2001-11-27 18:50:04 -07:00
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// frustum.cpp
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//
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// Copyright (C) 2000, Chris Laurel <claurel@shatters.net>
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//
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// This program is free software; you can redistribute it and/or
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// modify it under the terms of the GNU General Public License
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// as published by the Free Software Foundation; either version 2
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// of the License, or (at your option) any later version.
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#include "frustum.h"
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Frustum::Frustum(float fov, float aspectRatio, float n) :
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infinite(true)
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{
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init(fov, aspectRatio, n, n);
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}
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Frustum::Frustum(float fov, float aspectRatio, float n, float f) :
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infinite(false)
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{
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init(fov, aspectRatio, n, f);
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}
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void Frustum::init(float fov, float aspectRatio, float n, float f)
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{
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float h = (float) tan(fov / 2.0f);
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float w = h * aspectRatio;
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Vec3f normals[4];
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normals[Bottom] = Vec3f(0, 1, -h);
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normals[Top] = Vec3f(0, -1, -h);
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normals[Left] = Vec3f(1, 0, -w);
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normals[Right] = Vec3f(-1, 0, -w);
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for (int i = 0; i < 4; i++)
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{
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normals[i].normalize();
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planes[i] = Planef(normals[i], Point3f(0, 0, 0));
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}
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planes[Near] = Planef(Vec3f(0, 0, -1), -n);
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2003-07-23 12:02:25 -06:00
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planes[Far] = Planef(Vec3f(0, 0, 1), f);
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2001-11-27 18:50:04 -07:00
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}
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Frustum::Aspect Frustum::test(const Point3f& p) const
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{
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return testSphere(p, 0);
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}
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Frustum::Aspect Frustum::testSphere(const Point3f& center, float radius) const
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{
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int nPlanes = infinite ? 5 : 6;
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int intersections = 0;
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for (int i = 0; i < nPlanes; i++)
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{
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float distanceToPlane = planes[i].distanceTo(center);
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if (distanceToPlane < -radius)
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return Outside;
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else if (distanceToPlane <= radius)
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intersections |= (1 << i);
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}
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return (intersections == 0) ? Inside : Intersect;
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}
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2005-11-18 01:07:17 -07:00
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Frustum::Aspect Frustum::testSphere(const Point3d& center, double radius) const
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{
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int nPlanes = infinite ? 5 : 6;
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int intersections = 0;
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for (int i = 0; i < nPlanes; i++)
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{
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2007-11-08 13:41:31 -07:00
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//TODO: Celestia should incorporate some casting operators overloading to accommodate all this kind of stuff:
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2005-11-18 01:07:17 -07:00
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Vec3f plNormal = planes[i].normal;
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Vec3d plNormalDbl(plNormal.x, plNormal.y, plNormal.z);
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double distanceToPlane = plNormalDbl.x * center.x + plNormalDbl.y * center.y + plNormalDbl.z * center.z + planes[i].d;
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if (distanceToPlane < -radius)
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return Outside;
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else if (distanceToPlane <= radius)
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intersections |= (1 << i);
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}
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return (intersections == 0) ? Inside : Intersect;
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}
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2007-11-08 13:41:31 -07:00
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Frustum::Aspect Frustum::testCapsule(const Capsulef& capsule) const
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{
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int nPlanes = infinite ? 5 : 6;
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int intersections = 0;
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float r2 = capsule.radius * capsule.radius;
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for (int i = 0; i < nPlanes; i++)
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{
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float signedDist0 = planes[i].normal * Vec3f(capsule.origin.x, capsule.origin.y, capsule.origin.z) + planes[i].d;
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float signedDist1 = signedDist0 + planes[i].normal * capsule.axis;
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if (signedDist0 * signedDist1 > r2)
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{
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// Endpoints of capsule are on same side of plane; test closest endpoint to see if it
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// lies closer to the plane than radius
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if (abs(signedDist0) <= abs(signedDist1))
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{
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if (signedDist0 < -capsule.radius)
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return Outside;
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else if (signedDist0 < capsule.radius)
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intersections |= (1 << i);
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}
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else
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{
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if (signedDist1 < -capsule.radius)
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return Outside;
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else if (signedDist1 < capsule.radius)
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intersections |= (1 << i);
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}
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}
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else
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{
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// Capsule endpoints are on different sides of the plane, so we have an intersection
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intersections |= (1 << i);
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}
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#if 0
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Vec3f plNormal = planes[i].normal;
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Vec3d plNormalDbl(plNormal.x, plNormal.y, plNormal.z);
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double distanceToPlane = planes[i].distanceToSegment(capsule.origin, capsule.axis);
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if (distanceToPlane < -capsule.radius)
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return Outside;
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else if (distanceToPlane <= capsule.radius)
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intersections |= (1 << i);
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#endif
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}
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return (intersections == 0) ? Inside : Intersect;
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}
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2001-11-27 18:50:04 -07:00
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#if 0
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// See if the half space defined by the plane intersects the frustum. For the
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// plane equation p(x, y, z) = ax + by + cz + d = 0, the halfspace is
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// contains all points p(x, y, z) < 0.
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Frustum::Aspect Frustum::testHalfSpace(const Planef& plane)
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{
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return Intersect;
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}
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#endif
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2008-02-25 19:52:06 -07:00
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void Frustum::transform(const Mat3f& m)
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2001-11-27 18:50:04 -07:00
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{
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2008-02-25 19:52:06 -07:00
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int nPlanes = infinite ? 5 : 6;
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Mat3f invTranspose = m.inverse().transpose();
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for (int i = 0; i < nPlanes; i++)
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{
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planes[i] = planes[i] * invTranspose;
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float s = 1.0f / planes[i].normal.length();
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planes[i].normal = planes[i].normal * s;
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planes[i].d *= s;
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}
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2001-11-27 18:50:04 -07:00
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}
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void Frustum::transform(const Mat4f& m)
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{
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int nPlanes = infinite ? 5 : 6;
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Mat4f invTranspose = m.inverse().transpose();
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for (int i = 0; i < nPlanes; i++)
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{
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planes[i] = planes[i] * invTranspose;
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float s = 1.0f / planes[i].normal.length();
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planes[i].normal = planes[i].normal * s;
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planes[i].d *= s;
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}
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}
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