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			102 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			102 lines
		
	
	
	
		
			2.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| #include "lights.hpp"
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| 
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| #include <OgreLight.h>
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| 
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| 
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| namespace OEngine {
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| namespace Render {
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| 
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| Ogre::Real LightFunction::pulseAmplitude(Ogre::Real time)
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| {
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|     return std::sin(time);
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| }
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| 
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| Ogre::Real LightFunction::flickerAmplitude(Ogre::Real time)
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| {
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|     static const float fb = 1.17024f;
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|     static const float f[3] = { 1.5708f,   4.18774f, 5.19934f };
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|     static const float o[3] = { 0.804248f, 2.11115f, 3.46832f };
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|     static const float m[3] = { 1.0f,      0.785f,   0.876f   };
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|     static const float s = 0.394f;
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| 
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|     float v = 0.0f;
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|     for(int i = 0;i < 3;++i)
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|         v += std::sin(fb*time*f[i] + o[1])*m[i];
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|     return v * s;
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| }
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| 
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| Ogre::Real LightFunction::flickerFrequency(Ogre::Real phase)
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| {
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|     static const float fa = 0.785398f;
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|     static const float tdo = 0.94f;
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|     static const float tdm = 2.48f;
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| 
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|     return tdo + tdm*std::sin(fa * phase);
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| }
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| 
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| Ogre::Real LightFunction::calculate(Ogre::Real value)
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| {
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|     Ogre::Real brightness = 1.0f;
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|     float cycle_time;
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|     float time_distortion;
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| 
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|     if(mType == LT_Pulse || mType == LT_PulseSlow)
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|     {
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|         cycle_time = 2.0f * Ogre::Math::PI;
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|         time_distortion = 20.0f;
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|     }
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|     else
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|     {
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|         static const float fa = 0.785398f;
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|         static const float phase_wavelength = 120.0f * 3.14159265359f / fa;
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| 
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|         cycle_time = 500.0f;
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|         mPhase = std::fmod(mPhase + value, phase_wavelength);
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|         time_distortion = flickerFrequency(mPhase);
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|     }
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| 
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|     mDeltaCount += mDirection*value*time_distortion;
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|     if(mDirection > 0 && mDeltaCount > +cycle_time)
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|     {
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|         mDirection = -1.0f;
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|         mDeltaCount = 2.0f*cycle_time - mDeltaCount;
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|     }
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|     if(mDirection < 0 && mDeltaCount < -cycle_time)
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|     {
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|         mDirection = +1.0f;
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|         mDeltaCount = -2.0f*cycle_time - mDeltaCount;
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|     }
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| 
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|     static const float fast = 4.0f/1.0f;
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|     static const float slow = 1.0f/1.0f;
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| 
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|     // These formulas are just guesswork, but they work pretty well
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|     if(mType == LT_Normal)
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|     {
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|         // Less than 1/255 light modifier for a constant light:
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|         brightness = 1.0 + flickerAmplitude(mDeltaCount*slow)/255.0f;
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|     }
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|     else if(mType == LT_Flicker)
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|         brightness = 0.75 + flickerAmplitude(mDeltaCount*fast)*0.25;
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|     else if(mType == LT_FlickerSlow)
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|         brightness = 0.75 + flickerAmplitude(mDeltaCount*slow)*0.25;
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|     else if(mType == LT_Pulse)
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|         brightness = 1.0 + pulseAmplitude(mDeltaCount*fast)*0.25;
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|     else if(mType == LT_PulseSlow)
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|         brightness = 1.0 + pulseAmplitude(mDeltaCount*slow)*0.25;
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| 
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|     return brightness;
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| }
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| 
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| Ogre::Real LightValue::getValue() const
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| {
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|     return 0.0f;
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| }
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| 
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| void LightValue::setValue(Ogre::Real value)
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| {
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|     mTarget->setDiffuseColour(mColor * value);
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| }
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| 
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| }
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| }
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