WebSVN – gelsvn – Diff – /trunk/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), 
	scale(0.5*_eye_dist), 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(scale[0], scale[1]);
    }
    
    void QuatTrackBall::zoom(const Vec2f& new_v) 
    {
	eye_dist += (new_v[1] - last_pos[1]) * scale[2];
	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 277	Rev 299
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	`scale(0.5*_eye_dist), eye_dist(_eye_dist)`	20	`scale(0.5*_eye_dist), 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)`
-		36	`\|\| v[1] < 0 \|\| v[1] >= static_cast<int>(height))`
-		37	`return;`
-		38
35	`set_position(scalePoint(v));`	39	`set_position(scalePoint(v));`
36	`current_action = act;`	40	`current_action = act;`
37	`}`	41	`}`
38		42
39	`void QuatTrackBall::roll_ball(const Vec2i& v)`	43	`void QuatTrackBall::roll_ball(const Vec2i& v)`
40	`{`	44	`{`
-		45	`if(v[0] < 0 \|\| v[0] >= static_cast<int>(width)`
-		46	`\|\| v[1] < 0 \|\| v[1] >= static_cast<int>(height))`
-		47	`return;`
-		48
41	`Vec2f w = scalePoint(v);`	49	`Vec2f w = scalePoint(v);`
42		50
43	`if(v[0] < 0 \|\| v[0] >= static_cast<int>(width))`	-
44	`w[0] = last_pos[0];`	-
45	`if(v[1] < 0 \|\| v[1] >= static_cast<int>(height))`	-
46	`w[1] = last_pos[1];`	-
47		-
48	`switch (current_action)`	51	`switch (current_action)`
49	`{`	52	`{`
50	`case ROTATE_ACTION:`	53	`case ROTATE_ACTION:`
51	`rotate(w);`	54	`rotate(w);`
52	`break;`	55	`break;`
53		56
54	`case PAN_ACTION:`	57	`case PAN_ACTION:`
55	`pan(w);`	58	`pan(w);`
56	`break;`	59	`break;`
57		60
58	`case ZOOM_ACTION:`	61	`case ZOOM_ACTION:`
59	`zoom(w);`	62	`zoom(w);`
60	`break;`	63	`break;`
61	`}`	64	`}`
62	`last_pos = w;`	65	`last_pos = w;`
63	`}`	66	`}`
64		67
65	`// Call this when the user does a mouse down.`	68	`// Call this when the user does a mouse down.`
66	`// Stop the trackball glide, then remember the mouse`	69	`// Stop the trackball glide, then remember the mouse`
67	`// down point (for a future rotate, pan or zoom).`	70	`// down point (for a future rotate, pan or zoom).`
68	`void QuatTrackBall::set_position(const Vec2f& _last_pos)`	71	`void QuatTrackBall::set_position(const Vec2f& _last_pos)`
69	`{`	72	`{`
70	`stop_spin();`	73	`stop_spin();`
71	`last_pos = _last_pos;`	74	`last_pos = _last_pos;`
72	`}`	75	`}`
73		76
74	`// Rotationaly spin the trackball by the current increment.`	77	`// Rotationaly spin the trackball by the current increment.`
75	`// Use this to implement rotational glide.`	78	`// Use this to implement rotational glide.`
76	`void QuatTrackBall::do_spin()`	79	`void QuatTrackBall::do_spin()`
77	`{`	80	`{`
78	`qrot = qrot*qinc;`	81	`qrot = qrot*qinc;`
79	`}`	82	`}`
80		83
81	`// Cease any rotational glide by zeroing the increment.`	84	`// Cease any rotational glide by zeroing the increment.`
82	`void QuatTrackBall::stop_spin()`	85	`void QuatTrackBall::stop_spin()`
83	`{`	86	`{`
84	`qinc.set(0.0, 0.0, 0.0, 1.0);`	87	`qinc.set(0.0, 0.0, 0.0, 1.0);`
85	`}`	88	`}`
86		89
87	`void QuatTrackBall::rotate(const Vec2f& new_v)`	90	`void QuatTrackBall::rotate(const Vec2f& new_v)`
88	`{`	91	`{`
89	`calcRotation(new_v);`	92	`calcRotation(new_v);`
90	`do_spin();`	93	`do_spin();`
91	`}`	94	`}`
92		95
93	`void QuatTrackBall::pan(const Vec2f& new_v)`	96	`void QuatTrackBall::pan(const Vec2f& new_v)`
94	`{`	97	`{`
95	`trans += (new_v - last_pos) * Vec2f(scale[0], scale[1]);`	98	`trans += (new_v - last_pos) * Vec2f(scale[0], scale[1]);`
96	`}`	99	`}`
97		100
98	`void QuatTrackBall::zoom(const Vec2f& new_v)`	101	`void QuatTrackBall::zoom(const Vec2f& new_v)`
99	`{`	102	`{`
100	`eye_dist += (new_v[1] - last_pos[1]) * scale[2];`	103	`eye_dist += (new_v[1] - last_pos[1]) * scale[2];`
101	`eye_dist = max(eye_dist, 0.01f);`	104	`eye_dist = max(eye_dist, 0.01f);`
102	`}`	105	`}`
103		106
104	`void QuatTrackBall::calcRotation(const Vec2f& new_pos)`	107	`void QuatTrackBall::calcRotation(const Vec2f& new_pos)`
105	`{`	108	`{`
106	`// Check for zero rotation`	109	`// Check for zero rotation`
107	`if (new_pos == last_pos)`	110	`if (new_pos == last_pos)`
108	`qinc = Quatf(0.0f, 0.0f, 0.0f, 1.0f);`	111	`qinc = Quatf(0.0f, 0.0f, 0.0f, 1.0f);`
109	`else`	112	`else`
110	`{`	113	`{`
111	`// Form two vectors based on input points, find rotation axis`	114	`// Form two vectors based on input points, find rotation axis`
112	`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));`
113	`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));`
-		118	`/*`
-		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)));`
114		121
-		122	`q.normalize(); // q' = axis of rotation`
-		123	`q = sqrt((1 - L)/2); // q' = q' sin(phi)`
-		124
115	`qinc.make_rot(normalize(p1), normalize(p2));`	125	`qinc.set(q[0],q[1],q[2],sqrt((1 + L)/2));`
-		126	`*/`
116	`}`	127	`}`
117	`}`	128	`}`
118		129
119	`// 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`
120	`// if we are away from the center of the sphere.`	131	`// if we are away from the center of the sphere.`
121	`float QuatTrackBall::projectToSphere(const Vec2f& v)`	132	`float QuatTrackBall::projectToSphere(const Vec2f& v)`
122	`{`	133	`{`
123	`float d, t, z;`	134	`#ifndef M_SQRT_2`
-		135	`const double M_SQRT_2 = 0.707106781187;`
-		136	`#endif`
124		137
125	`d = v.length();`	138	`float d = v.length();`
-		139	`float t = ballsize*M_SQRT_2;`
-		140	`float z;`
126		141
127	`// Inside sphere`	142	`// Inside sphere`
128	`if (d < ballsize * 0.70710678118654752440) {`	143	`if(d < ballsize)`
129	`z = sqrt(ballsizeballsize - dd);`	144	`z = sqrt(ballsizeballsize - dd);`
-		145	`else if(d < t)`
130	`}`	146	`z = 0.0;`
131	`// On hyperbola`	147	`// On hyperbola`
132	`else {`	148	`else`
133	`t = ballsize / 1.41421356237309504880;`	-
134	`z = t*t / d;`	149	`z = t*t/d;`
135	`}`	-
136		150
137	`return z;`	151	`return z;`
138	`}`	152	`}`
139		153
140	`// Scales integer point to the range [-1, 1]`	154	`// Scales integer point to the range [-1, 1]`
141	`Vec2f QuatTrackBall::scalePoint(const Vec2i& v) const`	155	`Vec2f QuatTrackBall::scalePoint(const Vec2i& v) const`
142	`{`	156	`{`
143	`Vec2f w(v[0],height - v[1]);`	157	`Vec2f w(v[0],height - v[1]);`
144	`w -= Vec2f(screen_centre);`	158	`w -= Vec2f(screen_centre);`
145	`w /= Vec2f(width,height);`	159	`w /= Vec2f(width,height);`
146	`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));`
147	`return w;`	161	`return w;`
148	`}`	162	`}`
149		163
150	`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`
151	`{`	165	`{`
152	`up = qrot.apply_unit(Vec3f(0,1,0));`	166	`up = qrot.apply_unit(Vec3f(0,1,0));`
153	`Vec3f right = qrot.apply(Vec3f(1,0,0));`	167	`Vec3f right = qrot.apply(Vec3f(1,0,0));`
154	`_centre = centre - up * trans[1] - right * trans[0];`	168	`_centre = centre - up * trans[1] - right * trans[0];`
155	`eye = qrot.apply_unit(Vec3f(0,0,1)*eye_dist) + _centre;`	169	`eye = qrot.apply_unit(Vec3f(0,0,1)*eye_dist) + _centre;`
156	`}`	170	`}`
157		171
158		172
159	`// Modify the current gl matrix by the trackball rotation and translation.`	173	`// Modify the current gl matrix by the trackball rotation and translation.`
160	`void QuatTrackBall::set_gl_modelview() const`	174	`void QuatTrackBall::set_gl_modelview() const`
161	`{`	175	`{`
162	`glMatrixMode(GL_MODELVIEW);`	176	`glMatrixMode(GL_MODELVIEW);`
163	`glLoadIdentity();`	177	`glLoadIdentity();`
164	`Vec3f eye;`	178	`Vec3f eye;`
165	`Vec3f _centre;`	179	`Vec3f _centre;`
166	`Vec3f up;`	180	`Vec3f up;`
167	`get_view_param(eye, _centre, up);`	181	`get_view_param(eye, _centre, up);`
168	`gluLookAt(eye[0], eye[1], eye[2],`	182	`gluLookAt(eye[0], eye[1], eye[2],`
169	`_centre[0], _centre[1], _centre[2],`	183	`_centre[0], _centre[1], _centre[2],`
170	`up[0],up[1],up[2]);`	184	`up[0],up[1],up[2]);`
171	`}`	185	`}`
172		186
173	`bool QuatTrackBall::is_spinning() const`	187	`bool QuatTrackBall::is_spinning() const`
174	`{`	188	`{`
175	`static const Quatf null_quat(0,0,0,1);`	189	`static const Quatf null_quat(0,0,0,1);`
176	`if(qinc != null_quat)`	190	`if(!(qinc == null_quat))`
177	`return true;`	191	`return true;`
178	`return false;`	192	`return false;`
179	`}`	193	`}`
180	`}`	194	`}`
181		195

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(root)/trunk/src/GLGraphics/QuatTrackBall.cpp – Rev 277 → 299