Directional fog + horizon colors, based on sun & moon positions at sunrise / sunset

src/game.cpp

@@ -1318,7 +1318,7 @@ void the_game(
 	*/
 
 	Sky *sky = NULL;
-	sky = new Sky(smgr->getRootSceneNode(), smgr, -1);
+	sky = new Sky(smgr->getRootSceneNode(), smgr, -1, client.getEnv().getLocalPlayer());
 	
 	/*
 		A copy of the local inventory

src/sky.cpp

@@ -8,16 +8,18 @@
 #include "main.h" // g_profiler
 #include "profiler.h"
 #include "util/numeric.h" // MYMIN
+#include <cmath>
 
 //! constructor
-Sky::Sky(scene::ISceneNode* parent, scene::ISceneManager* mgr, s32 id):
+Sky::Sky(scene::ISceneNode* parent, scene::ISceneManager* mgr, s32 id, LocalPlayer* player):
 		scene::ISceneNode(parent, mgr, id),
 		m_first_update(true),
 		m_brightness(0.5),
 		m_cloud_brightness(0.5),
 		m_bgcolor_bright_f(1,1,1,1),
 		m_skycolor_bright_f(1,1,1,1),
-		m_cloudcolor_bright_f(1,1,1,1)
+		m_cloudcolor_bright_f(1,1,1,1),
+		m_player(player)
 {
 	setAutomaticCulling(scene::EAC_OFF);
 	Box.MaxEdge.set(0,0,0);
@@ -431,7 +433,8 @@ void Sky::update(float time_of_day, float time_brightness,
 			video::SColor(255, 240,240,255);
 	//video::SColorf cloudcolor_bright_dawn_f(1.0, 0.591, 0.4);
 	//video::SColorf cloudcolor_bright_dawn_f(1.0, 0.65, 0.44);
-	video::SColorf cloudcolor_bright_dawn_f(1.0, 0.7, 0.5);
+	//video::SColorf cloudcolor_bright_dawn_f(1.0, 0.7, 0.5);
+	video::SColorf cloudcolor_bright_dawn_f(1.0, 0.875, 0.75);
 
 	float cloud_color_change_fraction = 0.95;
 	if(sunlight_seen){
@@ -470,18 +473,50 @@ void Sky::update(float time_of_day, float time_brightness,
 	} else {
 		m_bgcolor_bright_f = m_bgcolor_bright_f.getInterpolated(
 				bgcolor_bright_indoor_f, color_change_fraction);
-		m_cloudcolor_bright_f = m_cloudcolor_bright_f.getInterpolated(
-				cloudcolor_bright_normal_f, color_change_fraction);
 		m_skycolor_bright_f = m_skycolor_bright_f.getInterpolated(
 				bgcolor_bright_indoor_f, color_change_fraction);
+		m_cloudcolor_bright_f = m_cloudcolor_bright_f.getInterpolated(
+				cloudcolor_bright_normal_f, color_change_fraction);
 		m_clouds_visible = false;
 	}
+
+	// Horizon coloring based on sun and moon direction during sunset and sunrise
+	video::SColor pointcolor = video::SColor(255, 255, 255, m_bgcolor.getAlpha());
+	if (m_horizon_blend() != 0)
+	{
+		// calculate hemisphere value from yaw
+		f32 pointcolor_blend = wrapDegrees_0_360(m_player->getYaw() + 90);
+		if (pointcolor_blend > 180)
+			pointcolor_blend = 360 - pointcolor_blend;
+		pointcolor_blend /= 180;
+		// bound view angle to determine where transition starts and ends
+		pointcolor_blend = rangelim(1 - pointcolor_blend * 1.375, 0, 1 / 1.375) * 1.375;
+		// combine the colors when looking up or down, otherwise turning looks weird
+		pointcolor_blend += (0.5 - pointcolor_blend) * (1 - MYMIN((90 - std::abs(m_player->getPitch())) / 90 * 1.5, 1));
+		// invert direction to match where the sun and moon are rising
+		if (m_time_of_day > 0.5)
+			pointcolor_blend = 1 - pointcolor_blend;
+
+		// horizon colors of sun and moon
+		f32 pointcolor_light = rangelim(m_time_brightness * 3, 0.2, 1);
+		video::SColorf pointcolor_sun_f(1, 1, 1, 1);
+		pointcolor_sun_f.r = pointcolor_light * 1;
+		pointcolor_sun_f.b = pointcolor_light * (0.25 + (rangelim(m_time_brightness, 0.25, 0.75) - 0.25) * 2 * 0.75);
+		pointcolor_sun_f.g = pointcolor_light * (pointcolor_sun_f.b * 0.375 + (rangelim(m_time_brightness, 0.05, 0.15) - 0.05) * 10 * 0.625);
+		video::SColorf pointcolor_moon_f(0.5 * pointcolor_light, 0.6 * pointcolor_light, 0.8 * pointcolor_light, 1);
+		video::SColor pointcolor_sun = pointcolor_sun_f.toSColor();
+		video::SColor pointcolor_moon = pointcolor_moon_f.toSColor();
+		// calculate the blend color
+		pointcolor = m_mix_scolor(pointcolor_moon, pointcolor_sun, pointcolor_blend);
+	}
+
 	video::SColor bgcolor_bright = m_bgcolor_bright_f.toSColor();
 	m_bgcolor = video::SColor(
 		255,
 		bgcolor_bright.getRed() * m_brightness,
 		bgcolor_bright.getGreen() * m_brightness,
 		bgcolor_bright.getBlue() * m_brightness);
+	m_bgcolor = m_mix_scolor(m_bgcolor, pointcolor, m_horizon_blend() * 0.5);
 
 	video::SColor skycolor_bright = m_skycolor_bright_f.toSColor();
 	m_skycolor = video::SColor(
@@ -489,22 +524,22 @@ void Sky::update(float time_of_day, float time_brightness,
 		skycolor_bright.getRed() * m_brightness,
 		skycolor_bright.getGreen() * m_brightness,
 		skycolor_bright.getBlue() * m_brightness);
+	m_skycolor = m_mix_scolor(m_skycolor, pointcolor, m_horizon_blend() * 0.25);
 
 	float cloud_direct_brightness = 0;
 	if(sunlight_seen){
-		cloud_direct_brightness = time_brightness;
+		cloud_direct_brightness = MYMIN(m_horizon_blend() * 0.15 + m_time_brightness, 1);
-		if(time_brightness >= 0.2 && time_brightness < 0.7)
-				cloud_direct_brightness *= 1.3;
 	} else {
 		cloud_direct_brightness = direct_brightness;
 	}
 	m_cloud_brightness = m_cloud_brightness * cloud_color_change_fraction +
 			cloud_direct_brightness * (1.0 - cloud_color_change_fraction);
 	m_cloudcolor_f = video::SColorf(
-			m_cloudcolor_bright_f.getRed() * m_cloud_brightness,
+			m_cloudcolor_bright_f.r * m_cloud_brightness,
-			m_cloudcolor_bright_f.getGreen() * m_cloud_brightness,
+			m_cloudcolor_bright_f.g * m_cloud_brightness,
-			m_cloudcolor_bright_f.getBlue() * m_cloud_brightness,
+			m_cloudcolor_bright_f.b * m_cloud_brightness,
 			1.0);
+	m_cloudcolor_f = m_mix_scolorf(m_cloudcolor_f, video::SColorf(pointcolor), m_horizon_blend() * 0.75);
 
 }
 

src/sky.h

@@ -19,6 +19,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "irrlichttypes_extrabloated.h"
 #include <ISceneNode.h>
+#include "localplayer.h"
 
 #ifndef SKY_HEADER
 #define SKY_HEADER
@@ -31,7 +32,7 @@ class Sky : public scene::ISceneNode
 {
 public:
 	//! constructor
-	Sky(scene::ISceneNode* parent, scene::ISceneManager* mgr, s32 id);
+	Sky(scene::ISceneNode* parent, scene::ISceneManager* mgr, s32 id, LocalPlayer* player);
 
 	virtual void OnRegisterSceneNode();
 
@@ -62,6 +63,41 @@ private:
 	core::aabbox3d<f32> Box;
 	video::SMaterial m_materials[SKY_MATERIAL_COUNT];
 
+	// How much sun & moon transition should affect horizon color
+	float m_horizon_blend()
+	{
+		if (!m_sunlight_seen)
+			return 0;
+		float x; m_time_of_day >= 0.5 ? x = (1 - m_time_of_day) * 2 : x = m_time_of_day * 2;
+		if (x <= 0.3)
+			return 0;
+		if (x <= 0.4) // when the sun and moon are aligned
+			return (x - 0.3) * 10;
+		if (x <= 0.5)
+			return (0.5 - x) * 10;
+		return 0;
+	}
+
+	// Mix two colors by a given amount
+	video::SColor m_mix_scolor(video::SColor col1, video::SColor col2, f32 factor)
+	{
+		video::SColor result = video::SColor(
+			col1.getAlpha() * (1 - factor) + col2.getAlpha() * factor,
+			col1.getRed() * (1 - factor) + col2.getRed() * factor,
+			col1.getGreen() * (1 - factor) + col2.getGreen() * factor,
+			col1.getBlue() * (1 - factor) + col2.getBlue() * factor);
+		return result;
+	}
+	video::SColorf m_mix_scolorf(video::SColorf col1, video::SColorf col2, f32 factor)
+	{
+		video::SColorf result = video::SColorf(
+			col1.r * (1 - factor) + col2.r * factor,
+			col1.g * (1 - factor) + col2.g * factor,
+			col1.b * (1 - factor) + col2.b * factor,
+			col1.a * (1 - factor) + col2.a * factor);
+		return result;
+	}
+
 	bool m_first_update;
 	float m_time_of_day;
 	float m_time_brightness;
@@ -78,6 +114,7 @@ private:
 	v3f m_stars[SKY_STAR_COUNT];
 	u16 m_star_indices[SKY_STAR_COUNT*4];
 	video::S3DVertex m_star_vertices[SKY_STAR_COUNT*4];
+	LocalPlayer* m_player;
 };
 
 #endif