src/particlesystem.cpp

   1 //  $Id$
   2 //
   3 //  SuperTux
   4 //  Copyright (C) 2004 Matthias Braun <matze@braunis.de>
   5 //
   6 //  This program is free software; you can redistribute it and/or
   7 //  modify it under the terms of the GNU General Public License
   8 //  as published by the Free Software Foundation; either version 2
   9 //  of the License, or (at your option) any later version.
  10 //
  11 //  This program is distributed in the hope that it will be useful,
  12 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 //  GNU General Public License for more details.
  15 //
  16 //  You should have received a copy of the GNU General Public License
  17 //  along with this program; if not, write to the Free Software
  18 //  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  19 #include "particlesystem.h"
  20
  21 #include <iostream>
  22 #include <math.h>
  23 #include "globals.h"
  24 #include "scene.h"
  25
  26 ParticleSystem::ParticleSystem()
  27 {
  28     virtual_width = screen->w;
  29     virtual_height = screen->h;
  30 }
  31
  32 ParticleSystem::~ParticleSystem()
  33 {
  34     std::vector<Particle*>::iterator i;
  35     for(i = particles.begin(); i != particles.end(); ++i) {
  36         delete *i;
  37     }
  38 }
  39
  40 void ParticleSystem::draw(float scrollx, float scrolly, int layer)
  41 {
  42     std::vector<Particle*>::iterator i;
  43     for(i = particles.begin(); i != particles.end(); ++i) {
  44         Particle* particle = *i;
  45         if(particle->layer != layer)
  46             continue;
  47
  48         // remap x,y coordinates onto screencoordinates
  49         float x = fmodf(particle->x - scrollx, virtual_width);
  50         if(x < 0) x += virtual_width;
  51         float y = fmodf(particle->y - scrolly, virtual_height);
  52         if(y < 0) y += virtual_height;
  53         float xmax = fmodf(x + particle->texture->w, virtual_width);
  54         float ymax = fmodf(y + particle->texture->h, virtual_height);
  55
  56         // particle on screen
  57         if(x >= screen->w && xmax >= screen->w)
  58             continue;
  59         if(y >= screen->h && ymax >= screen->h)
  60             continue;
  61
  62         if(x > screen->w) x -= virtual_width;
  63         if(y > screen->h) y -= virtual_height;
  64         texture_draw(particle->texture, x, y);
  65     }
  66 }
  67
  68 SnowParticleSystem::SnowParticleSystem()
  69 {
  70     texture_load(&snowimages[0], datadir+"/images/shared/snow0.png", USE_ALPHA);
  71     texture_load(&snowimages[1], datadir+"/images/shared/snow1.png", USE_ALPHA);
  72     texture_load(&snowimages[2], datadir+"/images/shared/snow2.png", USE_ALPHA);
  73
  74     virtual_width = screen->w * 2;
  75
  76     // create some random snowflakes
  77     size_t snowflakecount = size_t(virtual_width/10.0);
  78     for(size_t i=0; i<snowflakecount; ++i) {
  79         SnowParticle* particle = new SnowParticle;
  80         particle->x = rand() % int(virtual_width);
  81         particle->y = rand() % screen->h;
  82         particle->layer = i % 2;
  83         int snowsize = rand() % 3;
  84         particle->texture = &snowimages[snowsize];
  85         do {
  86             particle->speed = snowsize/60.0 + (float(rand()%10)/300.0);
  87         } while(particle->speed < 0.01);
  88         particle->speed *= gravity;
  89
  90         particles.push_back(particle);
  91     }
  92 }
  93
  94 SnowParticleSystem::~SnowParticleSystem()
  95 {
  96     for(int i=0;i<3;++i)
  97         texture_free(&snowimages[i]);
  98 }
  99
 100 void SnowParticleSystem::simulate(float elapsed_time)
 101 {
 102     std::vector<Particle*>::iterator i;
 103     for(i = particles.begin(); i != particles.end(); ++i) {
 104         SnowParticle* particle = (SnowParticle*) *i;
 105         particle->y += particle->speed * elapsed_time;
 106         if(particle->y > screen->h) {
 107             particle->y = 0;
 108             particle->x = rand() % int(virtual_width);
 109         }
 110     }
 111 }
 112
 113 CloudParticleSystem::CloudParticleSystem()
 114 {
 115     texture_load(&cloudimage, datadir + "/images/shared/cloud.png", USE_ALPHA);
 116
 117     virtual_width = 2000.0;
 118
 119     // create some random clouds
 120     for(size_t i=0; i<15; ++i) {
 121         CloudParticle* particle = new CloudParticle;
 122         particle->x = rand() % int(virtual_width);
 123         particle->y = rand() % int(virtual_height);
 124         particle->layer = 0;
 125         particle->texture = &cloudimage;
 126         particle->speed = -float(250 + rand() % 200) / 1000.0;
 127
 128         particles.push_back(particle);
 129     }
 130 }
 131
 132 CloudParticleSystem::~CloudParticleSystem()
 133 {
 134     texture_free(&cloudimage);
 135 }
 136
 137 void CloudParticleSystem::simulate(float elapsed_time)
 138 {
 139     std::vector<Particle*>::iterator i;
 140     for(i = particles.begin(); i != particles.end(); ++i) {
 141         CloudParticle* particle = (CloudParticle*) *i;
 142         particle->x += particle->speed * elapsed_time;
 143     }
 144 }