Improve sun illumination based on angular size and astronomical twilight

2 files changed, 15 insertions, 4 deletions

diff --git a/gfx/lightDirection.cpp b/gfx/lightDirection.cpp
index 6d7d1ea..3932872 100644
--- a/gfx/lightDirection.cpp
+++ b/gfx/lightDirection.cpp
@@ -1,8 +1,12 @@
 #include "lightDirection.h"
 #include "maths.h"
 
+constexpr auto ASTRONOMICAL_TWILIGHT = 18.0_degrees;
+constexpr auto SUN_ANGLUAR_SIZE = 0.5_degrees;
+
 LightDirection::LightDirection(const Direction2D sunPos) :
 	pos {sunPos}, vec {glm::mat3 {rotate_yp(pi + sunPos.x, -sunPos.y)} * north},
-	vert {-glm::clamp(-1.F, 0.F, vec.z - 0.1F)}
+	amb {glm::clamp(sunPos.y + ASTRONOMICAL_TWILIGHT, 0.F, 1.F)},
+	dir {glm::clamp(sunPos.y + SUN_ANGLUAR_SIZE, 0.F, 1.F)}
 {
 }
diff --git a/gfx/lightDirection.h b/gfx/lightDirection.h
index f1e1cc4..789830b 100644
--- a/gfx/lightDirection.h
+++ b/gfx/lightDirection.h
@@ -20,13 +20,20 @@ public:
 	}
 
 	[[nodiscard]] float
-	vertical() const noexcept
+	ambient() const noexcept
 	{
-		return vert;
+		return amb;
+	}
+
+	[[nodiscard]] float
+	directional() const noexcept
+	{
+		return dir;
 	}
 
 private:
 	Direction2D pos;
 	Direction3D vec;
-	float vert;
+	float amb;
+	float dir;
 };