1 /* -*- Mode: C; tab-width: 4 -*- */
2 /* bubble3d.c - 3D bubbles */
5 static const char sccsid[] = "@(#)bubble3d.c 4.11 98/06/16 xlockmore";
9 * BUBBLE3D (C) 1998 Richard W.M. Jones.
10 * Permission to use, copy, modify, and distribute this software and its
11 * documentation for any purpose and without fee is hereby granted,
12 * provided that the above copyright notice appear in all copies and that
13 * both that copyright notice and this permission notice appear in
14 * supporting documentation.
16 * This file is provided AS IS with no warranties of any kind. The author
17 * shall have no liability with respect to the infringement of copyrights,
18 * trade secrets or any patents by this file or any part thereof. In no
19 * event will the author be liable for any lost revenue or profits or
20 * other special, indirect and consequential damages.
25 * bubble.c: This code is responsible for creating and managing
26 * bubbles over their lifetime.
27 * The bubbles may be drawn inside out.
32 typedef struct bubble {
33 GLfloat *contributions; /* List of contributions from each
34 * nudge to each vertex. This list has
35 * length nr_vertices * nr_nudge_axes.
37 GLfloat x, y, z; /* (x,y,z) location of the bubble. */
38 GLfloat scale; /* Scaling factor applied to bubble. */
39 GLfloat y_incr, scale_incr; /* Change in y and scale each frame. */
40 GLfloat rotx, roty, rotz; /* Current rotation. */
41 GLfloat rotx_incr, roty_incr, rotz_incr; /* Amount by which we increase
44 GLfloat *nudge_angle; /* Current angle (radians) of each
45 * nudge. This list has length nr_nudge_axes.
47 GLfloat *nudge_angle_incr; /* Amount by which we increase each nudge
48 * angle in each frame.
52 /* Should be taken care of already... but just in case */
53 #if !defined( __GNUC__ ) && !defined(__cplusplus) && !defined(c_plusplus)
58 normalize(GLfloat v[3])
60 GLfloat d = (GLfloat) sqrt((double) (v[0] * v[0] + v[1] * v[1] +
68 v[0] = v[1] = v[2] = 0;
73 dotprod(GLfloat * v1, GLfloat * v2)
75 return v1[0] * v2[0] + v1[1] * v2[1] + v1[2] * v2[2];
79 max(GLfloat a, GLfloat b)
84 /* Create a new bubble. */
86 glb_bubble_new(GLfloat x, GLfloat y, GLfloat z, GLfloat scale,
87 GLfloat y_incr, GLfloat scale_incr)
91 /* GLfloat axes [glb_config.nr_nudge_axes][3]; */
92 GLfloat axes[5][3]; /* HARD CODED for SunCC */
94 glb_vertex *vertices = glb_sphere_get_vertices(&nr_vertices);
96 bubble *b = (bubble *) malloc(sizeof *b);
101 b->contributions = (GLfloat *) malloc(sizeof (GLfloat) * nr_vertices *
102 glb_config.nr_nudge_axes);
103 if (b->contributions == 0) {
104 (void) free((void *) b);
107 b->nudge_angle = (GLfloat *) malloc(sizeof (GLfloat) * glb_config.nr_nudge_axes);
108 if (b->nudge_angle == 0) {
109 (void) free((void *) b->contributions);
110 (void) free((void *) b);
113 b->nudge_angle_incr = (GLfloat *) malloc(sizeof (GLfloat) * glb_config.nr_nudge_axes);
114 if (b->nudge_angle_incr == 0) {
115 (void) free((void *) b->nudge_angle);
116 (void) free((void *) b->contributions);
117 (void) free((void *) b);
120 /* Initialize primitive elements. */
126 b->scale_incr = scale_incr;
127 b->rotx = b->roty = b->rotz = 0;
128 b->rotx_incr = glb_drand() * glb_config.rotation_factor * 2
129 - glb_config.rotation_factor;
130 b->roty_incr = glb_drand() * glb_config.rotation_factor * 2
131 - glb_config.rotation_factor;
132 b->rotz_incr = glb_drand() * glb_config.rotation_factor * 2
133 - glb_config.rotation_factor;
135 /* Initialize the nudge angle arrays. */
136 for (i = 0; i < glb_config.nr_nudge_axes; ++i) {
137 b->nudge_angle[i] = 0;
138 b->nudge_angle_incr[i] = glb_drand() * glb_config.nudge_angle_factor;
141 /* Choose some random nudge axes. */
142 for (i = 0; i < glb_config.nr_nudge_axes; ++i) {
143 axes[i][0] = glb_drand() * 2 - 1;
144 axes[i][1] = glb_drand() * 2 - 1;
145 axes[i][2] = glb_drand() * 2 - 1;
149 /* Calculate the contribution that each nudge axis has on each vertex. */
150 for (i = 0; i < nr_vertices; ++i)
151 for (j = 0; j < glb_config.nr_nudge_axes; ++j)
152 b->contributions[i * glb_config.nr_nudge_axes + j]
153 = max(0, dotprod(vertices[i], axes[j]));
158 /* Delete a bubble and free up all memory. */
160 glb_bubble_delete(void *bb)
162 bubble *b = (bubble *) bb;
165 if (b->nudge_angle_incr) {
166 (void) free((void *) b->nudge_angle_incr);
167 b->nudge_angle_incr = NULL;
169 if (b->nudge_angle) {
170 (void) free((void *) b->nudge_angle);
171 b->nudge_angle = NULL;
173 if (b->contributions) {
174 (void) free((void *) b->contributions);
175 b->contributions = NULL;
177 (void) free((void *) b);
182 /* Rotate and wobble a bubble by a single step. */
184 glb_bubble_step(void *bb)
187 bubble *b = (bubble *) bb;
189 /* Update the rotation. */
190 b->rotx += b->rotx_incr;
191 b->roty += b->roty_incr;
192 b->rotz += b->rotz_incr;
194 /* Update the nudge angles. */
195 for (i = 0; i < glb_config.nr_nudge_axes; ++i)
196 b->nudge_angle[i] += b->nudge_angle_incr[i];
198 /* Move it upwards & outwards. */
200 b->scale += b->scale_incr;
205 glb_bubble_draw(void *bb)
208 bubble *b = (bubble *) bb;
210 glb_vertex *vertices = glb_sphere_get_vertices(&nr_vertices);
212 glb_triangle *triangles = glb_sphere_get_triangles(&nr_triangles);
213 glb_vertex *new_vertices;
215 new_vertices = (glb_vertex *) malloc(sizeof (glb_vertex) * nr_vertices);
216 /* Calculate the vertices of this bubble, factoring in each nudge axis. */
217 for (i = 0; i < nr_vertices; ++i) {
220 for (j = 0; j < glb_config.nr_nudge_axes; ++j)
221 s += ((GLfloat) cos((double) (b->nudge_angle[j])) *
222 glb_config.nudge_factor - glb_config.nudge_factor / 2) *
223 b->contributions[i * glb_config.nr_nudge_axes + j];
225 new_vertices[i][0] = vertices[i][0] * (s + 1);
226 new_vertices[i][1] = vertices[i][1] * (s + 1);
227 new_vertices[i][2] = vertices[i][2] * (s + 1);
232 /* Apply translation, rotation and scalings. */
233 glTranslatef(b->x, b->y, b->z);
235 glRotatef(b->rotx, 1, 0, 0);
236 glRotatef(b->roty, 0, 1, 0);
237 glRotatef(b->rotz, 0, 0, 1);
239 glScalef(b->scale, b->scale, b->scale);
241 /* Draw the bubble. */
242 glBegin(GL_TRIANGLES);
243 for (i = 0; i < nr_triangles; ++i) {
244 glNormal3fv(new_vertices[triangles[i][0]]);
245 glVertex3fv(new_vertices[triangles[i][0]]);
246 glNormal3fv(new_vertices[triangles[i][1]]);
247 glVertex3fv(new_vertices[triangles[i][1]]);
248 glNormal3fv(new_vertices[triangles[i][2]]);
249 glVertex3fv(new_vertices[triangles[i][2]]);
253 (void) free((void *) new_vertices);
256 /* Return y value. */
258 glb_bubble_get_y(void *bb)
260 bubble *b = (bubble *) bb;