upgrade Filament to v1.41

ios/include/filament/Options.h

@@ -21,6 +21,8 @@
 
 #include <stdint.h>
 
+#include <math.h>
+
 namespace filament {
 
 class Texture;
@@ -151,19 +153,120 @@ struct BloomOptions {
 };
 
 /**
- * Options to control fog in the scene
+ * Options to control large-scale fog in the scene
  */
 struct FogOptions {
-    float distance = 0.0f;                 //!< distance in world units from the camera where the fog starts ( >= 0.0 )
-    float maximumOpacity = 1.0f;           //!< fog's maximum opacity between 0 and 1
-    float height = 0.0f;                   //!< fog's floor in world units
-    float heightFalloff = 1.0f;            //!< how fast fog dissipates with altitude
-    LinearColor color = {0.5f, 0.5f, 0.5f};//!< fog's color (linear), see fogColorFromIbl
-    float density = 0.1f;                  //!< fog's density at altitude given by 'height'
-    float inScatteringStart = 0.0f;        //!< distance in world units from the camera where in-scattering starts
-    float inScatteringSize = -1.0f;        //!< size of in-scattering (>0 to activate). Good values are >> 1 (e.g. ~10 - 100).
-    bool fogColorFromIbl = false;          //!< Fog color will be modulated by the IBL color in the view direction.
-    bool enabled = false;                  //!< enable or disable fog
+    /**
+     * Distance in world units [m] from the camera to where the fog starts ( >= 0.0 )
+     */
+    float distance = 0.0f;
+
+    /**
+     * Distance in world units [m] after which the fog calculation is disabled.
+     * This can be used to exclude the skybox, which is desirable if it already contains clouds or
+     * fog. The default value is +infinity which applies the fog to everything.
+     *
+     * Note: The SkyBox is typically at a distance of 1e19 in world space (depending on the near
+     * plane distance and projection used though).
+     */
+    float cutOffDistance = INFINITY;
+
+    /**
+     * fog's maximum opacity between 0 and 1
+     */
+    float maximumOpacity = 1.0f;
+
+    /**
+     * Fog's floor in world units [m]. This sets the "sea level".
+     */
+    float height = 0.0f;
+
+    /**
+     * How fast the fog dissipates with altitude. heightFalloff has a unit of [1/m].
+     * It can be expressed as 1/H, where H is the altitude change in world units [m] that causes a
+     * factor 2.78 (e) change in fog density.
+     *
+     * A falloff of 0 means the fog density is constant everywhere and may result is slightly
+     * faster computations.
+     */
+    float heightFalloff = 1.0f;
+
+    /**
+     *  Fog's color is used for ambient light in-scattering, a good value is
+     *  to use the average of the ambient light, possibly tinted towards blue
+     *  for outdoors environments. Color component's values should be between 0 and 1, values
+     *  above one are allowed but could create a non energy-conservative fog (this is dependant
+     *  on the IBL's intensity as well).
+     *
+     *  We assume that our fog has no absorption and therefore all the light it scatters out
+     *  becomes ambient light in-scattering and has lost all directionality, i.e.: scattering is
+     *  isotropic. This somewhat simulates Rayleigh scattering.
+     *
+     *  This value is used as a tint instead, when fogColorFromIbl is enabled.
+     *
+     *  @see fogColorFromIbl
+     */
+    LinearColor color = { 1.0f, 1.0f, 1.0f };
+
+    /**
+     * Extinction factor in [1/m] at altitude 'height'. The extinction factor controls how much
+     * light is absorbed and out-scattered per unit of distance. Each unit of extinction reduces
+     * the incoming light to 37% of its original value.
+     *
+     * Note: The extinction factor is related to the fog density, it's usually some constant K times
+     * the density at sea level (more specifically at fog height). The constant K depends on
+     * the composition of the fog/atmosphere.
+     *
+     * For historical reason this parameter is called `density`.
+     */
+    float density = 0.1f;
+
+    /**
+     * Distance in world units [m] from the camera where the Sun in-scattering starts.
+     */
+    float inScatteringStart = 0.0f;
+
+    /**
+     * Very inaccurately simulates the Sun's in-scattering. That is, the light from the sun that
+     * is scattered (by the fog) towards the camera.
+     * Size of the Sun in-scattering (>0 to activate). Good values are >> 1 (e.g. ~10 - 100).
+     * Smaller values result is a larger scattering size.
+     */
+    float inScatteringSize = -1.0f;
+
+    /**
+     * The fog color will be sampled from the IBL in the view direction and tinted by `color`.
+     * Depending on the scene this can produce very convincing results.
+     *
+     * This simulates a more anisotropic phase-function.
+     *
+     * `fogColorFromIbl` is ignored when skyTexture is specified.
+     *
+     * @see skyColor
+     */
+    bool fogColorFromIbl = false;
+
+    /**
+     * skyTexture must be a mipmapped cubemap. When provided, the fog color will be sampled from
+     * this texture, higher resolution mip levels will be used for objects at the far clip plane,
+     * and lower resolution mip levels for objects closer to the camera. The skyTexture should
+     * typically be heavily blurred; a typical way to produce this texture is to blur the base
+     * level with a strong gaussian filter or even an irradiance filter and then generate mip
+     * levels as usual. How blurred the base level is somewhat of an artistic decision.
+     *
+     * This simulates a more anisotropic phase-function.
+     *
+     * `fogColorFromIbl` is ignored when skyTexture is specified.
+     *
+     * @see Texture
+     * @see fogColorFromIbl
+     */
+    Texture* skyColor = nullptr;    //!< %codegen_skip_json% %codegen_skip_javascript%
+
+    /**
+     * Enable or disable large-scale fog
+     */
+    bool enabled = false;
 };
 
 /**