WebSVN – gelsvn – Diff – /branches/wireframe-experiments/src/GLGraphics/QuatTrackBall.cpp


#include <iostream>
#include "CGLA/CGLA.h"
#include "QuatTrackBall.h"
 
#include "gel_glu.h"
#include "GLViewController.h"
 
 
using namespace std;
using namespace CGLA;
 
namespace GLGraphics
{
    
    QuatTrackBall::QuatTrackBall(const Vec3f& _centre, 
			 float _eye_dist,
			 unsigned _width, 
			 unsigned _height):
	centre(_centre), width(_width), height(_height), 
	eye_dist(_eye_dist)
	{
	// This size should really be based on the distance from the center of
	// rotation to the point on the object underneath the mouse.  That
	// point would then track the mouse as closely as possible.  This is a
	// simple example, though, so that is left as an exercise.
	ballsize = 2.0f;
	screen_centre = Vec2i(width/2, height/2);
	qrot = Quatf(0.0, 0.0, 0.0, 1.0);
	qinc = Quatf(0.0, 0.0, 0.0, 1.0);
	trans = Vec2f(0.0, 0.0);
    }
    
    void QuatTrackBall::grab_ball(TrackBallAction act, const Vec2i& v)
    {
    if(v[0] < 0 || v[0] >= static_cast<int>(width)
       || v[1] < 0 || v[1] >= static_cast<int>(height))
      return;      
 
	set_position(scalePoint(v));
	current_action = act;
    }
    
    void QuatTrackBall::roll_ball(const Vec2i& v)
    {
    if(v[0] < 0 || v[0] >= static_cast<int>(width)
       || v[1] < 0 || v[1] >= static_cast<int>(height))
      return;      
 
	Vec2f w = scalePoint(v); 
	
	switch (current_action) 
	{
			case ROTATE_ACTION:
	    rotate(w);
	    break;
	    
			case PAN_ACTION:
	    pan(w);
	    break;
	    
			case ZOOM_ACTION:
	    zoom(w);
	    break;
	}
	last_pos = w;	
    }
    
    // Call this when the user does a mouse down.  
    // Stop the trackball glide, then remember the mouse
    // down point (for a future rotate, pan or zoom).
    void QuatTrackBall::set_position(const Vec2f& _last_pos) 
    {
	stop_spin();
	last_pos = _last_pos;
    }
    
    // Rotationaly spin the trackball by the current increment.
    // Use this to implement rotational glide.
    void QuatTrackBall::do_spin() 
    {
	qrot = qrot*qinc;
    }
    
    // Cease any rotational glide by zeroing the increment.
    void QuatTrackBall::stop_spin() 
    {
	qinc.set(0.0, 0.0, 0.0, 1.0);
    }
    
    void QuatTrackBall::rotate(const Vec2f& new_v) 
    {
	calcRotation(new_v);
	do_spin();	
    }
    
    void QuatTrackBall::pan(const Vec2f& new_v) 
    {
	trans += (new_v - last_pos) * Vec2f(eye_dist);
    }
    
    void QuatTrackBall::zoom(const Vec2f& new_v) 
    {
	eye_dist += (new_v[1] - last_pos[1]) * eye_dist;
	eye_dist = max(eye_dist, 0.01f);
    }
    
    void QuatTrackBall::calcRotation(const Vec2f& new_pos) 
    {
	// Check for zero rotation
	if (new_pos == last_pos) 
	    qinc = Quatf(0.0f, 0.0f, 0.0f, 1.0f);
	else
	{
		// Form two vectors based on input points, find rotation axis
		Vec3f p1 = Vec3f(new_pos[0], new_pos[1], projectToSphere(new_pos));
		Vec3f p2 = Vec3f(last_pos[0], last_pos[1], projectToSphere(last_pos));
        qinc.make_rot(normalize(p1), normalize(p2));
/*
		Vec3f q = cross(p1, p2);		// axis of rotation from p1 and p2 
		float L = sqrt(1.0f-dot(q,q) / (dot(p1,p1) * dot(p2,p2)));
		
		q.normalize();				// q' = axis of rotation 
		q *= sqrt((1 - L)/2);	// q' = q' * sin(phi)
		
		qinc.set(q[0],q[1],q[2],sqrt((1 + L)/2));
*/
	}
    }
    
    // Project an x,y pair onto a sphere of radius r OR a hyperbolic sheet
    // if we are away from the center of the sphere.
    float QuatTrackBall::projectToSphere(const Vec2f& v) 
    {
#ifndef M_SQRT_2
	  const double M_SQRT_2 = 0.707106781187;
#endif
 
      float d = v.length();
      float t = ballsize*M_SQRT_2;
      float z;
  
      // Inside sphere 
      if(d < ballsize) 
        z = sqrt(ballsize*ballsize - d*d);
      else if(d < t)
        z = 0.0;
      // On hyperbola 
      else 
        z = t*t/d;
 
      return z;
    }
    
    // Scales integer point to the range [-1, 1]
    Vec2f QuatTrackBall::scalePoint(const Vec2i& v) const
    {
	Vec2f w(v[0],height - v[1]);
	w -= Vec2f(screen_centre);
	w /= Vec2f(width,height);
	w = CGLA::v_min(Vec2f(1.0f), CGLA::v_max(Vec2f(-1), 2*w));
	return w; 
    }
    
    void QuatTrackBall::get_view_param(Vec3f& eye, Vec3f& _centre, Vec3f& up) const
    {
	up  = qrot.apply_unit(Vec3f(0,1,0));
	Vec3f right = qrot.apply(Vec3f(1,0,0));
	_centre = centre - up * trans[1] - right * trans[0]; 
	eye = qrot.apply_unit(Vec3f(0,0,1)*eye_dist) + _centre;
    }
    
    
    // Modify the current gl matrix by the trackball rotation and translation.
    void QuatTrackBall::set_gl_modelview() const
    {
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	Vec3f eye;
	Vec3f _centre;
	Vec3f up;
	get_view_param(eye, _centre, up);
	gluLookAt(eye[0], eye[1], eye[2],
		  _centre[0], _centre[1], _centre[2], 
		  up[0],up[1],up[2]);
    }
    
    bool QuatTrackBall::is_spinning() const
    {
	static const Quatf null_quat(0,0,0,1);
	if(!(qinc == null_quat))
	    return true;
	return false;
    }
}
 

Rev 392	Rev 393
1	`#include <iostream>`	1	`#include <iostream>`
2	`#include "CGLA/CGLA.h"`	2	`#include "CGLA/CGLA.h"`
3	`#include "QuatTrackBall.h"`	3	`#include "QuatTrackBall.h"`
4		4
5	`#include "gel_glu.h"`	5	`#include "gel_glu.h"`
6	`#include "GLViewController.h"`	6	`#include "GLViewController.h"`
7		7
8		8
9	`using namespace std;`	9	`using namespace std;`
10	`using namespace CGLA;`	10	`using namespace CGLA;`
11		11
12	`namespace GLGraphics`	12	`namespace GLGraphics`
13	`{`	13	`{`
14		14
15	`QuatTrackBall::QuatTrackBall(const Vec3f& _centre,`	15	`QuatTrackBall::QuatTrackBall(const Vec3f& _centre,`
16	`float _eye_dist,`	16	`float _eye_dist,`
17	`unsigned _width,`	17	`unsigned _width,`
18	`unsigned _height):`	18	`unsigned _height):`
19	`centre(_centre), width(_width), height(_height),`	19	`centre(_centre), width(_width), height(_height),`
20	`eye_dist(_eye_dist)`	20	`eye_dist(_eye_dist)`
21	`{`	21	`{`
22	`// This size should really be based on the distance from the center of`	22	`// This size should really be based on the distance from the center of`
23	`// rotation to the point on the object underneath the mouse. That`	23	`// rotation to the point on the object underneath the mouse. That`
24	`// point would then track the mouse as closely as possible. This is a`	24	`// point would then track the mouse as closely as possible. This is a`
25	`// simple example, though, so that is left as an exercise.`	25	`// simple example, though, so that is left as an exercise.`
26	`ballsize = 2.0f;`	26	`ballsize = 2.0f;`
27	`screen_centre = Vec2i(width/2, height/2);`	27	`screen_centre = Vec2i(width/2, height/2);`
28	`qrot = Quatf(0.0, 0.0, 0.0, 1.0);`	28	`qrot = Quatf(0.0, 0.0, 0.0, 1.0);`
29	`qinc = Quatf(0.0, 0.0, 0.0, 1.0);`	29	`qinc = Quatf(0.0, 0.0, 0.0, 1.0);`
30	`trans = Vec2f(0.0, 0.0);`	30	`trans = Vec2f(0.0, 0.0);`
31	`}`	31	`}`
32		32
33	`void QuatTrackBall::grab_ball(TrackBallAction act, const Vec2i& v)`	33	`void QuatTrackBall::grab_ball(TrackBallAction act, const Vec2i& v)`
34	`{`	34	`{`
35	`if(v[0] < 0 \|\| v[0] >= static_cast<int>(width)`	35	`if(v[0] < 0 \|\| v[0] >= static_cast<int>(width)`
36	`\|\| v[1] < 0 \|\| v[1] >= static_cast<int>(height))`	36	`\|\| v[1] < 0 \|\| v[1] >= static_cast<int>(height))`
37	`return;`	37	`return;`
38		38
39	`set_position(scalePoint(v));`	39	`set_position(scalePoint(v));`
40	`current_action = act;`	40	`current_action = act;`
41	`}`	41	`}`
42		42
43	`void QuatTrackBall::roll_ball(const Vec2i& v)`	43	`void QuatTrackBall::roll_ball(const Vec2i& v)`
44	`{`	44	`{`
45	`if(v[0] < 0 \|\| v[0] >= static_cast<int>(width)`	45	`if(v[0] < 0 \|\| v[0] >= static_cast<int>(width)`
46	`\|\| v[1] < 0 \|\| v[1] >= static_cast<int>(height))`	46	`\|\| v[1] < 0 \|\| v[1] >= static_cast<int>(height))`
47	`return;`	47	`return;`
48		48
49	`Vec2f w = scalePoint(v);`	49	`Vec2f w = scalePoint(v);`
50		50
51	`switch (current_action)`	51	`switch (current_action)`
52	`{`	52	`{`
53	`case ROTATE_ACTION:`	53	`case ROTATE_ACTION:`
54	`rotate(w);`	54	`rotate(w);`
55	`break;`	55	`break;`
56		56
57	`case PAN_ACTION:`	57	`case PAN_ACTION:`
58	`pan(w);`	58	`pan(w);`
59	`break;`	59	`break;`
60		60
61	`case ZOOM_ACTION:`	61	`case ZOOM_ACTION:`
62	`zoom(w);`	62	`zoom(w);`
63	`break;`	63	`break;`
64	`}`	64	`}`
65	`last_pos = w;`	65	`last_pos = w;`
66	`}`	66	`}`
67		67
68	`// Call this when the user does a mouse down.`	68	`// Call this when the user does a mouse down.`
69	`// Stop the trackball glide, then remember the mouse`	69	`// Stop the trackball glide, then remember the mouse`
70	`// down point (for a future rotate, pan or zoom).`	70	`// down point (for a future rotate, pan or zoom).`
71	`void QuatTrackBall::set_position(const Vec2f& _last_pos)`	71	`void QuatTrackBall::set_position(const Vec2f& _last_pos)`
72	`{`	72	`{`
73	`stop_spin();`	73	`stop_spin();`
74	`last_pos = _last_pos;`	74	`last_pos = _last_pos;`
75	`}`	75	`}`
76		76
77	`// Rotationaly spin the trackball by the current increment.`	77	`// Rotationaly spin the trackball by the current increment.`
78	`// Use this to implement rotational glide.`	78	`// Use this to implement rotational glide.`
79	`void QuatTrackBall::do_spin()`	79	`void QuatTrackBall::do_spin()`
80	`{`	80	`{`
81	`qrot = qrot*qinc;`	81	`qrot = qrot*qinc;`
82	`}`	82	`}`
83		83
84	`// Cease any rotational glide by zeroing the increment.`	84	`// Cease any rotational glide by zeroing the increment.`
85	`void QuatTrackBall::stop_spin()`	85	`void QuatTrackBall::stop_spin()`
86	`{`	86	`{`
87	`qinc.set(0.0, 0.0, 0.0, 1.0);`	87	`qinc.set(0.0, 0.0, 0.0, 1.0);`
88	`}`	88	`}`
89		89
90	`void QuatTrackBall::rotate(const Vec2f& new_v)`	90	`void QuatTrackBall::rotate(const Vec2f& new_v)`
91	`{`	91	`{`
92	`calcRotation(new_v);`	92	`calcRotation(new_v);`
93	`do_spin();`	93	`do_spin();`
94	`}`	94	`}`
95		95
96	`void QuatTrackBall::pan(const Vec2f& new_v)`	96	`void QuatTrackBall::pan(const Vec2f& new_v)`
97	`{`	97	`{`
98	`trans += (new_v - last_pos) * Vec2f(eye_dist);`	98	`trans += (new_v - last_pos) * Vec2f(eye_dist);`
99	`}`	99	`}`
100		100
101	`void QuatTrackBall::zoom(const Vec2f& new_v)`	101	`void QuatTrackBall::zoom(const Vec2f& new_v)`
102	`{`	102	`{`
103	`eye_dist += (new_v[1] - last_pos[1]) * eye_dist;`	103	`eye_dist += (new_v[1] - last_pos[1]) * eye_dist;`
104	`eye_dist = max(eye_dist, 0.01f);`	104	`eye_dist = max(eye_dist, 0.01f);`
105	`}`	105	`}`
106		106
107	`void QuatTrackBall::calcRotation(const Vec2f& new_pos)`	107	`void QuatTrackBall::calcRotation(const Vec2f& new_pos)`
108	`{`	108	`{`
109	`// Check for zero rotation`	109	`// Check for zero rotation`
110	`if (new_pos == last_pos)`	110	`if (new_pos == last_pos)`
111	`qinc = Quatf(0.0f, 0.0f, 0.0f, 1.0f);`	111	`qinc = Quatf(0.0f, 0.0f, 0.0f, 1.0f);`
112	`else`	112	`else`
113	`{`	113	`{`
114	`// Form two vectors based on input points, find rotation axis`	114	`// Form two vectors based on input points, find rotation axis`
115	`Vec3f p1 = Vec3f(new_pos[0], new_pos[1], projectToSphere(new_pos));`	115	`Vec3f p1 = Vec3f(new_pos[0], new_pos[1], projectToSphere(new_pos));`
116	`Vec3f p2 = Vec3f(last_pos[0], last_pos[1], projectToSphere(last_pos));`	116	`Vec3f p2 = Vec3f(last_pos[0], last_pos[1], projectToSphere(last_pos));`
117	`qinc.make_rot(normalize(p1), normalize(p2));`	117	`qinc.make_rot(normalize(p1), normalize(p2));`
118	`/*`	118	`/*`
119	`Vec3f q = cross(p1, p2); // axis of rotation from p1 and p2`	119	`Vec3f q = cross(p1, p2); // axis of rotation from p1 and p2`
120	`float L = sqrt(1.0f-dot(q,q) / (dot(p1,p1) * dot(p2,p2)));`	120	`float L = sqrt(1.0f-dot(q,q) / (dot(p1,p1) * dot(p2,p2)));`
121		121
122	`q.normalize(); // q' = axis of rotation`	122	`q.normalize(); // q' = axis of rotation`
123	`q = sqrt((1 - L)/2); // q' = q' sin(phi)`	123	`q = sqrt((1 - L)/2); // q' = q' sin(phi)`
124		124
125	`qinc.set(q[0],q[1],q[2],sqrt((1 + L)/2));`	125	`qinc.set(q[0],q[1],q[2],sqrt((1 + L)/2));`
126	`*/`	126	`*/`
127	`}`	127	`}`
128	`}`	128	`}`
129		129
130	`// Project an x,y pair onto a sphere of radius r OR a hyperbolic sheet`	130	`// Project an x,y pair onto a sphere of radius r OR a hyperbolic sheet`
131	`// if we are away from the center of the sphere.`	131	`// if we are away from the center of the sphere.`
132	`float QuatTrackBall::projectToSphere(const Vec2f& v)`	132	`float QuatTrackBall::projectToSphere(const Vec2f& v)`
133	`{`	133	`{`
134	`#ifndef M_SQRT_2`	134	`#ifndef M_SQRT_2`
135	`const double M_SQRT_2 = 0.707106781187;`	135	`const double M_SQRT_2 = 0.707106781187;`
136	`#endif`	136	`#endif`
137		137
138	`float d = v.length();`	138	`float d = v.length();`
139	`float t = ballsize*M_SQRT_2;`	139	`float t = ballsize*M_SQRT_2;`
140	`float z;`	140	`float z;`
141		141
142	`// Inside sphere`	142	`// Inside sphere`
143	`if(d < ballsize)`	143	`if(d < ballsize)`
144	`z = sqrt(ballsizeballsize - dd);`	144	`z = sqrt(ballsizeballsize - dd);`
145	`else if(d < t)`	145	`else if(d < t)`
146	`z = 0.0;`	146	`z = 0.0;`
147	`// On hyperbola`	147	`// On hyperbola`
148	`else`	148	`else`
149	`z = t*t/d;`	149	`z = t*t/d;`
150		150
151	`return z;`	151	`return z;`
152	`}`	152	`}`
153		153
154	`// Scales integer point to the range [-1, 1]`	154	`// Scales integer point to the range [-1, 1]`
155	`Vec2f QuatTrackBall::scalePoint(const Vec2i& v) const`	155	`Vec2f QuatTrackBall::scalePoint(const Vec2i& v) const`
156	`{`	156	`{`
157	`Vec2f w(v[0],height - v[1]);`	157	`Vec2f w(v[0],height - v[1]);`
158	`w -= Vec2f(screen_centre);`	158	`w -= Vec2f(screen_centre);`
159	`w /= Vec2f(width,height);`	159	`w /= Vec2f(width,height);`
160	`w = CGLA::v_min(Vec2f(1.0f), CGLA::v_max(Vec2f(-1), 2*w));`	160	`w = CGLA::v_min(Vec2f(1.0f), CGLA::v_max(Vec2f(-1), 2*w));`
161	`return w;`	161	`return w;`
162	`}`	162	`}`
163		163
164	`void QuatTrackBall::get_view_param(Vec3f& eye, Vec3f& _centre, Vec3f& up) const`	164	`void QuatTrackBall::get_view_param(Vec3f& eye, Vec3f& _centre, Vec3f& up) const`
165	`{`	165	`{`
166	`up = qrot.apply_unit(Vec3f(0,1,0));`	166	`up = qrot.apply_unit(Vec3f(0,1,0));`
167	`Vec3f right = qrot.apply(Vec3f(1,0,0));`	167	`Vec3f right = qrot.apply(Vec3f(1,0,0));`
168	`_centre = centre - up * trans[1] - right * trans[0];`	168	`_centre = centre - up * trans[1] - right * trans[0];`
169	`eye = qrot.apply_unit(Vec3f(0,0,1)*eye_dist) + _centre;`	169	`eye = qrot.apply_unit(Vec3f(0,0,1)*eye_dist) + _centre;`
170	`}`	170	`}`
171		171
172		172
173	`// Modify the current gl matrix by the trackball rotation and translation.`	173	`// Modify the current gl matrix by the trackball rotation and translation.`
174	`void QuatTrackBall::set_gl_modelview() const`	174	`void QuatTrackBall::set_gl_modelview() const`
175	`{`	175	`{`
176	`glMatrixMode(GL_MODELVIEW);`	176	`glMatrixMode(GL_MODELVIEW);`
177	`glLoadIdentity();`	177	`glLoadIdentity();`
178	`Vec3f eye;`	178	`Vec3f eye;`
179	`Vec3f _centre;`	179	`Vec3f _centre;`
180	`Vec3f up;`	180	`Vec3f up;`
181	`get_view_param(eye, _centre, up);`	181	`get_view_param(eye, _centre, up);`
182	`gluLookAt(eye[0], eye[1], eye[2],`	182	`gluLookAt(eye[0], eye[1], eye[2],`
183	`_centre[0], _centre[1], _centre[2],`	183	`_centre[0], _centre[1], _centre[2],`
184	`up[0],up[1],up[2]);`	184	`up[0],up[1],up[2]);`
185	`}`	185	`}`
186		186
187	`bool QuatTrackBall::is_spinning() const`	187	`bool QuatTrackBall::is_spinning() const`
188	`{`	188	`{`
189	`static const Quatf null_quat(0,0,0,1);`	189	`static const Quatf null_quat(0,0,0,1);`
190	`if(!(qinc == null_quat))`	190	`if(!(qinc == null_quat))`
191	`return true;`	191	`return true;`
192	`return false;`	192	`return false;`
193	`}`	193	`}`
194	`}`	194	`}`
195		195

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(root)/branches/wireframe-experiments/src/GLGraphics/QuatTrackBall.cpp – Rev 392 → 393