Brian Paul | 5b0a7f3 | 2000-06-27 16:52:38 +0000 | [diff] [blame] | 1 | /* |
| 2 | * This program is under the GNU GPL. |
| 3 | * Use at your own risk. |
| 4 | * |
| 5 | * written by David Bucciarelli (humanware@plus.it) |
| 6 | * Humanware s.r.l. |
| 7 | */ |
| 8 | |
| 9 | #include <stdlib.h> |
| 10 | |
| 11 | #include "particles.h" |
| 12 | |
| 13 | #define vinit(a,i,j,k) {\ |
| 14 | (a)[0]=i;\ |
| 15 | (a)[1]=j;\ |
| 16 | (a)[2]=k;\ |
| 17 | } |
| 18 | |
| 19 | #define vadds(a,dt,b) {\ |
| 20 | (a)[0]+=(dt)*(b)[0];\ |
| 21 | (a)[1]+=(dt)*(b)[1];\ |
| 22 | (a)[2]+=(dt)*(b)[2];\ |
| 23 | } |
| 24 | |
| 25 | #define vequ(a,b) {\ |
| 26 | (a)[0]=(b)[0];\ |
| 27 | (a)[1]=(b)[1];\ |
| 28 | (a)[2]=(b)[2];\ |
| 29 | } |
| 30 | |
| 31 | #define vinter(a,dt,b,c) {\ |
| 32 | (a)[0]=(dt)*(b)[0]+(1.0-dt)*(c)[0];\ |
| 33 | (a)[1]=(dt)*(b)[1]+(1.0-dt)*(c)[1];\ |
| 34 | (a)[2]=(dt)*(b)[2]+(1.0-dt)*(c)[2];\ |
| 35 | } |
| 36 | |
| 37 | #define clamp(a) ((a) < 0.0 ? 0.0 : ((a) < 1.0 ? (a) : 1.0)) |
| 38 | |
| 39 | #define vclamp(v) {\ |
| 40 | (v)[0]=clamp((v)[0]);\ |
| 41 | (v)[1]=clamp((v)[1]);\ |
| 42 | (v)[2]=clamp((v)[2]);\ |
| 43 | } |
| 44 | |
| 45 | |
| 46 | float rainParticle::min[3]; |
| 47 | float rainParticle::max[3]; |
| 48 | float rainParticle::partLength=0.2f; |
| 49 | |
| 50 | |
| 51 | static float vrnd(void) |
| 52 | { |
| 53 | return(((float)rand())/RAND_MAX); |
| 54 | } |
| 55 | |
| 56 | |
| 57 | particle::particle() |
| 58 | { |
| 59 | age=0.0f; |
| 60 | |
| 61 | vinit(acc,0.0f,0.0f,0.0f); |
| 62 | vinit(vel,0.0f,0.0f,0.0f); |
| 63 | vinit(pos,0.0f,0.0f,0.0f); |
| 64 | } |
| 65 | |
| 66 | void particle::elapsedTime(float dt) |
| 67 | { |
| 68 | age+=dt; |
| 69 | |
| 70 | vadds(vel,dt,acc); |
| 71 | |
| 72 | vadds(pos,dt,vel); |
| 73 | } |
| 74 | |
| 75 | ///////////////////////////////////////// |
| 76 | // Particle System |
| 77 | ///////////////////////////////////////// |
| 78 | |
| 79 | particleSystem::particleSystem() |
| 80 | { |
| 81 | t=0.0f; |
| 82 | |
| 83 | part=NULL; |
| 84 | |
| 85 | particleNum=0; |
| 86 | } |
| 87 | |
| 88 | particleSystem::~particleSystem() |
| 89 | { |
| 90 | if(part) |
| 91 | free(part); |
| 92 | } |
| 93 | |
| 94 | void particleSystem::addParticle(particle *p) |
| 95 | { |
| 96 | if(!part) { |
| 97 | part=(particle **)calloc(1,sizeof(particle *)); |
| 98 | part[0]=p; |
| 99 | particleNum=1; |
| 100 | } else { |
| 101 | particleNum++; |
| 102 | part=(particle **)realloc(part,sizeof(particle *)*particleNum); |
| 103 | part[particleNum-1]=p; |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | void particleSystem::reset(void) |
| 108 | { |
| 109 | if(part) |
| 110 | free(part); |
| 111 | |
| 112 | t=0.0f; |
| 113 | |
| 114 | part=NULL; |
| 115 | |
| 116 | particleNum=0; |
| 117 | } |
| 118 | |
| 119 | void particleSystem::draw(void) |
| 120 | { |
| 121 | if(!part) |
| 122 | return; |
| 123 | |
| 124 | part[0]->beginDraw(); |
| 125 | for(unsigned int i=0;i<particleNum;i++) |
| 126 | part[i]->draw(); |
| 127 | part[0]->endDraw(); |
| 128 | } |
| 129 | |
| 130 | void particleSystem::addTime(float dt) |
| 131 | { |
| 132 | if(!part) |
| 133 | return; |
| 134 | |
| 135 | for(unsigned int i=0;i<particleNum;i++) { |
| 136 | part[i]->elapsedTime(dt); |
| 137 | part[i]->checkAge(); |
| 138 | } |
| 139 | } |
| 140 | |
| 141 | ///////////////////////////////////////// |
| 142 | // Rain |
| 143 | ///////////////////////////////////////// |
| 144 | |
| 145 | void rainParticle::init(void) |
| 146 | { |
| 147 | age=0.0f; |
| 148 | |
| 149 | acc[0]=0.0f; |
| 150 | acc[1]=-0.98f; |
| 151 | acc[2]=0.0f; |
| 152 | |
| 153 | vel[0]=0.0f; |
| 154 | vel[1]=0.0f; |
| 155 | vel[2]=0.0f; |
| 156 | |
| 157 | oldpos[0]=pos[0]=min[0]+(max[0]-min[0])*vrnd(); |
| 158 | oldpos[1]=pos[1]=max[1]+0.2f*max[1]*vrnd(); |
| 159 | oldpos[2]=pos[2]=min[2]+(max[2]-min[2])*vrnd(); |
| 160 | |
| 161 | vadds(oldpos,-partLength,vel); |
| 162 | } |
| 163 | |
| 164 | rainParticle::rainParticle() |
| 165 | { |
| 166 | init(); |
| 167 | } |
| 168 | |
| 169 | void rainParticle::setRainingArea(float minx, float miny, float minz, |
| 170 | float maxx, float maxy, float maxz) |
| 171 | { |
| 172 | vinit(min,minx,miny,minz); |
| 173 | vinit(max,maxx,maxy,maxz); |
| 174 | } |
| 175 | |
| 176 | void rainParticle::setLength(float l) |
| 177 | { |
| 178 | partLength=l; |
| 179 | } |
| 180 | |
| 181 | void rainParticle::draw(void) |
| 182 | { |
| 183 | glColor4f(0.7f,0.95f,1.0f,0.0f); |
| 184 | glVertex3fv(oldpos); |
| 185 | |
| 186 | glColor4f(0.3f,0.7f,1.0f,1.0f); |
| 187 | glVertex3fv(pos); |
| 188 | } |
| 189 | |
| 190 | void rainParticle::checkAge(void) |
| 191 | { |
| 192 | if(pos[1]<min[1]) |
| 193 | init(); |
| 194 | } |
| 195 | |
| 196 | void rainParticle::elapsedTime(float dt) |
| 197 | { |
| 198 | particle::elapsedTime(dt); |
| 199 | |
| 200 | if(pos[0]<min[0]) |
| 201 | pos[0]=max[0]-(min[0]-pos[0]); |
| 202 | if(pos[2]<min[2]) |
| 203 | pos[2]=max[2]-(min[2]-pos[2]); |
| 204 | |
| 205 | if(pos[0]>max[0]) |
| 206 | pos[0]=min[0]+(pos[0]-max[0]); |
| 207 | if(pos[2]>max[2]) |
| 208 | pos[2]=min[2]+(pos[2]-max[2]); |
| 209 | |
| 210 | vequ(oldpos,pos); |
| 211 | vadds(oldpos,-partLength,vel); |
| 212 | } |
| 213 | |
| 214 | void rainParticle::randomHeight(void) |
| 215 | { |
| 216 | pos[1]=(max[1]-min[1])*vrnd()+min[1]; |
| 217 | |
| 218 | oldpos[1]=pos[1]-partLength*vel[1]; |
| 219 | } |