SpotLightSource.cpp [plain text]
#include "config.h"
#include "SpotLightSource.h"
#include "FilterEffect.h"
#include <wtf/text/TextStream.h>
namespace WebCore {
static const float antiAliasTreshold = 0.016f;
void SpotLightSource::initPaintingData(const FilterEffect& filterEffect, PaintingData& paintingData)
{
m_bufferPosition.setXY(filterEffect.mapPointFromUserSpaceToBuffer(m_userSpacePosition.xy()));
FloatPoint mappedZ = filterEffect.mapPointFromUserSpaceToBuffer({ m_userSpacePosition.x() + m_userSpacePosition.z(), m_userSpacePosition.y() });
m_bufferPosition.setZ(mappedZ.x() - m_bufferPosition.x());
paintingData.directionVector = m_userSpacePointsAt - m_userSpacePosition;
paintingData.directionVector.normalize();
if (!m_limitingConeAngle) {
paintingData.coneCutOffLimit = 0.0f;
paintingData.coneFullLight = -antiAliasTreshold;
} else {
float limitingConeAngle = m_limitingConeAngle;
if (limitingConeAngle < 0.0f)
limitingConeAngle = -limitingConeAngle;
if (limitingConeAngle > 90.0f)
limitingConeAngle = 90.0f;
paintingData.coneCutOffLimit = cosf(deg2rad(180.0f - limitingConeAngle));
paintingData.coneFullLight = paintingData.coneCutOffLimit - antiAliasTreshold;
}
if (!m_specularExponent)
paintingData.specularExponent = 0;
else if (m_specularExponent == 1.0f)
paintingData.specularExponent = 1;
else paintingData.specularExponent = 2;
}
LightSource::ComputedLightingData SpotLightSource::computePixelLightingData(const PaintingData& paintingData, int x, int y, float z) const
{
FloatPoint3D lightVector = {
m_bufferPosition.x() - x,
m_bufferPosition.y() - y,
m_bufferPosition.z() - z
};
float lightVectorLength = lightVector.length();
float cosineOfAngle = (lightVector * paintingData.directionVector) / lightVectorLength;
if (cosineOfAngle > paintingData.coneCutOffLimit) {
return { lightVector, { }, lightVectorLength };
}
float lightStrength;
switch (paintingData.specularExponent) {
case 0:
lightStrength = 1.0f; break;
case 1:
lightStrength = -cosineOfAngle; break;
default:
lightStrength = powf(-cosineOfAngle, m_specularExponent);
break;
}
if (cosineOfAngle > paintingData.coneFullLight)
lightStrength *= (paintingData.coneCutOffLimit - cosineOfAngle) / (paintingData.coneCutOffLimit - paintingData.coneFullLight);
if (lightStrength > 1.0f)
lightStrength = 1.0f;
return {
lightVector,
paintingData.initialLightingData.colorVector * lightStrength,
lightVectorLength
};
}
bool SpotLightSource::setX(float x)
{
if (m_userSpacePosition.x() == x)
return false;
m_userSpacePosition.setX(x);
return true;
}
bool SpotLightSource::setY(float y)
{
if (m_userSpacePosition.y() == y)
return false;
m_userSpacePosition.setY(y);
return true;
}
bool SpotLightSource::setZ(float z)
{
if (m_userSpacePosition.z() == z)
return false;
m_userSpacePosition.setZ(z);
return true;
}
bool SpotLightSource::setPointsAtX(float pointsAtX)
{
if (m_userSpacePointsAt.x() == pointsAtX)
return false;
m_userSpacePointsAt.setX(pointsAtX);
return true;
}
bool SpotLightSource::setPointsAtY(float pointsAtY)
{
if (m_userSpacePointsAt.y() == pointsAtY)
return false;
m_userSpacePointsAt.setY(pointsAtY);
return true;
}
bool SpotLightSource::setPointsAtZ(float pointsAtZ)
{
if (m_userSpacePointsAt.z() == pointsAtZ)
return false;
m_userSpacePointsAt.setZ(pointsAtZ);
return true;
}
bool SpotLightSource::setSpecularExponent(float specularExponent)
{
if (m_specularExponent == specularExponent)
return false;
m_specularExponent = specularExponent;
return true;
}
bool SpotLightSource::setLimitingConeAngle(float limitingConeAngle)
{
if (m_limitingConeAngle == limitingConeAngle)
return false;
m_limitingConeAngle = limitingConeAngle;
return true;
}
TextStream& SpotLightSource::externalRepresentation(TextStream& ts) const
{
ts << "[type=SPOT-LIGHT] ";
ts << "[position=\"" << position() << "\"]";
ts << "[direction=\"" << direction() << "\"]";
ts << "[specularExponent=\"" << specularExponent() << "\"]";
ts << "[limitingConeAngle=\"" << limitingConeAngle() << "\"]";
return ts;
}
};