s/baricStep/scaleHeight

data/shaders/opengl/basesphere_uniforms.glsl

@@ -26,7 +26,7 @@ layout(std140) uniform BaseSphereData {
 	vec4 atmosColor;
 	vec3 coefficientsR;			// coefficients for approximating the Rayleigh contribution
 	vec3 coefficientsM;			// coefficients for approximating the Mie contribution
-	vec2 baricStep;				// height for (R, M) in km, at which density will be reduced by e
+	vec2 scaleHeight;			// height for (R, M) in km, at which density will be reduced by e
 
 	// Eclipse data
 	Eclipse eclipse;

data/shaders/opengl/rayleigh.glsl

@@ -10,7 +10,7 @@ void scatter(out vec2 density, const in vec3 orig, const in vec3 center)
 {
 	float height = height(orig, center);
 
-	density = -height / baricStep;
+	density = -height / scaleHeight;
 
 	// earth atmospheric density: 1.225 kg/m^3, divided by 1e5
 	// 1/1.225e-5 = 81632.65306

src/BaseSphere.cpp

@@ -21,7 +21,7 @@ struct BaseSphereDataBlock {
 	Color4f atmosColor;
 	alignas(16) vector3f coefficientsR;
 	alignas(16) vector3f coefficientsM;
-	alignas(16) vector2f baricStep;
+	alignas(16) vector2f scaleHeight;
 
 	// Eclipse struct data
 	alignas(16) vector3f shadowCentreX;
@@ -102,7 +102,7 @@ void BaseSphere::SetMaterialParameters(const matrix4x4d &trans, const float radi
 	matData.atmosColor = ap.atmosCol.ToColor4f();
 	matData.coefficientsR = ap.rayleighCoefficients;
 	matData.coefficientsM = ap.mieCoefficients;
-	matData.baricStep = ap.baricStep;
+	matData.scaleHeight = ap.scaleHeight;
 
 	// we handle up to three shadows at a time
 	auto it = shadows.cbegin(), itEnd = shadows.cend();

src/galaxy/AtmosphereParameters.h

@@ -13,7 +13,7 @@ struct AtmosphereParameters {
 	vector3d center;
 	vector3f rayleighCoefficients;
 	vector3f mieCoefficients;
-	vector2f baricStep;
+	vector2f scaleHeight;
 };
 
 #endif // ATMOSPHEREPARAMETERS_H_INCLUDED

src/galaxy/SystemBody.cpp

@@ -267,7 +267,7 @@ bool SystemBody::IsScoopable() const
 // planet radius, height of atmosphere (not its radius), length of perpendicular between ray and planet center, lapse rate at which density fades out by rate of e
 // this function is used in GetCoefficients
 // all input units are in km
-double SystemBody::ComputeDensity(const double radius, const double atmosphereHeight, const double h, const double baricStep) const
+double SystemBody::ComputeDensity(const double radius, const double atmosphereHeight, const double h, const double scaleHeight) const
 {
 	int numSamples = 16;
 	double totalHeight = radius + atmosphereHeight;
@@ -281,7 +281,7 @@ double SystemBody::ComputeDensity(const double radius, const double atmosphereHe
 	for (int i = 0; i < numSamples; ++i) {
 		double t = tmin + step * (i + 0.5);
 		double h = sqrt(minHeight * minHeight + t * t) - radius;
-		density += step * exp(-h / baricStep);
+		density += step * exp(-h / scaleHeight);
 	}
 
 	return density;
@@ -290,20 +290,20 @@ double SystemBody::ComputeDensity(const double radius, const double atmosphereHe
 // these coefficients are to be passed into shaders, meant to accelerate scattering computation per-pixel
 // instead of sampling each one (which I suspect is VERY SLOW)
 // all input units are in km
-vector3f SystemBody::GetCoefficients(const double radius, const double atmHeight, const double baricStep) const
+vector3f SystemBody::GetCoefficients(const double radius, const double atmHeight, const double scaleHeight) const
 {
 	float k, b, c;
 
 	// compute full out-scattering densities at 0 and 1 km heights
 	// k = density at 0 km
 	// b = log(density0km / density1km) - log is used to multiply it by actual height
-	k = ComputeDensity(radius, atmHeight, 0.f, baricStep);
-	b = log(k / ComputeDensity(radius, atmHeight, 1.f, baricStep));
+	k = ComputeDensity(radius, atmHeight, 0.f, scaleHeight);
+	b = log(k / ComputeDensity(radius, atmHeight, 1.f, scaleHeight));
 
 	// compute c - erf coefficient, which adjusts slope of erf near t=0 to match actual in-scattering
 	float erf1_minus_erf0 = 0.421463;
 	float sHeight = sqrt(radius * radius + 1.f) - radius;
-	float c1 = exp(-sHeight / baricStep);
+	float c1 = exp(-sHeight / scaleHeight);
 	float c2 = k * erf1_minus_erf0;
 	c = c1 / c2;
 	return vector3f(k, b, c);
@@ -371,7 +371,7 @@ AtmosphereParameters SystemBody::CalcAtmosphereParams() const
 	const float atmosHeight_in_km = radiusPlanet_in_km * (params.atmosRadius - 1);
 	params.rayleighCoefficients = GetCoefficients(radiusPlanet_in_km, atmosHeight_in_km, atmosScaleHeight);
 	params.mieCoefficients = GetCoefficients(radiusPlanet_in_km, atmosHeight_in_km, atmosScaleHeight / 6.66); // 7994 / 1200 = 6.61
-	params.baricStep = vector2f(atmosScaleHeight, atmosScaleHeight / 6.66);
+	params.scaleHeight = vector2f(atmosScaleHeight, atmosScaleHeight / 6.66);
 
 	return params;
 }

src/galaxy/SystemBody.h

@@ -293,8 +293,8 @@ class SystemBody : public RefCounted, public SystemBodyType, protected SystemBod
 	double GetAtmDensity(double altitude, double pressure) const;
 
 	// for rayleigh scattering
-	double ComputeDensity(const double radius, const double atmosphereHeight, const double h, const double baricStep) const;
-	vector3f GetCoefficients(const double radius, const double atmHeight, const double baricStep) const;
+	double ComputeDensity(const double radius, const double atmosphereHeight, const double h, const double scaleHeight) const;
+	vector3f GetCoefficients(const double radius, const double atmHeight, const double scaleHeight) const;
 
 	AtmosphereParameters CalcAtmosphereParams() const;