Unable to properly sample IES light on the CPU about ies

[Zeta48]

I found out my mistake. I should use angles instead of directly using interpolateBilinear.
`

void dirToSphericalAngles(const Math::Vec3& dir, nbFloat32& angleH, nbFloat32& angleV)
{
	angleH = (0.5f + 0.5f * atan2(dir.x, dir.z) / Math::Pi.getValue()) * 360.0f;
	angleV = (1.f - acos(dir.y) / Math::Pi.getValue()) * 180.0f;
}

struct SampleToLight
{
	Math::Vec3 L;
	float length;
	float intensityMultiplier = 1.0f;
};

SampleToLight IesLight::generateSampleToLight(const Math::Vec3& P) const
{
	const Math::Vec3 lightWsPosition = this->readPosition();

	SampleToLight sample;
	sample.L = lightWsPosition - P;
	sample.length = glm::length(sample.L);
	sample.L /= sample.length;

	nbFloat32 angleH, angleV;
	dirToSphericalAngles(-sample.L, angleH, angleV);
	sample.intensityMultiplier = m_iesLoadHelper.interpolate2D(*m_iesFileInfo, angleV, angleH);

	return sample;
}

`