source-engine/mathlib/lightdesc.cpp

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2020-04-22 16:56:21 +00:00
//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
//=====================================================================================//
#include <ssemath.h>
#include <lightdesc.h>
#include "mathlib.h"
void LightDesc_t::RecalculateDerivedValues(void)
{
m_Flags = LIGHTTYPE_OPTIMIZATIONFLAGS_DERIVED_VALUES_CALCED;
if (m_Attenuation0)
m_Flags|=LIGHTTYPE_OPTIMIZATIONFLAGS_HAS_ATTENUATION0;
if (m_Attenuation1)
m_Flags|=LIGHTTYPE_OPTIMIZATIONFLAGS_HAS_ATTENUATION1;
if (m_Attenuation2)
m_Flags|=LIGHTTYPE_OPTIMIZATIONFLAGS_HAS_ATTENUATION2;
if (m_Type==MATERIAL_LIGHT_SPOT)
{
m_ThetaDot=cos(m_Theta);
m_PhiDot=cos(m_Phi);
float spread=m_ThetaDot-m_PhiDot;
if (spread>1.0e-10)
{
// note - this quantity is very sensitive to round off error. the sse
// reciprocal approximation won't cut it here.
OneOver_ThetaDot_Minus_PhiDot=1.0/spread;
}
else
{
// hard falloff instead of divide by zero
OneOver_ThetaDot_Minus_PhiDot=1.0;
}
}
if (m_Type==MATERIAL_LIGHT_DIRECTIONAL)
{
// set position to be real far away in the right direction
m_Position=m_Direction;
m_Position *= 2.0e6;
}
m_RangeSquared=m_Range*m_Range;
}
void LightDesc_t::ComputeLightAtPointsForDirectional(
const FourVectors &pos, const FourVectors &normal,
FourVectors &color, bool DoHalfLambert ) const
{
FourVectors delta;
delta.DuplicateVector(m_Direction);
// delta.VectorNormalizeFast();
fltx4 strength=delta*normal;
if (DoHalfLambert)
{
strength=AddSIMD(MulSIMD(strength,Four_PointFives),Four_PointFives);
}
else
strength=MaxSIMD(Four_Zeros,delta*normal);
color.x=AddSIMD(color.x,MulSIMD(strength,ReplicateX4(m_Color.x)));
color.y=AddSIMD(color.y,MulSIMD(strength,ReplicateX4(m_Color.y)));
color.z=AddSIMD(color.z,MulSIMD(strength,ReplicateX4(m_Color.z)));
}
void LightDesc_t::ComputeLightAtPoints( const FourVectors &pos, const FourVectors &normal,
FourVectors &color, bool DoHalfLambert ) const
{
FourVectors delta;
Assert((m_Type==MATERIAL_LIGHT_POINT) || (m_Type==MATERIAL_LIGHT_SPOT) || (m_Type==MATERIAL_LIGHT_DIRECTIONAL));
switch (m_Type)
{
case MATERIAL_LIGHT_POINT:
case MATERIAL_LIGHT_SPOT:
delta.DuplicateVector(m_Position);
delta-=pos;
break;
case MATERIAL_LIGHT_DIRECTIONAL:
ComputeLightAtPointsForDirectional( pos, normal, color, DoHalfLambert );
return;
}
fltx4 dist2 = delta*delta;
dist2=MaxSIMD( Four_Ones, dist2 );
fltx4 falloff;
if( m_Flags & LIGHTTYPE_OPTIMIZATIONFLAGS_HAS_ATTENUATION0 )
{
falloff = ReplicateX4(m_Attenuation0);
}
else
falloff= Four_Epsilons;
if( m_Flags & LIGHTTYPE_OPTIMIZATIONFLAGS_HAS_ATTENUATION1 )
{
falloff=AddSIMD(falloff,MulSIMD(ReplicateX4(m_Attenuation1),SqrtEstSIMD(dist2)));
}
if( m_Flags & LIGHTTYPE_OPTIMIZATIONFLAGS_HAS_ATTENUATION2 )
{
falloff=AddSIMD(falloff,MulSIMD(ReplicateX4(m_Attenuation2),dist2));
}
falloff=ReciprocalEstSIMD(falloff);
// Cull out light beyond this radius
// now, zero out elements for which dist2 was > range^2. !!speed!! lights should store dist^2 in sse format
if (m_Range != 0.f)
{
fltx4 RangeSquared=ReplicateX4(m_RangeSquared); // !!speed!!
falloff=AndSIMD(falloff,CmpLtSIMD(dist2,RangeSquared));
}
delta.VectorNormalizeFast();
fltx4 strength=delta*normal;
if (DoHalfLambert)
{
strength=AddSIMD(MulSIMD(strength,Four_PointFives),Four_PointFives);
}
else
strength=MaxSIMD(Four_Zeros,delta*normal);
switch(m_Type)
{
case MATERIAL_LIGHT_POINT:
// half-lambert
break;
case MATERIAL_LIGHT_SPOT:
{
fltx4 dot2=SubSIMD(Four_Zeros,delta*m_Direction); // dot position with spot light dir for cone falloff
fltx4 cone_falloff_scale=MulSIMD(ReplicateX4(OneOver_ThetaDot_Minus_PhiDot),
SubSIMD(dot2,ReplicateX4(m_PhiDot)));
cone_falloff_scale=MinSIMD(cone_falloff_scale,Four_Ones);
if ((m_Falloff!=0.0) && (m_Falloff!=1.0))
{
// !!speed!! could compute integer exponent needed by powsimd and store in light
cone_falloff_scale=PowSIMD(cone_falloff_scale,m_Falloff);
}
strength=MulSIMD(cone_falloff_scale,strength);
// now, zero out lighting where dot2<phidot. This will mask out any invalid results
// from pow function, etc
fltx4 OutsideMask=CmpGtSIMD(dot2,ReplicateX4(m_PhiDot)); // outside light cone?
strength=AndSIMD(OutsideMask,strength);
}
break;
}
strength=MulSIMD(strength,falloff);
color.x=AddSIMD(color.x,MulSIMD(strength,ReplicateX4(m_Color.x)));
color.y=AddSIMD(color.y,MulSIMD(strength,ReplicateX4(m_Color.y)));
color.z=AddSIMD(color.z,MulSIMD(strength,ReplicateX4(m_Color.z)));
}
void LightDesc_t::ComputeNonincidenceLightAtPoints( const FourVectors &pos, FourVectors &color ) const
{
FourVectors delta;
Assert((m_Type==MATERIAL_LIGHT_POINT) || (m_Type==MATERIAL_LIGHT_SPOT) || (m_Type==MATERIAL_LIGHT_DIRECTIONAL));
switch (m_Type)
{
case MATERIAL_LIGHT_POINT:
case MATERIAL_LIGHT_SPOT:
delta.DuplicateVector(m_Position);
delta-=pos;
break;
case MATERIAL_LIGHT_DIRECTIONAL:
return;
}
fltx4 dist2 = delta*delta;
dist2=MaxSIMD( Four_Ones, dist2 );
fltx4 falloff;
if( m_Flags & LIGHTTYPE_OPTIMIZATIONFLAGS_HAS_ATTENUATION0 )
{
falloff = ReplicateX4(m_Attenuation0);
}
else
falloff= Four_Epsilons;
if( m_Flags & LIGHTTYPE_OPTIMIZATIONFLAGS_HAS_ATTENUATION1 )
{
falloff=AddSIMD(falloff,MulSIMD(ReplicateX4(m_Attenuation1),SqrtEstSIMD(dist2)));
}
if( m_Flags & LIGHTTYPE_OPTIMIZATIONFLAGS_HAS_ATTENUATION2 )
{
falloff=AddSIMD(falloff,MulSIMD(ReplicateX4(m_Attenuation2),dist2));
}
falloff=ReciprocalEstSIMD(falloff);
// Cull out light beyond this radius
// now, zero out elements for which dist2 was > range^2. !!speed!! lights should store dist^2 in sse format
if (m_Range != 0.f)
{
fltx4 RangeSquared=ReplicateX4(m_RangeSquared); // !!speed!!
falloff=AndSIMD(falloff,CmpLtSIMD(dist2,RangeSquared));
}
delta.VectorNormalizeFast();
fltx4 strength = Four_Ones;
//fltx4 strength=delta;
//fltx4 strength = MaxSIMD(Four_Zeros,delta);
switch(m_Type)
{
case MATERIAL_LIGHT_POINT:
// half-lambert
break;
case MATERIAL_LIGHT_SPOT:
{
fltx4 dot2=SubSIMD(Four_Zeros,delta*m_Direction); // dot position with spot light dir for cone falloff
fltx4 cone_falloff_scale=MulSIMD(ReplicateX4(OneOver_ThetaDot_Minus_PhiDot),
SubSIMD(dot2,ReplicateX4(m_PhiDot)));
cone_falloff_scale=MinSIMD(cone_falloff_scale,Four_Ones);
if ((m_Falloff!=0.0) && (m_Falloff!=1.0))
{
// !!speed!! could compute integer exponent needed by powsimd and store in light
cone_falloff_scale=PowSIMD(cone_falloff_scale,m_Falloff);
}
strength=MulSIMD(cone_falloff_scale,strength);
// now, zero out lighting where dot2<phidot. This will mask out any invalid results
// from pow function, etc
fltx4 OutsideMask=CmpGtSIMD(dot2,ReplicateX4(m_PhiDot)); // outside light cone?
strength=AndSIMD(OutsideMask,strength);
}
break;
}
strength=MulSIMD(strength,falloff);
color.x=AddSIMD(color.x,MulSIMD(strength,ReplicateX4(m_Color.x)));
color.y=AddSIMD(color.y,MulSIMD(strength,ReplicateX4(m_Color.y)));
color.z=AddSIMD(color.z,MulSIMD(strength,ReplicateX4(m_Color.z)));
}
void LightDesc_t::SetupOldStyleAttenuation( float fQuadraticAttn, float fLinearAttn, float fConstantAttn )
{
// old-style manually typed quadrtiac coefficients
if ( fQuadraticAttn < EQUAL_EPSILON )
fQuadraticAttn = 0;
if ( fLinearAttn < EQUAL_EPSILON)
fLinearAttn = 0;
if ( fConstantAttn < EQUAL_EPSILON)
fConstantAttn = 0;
if ( ( fConstantAttn < EQUAL_EPSILON ) &&
( fLinearAttn < EQUAL_EPSILON ) &&
( fQuadraticAttn < EQUAL_EPSILON ) )
fConstantAttn = 1;
m_Attenuation2=fQuadraticAttn;
m_Attenuation1=fLinearAttn;
m_Attenuation0=fConstantAttn;
float fScaleFactor = fQuadraticAttn * 10000 + fLinearAttn * 100 + fConstantAttn;
if ( fScaleFactor > 0 )
m_Color *= fScaleFactor;
}
void LightDesc_t::SetupNewStyleAttenuation( float fFiftyPercentDistance,
float fZeroPercentDistance )
{
// new style storing 50% and 0% distances
float d50=fFiftyPercentDistance;
float d0=fZeroPercentDistance;
if (d0<d50)
{
// !!warning in lib code???!!!
Warning("light has _fifty_percent_distance of %f but no zero_percent_distance\n",d50);
d0=2.0*d50;
}
float a=0,b=1,c=0;
if (! SolveInverseQuadraticMonotonic(0,1.0,d50,2.0,d0,256.0,a,b,c))
{
Warning("can't solve quadratic for light %f %f\n",d50,d0);
}
float v50=c+d50*(b+d50*a);
float scale=2.0/v50;
a*=scale;
b*=scale;
c*=scale;
m_Attenuation2=a;
m_Attenuation1=b;
m_Attenuation0=c;
}