src/cave/particle.cpp

   1 /*
   2  * Copyright (c) 2007-2013, Czirkos Zoltan http://code.google.com/p/gdash/
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  18  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
  19  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
  20  * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  21  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include <glib.h>
  25
  26 #include "cave/particle.hpp"
  27
  28 ParticleSet::ParticleSet(int count, float size, float opacity, float p0x, float p0y, float dp0x, float dp0y, float v0x, float v0y, float dvx, float dvy, const GdColor &color)
  29     : color(color)
  30     , life(1000)
  31     , is_new(true)
  32     , size(size)
  33     , opacity(opacity)
  34     , particles(count) {
  35     for (size_t i = 0; i < particles.size(); ++i) {
  36         Particle &p = particles[i];
  37         p.px = p0x + g_random_double_range(-dp0x, dp0x);
  38         p.py = p0y + g_random_double_range(-dp0y, dp0y);
  39         p.vx = v0x + g_random_double_range(-dvx, dvx);
  40         p.vy = v0y + g_random_double_range(-dvy, dvy);
  41     }
  42 }
  43
  44
  45 void ParticleSet::move(int dt_ms) {
  46     float dt = dt_ms / 1000.0;
  47
  48     for (size_t i = 0; i < particles.size(); ++i) {
  49         Particle &p = particles[i];
  50         p.px += p.vx * dt;
  51         p.py += p.vy * dt;
  52     }
  53
  54     life -= dt_ms;
  55 }
  56
  57
  58 void ParticleSet::normalize(double factor) {
  59     if (!is_new)
  60         return;
  61     is_new = false;
  62
  63     size *= factor;
  64     for (size_t i = 0; i < particles.size(); ++i) {
  65         Particle &p = particles[i];
  66         p.px *= factor;
  67         p.py *= factor;
  68         p.vx *= factor;
  69         p.vy *= factor;
  70     }
  71 }