1 /* -*- Mode: C; tab-width: 4 -*- */
2 /* bubble3d.c - 3D bubbles */
4 #if !defined( lint ) && !defined( SABER )
5 static const char sccsid[] = "@(#)bubble3d.c 4.11 98/06/16 xlockmore";
10 * BUBBLE3D (C) 1998 Richard W.M. Jones.
11 * Permission to use, copy, modify, and distribute this software and its
12 * documentation for any purpose and without fee is hereby granted,
13 * provided that the above copyright notice appear in all copies and that
14 * both that copyright notice and this permission notice appear in
15 * supporting documentation.
17 * This file is provided AS IS with no warranties of any kind. The author
18 * shall have no liability with respect to the infringement of copyrights,
19 * trade secrets or any patents by this file or any part thereof. In no
20 * event will the author be liable for any lost revenue or profits or
21 * other special, indirect and consequential damages.
26 * bubble.c: This code is responsible for creating and managing
27 * bubbles over their lifetime.
28 * The bubbles may be drawn inside out.
33 typedef struct bubble {
34 GLfloat *contributions; /* List of contributions from each
35 * nudge to each vertex. This list has
36 * length nr_vertices * nr_nudge_axes.
38 GLfloat x, y, z; /* (x,y,z) location of the bubble. */
39 GLfloat scale; /* Scaling factor applied to bubble. */
40 GLfloat y_incr, scale_incr; /* Change in y and scale each frame. */
41 GLfloat rotx, roty, rotz; /* Current rotation. */
42 GLfloat rotx_incr, roty_incr, rotz_incr; /* Amount by which we increase
45 GLfloat *nudge_angle; /* Current angle (radians) of each
46 * nudge. This list has length nr_nudge_axes.
48 GLfloat *nudge_angle_incr; /* Amount by which we increase each nudge
49 * angle in each frame.
53 /* Should be taken care of already... but just in case */
54 #if !defined( __GNUC__ ) && !defined(__cplusplus) && !defined(c_plusplus)
59 normalize(GLfloat v[3])
61 GLfloat d = (GLfloat) sqrt((double) (v[0] * v[0] + v[1] * v[1] +
69 v[0] = v[1] = v[2] = 0;
74 dotprod(GLfloat * v1, GLfloat * v2)
76 return v1[0] * v2[0] + v1[1] * v2[1] + v1[2] * v2[2];
80 max(GLfloat a, GLfloat b)
85 /* Create a new bubble. */
87 glb_bubble_new(GLfloat x, GLfloat y, GLfloat z, GLfloat scale,
88 GLfloat y_incr, GLfloat scale_incr)
92 /* GLfloat axes [glb_config.nr_nudge_axes][3]; */
93 GLfloat axes[5][3]; /* HARD CODED for SunCC */
95 glb_vertex *vertices = glb_sphere_get_vertices(&nr_vertices);
97 bubble *b = (bubble *) malloc(sizeof *b);
102 b->contributions = (GLfloat *) malloc(sizeof (GLfloat) * nr_vertices *
103 glb_config.nr_nudge_axes);
104 if (b->contributions == 0) {
105 (void) free((void *) b);
108 b->nudge_angle = (GLfloat *) malloc(sizeof (GLfloat) * glb_config.nr_nudge_axes);
109 if (b->nudge_angle == 0) {
110 (void) free((void *) b->contributions);
111 (void) free((void *) b);
114 b->nudge_angle_incr = (GLfloat *) malloc(sizeof (GLfloat) * glb_config.nr_nudge_axes);
115 if (b->nudge_angle_incr == 0) {
116 (void) free((void *) b->nudge_angle);
117 (void) free((void *) b->contributions);
118 (void) free((void *) b);
121 /* Initialize primitive elements. */
127 b->scale_incr = scale_incr;
128 b->rotx = b->roty = b->rotz = 0;
129 b->rotx_incr = glb_drand() * glb_config.rotation_factor * 2
130 - glb_config.rotation_factor;
131 b->roty_incr = glb_drand() * glb_config.rotation_factor * 2
132 - glb_config.rotation_factor;
133 b->rotz_incr = glb_drand() * glb_config.rotation_factor * 2
134 - glb_config.rotation_factor;
136 /* Initialize the nudge angle arrays. */
137 for (i = 0; i < glb_config.nr_nudge_axes; ++i) {
138 b->nudge_angle[i] = 0;
139 b->nudge_angle_incr[i] = glb_drand() * glb_config.nudge_angle_factor;
142 /* Choose some random nudge axes. */
143 for (i = 0; i < glb_config.nr_nudge_axes; ++i) {
144 axes[i][0] = glb_drand() * 2 - 1;
145 axes[i][1] = glb_drand() * 2 - 1;
146 axes[i][2] = glb_drand() * 2 - 1;
150 /* Calculate the contribution that each nudge axis has on each vertex. */
151 for (i = 0; i < nr_vertices; ++i)
152 for (j = 0; j < glb_config.nr_nudge_axes; ++j)
153 b->contributions[i * glb_config.nr_nudge_axes + j]
154 = max(0, dotprod(vertices[i], axes[j]));
159 /* Delete a bubble and free up all memory. */
161 glb_bubble_delete(void *bb)
163 bubble *b = (bubble *) bb;
166 if (b->nudge_angle_incr) {
167 (void) free((void *) b->nudge_angle_incr);
168 b->nudge_angle_incr = NULL;
170 if (b->nudge_angle) {
171 (void) free((void *) b->nudge_angle);
172 b->nudge_angle = NULL;
174 if (b->contributions) {
175 (void) free((void *) b->contributions);
176 b->contributions = NULL;
178 (void) free((void *) b);
183 /* Rotate and wobble a bubble by a single step. */
185 glb_bubble_step(void *bb)
188 bubble *b = (bubble *) bb;
190 /* Update the rotation. */
191 b->rotx += b->rotx_incr;
192 b->roty += b->roty_incr;
193 b->rotz += b->rotz_incr;
195 /* Update the nudge angles. */
196 for (i = 0; i < glb_config.nr_nudge_axes; ++i)
197 b->nudge_angle[i] += b->nudge_angle_incr[i];
199 /* Move it upwards & outwards. */
201 b->scale += b->scale_incr;
206 glb_bubble_draw(void *bb)
209 bubble *b = (bubble *) bb;
211 glb_vertex *vertices = glb_sphere_get_vertices(&nr_vertices);
213 glb_triangle *triangles = glb_sphere_get_triangles(&nr_triangles);
214 glb_vertex *new_vertices;
216 new_vertices = (glb_vertex *) malloc(sizeof (glb_vertex) * nr_vertices);
217 /* Calculate the vertices of this bubble, factoring in each nudge axis. */
218 for (i = 0; i < nr_vertices; ++i) {
221 for (j = 0; j < glb_config.nr_nudge_axes; ++j)
222 s += ((GLfloat) cos((double) (b->nudge_angle[j])) *
223 glb_config.nudge_factor - glb_config.nudge_factor / 2) *
224 b->contributions[i * glb_config.nr_nudge_axes + j];
226 new_vertices[i][0] = vertices[i][0] * (s + 1);
227 new_vertices[i][1] = vertices[i][1] * (s + 1);
228 new_vertices[i][2] = vertices[i][2] * (s + 1);
233 /* Apply translation, rotation and scalings. */
234 glTranslatef(b->x, b->y, b->z);
236 glRotatef(b->rotx, 1, 0, 0);
237 glRotatef(b->roty, 0, 1, 0);
238 glRotatef(b->rotz, 0, 0, 1);
240 glScalef(b->scale, b->scale, b->scale);
242 /* Draw the bubble. */
243 glBegin(GL_TRIANGLES);
244 for (i = 0; i < nr_triangles; ++i) {
245 glNormal3fv(new_vertices[triangles[i][0]]);
246 glVertex3fv(new_vertices[triangles[i][0]]);
247 glNormal3fv(new_vertices[triangles[i][1]]);
248 glVertex3fv(new_vertices[triangles[i][1]]);
249 glNormal3fv(new_vertices[triangles[i][2]]);
250 glVertex3fv(new_vertices[triangles[i][2]]);
254 (void) free((void *) new_vertices);
257 /* Return y value. */
259 glb_bubble_get_y(void *bb)
261 bubble *b = (bubble *) bb;