

float Menge::SceneGraph::GLCamera::getFarPlane ( ) const

inline

Reports the camera's current far plane distance.

Returns: The camera's current far plane distance.

float Menge::SceneGraph::GLCamera::getNearPlane ( ) const

inline

Reports the camera's current near plane distance.

Returns: The camera's current near plane distance.

float Menge::SceneGraph::GLCamera::getOrthoScaleFactor ( ) const

Reports the orthographic scale factor for this camera.

The orthographic scale factor is the value which determines how "zoomed in" an orthographic camera is. It is the ratio of the distance between camera and target and the width of the viewable region in orthographic.

Returns: The orthographic scale

Vector3 Menge::SceneGraph::GLCamera::getPosition ( ) const

inline

Return the position of the camera.

Returns: The position fo the camera in 3D space.

Vector3 Menge::SceneGraph::GLCamera::getRightDir ( ) const

Returns the normalized vector representing the camera's horizontal axis pointing to right.

Returns: The direction of the camera's right in world space.

Vector3 Menge::SceneGraph::GLCamera::getTarget ( ) const

inline

Return the position of the camera's view target.

Returns: The position of the camera's view target.

Vector3 Menge::SceneGraph::GLCamera::getUp ( ) const

inline

Return the orientation of the camera's up direction.

Returns: The orientation of the camera's up direction.

void Menge::SceneGraph::GLCamera::orbitHorizontalAxis ( float angle )

Camera rotates, at distance, around target on axis parallel to camera's horizontal axis.

Parameters

angle The angle of rotation (in radians). Positive values move the camera in its upward direction, negative to its downward.

void Menge::SceneGraph::GLCamera::orbitVerticalAxis ( float angle )

Causes the camera to rotate an axis, parallel with the world vertical axis centered on the camera's target.

Parameters

angle The angle of rotation (in radians). Positive values move the camera to its right, negative to its left.

void Menge::SceneGraph::GLCamera::outputState ( ) const

Outputs the state of the camera to the console.

The format can be cut-and-pasted into a view configuration file.

void Menge::SceneGraph::GLCamera::pan ( float angle )

Causes the camera to "pan" the given angle.

The camera "pans" by rotating around its own center along the world's vertical axis (i.e., turning left and right).

Parameters

angle The amount of pan (in radians). Positive values cause the camera to turn left, negative values turn the camera right.

void Menge::SceneGraph::GLCamera::setFarPlane ( float fp )

inline

Sets the far plane distance.

Parameters

fp	The desired far plane distance.

void Menge::SceneGraph::GLCamera::setFOV ( float fov )

inline

Sets the field of view of the camera – only applicable when using the perspective projection.

Parameters

fov	The horizontal field of view (in degrees).

void Menge::SceneGraph::GLCamera::setNearPlane ( float np )

inline

Sets the near plane distance.

Parameters

np	The desired near plane distance.

void Menge::SceneGraph::GLCamera::setOrtho ( float scaleFactor = 1.f )

Sets the camera to use an orthographic projection.

Parameters

scaleFactor Defines the horizontal span of the orthographic view as a function of the distance to target. This "zooms" the orthographic camera closer.

void Menge::SceneGraph::GLCamera::setPosition ( const Vector3 & p )

Set the camera position explicitly from a Vector3.

Parameters

p	The desired position of the camera.

void Menge::SceneGraph::GLCamera::setPosition	(	float	x,
		float	y,
		float	z
	)

Set the camera position explicitly from three values.

Parameters

x	The position of the camera along the x-axis.
y	The position of the camera along the y-axis.
z	The position of the camera along the z-axis.

void Menge::SceneGraph::GLCamera::setProjMat	(	int	w,
		int	h
	)		const

Create OpenGL commands.

Emits the appropriate OpenGL commands for setting up a projection matrix.

Parameters

w	The viewport width (in pixels).
h	The viewport height (in pixels).

void Menge::SceneGraph::GLCamera::setSelectMat ( int * selectPoint ) const

Emits the appropriate OpenGL commands for setting up a selection context.

Parameters

selectPoint A pointer to an array of two floats interpreted as the x- and y-positions of the selection point, in screen space.

void Menge::SceneGraph::GLCamera::setTarget ( const Vector3 & p )

Set the position of the camera's view target explicitly from a Vector3.

Parameters

p	The desired position of the camera's view target.

void Menge::SceneGraph::GLCamera::setTarget	(	float	x,
		float	y,
		float	z
	)

Set the position of the camera's view target explicitly from three values.

Parameters

x	The position of the camera's view target along the x-axis.
y	The position of the camera's view target along the y-axis.
z	The position of the camera's view target along the z-axis.

void Menge::SceneGraph::GLCamera::setUp ( const Vector3 & u )

Set the orientation of the camera's up vector from a Vector3.

Parameters

u	The desired direction of the camera's up direction. It is assumed to be of normal length.

void Menge::SceneGraph::GLCamera::setUp	(	float	x,
		float	y,
		float	z
	)

Set the orientation of the camera's up vector from three values.

Parameters

x	The x-component of the camera's up vector.
y	The y-component of the camera's up vector.
z	The z-component of the camera's up vector.

void Menge::SceneGraph::GLCamera::setViewport	(	int	w,
		int	h,
		int	left = `0`,
		int	bottom = `0`
	)

Sets the camera's viewport to a view with the given width and height dimensions.

Parameters

w	The width of the viewport (in pixels)
h	The height of the viewport (in pixels )
left	The position of the left-most edge of the viewport in pixels. Defaults to zero.
bottom	The position of the bottom-most edge of the viewport in pixels. Defaults to zero.

Vector3 Menge::SceneGraph::GLCamera::targetDir ( ) const

Returns the unit-length vector indicating direction FROM camera to TARGET.

Returns: Direction to target in world space.

float Menge::SceneGraph::GLCamera::targetDistance ( ) const

Camera state.

Returns distance between camera and target

Returns: The distance between camera and its target.

void Menge::SceneGraph::GLCamera::tilt ( float angle )

Causes the camera to "tilt" the given angle.

The camera "tilts" by rotating around its own center along the its own horizontal axis (i.e., looking up and down).

Parameters

angle The amount of pan (in radians). Postive values rotates the camera down, negative rotates up.

void Menge::SceneGraph::GLCamera::truck ( float amount )

Causes the camera to "truck" the given amount.

"Trucking" is moving the camera side to side on its own horizontal axis (i.e., "strafe" left and right).

Parameters

amount The amount to move. Postive values move the camera to its right and negative values move left.

void Menge::SceneGraph::GLCamera::viewXAxis ( bool downPositive = true )

Sets the camera to look along the world's x-axis.

The camera's distance from the origin is the same as its previous displacement from the origin along the x-axis.

Parameters

downPositive If true, the camera looks along the positive x-axis direction. If false, it looks in the negative direction.

void Menge::SceneGraph::GLCamera::viewYAxis ( bool downPositive = true )

Sets the camera to look along the world's y-axis.

The camera's distance from the origin is the same as its previous displacement from the origin along the y-axis.

Parameters

downPositive If true, the camera looks along the positive y-axis direction. If false, it looks in the negative direction.

void Menge::SceneGraph::GLCamera::viewZAxis ( bool downPositive = true )

Sets the camera to look along the world's z-axis.

The camera's distance from the origin is the same as its previous displacement from the origin along the z-axis.

Parameters

downPositive If true, the camera looks along the positive z-axis direction. If false, it looks in the negative direction.

void Menge::SceneGraph::GLCamera::zoom ( float amount )

Causes the camera to "zoom" toward its target.

This is not a zoom in the sense that the lens focal length changes. This merely moves the camera along its facing direction while holding the target stationary.

Parameters

amount The amount to zoom. Positive values move forward and negative values move backward.

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

src/menge/MengeCore/SceneGraph/GLCamera.h
src/menge/MengeCore/SceneGraph/GLCamera.cpp

Public Types

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation