src/add-ons/screen_savers/gravity/Particle.cpp

   1 /*
   2  * Copyright 2012-2013 Tri-Edge AI <triedgeai@gmail.com>
   3  * Copyright 2014 Haiku, Inc. All rights reserved.
   4  *
   5  * Distributed under the terms of the MIT license.
   6  *
   7  * Authors:
   8  *              Tri-Edge AI
   9  *              John Scipione, jscipione@gmail.com
  10  */
  11
  12
  13 #include "Particle.h"
  14
  15 #include <stdlib.h>
  16
  17
  18 #define frand() ((float)rand() / (float)RAND_MAX)
  19
  20
  21 BObjectList<Particle>* Particle::list;
  22
  23
  24 /*static*/ void
  25 Particle::Initialize(int32 size, int32 shade)
  26 {
  27         list = new BObjectList<Particle>(2048);
  28
  29         for (int32 i = 0; i < size; i++) {
  30                 Particle* p = new Particle();
  31                 Particle::_FillParticle(p, size, shade);
  32                 list->AddItem(p);
  33         }
  34 }
  35
  36
  37 /*static*/ void
  38 Particle::AddParticles(int32 size, int32 shade)
  39 {
  40         for (int32 i = list->CountItems(); i < size; i++) {
  41                 Particle* p = new Particle();
  42                 Particle::_FillParticle(p, size, shade);
  43                 list->AddItem(p);
  44         }
  45 }
  46
  47
  48 /*static*/ void
  49 Particle::RemoveParticles(int32 size, int32 shade)
  50 {
  51         while (list->CountItems() > size)
  52                 delete list->RemoveItemAt(list->CountItems() - 1);
  53 }
  54
  55
  56 /*static*/ void
  57 Particle::ColorParticles(int32 size, int32 shade)
  58 {
  59         for (int32 i = 0; i < size; i++) {
  60                 Particle* p = list->ItemAt(i);
  61                 Particle::_ColorParticle(p, size, shade);
  62         }
  63 }
  64
  65
  66 /*static*/ void
  67 Particle::Terminate()
  68 {
  69         list->MakeEmpty();
  70         delete list;
  71 }
  72
  73
  74 /*static*/ void
  75 Particle::Tick()
  76 {
  77         for (int32 i = 0; i < list->CountItems(); i++) {
  78                 Particle* p = list->ItemAt(i);
  79                 p->_Logic();
  80                 p->_Render();
  81         }
  82 }
  83
  84
  85 void
  86 Particle::_Logic()
  87 {
  88         // Motion
  89         x += vx;
  90         y += vy;
  91         z += vz;
  92         r += vr;
  93
  94         // Friction
  95         vx *= 0.98f;
  96         vy *= 0.98f;
  97         vz *= 0.98f;
  98         vr *= 0.98f;
  99 }
 100
 101
 102 void
 103 Particle::_Render() const
 104 {
 105         glPushMatrix();
 106         glTranslatef(x, y, z);
 107         glRotatef(r, 0.0f, 0.0f, 1.0f);
 108         glColor3f(red, green, blue);
 109         glBegin(GL_QUADS);
 110         glVertex3f(-0.25f,  0.25f,  0.0f);
 111         glVertex3f(-0.25f, -0.25f,  0.0f);
 112         glVertex3f( 0.25f, -0.25f,  0.0f);
 113         glVertex3f( 0.25f,  0.25f,  0.0f);
 114         glEnd();
 115         glPopMatrix();
 116 }
 117
 118
 119 /*static*/ void
 120 Particle::_FillParticle(Particle* p, int32 size, int32 shade)
 121 {
 122         p->x = frand() * 30.0f - 15.0f;
 123         p->y = frand() * 30.0f - 15.0f;
 124         p->z = frand() * 5.0f;
 125         p->r = frand() * 360.0f;
 126
 127         p->vx = frand() - 0.5f;
 128         p->vy = frand() - 0.5f;
 129         p->vz = frand() - 0.5f;
 130         p->vr = (frand() - 0.5f) * 180.0f;
 131
 132         Particle::_ColorParticle(p, size, shade);
 133 }
 134
 135
 136 /*static*/ void
 137 Particle::_ColorParticle(Particle* p, int32 size, int32 shade)
 138 {
 139         switch(shade) {
 140                 case 0:
 141                         // Red
 142                         p->red   = 0.1f + frand() * 0.2f;
 143                         p->green = 0.0f;
 144                         p->blue  = frand() * 0.05f;
 145                         break;
 146
 147                 case 1:
 148                         // Green
 149                         p->red   = 0;
 150                         p->green = 0.1f + frand() * 0.2f;
 151                         p->blue  = frand() * 0.05f;
 152                         break;
 153
 154                 case 2:
 155                 default:
 156                         // Blue
 157                         p->red   = 0;
 158                         p->green = frand() * 0.05f;
 159                         p->blue  = 0.1f + frand() * 0.2f;
 160                         break;
 161
 162                 case 3:
 163                         // Orange
 164                         p->red   = 0.1f + frand() * 0.1f;
 165                         p->green = 0.05f + frand() * 0.1f;
 166                         p->blue  = 0.0f;
 167                         break;
 168
 169                 case 4:
 170                         // Purple
 171                         p->red   = 0.1f + frand() * 0.2f;
 172                         p->green = 0.0f;
 173                         p->blue  = 0.1f + frand() * 0.2f;
 174                         break;
 175
 176                 case 5:
 177                         // White
 178                         p->red = p->green = p->blue = 0.1f + frand() * 0.2f;
 179                         break;
 180
 181                 case 6:
 182                         // Rainbow
 183                         p->red   = 0.1f + frand() * 0.2f;
 184                         p->green = 0.1f + frand() * 0.2f;
 185                         p->blue  = 0.1f + frand() * 0.2f;
 186                         break;
 187         }
 188 }