Imported existing code

indra/llmath/llcamera.cpp

@@ -0,0 +1,744 @@
+/** 
+ * @file llcamera.cpp
+ * @brief Implementation of the LLCamera class.
+ *
+ * $LicenseInfo:firstyear=2000&license=viewergpl$
+ * 
+ * Copyright (c) 2000-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "llmath.h"
+#include "llcamera.h"
+
+// ---------------- Constructors and destructors ----------------
+
+LLCamera::LLCamera() :
+	LLCoordFrame(),
+	mView(DEFAULT_FIELD_OF_VIEW),
+	mAspect(DEFAULT_ASPECT_RATIO),
+	mViewHeightInPixels( -1 ),			// invalid height
+	mNearPlane(DEFAULT_NEAR_PLANE),
+	mFarPlane(DEFAULT_FAR_PLANE),
+	mFixedDistance(-1.f),
+	mPlaneCount(6)
+{
+	calculateFrustumPlanes();
+} 
+
+
+LLCamera::LLCamera(F32 vertical_fov_rads, F32 aspect_ratio, S32 view_height_in_pixels, F32 near_plane, F32 far_plane) :
+	LLCoordFrame(),
+	mViewHeightInPixels(view_height_in_pixels),
+	mFixedDistance(-1.f),
+	mPlaneCount(6)
+{
+	mAspect = llclamp(aspect_ratio, MIN_ASPECT_RATIO, MAX_ASPECT_RATIO);
+	mNearPlane = llclamp(near_plane, MIN_NEAR_PLANE, MAX_NEAR_PLANE);
+	if(far_plane < 0) far_plane = DEFAULT_FAR_PLANE;
+	mFarPlane = llclamp(far_plane, MIN_FAR_PLANE, MAX_FAR_PLANE);
+
+	setView(vertical_fov_rads);
+} 
+
+
+// ---------------- LLCamera::getFoo() member functions ----------------
+
+F32 LLCamera::getMinView() const 
+{
+	// minimum vertical fov needs to be constrained in narrow windows.
+	return mAspect > 1
+		? MIN_FIELD_OF_VIEW // wide views
+		: MIN_FIELD_OF_VIEW * 1/mAspect; // clamps minimum width in narrow views
+}
+
+F32 LLCamera::getMaxView() const 
+{
+	// maximum vertical fov needs to be constrained in wide windows.
+	return mAspect > 1 
+		? MAX_FIELD_OF_VIEW / mAspect  // clamps maximum width in wide views
+		: MAX_FIELD_OF_VIEW; // narrow views
+}
+
+// ---------------- LLCamera::setFoo() member functions ----------------
+
+void LLCamera::setUserClipPlane(LLPlane plane)
+{
+	mPlaneCount = 7;
+	mAgentPlanes[6].p = plane;
+	mAgentPlanes[6].mask = calcPlaneMask(plane);
+}
+
+void LLCamera::disableUserClipPlane()
+{
+	mPlaneCount = 6;
+}
+
+void LLCamera::setView(F32 vertical_fov_rads) 
+{
+	mView = llclamp(vertical_fov_rads, MIN_FIELD_OF_VIEW, MAX_FIELD_OF_VIEW);
+	calculateFrustumPlanes();
+}
+
+void LLCamera::setViewHeightInPixels(S32 height)
+{
+	mViewHeightInPixels = height;
+
+	// Don't really need to do this, but update the pixel meter ratio with it.
+	calculateFrustumPlanes();
+}
+
+void LLCamera::setAspect(F32 aspect_ratio) 
+{
+	mAspect = llclamp(aspect_ratio, MIN_ASPECT_RATIO, MAX_ASPECT_RATIO);
+	calculateFrustumPlanes();
+}
+
+
+void LLCamera::setNear(F32 near_plane) 
+{
+	mNearPlane = llclamp(near_plane, MIN_NEAR_PLANE, MAX_NEAR_PLANE);
+	calculateFrustumPlanes();
+}
+
+
+void LLCamera::setFar(F32 far_plane) 
+{
+	mFarPlane = llclamp(far_plane, MIN_FAR_PLANE, MAX_FAR_PLANE);
+	calculateFrustumPlanes();
+}
+
+
+// ---------------- read/write to buffer ---------------- 
+
+size_t LLCamera::writeFrustumToBuffer(char *buffer) const
+{
+	memcpy(buffer, &mView, sizeof(F32));		/* Flawfinder: ignore */		
+	buffer += sizeof(F32);
+	memcpy(buffer, &mAspect, sizeof(F32));		/* Flawfinder: ignore */
+	buffer += sizeof(F32);
+	memcpy(buffer, &mNearPlane, sizeof(F32));	/* Flawfinder: ignore */
+	buffer += sizeof(F32);
+	memcpy(buffer, &mFarPlane, sizeof(F32));		/* Flawfinder: ignore */
+	return 4*sizeof(F32);
+}
+
+size_t LLCamera::readFrustumFromBuffer(const char *buffer)
+{
+	memcpy(&mView, buffer, sizeof(F32));		/* Flawfinder: ignore */
+	buffer += sizeof(F32);
+	memcpy(&mAspect, buffer, sizeof(F32));		/* Flawfinder: ignore */
+	buffer += sizeof(F32);
+	memcpy(&mNearPlane, buffer, sizeof(F32));	/* Flawfinder: ignore */
+	buffer += sizeof(F32);
+	memcpy(&mFarPlane, buffer, sizeof(F32));		/* Flawfinder: ignore */
+	return 4*sizeof(F32);
+}
+
+
+// ---------------- test methods  ---------------- 
+
+S32 LLCamera::AABBInFrustum(const LLVector3 &center, const LLVector3& radius) 
+{
+	static const LLVector3 scaler[] = {
+		LLVector3(-1,-1,-1),
+		LLVector3( 1,-1,-1),
+		LLVector3(-1, 1,-1),
+		LLVector3( 1, 1,-1),
+		LLVector3(-1,-1, 1),
+		LLVector3( 1,-1, 1),
+		LLVector3(-1, 1, 1),
+		LLVector3( 1, 1, 1)
+	};
+
+	U8 mask = 0;
+	S32 result = 2;
+
+	if (radius.magVecSquared() > mFrustumCornerDist * mFrustumCornerDist)
+	{ //box is larger than frustum, check frustum quads against box planes
+
+		static const LLVector3 dir[] = 
+		{
+			LLVector3(1, 0, 0),
+			LLVector3(-1, 0, 0),
+			LLVector3(0, 1, 0),
+			LLVector3(0, -1, 0),
+			LLVector3(0, 0, 1),
+			LLVector3(0, 0, -1)
+		};
+
+		U32 quads[] = 
+		{
+			0, 1, 2, 3,
+			0, 1, 5, 4,
+			2, 3, 7, 6,
+			3, 0, 7, 4,
+			1, 2, 6, 4,
+			4, 5, 6, 7
+		};
+
+		result = 0;
+
+		BOOL total_inside = TRUE;
+		for (U32 i = 0; i < 6; i++)
+		{ 
+			LLVector3 p = center + radius.scaledVec(dir[i]);
+			F32 d = -p*dir[i];
+
+			for (U32 j = 0; j <	6; j++)
+			{ //for each quad
+				F32 dist = mAgentFrustum[quads[j*4+0]]*dir[i] + d;
+				if (dist > 0)
+				{ //at least one frustum point is outside the AABB
+					total_inside = FALSE;
+					for (U32 k = 1; k < 4; k++)
+					{ //for each other point on quad
+						if ( mAgentFrustum[quads[j*4+k]]*dir[i]+d  <= 0.f)
+						{ //quad is straddling some plane of AABB
+							return 1;
+						}
+					}
+				}
+				else
+				{
+					for (U32 k = 1; k < 4; k++)
+					{
+						if (mAgentFrustum[quads[j*4+k]]*dir[i]+d > 0.f)
+						{
+							return 1;
+						}
+					}
+				}
+			}
+		}
+
+		if (total_inside)
+		{
+			result = 1;
+		}
+	}
+	else
+	{
+		for (U32 i = 0; i < mPlaneCount; i++)
+		{
+			mask = mAgentPlanes[i].mask;
+			LLPlane p = mAgentPlanes[i].p;
+			LLVector3 n = LLVector3(p);
+			float d = p.mV[3];
+			LLVector3 rscale = radius.scaledVec(scaler[mask]);
+
+			LLVector3 minp = center - rscale;
+			LLVector3 maxp = center + rscale;
+
+			if (n * minp > -d) 
+			{
+				return 0;
+			}
+		
+			if (n * maxp > -d)
+			{
+				result = 1;
+			}
+		}
+	}
+
+	
+	return result;
+}
+
+S32 LLCamera::AABBInFrustumNoFarClip(const LLVector3 &center, const LLVector3& radius) 
+{
+	static const LLVector3 scaler[] = {
+		LLVector3(-1,-1,-1),
+		LLVector3( 1,-1,-1),
+		LLVector3(-1, 1,-1),
+		LLVector3( 1, 1,-1),
+		LLVector3(-1,-1, 1),
+		LLVector3( 1,-1, 1),
+		LLVector3(-1, 1, 1),
+		LLVector3( 1, 1, 1)
+	};
+
+	U8 mask = 0;
+	S32 result = 2;
+
+	for (U32 i = 0; i < mPlaneCount; i++)
+	{
+		if (i == 5)
+		{
+			continue;
+		}
+
+		mask = mAgentPlanes[i].mask;
+		LLPlane p = mAgentPlanes[i].p;
+		LLVector3 n = LLVector3(p);
+		float d = p.mV[3];
+		LLVector3 rscale = radius.scaledVec(scaler[mask]);
+
+		LLVector3 minp = center - rscale;
+		LLVector3 maxp = center + rscale;
+
+		if (n * minp > -d) 
+		{
+			return 0;
+		}
+	
+		if (n * maxp > -d)
+		{
+			result = 1;
+		}
+	}
+
+	return result;
+}
+
+int LLCamera::sphereInFrustumQuick(const LLVector3 &sphere_center, const F32 radius) 
+{
+	LLVector3 dist = sphere_center-mFrustCenter;
+	float dsq = dist * dist;
+	float rsq = mFarPlane*0.5f + radius;
+	rsq *= rsq;
+
+	if (dsq < rsq) 
+	{
+		return 1;
+	}
+	
+	return 0;	
+}
+
+// HACK: This version is still around because the version below doesn't work
+// unless the agent planes are initialized.
+// Return 1 if sphere is in frustum, 2 if fully in frustum, otherwise 0.
+// NOTE: 'center' is in absolute frame.
+int LLCamera::sphereInFrustumOld(const LLVector3 &sphere_center, const F32 radius) const 
+{
+	// Returns 1 if sphere is in frustum, 0 if not.
+	// modified so that default view frust is along X with Z vertical
+	F32 x, y, z, rightDist, leftDist, topDist, bottomDist;
+
+	// Subtract the view position 
+	//LLVector3 relative_center;
+	//relative_center = sphere_center - getOrigin();
+	LLVector3 rel_center(sphere_center);
+	rel_center -= mOrigin;
+
+	bool all_in = TRUE;
+
+	// Transform relative_center.x to camera frame
+	x = mXAxis * rel_center;
+	if (x < MIN_NEAR_PLANE - radius)
+	{
+		return 0;
+	}
+	else if (x < MIN_NEAR_PLANE + radius)
+	{
+		all_in = FALSE;
+	}
+
+	if (x > mFarPlane + radius)
+	{
+		return 0;
+	}
+	else if (x > mFarPlane - radius)
+	{
+		all_in = FALSE;
+	}
+
+	// Transform relative_center.y to camera frame
+	y = mYAxis * rel_center;
+
+	// distance to plane is the dot product of (x, y, 0) * plane_normal
+	rightDist = x * mLocalPlanes[PLANE_RIGHT][VX] + y * mLocalPlanes[PLANE_RIGHT][VY];
+	if (rightDist < -radius)
+	{
+		return 0;
+	}
+	else if (rightDist < radius)
+	{
+		all_in = FALSE;
+	}
+
+	leftDist = x * mLocalPlanes[PLANE_LEFT][VX] + y * mLocalPlanes[PLANE_LEFT][VY];
+	if (leftDist < -radius)
+	{
+		return 0;
+	}
+	else if (leftDist < radius)
+	{
+		all_in = FALSE;
+	}
+
+	// Transform relative_center.y to camera frame
+	z = mZAxis * rel_center;
+
+	topDist = x * mLocalPlanes[PLANE_TOP][VX] + z * mLocalPlanes[PLANE_TOP][VZ];
+	if (topDist < -radius)
+	{
+		return 0;
+	}
+	else if (topDist < radius)
+	{
+		all_in = FALSE;
+	}
+
+	bottomDist = x * mLocalPlanes[PLANE_BOTTOM][VX] + z * mLocalPlanes[PLANE_BOTTOM][VZ];
+	if (bottomDist < -radius)
+	{
+		return 0;
+	}
+	else if (bottomDist < radius)
+	{
+		all_in = FALSE;
+	}
+
+	if (all_in)
+	{
+		return 2;
+	}
+
+	return 1;
+}
+
+
+// HACK: This (presumably faster) version only currently works if you set up the
+// frustum planes using GL.  At some point we should get those planes through another
+// mechanism, and then we can get rid of the "old" version above.
+
+// Return 1 if sphere is in frustum, 2 if fully in frustum, otherwise 0.
+// NOTE: 'center' is in absolute frame.
+int LLCamera::sphereInFrustum(const LLVector3 &sphere_center, const F32 radius) const 
+{
+	// Returns 1 if sphere is in frustum, 0 if not.
+	int res = 2;
+	for (int i = 0; i < 6; i++)
+	{
+		float d = mAgentPlanes[i].p.dist(sphere_center);
+
+		if (d > radius) 
+		{
+			return 0;
+		}
+
+		if (d > -radius)
+		{
+			res = 1;
+		}
+	}
+
+	return res;
+}
+
+
+// return height of a sphere of given radius, located at center, in pixels
+F32 LLCamera::heightInPixels(const LLVector3 &center, F32 radius ) const
+{
+	if (radius == 0.f) return 0.f;
+
+	// If height initialized
+	if (mViewHeightInPixels > -1)
+	{
+		// Convert sphere to coord system with 0,0,0 at camera
+		LLVector3 vec = center - mOrigin;
+
+		// Compute distance to sphere
+		F32 dist = vec.magVec();
+
+		// Calculate angle of whole object
+		F32 angle = 2.0f * (F32) atan2(radius, dist);
+
+		// Calculate fraction of field of view
+		F32 fraction_of_fov = angle / mView;
+
+		// Compute number of pixels tall, based on vertical field of view
+		return (fraction_of_fov * mViewHeightInPixels);
+	}
+	else
+	{
+		// return invalid height
+		return -1.0f;
+	}
+}
+
+// If pos is visible, return the distance from pos to the camera.
+// Use fudge distance to scale rad against top/bot/left/right planes
+// Otherwise, return -distance
+F32 LLCamera::visibleDistance(const LLVector3 &pos, F32 rad, F32 fudgedist, U32 planemask) const
+{
+	if (mFixedDistance > 0)
+	{
+		return mFixedDistance;
+	}
+	LLVector3 dvec = pos - mOrigin;
+	// Check visibility
+	F32 dist = dvec.magVec();
+	if (dist > rad)
+	{
+ 		F32 dp,tdist;
+ 		dp = dvec * mXAxis;
+  		if (dp < -rad)
+  			return -dist;
+
+		rad *= fudgedist;
+		LLVector3 tvec(pos);
+		for (int p=0; p<PLANE_NUM; p++)
+		{
+			if (!(planemask & (1<<p)))
+				continue;
+			tdist = -(mWorldPlanes[p].dist(tvec));
+			if (tdist > rad)
+				return -dist;
+		}
+	}
+	return dist;
+}
+
+// Like visibleDistance, except uses mHorizPlanes[], which are left and right
+//  planes perpindicular to (0,0,1) in world space
+F32 LLCamera::visibleHorizDistance(const LLVector3 &pos, F32 rad, F32 fudgedist, U32 planemask) const
+{
+	if (mFixedDistance > 0)
+	{
+		return mFixedDistance;
+	}
+	LLVector3 dvec = pos - mOrigin;
+	// Check visibility
+	F32 dist = dvec.magVec();
+	if (dist > rad)
+	{
+		rad *= fudgedist;
+		LLVector3 tvec(pos);
+		for (int p=0; p<HORIZ_PLANE_NUM; p++)
+		{
+			if (!(planemask & (1<<p)))
+				continue;
+			F32 tdist = -(mHorizPlanes[p].dist(tvec));
+			if (tdist > rad)
+				return -dist;
+		}
+	}
+	return dist;
+}
+
+// ---------------- friends and operators ----------------  
+
+std::ostream& operator<<(std::ostream &s, const LLCamera &C) 
+{
+	s << "{ \n";
+	s << "  Center = " << C.getOrigin() << "\n";
+	s << "  AtAxis = " << C.getXAxis() << "\n";
+	s << "  LeftAxis = " << C.getYAxis() << "\n";
+	s << "  UpAxis = " << C.getZAxis() << "\n";
+	s << "  View = " << C.getView() << "\n";
+	s << "  Aspect = " << C.getAspect() << "\n";
+	s << "  NearPlane   = " << C.mNearPlane << "\n";
+	s << "  FarPlane    = " << C.mFarPlane << "\n";
+	s << "  TopPlane    = " << C.mLocalPlanes[LLCamera::PLANE_TOP][VX] << "  " 
+							<< C.mLocalPlanes[LLCamera::PLANE_TOP][VY] << "  " 
+							<< C.mLocalPlanes[LLCamera::PLANE_TOP][VZ] << "\n";
+	s << "  BottomPlane = " << C.mLocalPlanes[LLCamera::PLANE_BOTTOM][VX] << "  " 
+							<< C.mLocalPlanes[LLCamera::PLANE_BOTTOM][VY] << "  " 
+							<< C.mLocalPlanes[LLCamera::PLANE_BOTTOM][VZ] << "\n";
+	s << "  LeftPlane   = " << C.mLocalPlanes[LLCamera::PLANE_LEFT][VX] << "  " 
+							<< C.mLocalPlanes[LLCamera::PLANE_LEFT][VY] << "  " 
+							<< C.mLocalPlanes[LLCamera::PLANE_LEFT][VZ] << "\n";
+	s << "  RightPlane  = " << C.mLocalPlanes[LLCamera::PLANE_RIGHT][VX] << "  " 
+							<< C.mLocalPlanes[LLCamera::PLANE_RIGHT][VY] << "  " 
+							<< C.mLocalPlanes[LLCamera::PLANE_RIGHT][VZ] << "\n";
+	s << "}";
+	return s;
+}
+
+
+
+// ----------------  private member functions ----------------
+
+void LLCamera::calculateFrustumPlanes() 
+{
+	// The planes only change when any of the frustum descriptions change.
+	// They are not affected by changes of the position of the Frustum
+	// because they are known in the view frame and the position merely
+	// provides information on how to get from the absolute frame to the 
+	// view frame.
+
+	F32 left,right,top,bottom;
+	top = mFarPlane * (F32)tanf(0.5f * mView);
+	bottom = -top;
+	left = top * mAspect;
+	right = -left;
+
+	calculateFrustumPlanes(left, right, top, bottom);
+}
+
+LLPlane planeFromPoints(LLVector3 p1, LLVector3 p2, LLVector3 p3)
+{
+	LLVector3 n = ((p2-p1)%(p3-p1));
+	n.normVec();
+
+	return LLPlane(p1, n);
+}
+
+U8 LLCamera::calcPlaneMask(const LLPlane& plane)
+{
+	U8 mask = 0;
+	
+	if (plane.mV[0] >= 0)
+	{
+		mask |= 1;
+	}
+	if (plane.mV[1] >= 0)
+	{
+		mask |= 2;
+	}
+	if (plane.mV[2] >= 0)
+	{
+		mask |= 4;
+	}
+
+	return mask;
+}
+
+void LLCamera::calcAgentFrustumPlanes(LLVector3* frust)
+{
+
+	for (int i = 0; i < 8; i++)
+	{
+		mAgentFrustum[i] = frust[i];
+	}
+
+	mFrustumCornerDist = (frust[5] - getOrigin()).magVec();
+
+	//frust contains the 8 points of the frustum, calculate 6 planes
+
+	//order of planes is important, keep most likely to fail in the front of the list
+
+	//near - frust[0], frust[1], frust[2]
+	mAgentPlanes[2].p = planeFromPoints(frust[0], frust[1], frust[2]);
+
+	//far  
+	mAgentPlanes[5].p = planeFromPoints(frust[5], frust[4], frust[6]);
+
+	//left  
+	mAgentPlanes[0].p = planeFromPoints(frust[4], frust[0], frust[7]);
+
+	//right  
+	mAgentPlanes[1].p = planeFromPoints(frust[1], frust[5], frust[6]);
+
+	//top  
+	mAgentPlanes[4].p = planeFromPoints(frust[3], frust[2], frust[6]);
+
+	//bottom  
+	mAgentPlanes[3].p = planeFromPoints(frust[1], frust[0], frust[4]);
+
+	//cache plane octant facing mask for use in AABBInFrustum
+	for (U32 i = 0; i < mPlaneCount; i++)
+	{
+		mAgentPlanes[i].mask = calcPlaneMask(mAgentPlanes[i].p);
+	}
+}
+
+void LLCamera::calculateFrustumPlanes(F32 left, F32 right, F32 top, F32 bottom)
+{
+	LLVector3 a, b, c;
+
+	// For each plane we need to define 3 points (LLVector3's) in camera view space.  
+	// The order in which we pass the points to planeFromPoints() matters, because the 
+	// plane normal has a degeneracy of 2; we want it pointing _into_ the frustum. 
+
+	a.setVec(0.0f, 0.0f, 0.0f);
+	b.setVec(mFarPlane, right, top);
+	c.setVec(mFarPlane, right, bottom);
+	mLocalPlanes[PLANE_RIGHT].setVec(a, b, c);
+
+	c.setVec(mFarPlane, left, top);
+	mLocalPlanes[PLANE_TOP].setVec(a, c, b);
+
+	b.setVec(mFarPlane, left, bottom);
+	mLocalPlanes[PLANE_LEFT].setVec(a, b, c);
+
+	c.setVec(mFarPlane, right, bottom);
+	mLocalPlanes[PLANE_BOTTOM].setVec( a, c, b); 
+
+	//calculate center and radius squared of frustum in world absolute coordinates
+	mFrustCenter = X_AXIS*mFarPlane*0.5f;
+	mFrustCenter = transformToAbsolute(mFrustCenter);
+	mFrustRadiusSquared = mFarPlane*0.5f;
+	mFrustRadiusSquared *= mFrustRadiusSquared * 1.05f; //pad radius squared by 5%
+}
+
+// x and y are in WINDOW space, so x = Y-Axis (left/right), y= Z-Axis(Up/Down)
+void LLCamera::calculateFrustumPlanesFromWindow(F32 x1, F32 y1, F32 x2, F32 y2)
+{
+	F32 bottom, top, left, right;
+	F32 view_height = (F32)tanf(0.5f * mView) * mFarPlane;
+	F32 view_width = view_height * mAspect;
+	
+	left = 	 x1 * -2.f * view_width;
+	right =  x2 * -2.f * view_width;
+	bottom = y1 * 2.f * view_height; 
+	top = 	 y2 * 2.f * view_height;
+
+	calculateFrustumPlanes(left, right, top, bottom);
+}
+
+void LLCamera::calculateWorldFrustumPlanes() 
+{
+	F32 d;
+	LLVector3 center = mOrigin - mXAxis*mNearPlane;
+	mWorldPlanePos = center;
+	for (int p=0; p<4; p++)
+	{
+		LLVector3 pnorm = LLVector3(mLocalPlanes[p]);
+		LLVector3 norm = rotateToAbsolute(pnorm);
+		norm.normVec();
+		d = -(center * norm);
+		mWorldPlanes[p] = LLPlane(norm, d);
+	}
+	// horizontal planes, perpindicular to (0,0,1);
+	LLVector3 zaxis(0, 0, 1.0f);
+	F32 yaw = getYaw();
+	{
+		LLVector3 tnorm = LLVector3(mLocalPlanes[PLANE_LEFT]);
+		tnorm.rotVec(yaw, zaxis);
+		d = -(mOrigin * tnorm);
+		mHorizPlanes[HORIZ_PLANE_LEFT] = LLPlane(tnorm, d);
+	}
+	{
+		LLVector3 tnorm = LLVector3(mLocalPlanes[PLANE_RIGHT]);
+		tnorm.rotVec(yaw, zaxis);
+		d = -(mOrigin * tnorm);
+		mHorizPlanes[HORIZ_PLANE_RIGHT] = LLPlane(tnorm, d);
+	}
+}
+
+// NOTE: this is the OpenGL matrix that will transform the default OpenGL view 
+// (-Z=at, Y=up) to the default view of the LLCamera class (X=at, Z=up):
+// 
+// F32 cfr_transform =  {  0.f,  0.f, -1.f,  0.f,   // -Z becomes X
+// 						  -1.f,  0.f,  0.f,  0.f,   // -X becomes Y
+//  					   0.f,  1.f,  0.f,  0.f,   //  Y becomes Z
+// 						   0.f,  0.f,  0.f,  1.f };