paramGL.c File Reference

#include <ARX/AR/paramGL.h>

Include dependency graph for paramGL.c:

Functions
void	arglCameraFrustumRH (const ARParam *cparam, const ARdouble focalmin, const ARdouble focalmax, ARdouble m_projection[16])
	Create an OpenGL perspective projection matrix. More...
void	arglCameraViewRH (const ARdouble para[3][4], ARdouble m_modelview[16], const ARdouble scale)
	Create an OpenGL viewing transformation matrix. More...
void	arglCameraFrustumRHf (const ARParam *cparam, const float focalmin, const float focalmax, float m_projection[16])
void	arglCameraViewRHf (float para[3][4], float m_modelview[16], const float scale)

Function Documentation

arglCameraFrustumRH()

void arglCameraFrustumRH	(	const ARParam *	cparam,
		const ARdouble	focalmin,
		const ARdouble	focalmax,
		ARdouble	m_projection[16]
	)

Create an OpenGL perspective projection matrix.

Use this function to create a matrix suitable for passing to OpenGL to set the viewing projection.

Parameters

cparam	Pointer to a set of artoolkitX camera parameters for the current video source.
focalmax	The maximum distance at which geometry will be rendered. Any geometry further away from the camera than this distance will be clipped and will not be appear in a rendered frame. Thus, this value should be set high enough to avoid clipping of any geometry you care about. However, the precision of the depth buffer is correlated with the ratio of focalmin to focalmax, thus you should not set focalmax any higher than it needs to be. This value should be specified in the same units as your OpenGL drawing.
focalmin	The minimum distance at which geometry will be rendered. Any geometry closer to the camera than this distance will be clipped and will not be appear in a rendered frame. Thus, this value should be set low enough to avoid clipping of any geometry you care about. However, the precision of the depth buffer is correlated with the ratio of focalmin to focalmax, thus you should not set focalmin any lower than it needs to be. Additionally, geometry viewed in a stereo projections that is too close to camera is difficult and tiring to view, so if you are rendering stereo perspectives you should set this value no lower than the near-point of he eyes. The near point in humans varies, but usually lies between 0.1 m 0.3 m. This value should be specified in the same units as your OpenGL drawing.
m_projection	(description)

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arglCameraFrustumRHf()

void arglCameraFrustumRHf	(	const ARParam *	cparam,
		const float	focalmin,
		const float	focalmax,
		float	m_projection[16]
	)

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arglCameraViewRH()

void arglCameraViewRH	(	const ARdouble	para[3][4],
		ARdouble	m_modelview[16],
		const ARdouble	scale
	)

Create an OpenGL viewing transformation matrix.

Use this function to create a matrix suitable for passing to OpenGL to set the viewing transformation of the virtual camera.

The matrix is formed so that the world coordinate system is placed at the centre of the marker, with the marker lying in the x-y plane. The positive x axis points to the right of the marker, the positive y axis to the top of the marker, and the positive z axis out of the marker. This is a right-hand coordinate system with the usual sense for OpenGL graphics.

Parameters

para	Pointer to 3x4 matrix array of doubles which specify the position of an artoolkitX marker, as returned by arGetTransMat().
m_modelview	Pointer to a array of 16 GLdoubles, which will be filled out with a modelview matrix suitable for passing to OpenGL. The matrix is specified in column major order.
scale	Specifies a scaling between artoolkitX's units (usually millimeters) and OpenGL's coordinate system units. What you pass for the scalefactor parameter depends on what units you want to do your OpenGL drawing in. If you use a scalefactor of 1.0, then 1.0 OpenGL unit will equal 1.0 millimetre (artoolkitX's default units). To use different OpenGL units, e.g. metres, then you would pass 0.001.

arglCameraViewRHf()

void arglCameraViewRHf	(	float	para[3][4],
		float	m_modelview[16],
		const float	scale
	)