Kristian Høgsberg | 8a9cda8 | 2008-11-03 15:31:30 -0500 | [diff] [blame^] | 1 | #include <stdlib.h> |
| 2 | #include <math.h> |
| 3 | #include <GL/gl.h> |
| 4 | #include "gears.h" |
| 5 | |
| 6 | struct gears { |
| 7 | GLint gear1, gear2, gear3; |
| 8 | }; |
| 9 | |
| 10 | static void |
| 11 | gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width, |
| 12 | GLint teeth, GLfloat tooth_depth) |
| 13 | { |
| 14 | GLint i; |
| 15 | GLfloat r0, r1, r2; |
| 16 | GLfloat angle, da; |
| 17 | GLfloat u, v, len; |
| 18 | |
| 19 | r0 = inner_radius; |
| 20 | r1 = outer_radius - tooth_depth / 2.0; |
| 21 | r2 = outer_radius + tooth_depth / 2.0; |
| 22 | |
| 23 | da = 2.0 * M_PI / teeth / 4.0; |
| 24 | |
| 25 | glShadeModel(GL_FLAT); |
| 26 | |
| 27 | glNormal3f(0.0, 0.0, 1.0); |
| 28 | |
| 29 | /* draw front face */ |
| 30 | glBegin(GL_QUAD_STRIP); |
| 31 | for (i = 0; i <= teeth; i++) { |
| 32 | angle = i * 2.0 * M_PI / teeth; |
| 33 | glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5); |
| 34 | glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5); |
| 35 | if (i < teeth) { |
| 36 | glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5); |
| 37 | glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5); |
| 38 | } |
| 39 | } |
| 40 | glEnd(); |
| 41 | |
| 42 | /* draw front sides of teeth */ |
| 43 | glBegin(GL_QUADS); |
| 44 | da = 2.0 * M_PI / teeth / 4.0; |
| 45 | for (i = 0; i < teeth; i++) { |
| 46 | angle = i * 2.0 * M_PI / teeth; |
| 47 | |
| 48 | glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5); |
| 49 | glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5); |
| 50 | glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5); |
| 51 | glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5); |
| 52 | } |
| 53 | glEnd(); |
| 54 | |
| 55 | glNormal3f(0.0, 0.0, -1.0); |
| 56 | |
| 57 | /* draw back face */ |
| 58 | glBegin(GL_QUAD_STRIP); |
| 59 | for (i = 0; i <= teeth; i++) { |
| 60 | angle = i * 2.0 * M_PI / teeth; |
| 61 | glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5); |
| 62 | glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5); |
| 63 | if (i < teeth) { |
| 64 | glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5); |
| 65 | glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5); |
| 66 | } |
| 67 | } |
| 68 | glEnd(); |
| 69 | |
| 70 | /* draw back sides of teeth */ |
| 71 | glBegin(GL_QUADS); |
| 72 | da = 2.0 * M_PI / teeth / 4.0; |
| 73 | for (i = 0; i < teeth; i++) { |
| 74 | angle = i * 2.0 * M_PI / teeth; |
| 75 | |
| 76 | glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5); |
| 77 | glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5); |
| 78 | glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5); |
| 79 | glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5); |
| 80 | } |
| 81 | glEnd(); |
| 82 | |
| 83 | /* draw outward faces of teeth */ |
| 84 | glBegin(GL_QUAD_STRIP); |
| 85 | for (i = 0; i < teeth; i++) { |
| 86 | angle = i * 2.0 * M_PI / teeth; |
| 87 | |
| 88 | glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5); |
| 89 | glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5); |
| 90 | u = r2 * cos(angle + da) - r1 * cos(angle); |
| 91 | v = r2 * sin(angle + da) - r1 * sin(angle); |
| 92 | len = sqrt(u * u + v * v); |
| 93 | u /= len; |
| 94 | v /= len; |
| 95 | glNormal3f(v, -u, 0.0); |
| 96 | glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5); |
| 97 | glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5); |
| 98 | glNormal3f(cos(angle), sin(angle), 0.0); |
| 99 | glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5); |
| 100 | glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5); |
| 101 | u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da); |
| 102 | v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da); |
| 103 | glNormal3f(v, -u, 0.0); |
| 104 | glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5); |
| 105 | glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5); |
| 106 | glNormal3f(cos(angle), sin(angle), 0.0); |
| 107 | } |
| 108 | |
| 109 | glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5); |
| 110 | glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5); |
| 111 | |
| 112 | glEnd(); |
| 113 | |
| 114 | glShadeModel(GL_SMOOTH); |
| 115 | |
| 116 | /* draw inside radius cylinder */ |
| 117 | glBegin(GL_QUAD_STRIP); |
| 118 | for (i = 0; i <= teeth; i++) { |
| 119 | angle = i * 2.0 * M_PI / teeth; |
| 120 | glNormal3f(-cos(angle), -sin(angle), 0.0); |
| 121 | glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5); |
| 122 | glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5); |
| 123 | } |
| 124 | glEnd(); |
| 125 | } |
| 126 | |
| 127 | struct gears * |
| 128 | gears_create(void) |
| 129 | { |
| 130 | static GLfloat red[4] = {0.8, 0.1, 0.0, 1.0}; |
| 131 | static GLfloat green[4] = {0.0, 0.8, 0.2, 1.0}; |
| 132 | static GLfloat blue[4] = {0.2, 0.2, 1.0, 1.0}; |
| 133 | static GLfloat pos[4] = {5.0, 5.0, 10.0, 0.0}; |
| 134 | struct gears *gears; |
| 135 | |
| 136 | gears = malloc(sizeof *gears); |
| 137 | /* make the gears */ |
| 138 | gears->gear1 = glGenLists(1); |
| 139 | glNewList(gears->gear1, GL_COMPILE); |
| 140 | glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red); |
| 141 | gear(1.0, 4.0, 1.0, 20, 0.7); |
| 142 | glEndList(); |
| 143 | |
| 144 | gears->gear2 = glGenLists(1); |
| 145 | glNewList(gears->gear2, GL_COMPILE); |
| 146 | glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green); |
| 147 | gear(0.5, 2.0, 2.0, 10, 0.7); |
| 148 | glEndList(); |
| 149 | |
| 150 | gears->gear3 = glGenLists(1); |
| 151 | glNewList(gears->gear3, GL_COMPILE); |
| 152 | glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue); |
| 153 | gear(1.3, 2.0, 0.5, 10, 0.7); |
| 154 | glEndList(); |
| 155 | |
| 156 | glEnable(GL_NORMALIZE); |
| 157 | |
| 158 | glMatrixMode(GL_PROJECTION); |
| 159 | glLoadIdentity(); |
| 160 | glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 200.0); |
| 161 | glMatrixMode(GL_MODELVIEW); |
| 162 | |
| 163 | glLightfv(GL_LIGHT0, GL_POSITION, pos); |
| 164 | glEnable(GL_CULL_FACE); |
| 165 | glEnable(GL_LIGHTING); |
| 166 | glEnable(GL_LIGHT0); |
| 167 | glEnable(GL_DEPTH_TEST); |
| 168 | |
| 169 | return gears; |
| 170 | } |
| 171 | |
| 172 | void |
| 173 | gears_draw(struct gears *gears, GLfloat angle) |
| 174 | { |
| 175 | GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0; |
| 176 | |
| 177 | glPushMatrix(); |
| 178 | |
| 179 | glTranslatef(0.0, 0.0, -50); |
| 180 | |
| 181 | glRotatef(view_rotx, 1.0, 0.0, 0.0); |
| 182 | glRotatef(view_roty, 0.0, 1.0, 0.0); |
| 183 | glRotatef(view_rotz, 0.0, 0.0, 1.0); |
| 184 | |
| 185 | glPushMatrix(); |
| 186 | glTranslatef(-3.0, -2.0, 0.0); |
| 187 | glRotatef(angle, 0.0, 0.0, 1.0); |
| 188 | glCallList(gears->gear1); |
| 189 | glPopMatrix(); |
| 190 | |
| 191 | glPushMatrix(); |
| 192 | glTranslatef(3.1, -2.0, 0.0); |
| 193 | glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0); |
| 194 | glCallList(gears->gear2); |
| 195 | glPopMatrix(); |
| 196 | |
| 197 | |
| 198 | glPushMatrix(); |
| 199 | glTranslatef(-3.1, 4.2, 0.0); |
| 200 | glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0); |
| 201 | glCallList(gears->gear3); |
| 202 | glPopMatrix(); |
| 203 | |
| 204 | glPopMatrix(); |
| 205 | |
| 206 | glFlush(); |
| 207 | } |