source: anuga_work/development/anugavis/src/camera.c @ 5598

Last change on this file since 5598 was 5385, checked in by jack, 15 years ago

Added 'h' to warp the camera back home.

File size: 2.7 KB
Line 
1#ifdef HAVE_CONFIG_H
2#  include "config.h"
3#endif
4
5#ifdef HAVE_GL_GL_H
6#  include <GL/gl.h>
7#elif HAVE_OPENGL_GL_H
8#  include <OpenGL/gl.h>
9#endif
10#include <math.h>
11#include "camera.h"
12#include "globals.h"
13#include "vector.h"
14
15static const vector up = {0.0, 0.0, 1.0};
16
17void camera_home(void){
18  vector releye;
19  anugavis.eye[0] = anugavis.minX;
20  anugavis.eye[1] = anugavis.minY;
21  anugavis.eye[2] = 0;
22  anugavis.focus[0] = anugavis.minX + (anugavis.maxX - anugavis.minX) / 2;
23  anugavis.focus[1] = anugavis.minY + (anugavis.maxY - anugavis.minY) / 2;
24  anugavis.focus[2] = 0;
25  vsub(anugavis.eye, anugavis.focus, releye);
26  anugavis.eye[2] = vlen(releye);
27}
28
29void camera_pitch(float theta){
30  float c = cos(theta);
31  float s = sin(theta);
32  float x;
33  float y;
34  float z;
35  vector releye;
36  vector newreleye;
37  vector axis;
38  float dot;
39  float len;
40  vsub(anugavis.eye, anugavis.focus, releye);
41  /* Check we're not too near the vertical */
42  dot = vdot(up, releye); len = vlen(releye);
43  if(((dot > 0.99 * len) && (theta > 0)) ||
44     ((dot < -0.99 * len) && (theta < 0))) return;
45  /* Calculation from glRotatef manpage. */
46  vcross(releye, up, axis);
47  vscale(axis, 1.0/vlen(axis), axis);
48  x = axis[0]; y = axis[1]; z = axis[2];
49  newreleye[0] =
50    releye[0] * (x*x*(1-c)+c) +
51    releye[1] * (x*y*(1-c)-z*s) +
52    releye[2] * (x*z*(1-c)+y*s);
53  newreleye[1] =
54    releye[0] * (y*x*(1-c)+z*s) +
55    releye[1] * (y*y*(1-c)+c) +
56    releye[2] * (y*z*(1-c)-x*s);
57  newreleye[2] =
58    releye[0] * (z*x*(1-c)-y*s) +
59    releye[1] * (z*y*(1-c)+x*s) +
60    releye[2] * (z*z*(1-c)+c);
61  vadd(newreleye, anugavis.focus, anugavis.eye);
62}
63
64void camera_strafe(float dist){
65  vector releye;
66  vector dir;
67  vsub(anugavis.eye, anugavis.focus, releye);
68  vcross(releye, up, dir);
69  vscale(dir, dist/vlen(dir), dir);
70  vadd(anugavis.eye, dir, anugavis.eye);
71  vadd(anugavis.focus, dir, anugavis.focus);
72}
73
74void camera_track(float dist){
75  vector dir = {0, 0, 0};
76  vsub(anugavis.eye, anugavis.focus, dir);
77  dir[2] = 0;
78  vscale(dir, dist/vlen(dir), dir);
79  vadd(anugavis.eye, dir, anugavis.eye);
80  vadd(anugavis.focus, dir, anugavis.focus);
81}
82
83void camera_yaw(float theta){
84  float c = cos(theta);
85  float s = sin(theta);
86  vector releye;
87  vector newreleye;
88  vsub(anugavis.eye, anugavis.focus, releye);
89  newreleye[0] = releye[0] * c + releye[1] * s;
90  newreleye[1] = releye[0] * -1 * s + releye[1] * c;
91  newreleye[2] = releye[2];
92  vadd(newreleye, anugavis.focus, anugavis.eye);
93}
94
95void camera_zoom(float dist){
96  vector releye;
97  float len;
98  vsub(anugavis.focus, anugavis.eye, releye);
99  if((len = vlen(releye)) < dist) return;
100  vscale(releye, dist/len, releye);
101  vadd(anugavis.eye, releye, anugavis.eye);
102}
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