[136] | 1 | // This file is part of Eigen, a lightweight C++ template library
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| 2 | // for linear algebra.
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| 3 | //
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| 4 | // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
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| 5 | //
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| 6 | // This Source Code Form is subject to the terms of the Mozilla
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| 7 | // Public License v. 2.0. If a copy of the MPL was not distributed
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| 8 | // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
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| 9 |
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| 10 | #include "trackball.h"
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| 11 | #include "camera.h"
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| 12 |
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| 13 | using namespace Eigen;
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| 14 |
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| 15 | void Trackball::track(const Vector2i& point2D)
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| 16 | {
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| 17 | if (mpCamera==0)
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| 18 | return;
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| 19 | Vector3f newPoint3D;
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| 20 | bool newPointOk = mapToSphere(point2D, newPoint3D);
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| 21 |
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| 22 | if (mLastPointOk && newPointOk)
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| 23 | {
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| 24 | Vector3f axis = mLastPoint3D.cross(newPoint3D).normalized();
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| 25 | float cos_angle = mLastPoint3D.dot(newPoint3D);
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| 26 | if ( internal::abs(cos_angle) < 1.0 )
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| 27 | {
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| 28 | float angle = 2. * acos(cos_angle);
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| 29 | if (mMode==Around)
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| 30 | mpCamera->rotateAroundTarget(Quaternionf(AngleAxisf(angle, axis)));
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| 31 | else
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| 32 | mpCamera->localRotate(Quaternionf(AngleAxisf(-angle, axis)));
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| 33 | }
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| 34 | }
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| 35 |
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| 36 | mLastPoint3D = newPoint3D;
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| 37 | mLastPointOk = newPointOk;
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| 38 | }
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| 39 |
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| 40 | bool Trackball::mapToSphere(const Vector2i& p2, Vector3f& v3)
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| 41 | {
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| 42 | if ((p2.x() >= 0) && (p2.x() <= int(mpCamera->vpWidth())) &&
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| 43 | (p2.y() >= 0) && (p2.y() <= int(mpCamera->vpHeight())) )
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| 44 | {
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| 45 | double x = (double)(p2.x() - 0.5*mpCamera->vpWidth()) / (double)mpCamera->vpWidth();
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| 46 | double y = (double)(0.5*mpCamera->vpHeight() - p2.y()) / (double)mpCamera->vpHeight();
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| 47 | double sinx = sin(M_PI * x * 0.5);
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| 48 | double siny = sin(M_PI * y * 0.5);
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| 49 | double sinx2siny2 = sinx * sinx + siny * siny;
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| 50 |
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| 51 | v3.x() = sinx;
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| 52 | v3.y() = siny;
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| 53 | v3.z() = sinx2siny2 < 1.0 ? sqrt(1.0 - sinx2siny2) : 0.0;
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| 54 |
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| 55 | return true;
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| 56 | }
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| 57 | else
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| 58 | return false;
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| 59 | }
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