windEmitter.cpp

Detailed Description

  1
  2//-----------------------------------------------------------------------------
  3// Copyright (c) 2012 GarageGames, LLC
  4//
  5// Permission is hereby granted, free of charge, to any person obtaining a copy
  6// of this software and associated documentation files (the "Software"), to
  7// deal in the Software without restriction, including without limitation the
  8// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  9// sell copies of the Software, and to permit persons to whom the Software is
 10// furnished to do so, subject to the following conditions:
 11//
 12// The above copyright notice and this permission notice shall be included in
 13// all copies or substantial portions of the Software.
 14//
 15// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 16// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 17// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 18// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 19// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 20// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 21// IN THE SOFTWARE.
 22//-----------------------------------------------------------------------------
 23
 24#include "platform/platform.h"
 25#include "T3D/fx/windEmitter.h"
 26
 27#include "math/mBox.h"
 28#include "core/tAlgorithm.h"
 29#include "platform/profiler.h"
 30
 31
 32Vector<WindEmitter*> WindEmitter::smAllEmitters;
 33
 34
 35WindEmitter::WindEmitter()
 36{
 37   smAllEmitters.push_back( this );
 38
 39   mEnabled = true;
 40   mScore = 0.0f;
 41   mSphere.center.zero();
 42   mSphere.radius = 0.0f;
 43   mStrength = 0.0f;
 44   mTurbulenceFrequency = 0.0f;
 45   mTurbulenceStrength = 0.0f;
 46   mVelocity.zero();
 47}
 48
 49WindEmitter::~WindEmitter()
 50{
 51   WindEmitterList::iterator iter = T3D::find( smAllEmitters.begin(), smAllEmitters.end(), this );
 52   smAllEmitters.erase( iter );
 53}
 54
 55void WindEmitter::setPosition( const Point3F& pos )
 56{
 57   mSphere.center = pos;
 58}
 59
 60void WindEmitter::update( const Point3F& pos, const VectorF& velocity )
 61{
 62   mSphere.center = pos;
 63   mVelocity = velocity;
 64}
 65
 66void WindEmitter::setRadius( F32 radius )
 67{
 68   mSphere.radius = radius;
 69}
 70
 71void WindEmitter::setStrength( F32 strength )
 72{
 73   mStrength = strength;
 74}
 75
 76void WindEmitter::setTurbulency( F32 frequency, F32 strength )
 77{
 78   mTurbulenceFrequency = frequency;
 79   mTurbulenceStrength = strength;
 80}
 81
 82S32 QSORT_CALLBACK WindEmitter::_sortByScore(const void* a, const void* b)
 83{
 84   return mSign((*(WindEmitter**)b)->mScore - (*(WindEmitter**)a)->mScore);
 85}
 86
 87bool WindEmitter::findBest(   const Point3F& cameraPos, 
 88                              const VectorF& cameraDir,
 89                              F32 viewDistance,
 90                              U32 maxResults,
 91                              WindEmitterList* results )
 92{
 93   PROFILE_START(WindEmitter_findBest);
 94
 95   // Build a sphere from the camera point.
 96   SphereF cameraSphere;
 97   cameraSphere.center = cameraPos;
 98   cameraSphere.radius = viewDistance;
 99
100   // Collect the active spheres within the camera space and score them.
101   WindEmitterList best;
102   WindEmitterList::iterator iter = smAllEmitters.begin();
103   for ( ; iter != smAllEmitters.end(); iter++ )
104   {        
105      const SphereF& sphere = *(*iter);
106
107      // Skip any spheres outside of our camera range or that are disabled.
108      if ( !(*iter)->mEnabled || !cameraSphere.isIntersecting( sphere ) )
109         continue;
110
111      // Simple score calculation...
112      //
113      // score = ( radius / distance to camera ) * dot( cameraDir, vector from camera to sphere )
114      //
115      Point3F vect = sphere.center - cameraSphere.center;
116      F32 dist = vect.len();
117      (*iter)->mScore = dist * sphere.radius;
118      vect /= getMax( dist, 0.001f );
119      (*iter)->mScore *= mDot( vect, cameraDir );
120
121      best.push_back( *iter );
122   }
123
124   // Sort the results by score!
125   dQsort( best.address(), best.size(), sizeof(WindEmitter*), &WindEmitter::_sortByScore );
126
127   // Clip the results to the max requested.
128   if ( best.size() > maxResults )
129      best.setSize( maxResults );
130
131   // Merge the results and return.
132   results->merge( best );
133
134   PROFILE_END(); // WindEmitter_findBest
135
136   return best.size() > 0;
137}
138