[occt.git] / src / Shaders / PointLightAttenuation.glsl

//! Returns point light source attenuation factor
float occRangedPointLightAttenuation (in float theDistance, in float theRange)
{
  if (theDistance <= theRange)
  {
    float aResult = theDistance / theRange;
    aResult *= aResult;
    aResult *= aResult;
    aResult = 1.0 - aResult;
    aResult = clamp(aResult, 0.0, 1.0);
    aResult /= max(0.0001, theDistance * theDistance);
    return aResult;
  }
  return -1.0;
}

//! Returns point light source attenuation factor with quadratic attenuation in case of zero range.
float occPointLightAttenuation (in float theDistance, in float theRange)
{
  if (theRange == 0.0)
  {
    return 1.0 / max(0.0001, theDistance * theDistance);
  }
  return occRangedPointLightAttenuation (theDistance, theRange);
}

//! Returns point light source attenuation factor with linear attenuation in case of zero range.
float occPointLightAttenuation (in float theDistance, in float theRange, in float theLinearAttenuation, in float theConstAttenuation)
{
  if (theRange == 0.0)
  {
    return 1.0 / (theConstAttenuation + theLinearAttenuation * theDistance);
  }
  return occRangedPointLightAttenuation (theDistance, theRange);
}
Commit	Line	Data
88b312d3	1	//! Returns point light source attenuation factor
	2	float occRangedPointLightAttenuation (in float theDistance, in float theRange)
	3	{
	4	if (theDistance <= theRange)
	5	{
	6	float aResult = theDistance / theRange;
	7	aResult *= aResult;
	8	aResult *= aResult;
	9	aResult = 1.0 - aResult;
	10	aResult = clamp(aResult, 0.0, 1.0);
	11	aResult /= max(0.0001, theDistance * theDistance);
	12	return aResult;
	13	}
	14	return -1.0;
	15	}
	16
	17	//! Returns point light source attenuation factor with quadratic attenuation in case of zero range.
	18	float occPointLightAttenuation (in float theDistance, in float theRange)
	19	{
	20	if (theRange == 0.0)
	21	{
	22	return 1.0 / max(0.0001, theDistance * theDistance);
	23	}
	24	return occRangedPointLightAttenuation (theDistance, theRange);
	25	}
	26
	27	//! Returns point light source attenuation factor with linear attenuation in case of zero range.
	28	float occPointLightAttenuation (in float theDistance, in float theRange, in float theLinearAttenuation, in float theConstAttenuation)
	29	{
	30	if (theRange == 0.0)
	31	{
	32	return 1.0 / (theConstAttenuation + theLinearAttenuation * theDistance);
	33	}
	34	return occRangedPointLightAttenuation (theDistance, theRange);
78607702	35	}