1 files changed, 112 insertions, 0 deletions
diff --git a/src/particleemitterprop.h b/src/particleemitterprop.h
new file mode 100644
index 00000000..e645c169
--- /dev/null
+++ b/src/particleemitterprop.h
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+/*
+ *  The Mana World
+ *  Copyright 2006 The Mana World Development Team
+ *
+ *  This file is part of The Mana World.
+ *
+ *  The Mana World is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  any later version.
+ *
+ *  The Mana World is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with The Mana World; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *  $Id$
+ */
+
+#include <cstdlib>
+#include <cmath>
+
+/**
+ * Returns a random numeric value that is larger than or equal min and smaller
+ * than max
+ */
+
+enum ChangeFunc
+{
+    FUNC_NONE,
+    FUNC_SINE,
+    FUNC_SAW,
+    FUNC_TRIANGLE,
+    FUNC_SQUARE
+};
+
+template <typename T> struct ParticleEmitterProp
+{
+    ParticleEmitterProp():
+        changeFunc(FUNC_NONE)
+    {
+    }
+
+    void set(T min, T max)
+    {
+        minVal=min; maxVal=max;
+    }
+
+    void set(T val)
+    {
+        set(val, val);
+    }
+
+    void setFunction(ChangeFunc func, T amplitude, int period, int phase)
+    {
+        changeFunc = func;
+        changeAmplitude = amplitude;
+        changePeriod = period;
+        changePhase = phase;
+    }
+
+    T value(int tick)
+    {
+        tick += changePhase;
+        T val = (T) (minVal + (maxVal - minVal) * (rand() / ((double) RAND_MAX + 1)));
+
+        switch (changeFunc)
+        {
+            case FUNC_SINE:
+                val += (T) std::sin(M_PI * 2 * ((double)(tick%changePeriod) / (double)changePeriod)) * changeAmplitude;
+                break;
+            case FUNC_SAW:
+                val += (T) (changeAmplitude * ((double)(tick%changePeriod) / (double)changePeriod)) * 2 - changeAmplitude;
+                break;
+            case FUNC_TRIANGLE:
+                if ((tick%changePeriod) * 2 < changePeriod)
+                {
+                    val += changeAmplitude - (T)((tick%changePeriod) / (double)changePeriod) * changeAmplitude * 4;
+                } else {
+                    val += changeAmplitude * -3 + (T)((tick%changePeriod) / (double)changePeriod) * changeAmplitude * 4;
+                    // I have no idea why this works but it does
+                }
+                break;
+            case FUNC_SQUARE:
+                if ((tick%changePeriod) * 2 < changePeriod)
+                {
+                    val += changeAmplitude;
+                } else {
+                    val -= changeAmplitude;
+                }
+                break;
+            case FUNC_NONE:
+            default:
+                //nothing
+                break;
+        }
+
+        return val;
+    }
+
+    T minVal;
+    T maxVal;
+
+    ChangeFunc changeFunc;
+    T changeAmplitude;
+    int changePeriod;
+    int changePhase;
+};