src/gui/guiFormSpecMenu.cpp

/*
Minetest
Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
Copyright (C) 2020 numzero, Lobachevskiy Vitaliy <numzer0@yandex.ru>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include <cmath>
#include "sky.h"
#include <ITexture.h>
#include <IVideoDriver.h>
#include <ISceneManager.h>
#include <ICameraSceneNode.h>
#include <S3DVertex.h>
#include "client/tile.h"
#include "noise.h" // easeCurve
#include "profiler.h"
#include "util/numeric.h"
#include "client/renderingengine.h"
#include "settings.h"
#include "camera.h" // CameraModes

using namespace irr::core;

static video::SMaterial baseMaterial()
{
	video::SMaterial mat;
	mat.Lighting = false;
#if IRRLICHT_VERSION_MAJOR == 1 && IRRLICHT_VERSION_MINOR > 8
	mat.ZBuffer = video::ECFN_DISABLED;
	mat.ZWriteEnable = video::EZW_OFF;
#else
	mat.ZWriteEnable = false;
	mat.ZBuffer = video::ECFN_NEVER;
#endif
	mat.AntiAliasing = 0;
	mat.TextureLayer[0].TextureWrapU = video::ETC_CLAMP_TO_EDGE;
	mat.TextureLayer[0].TextureWrapV = video::ETC_CLAMP_TO_EDGE;
	mat.BackfaceCulling = false;
	return mat;
}

static inline void disableTextureFiltering(video::SMaterial &mat)
{
	mat.setFlag(video::E_MATERIAL_FLAG::EMF_BILINEAR_FILTER, false);
	mat.setFlag(video::E_MATERIAL_FLAG::EMF_TRILINEAR_FILTER, false);
	mat.setFlag(video::E_MATERIAL_FLAG::EMF_ANISOTROPIC_FILTER, false);
}

Sky::Sky(s32 id, RenderingEngine *rendering_engine, ITextureSource *tsrc, IShaderSource *ssrc) :
		scene::ISceneNode(rendering_engine->get_scene_manager()->getRootSceneNode(),
			rendering_engine->get_scene_manager(), id)
{
	m_seed = (u64)myrand() << 32 | myrand();

	setAutomaticCulling(scene::EAC_OFF);
	m_box.MaxEdge.set(0, 0, 0);
	m_box.MinEdge.set(0, 0, 0);

	m_enable_shaders = g_settings->getBool("enable_shaders");

	m_sky_params = SkyboxDefaults::getSkyDefaults();
	m_sun_params = SkyboxDefaults::getSunDefaults();
	m_moon_params = SkyboxDefaults::getMoonDefaults();
	m_star_params = SkyboxDefaults::getStarDefaults();

	// Create materials

	m_materials[0] = baseMaterial();
	m_materials[0].MaterialType = ssrc->getShaderInfo(ssrc->getShader("stars_shader", TILE_MATERIAL_ALPHA)).material;
	m_materials[0].Lighting = true;
	m_materials[0].ColorMaterial = video::ECM_NONE;

	m_materials[1] = baseMaterial();
	m_materials[1].MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;

	m_materials[2] = baseMaterial();
	m_materials[2].setTexture(0, tsrc->getTextureForMesh("sunrisebg.png"));
	m_materials[2].MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;

	setSunTexture(m_sun_params.texture, m_sun_params.tonemap, tsrc);

	setMoonTexture(m_moon_params.texture, m_moon_params.tonemap, tsrc);

	for (int i = 5; i < 11; i++) {
		m_materials[i] = baseMaterial();
		m_materials[i].Lighting = true;
		m_materials[i].MaterialType = video::EMT_SOLID;
	}

	m_directional_colored_fog = g_settings->getBool("directional_colored_fog");

	if (g_settings->getBool("enable_dynamic_shadows")) {
		float val = g_settings->getFloat("shadow_sky_body_orbit_tilt");
		m_sky_body_orbit_tilt = rangelim(val, 0.0f, 60.0f);
	}

	setStarCount(1000);
}

void Sky::OnRegisterSceneNode()
{
	if (IsVisible)
		SceneManager->registerNodeForRendering(this, scene::ESNRP_SKY_BOX);

	scene::ISceneNode::OnRegisterSceneNode();
}

void Sky::render()
{
	video::IVideoDriver *driver = SceneManager->getVideoDriver();
	scene::ICameraSceneNode *camera = SceneManager->getActiveCamera();

	if (!camera || !driver)
		return;

	ScopeProfiler sp(g_profiler, "Sky::render()", SPT_AVG);

	// Draw perspective skybox

	core::matrix4 translate(AbsoluteTransformation);
	translate.setTranslation(camera->getAbsolutePosition());

	// Draw the sky box between the near and far clip plane
	const f32 viewDistance = (camera->getNearValue() + camera->getFarValue()) * 0.5f;
	core::matrix4 scale;
	scale.setScale(core::vector3df(viewDistance, viewDistance, viewDistance));

	driver->setTransform(video::ETS_WORLD, translate * scale);

	if (m_sunlight_seen) {
		float sunsize = 0.07;
		video::SColorf suncolor_f(1, 1, 0, 1);
		//suncolor_f.r = 1;
		//suncolor_f.g = MYMAX(0.3, MYMIN(1.0, 0.7 + m_time_brightness * 0.5));
		//suncolor_f.b = MYMAX(0.0, m_brightness * 0.95);
		video::SColorf suncolor2_f(1, 1, 1, 1);
		// The values below were probably meant to be suncolor2_f instead of a
		// reassignment of suncolor_f. However, the resulting colour was chosen
		// and is our long-running classic colour. So preserve, but comment-out
		// the unnecessary first assignments above.
		suncolor_f.r = 1;
		suncolor_f.g = MYMAX(0.3, MYMIN(1.0, 0.85 + m_time_brightness * 0.5));
		suncolor_f.b = MYMAX(0.0, m_brightness);

		float moonsize = 0.04;
		video::SColorf mooncolor_f(0.50, 0.57, 0.65, 1);
		video::SColorf mooncolor2_f(0.85, 0.875, 0.9, 1);

		float wicked_time_of_day = getWickedTimeOfDay(m_time_of_day);

		video::SColor suncolor = suncolor_f.toSColor();
		video::SColor suncolor2 = suncolor2_f.toSColor();
		video::SColor mooncolor = mooncolor_f.toSColor();
		video::SColor mooncolor2 = mooncolor2_f.toSColor();

		// Calculate offset normalized to the X dimension of a 512x1 px tonemap
		float offset = (1.0 - fabs(sin((m_time_of_day - 0.5) * irr::core::PI))) * 511;

		if (m_sun_tonemap) {
			u8 * texels = (u8 *)m_sun_tonemap->lock();
			video::SColor* texel = (video::SColor *)(texels + (u32)offset * 4);
			video::SColor texel_color (255, texel->getRed(),
				texel->getGreen(), texel->getBlue());
			m_sun_tonemap->unlock();
			m_materials[3].EmissiveColor = texel_color;
		}

		if (m_moon_tonemap) {
			u8 * texels = (u8 *)m_moon_tonemap->lock();
			video::SColor* texel = (video::SColor *)(texels + (u32)offset * 4);
			video::SColor texel_color (255, texel->getRed(),
				texel->getGreen(), texel->getBlue());
			m_moon_tonemap->unlock();
			m_materials[4].EmissiveColor = texel_color;
		}

		const f32 t = 1.0f;
		const f32 o = 0.0f;
		static const u16 indices[6] = {0, 1, 2, 0, 2, 3};
		video::S3DVertex vertices[4];

		driver->setMaterial(m_materials[1]);

		video::SColor cloudyfogcolor = m_bgcolor;

		// Abort rendering if we're in the clouds.
		// Stops rendering a pure white hole in the bottom of the skybox.
		if (m_in_clouds)
			return;

		// Draw the six sided skybox,
		if (m_sky_params.textures.size() == 6) {
			for (u32 j = 5; j < 11; j++) {
				video::SColor c(255, 255, 255, 255);
				driver->setMaterial(m_materials[j]);
				// Use 1.05 rather than 1.0 to avoid colliding with the
				// sun, moon and stars, as this is a background skybox.
				vertices[0] = video::S3DVertex(-1.05, -1.05, -1.05, 0, 0, 1, c, t, t);
				vertices[1] = video::S3DVertex( 1.05, -1.05, -1.05, 0, 0, 1, c, o, t);
				vertices[2] = video::S3DVertex( 1.05,  1.05, -1.05, 0, 0, 1, c, o, o);
				vertices[3] = video::S3DVertex(-1.05,  1.05, -1.05, 0, 0, 1, c, t, o);
				for (video::S3DVertex &vertex : vertices) {
					if (j == 5) { // Top texture
						vertex.Pos.rotateYZBy(90);
						vertex.Pos.rotateXZBy(90);
					} else if (j == 6) { // Bottom texture
						vertex.Pos.rotateYZBy(-90);
						vertex.Pos.rotateXZBy(90);
					} else if (j == 7) { // Left texture
						vertex.Pos.rotateXZBy(90);
					} else if (j == 8) { // Right texture
						vertex.Pos.rotateXZBy(-90);
					} else if (j == 9) { // Front texture, do nothing
						// Irrlicht doesn't like it when vertexes are left
						// alone and not rotated for some reason.
						vertex.Pos.rotateXZBy(0);
					} else {// Back texture
						vertex.Pos.rotateXZBy(180);
					}
				}
				driver->drawIndexedTriangleList(&vertices[0], 4, indices, 2);
			}
		}

		// Draw far cloudy fog thing blended with skycolor
		if (m_visible) {
			driver->setMaterial(m_materials[1]);
			for (u32 j = 0; j < 4; j++) {
				vertices[0] = video::S3DVertex(-1, -0.02, -1, 0, 0, 1, m_bgcolor, t, t);
				vertices[1] = video::S3DVertex( 1, -0.02, -1, 0, 0, 1, m_bgcolor, o, t);
				vertices[2] = video::S3DVertex( 1, 0.45, -1, 0, 0, 1, m_skycolor, o, o);
				vertices[3] = video::S3DVertex(-1, 0.45, -1, 0, 0, 1, m_skycolor, t, o);
				for (video::S3DVertex &vertex : vertices) {
					if (j == 0)
						// Don't switch
						{}
					else if (j == 1)
						// Switch from -Z (south) to +X (east)
						vertex.Pos.rotateXZBy(90);
					else if (j == 2)
						// Switch from -Z (south) to -X (west)
						vertex.Pos.rotateXZBy(-90);
					else
						// Switch from -Z (south) to +Z (north)
						vertex.Pos.rotateXZBy(-180);
				}
				driver->drawIndexedTriangleList(&vertices[0], 4, indices, 2);
			}
		}

		// Draw stars before sun and moon to be behind them
		if (m_star_params.visible)
			draw_stars(driver, wicked_time_of_day);

		// Draw sunrise/sunset horizon glow texture
		// (textures/base/pack/sunrisebg.png)
		if (m_sun_params.sunrise_visible) {
			driver->setMaterial(m_materials[2]);
			float mid1 = 0.25;
			float mid = wicked_time_of_day < 0.5 ? mid1 : (1.0 - mid1);
			float a_ = 1.0f - std::fabs(wicked_time_of_day - mid) * 35.0f;
			float a = easeCurve(MYMAX(0, MYMIN(1, a_)));
			//std::cerr<<"a_="<<a_<<" a="<<a<<std::endl;
			video::SColor c(255, 255, 255, 255);
			float y = -(1.0 - a) * 0.22;
			vertices[0] = video::S3DVertex(-1, -0.05 + y, -1, 0, 0, 1, c, t, t);
			vertices[1] = video::S3DVertex( 1, -0.05 + y, -1, 0, 0, 1, c, o, t);
			vertices[2] = video::S3DVertex( 1,   0.2 + y, -1, 0, 0, 1, c, o, o);
			vertices[3] = video::S3DVertex(-1,   0.2 + y, -1, 0, 0, 1, c, t, o);
			for (video::S3DVertex &vertex : vertices) {
				if (wicked_time_of_day < 0.5)
					// Switch from -Z (south) to +X (east)
					vertex.Pos.rotateXZBy(90);
				else
					// Switch from -Z (south) to -X (west)
					vertex.Pos.rotateXZBy(-90);
			}
			driver->drawIndexedTriangleList(&vertices[0], 4, indices, 2);
		}

		// Draw sun
		if (m_sun_params.visible)
			draw_sun(driver, sunsize, suncolor, suncolor2, wicked_time_of_day);

		// Draw moon
		if (m_moon_params.visible)
			draw_moon(driver, moonsize, mooncolor, mooncolor2, wicked_time_of_day);

		// Draw far cloudy fog thing below all horizons in front of sun, moon
		// and stars.
		if (m_visible) {
			driver->setMaterial(m_materials[1]);

			for (u32 j = 0; j < 4; j++) {
				video::SColor c = cloudyfogcolor;
				vertices[0] = video::S3DVertex(-1, -1.0,  -1, 0, 0, 1, c, t, t);
				vertices[1] = video::S3DVertex( 1, -1.0,  -1, 0, 0, 1, c, o, t);
				vertices[2] = video::S3DVertex( 1, -0.02, -1, 0, 0, 1, c, o, o);
				vertices[3] = video::S3DVertex(-1, -0.02, -1, 0, 0, 1, c, t, o);
				for (video::S3DVertex &vertex : vertices) {
					if (j == 0)
						// Don't switch
						{}
					else if (j == 1)
						// Switch from -Z (south) to +X (east)
						vertex.Pos.rotateXZBy(90);
					else if (j == 2)
						// Switch from -Z (south) to -X (west)
						vertex.Pos.rotateXZBy(-90);
					else
						// Switch from -Z (south) to +Z (north)
						vertex.Pos.rotateXZBy(-180);
				}
				driver->drawIndexedTriangleList(&vertices[0], 4, indices, 2);
			}

			// Draw bottom far cloudy fog thing in front of sun, moon and stars
			video::SColor c = cloudyfogcolor;
			vertices[0] = video::S3DVertex(-1, -1.0, -1, 0, 1, 0, c, t, t);
			vertices[1] = video::S3DVertex( 1, -1.0, -1, 0, 1, 0, c, o, t);
			vertices[2] = video::S3DVertex( 1, -1.0, 1, 0, 1, 0, c, o, o);
			vertices[3] = video::S3DVertex(-1, -1.0, 1, 0, 1, 0, c, t, o);
			driver->drawIndexedTriangleList(&vertices[0], 4, indices, 2);
		}
	}
}

void Sky::update(float time_of_day, float time_brightness,
	float direct_brightness, bool sunlight_seen,
	CameraMode cam_mode, float yaw, float pitch)
{
	// Stabilize initial brightness and color values by flooding updates
	if (m_first_update) {
		/*dstream<<"First update with time_of_day="<<time_of_day
				<<" time_brightness="<<time_brightness
				<<" direct_brightness="<<direct_brightness
				<<" sunlight_seen="<<sunlight_seen<<std::endl;*/
		m_first_update = false;
		for (u32 i = 0; i < 100; i++) {
			update(time_of_day, time_brightness, direct_brightness,
					sunlight_seen, cam_mode, yaw, pitch);
		}
		return;
	}

	m_time_of_day = time_of_day;
	m_time_brightness = time_brightness;
	m_sunlight_seen = sunlight_seen;
	m_in_clouds = false;

	bool is_dawn = (time_brightness >= 0.20 && time_brightness < 0.35);

	video::SColorf bgcolor_bright_normal_f = m_sky_params.sky_color.day_horizon;
	video::SColorf bgcolor_bright_indoor_f = m_sky_params.sky_color.indoors;
	video::SColorf bgcolor_bright_dawn_f = m_sky_params.sky_color.dawn_horizon;
	video::SColorf bgcolor_bright_night_f = m_sky_params.sky_color.night_horizon;

	video::SColorf skycolor_bright_normal_f = m_sky_params.sky_color.day_sky;
	video::SColorf skycolor_bright_dawn_f = m_sky_params.sky_color.dawn_sky;
	video::SColorf skycolor_bright_night_f = m_sky_params.sky_color.night_sky;

	video::SColorf cloudcolor_bright_normal_f = m_cloudcolor_day_f;
	video::SColorf cloudcolor_bright_dawn_f = m_cloudcolor_dawn_f;

	float cloud_color_change_fraction = 0.95;
	if (sunlight_seen) {
		if (std::fabs(time_brightness - m_brightness) < 0.2f) {
			m_brightness = m_brightness * 0.95 + time_brightness * 0.05;
		} else {
			m_brightness = m_brightness * 0.80 + time_brightness * 0.20;
			cloud_color_change_fraction = 0.0;
		}
	} else {
		if (direct_brightness < m_brightness)
			m_brightness = m_brightness * 0.95 + direct_brightness * 0.05;
		else
			m_brightness = m_brightness * 0.98 + direct_brightness * 0.02;
	}

	m_clouds_visible = true;
	float color_change_fraction = 0.98f;
	if (sunlight_seen) {
		if (is_dawn) { // Dawn
			m_bgcolor_bright_f = m_bgcolor_bright_f.getInterpolated(
				bgcolor_bright_dawn_f, color_change_fraction);
			m_skycolor_bright_f = m_skycolor_bright_f.getInterpolated(
				skycolor_bright_dawn_f, color_change_fraction);
			m_cloudcolor_bright_f = m_cloudcolor_bright_f.getInterpolated(
				cloudcolor_bright_dawn_f, color_change_fraction);
		} else {
			if (time_brightness < 0.13f) { // Night
				m_bgcolor_bright_f = m_bgcolor_bright_f.getInterpolated(
					bgcolor_bright_night_f, color_change_fraction);
				m_skycolor_bright_f = m_skycolor_bright_f.getInterpolated(
					skycolor_bright_night_f, color_change_fraction);
			} else { // Day
				m_bgcolor_bright_f = m_bgcolor_bright_f.getInterpolated(
					bgcolor_bright_normal_f, color_change_fraction);
				m_skycolor_bright_f = m_skycolor_bright_f.getInterpolated(
					skycolor_bright_normal_f, color_change_fraction);
			}

			m_cloudcolor_bright_f = m_cloudcolor_bright_f.getInterpolated(
				cloudcolor_bright_normal_f, color_change_fraction);
		}
	} else {
		m_bgcolor_bright_f = m_bgcolor_bright_f.getInterpolated(
			bgcolor_bright_indoor_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;
	}

	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
	);

	video::SColor skycolor_bright = m_skycolor_bright_f.toSColor();
	m_skycolor = video::SColor(
		255,
		skycolor_bright.getRed() * m_brightness,
		skycolor_bright.getGreen() * m_brightness,
		skycolor_bright.getBlue() * m_brightness
	);

	// Horizon coloring based on sun and moon direction during sunset and sunrise
	video::SColor pointcolor = video::SColor(m_bgcolor.getAlpha(), 255, 255, 255);
	if (m_directional_colored_fog) {
		if (m_horizon_blend() != 0) {
			// Calculate hemisphere value from yaw, (inverted in third person front view)
			s8 dir_factor = 1;
			if (cam_mode > CAMERA_MODE_THIRD)
				dir_factor = -1;
			f32 pointcolor_blend = wrapDegrees_0_360(yaw * dir_factor + 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::fabs(pitch)) / 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);
			// Use tonemap only if default sun/moon tinting is used
			// which keeps previous behaviour.
			if (m_sun_tonemap && m_default_tint) {
				pointcolor_sun_f.r = pointcolor_light *
					(float)m_materials[3].EmissiveColor.getRed() / 255;
				pointcolor_sun_f.b = pointcolor_light *
					(float)m_materials[3].EmissiveColor.getBlue() / 255;
				pointcolor_sun_f.g = pointcolor_light *
					(float)m_materials[3].EmissiveColor.getGreen() / 255;
			} else if (!m_default_tint) {
				pointcolor_sun_f = m_sky_params.fog_sun_tint;
			} else {
				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;
			if (m_default_tint) {
				pointcolor_moon_f = video::SColorf(
					0.5 * pointcolor_light,
					0.6 * pointcolor_light,
					0.8 * pointcolor_light,
					1
				);
			} else {
				pointcolor_moon_f = video::SColorf(
					(m_sky_params.fog_moon_tint.getRed() / 255) * pointcolor_light,
					(m_sky_params.fog_moon_tint.getGreen() / 255) * pointcolor_light,
					(m_sky_params.fog_moon_tint.getBlue() / 255) * pointcolor_light,
					1
				);
			}
			if (m_moon_tonemap && m_default_tint) {
				pointcolor_moon_f.r = pointcolor_light *
					(float)m_materials[4].EmissiveColor.getRed() / 255;
				pointcolor_moon_f.b = pointcolor_light *
					(float)m_materials[4].EmissiveColor.getBlue() / 255;
				pointcolor_moon_f.g = pointcolor_light *
					(float)m_materials[4].EmissiveColor.getGreen() / 255;
			}

			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);
		}
		m_bgcolor = m_mix_scolor(m_bgcolor, pointcolor, m_horizon_blend() * 0.5);
		m_skycolor = m_mix_scolor(m_skycolor, pointcolor, m_horizon_blend() * 0.25);
	}

	float cloud_direct_brightness = 0.0f;
	if (sunlight_seen) {
		if (!m_directional_colored_fog) {
			cloud_direct_brightness = time_brightness;
			// Boost cloud brightness relative to sky, at dawn, dusk and at night
			if (time_brightness < 0.7f)
				cloud_direct_brightness *= 1.3f;
		} else {
			cloud_direct_brightness = std::fmin(m_horizon_blend() * 0.15f +
				m_time_brightness, 1.0f);
			// Set the same minimum cloud brightness at night
			if (time_brightness < 0.5f)
				cloud_direct_brightness = std::fmax(cloud_direct_brightness,
					time_brightness * 1.3f);
		}
	} 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.r * m_cloud_brightness,
		m_cloudcolor_bright_f.g * m_cloud_brightness,
		m_cloudcolor_bright_f.b * m_cloud_brightness,
		1.0
	);
	if (m_directional_colored_fog) {
		m_cloudcolor_f = m_mix_scolorf(m_cloudcolor_f,
			video::SColorf(pointcolor), m_horizon_blend() * 0.25);
	}
}

void Sky::draw_sun(video::IVideoDriver *driver, float sunsize, const video::SColor &suncolor,
	const video::SColor &suncolor2, float wicked_time_of_day)
	/* Draw sun in the sky.
	 * driver: Video driver object used to draw
	 * sunsize: the default size of the sun
	 * suncolor: main sun color
	 * suncolor2: second sun color
	 * wicked_time_of_day: current time of day, to know where should be the sun in the sky
	 */
{
	static const u16 indices[] = {0, 1, 2, 0, 2, 3};
	std::array<video::S3DVertex, 4> vertices;
	if (!m_sun_texture) {
		driver->setMaterial(m_materials[1]);
		const float sunsizes[4] = {
			(sunsize * 1.7f) * m_sun_params.scale,
			(sunsize * 1.2f) * m_sun_params.scale,
			(sunsize) * m_sun_params.scale,
			(sunsize * 0.7f) * m_sun_params.scale
		};
		video::SColor c1 = suncolor;
		video::SColor c2 = suncolor;
		c1.setAlpha(0.05 * 255);
		c2.setAlpha(0.15 * 255);
		const video::SColor colors[4] = {c1, c2, suncolor, suncolor2};
		for (int i = 0; i < 4; i++) {
			draw_sky_body(vertices, -sunsizes[i], sunsizes[i], colors[i]);
			place_sky_body(vertices, 90, wicked_time_of_day * 360 - 90);
			driver->drawIndexedTriangleList(&vertices[0], 4, indices, 2);
		}
	} else {
		driver->setMaterial(m_materials[3]);
		float d = (sunsize * 1.7) * m_sun_params.scale;
		video::SColor c;
		if (m_sun_tonemap)
			c = video::SColor(0, 0, 0, 0);
		else
			c = video::SColor(255, 255, 255, 255);
		draw_sky_body(vertices, -d, d, c);
		place_sky_body(vertices, 90, wicked_time_of_day * 360 - 90);
		driver->drawIndexedTriangleList(&vertices[0], 4, indices, 2);
	}
}


void Sky::draw_moon(video::IVideoDriver *driver, float moonsize, const video::SColor &mooncolor,
	const video::SColor &mooncolor2, float wicked_time_of_day)
/*
	* Draw moon in the sky.
	* driver: Video driver object used to draw
	* moonsize: the default size of the moon
	* mooncolor: main moon color
	* mooncolor2: second moon color
	* wicked_time_of_day: current time of day, to know where should be the moon in
	* the sky
	*/
{
	static const u16 indices[] = {0, 1, 2, 0, 2, 3};
	std::array<video::S3DVertex, 4> vertices;
	if (!m_moon_texture) {
		driver->setMaterial(m_materials[1]);
		const float moonsizes_1[4] = {
			(-moonsize * 1.9f) * m_moon_params.scale,
			(-moonsize * 1.3f) * m_moon_params.scale,
			(-moonsize) * m_moon_params.scale,
			(-moonsize) * m_moon_params.scale
		};
		const float moonsizes_2[4] = {
			(moonsize * 1.9f) * m_moon_params.scale,
			(moonsize * 1.3f) * m_moon_params.scale,
			(moonsize) *m_moon_params.scale,
			(moonsize * 0.6f) * m_moon_params.scale
		};
		video::SColor c1 = mooncolor;
		video::SColor c2 = mooncolor;
		c1.setAlpha(0.05 * 255);
		c2.setAlpha(0.15 * 255);
		const video::SColor colors[4] = {c1, c2, mooncolor, mooncolor2};
		for (int i = 0; i < 4; i++) {
			draw_sky_body(vertices, moonsizes_1[i], moonsizes_2[i], colors[i]);
			place_sky_body(vertices, -90, wicked_time_of_day * 360 - 90);
			driver->drawIndexedTriangleList(&vertices[0], 4, indices, 2);
		}
	} else {
		driver->setMaterial(m_materials[4]);
		float d = (moonsize * 1.9) * m_moon_params.scale;
		video::SColor c;
		if (m_moon_tonemap)
			c = video::SColor(0, 0, 0, 0);
		else
			c = video::SColor(255, 255, 255, 255);
		draw_sky_body(vertices, -d, d, c);
		place_sky_body(vertices, -90, wicked_time_of_day * 360 - 90);
		driver->drawIndexedTriangleList(&vertices[0], 4, indices, 2);
	}
}

void Sky::draw_stars(video::IVideoDriver * driver, float wicked_time_of_day)
{
	// Tune values so that stars first appear just after the sun
	// disappears over the horizon, and disappear just before the sun
	// appears over the horizon.
	// Also tune so that stars are at full brightness from time 20000
	// to time 4000.

	float tod = wicked_time_of_day < 0.5f ? wicked_time_of_day : (1.0f - wicked_time_of_day);
	float starbrightness = (0.25f - fabsf(tod)) * 20.0f;
	m_star_color = m_star_params.starcolor;
	m_star_color.a *= clamp(starbrightness, 0.0f, 1.0f);
	if (m_star_color.a <= 0.0f) // Stars are only drawn when not fully transparent
		return;
	m_materials[0].DiffuseColor = m_materials[0].EmissiveColor = m_star_color.toSColor();
	auto sky_rotation = core::matrix4().setRotationAxisRadians(2.0f * M_PI * (wicked_time_of_day - 0.25f), v3f(0.0f, 0.0f, 1.0f));
	auto world_matrix = driver->getTransform(video::ETS_WORLD);
	driver->setTransform(video::ETS_WORLD, world_matrix * sky_rotation);
	driver->setMaterial(m_materials[0]);
	driver->drawMeshBuffer(m_stars.get());
	driver->setTransform(video::ETS_WORLD, world_matrix);
}

void Sky::draw_sky_body(std::array<video::S3DVertex, 4> &vertices, float pos_1, float pos_2, const video::SColor &c)
{
	/*
	* Create an array of vertices with the dimensions specified.
	* pos_1, pos_2: position of the body's vertices
	* c: color of the body
	*/

	const f32 t = 1.0f;
	const f32 o = 0.0f;
	vertices[0] = video::S3DVertex(pos_1, pos_1, -1, 0, 0, 1, c, t, t);
	vertices[1] = video::S3DVertex(pos_2, pos_1, -1, 0, 0, 1, c, o, t);
	vertices[2] = video::S3DVertex(pos_2, pos_2, -1, 0, 0, 1, c, o, o);
	vertices[3] = video::S3DVertex(pos_1, pos_2, -1, 0, 0, 1, c, t, o);
}


void Sky::place_sky_body(
	std::array<video::S3DVertex, 4> &vertices, float horizon_position, float day_position)
	/*
	* Place body in the sky.
	* vertices: The body as a rectangle of 4 vertices
	* horizon_position: turn the body around the Y axis
	* day_position: turn the body around the Z axis, to place it depending of the time of the day
	*/
{
	v3f centrum(0, 0, -1);
	centrum.rotateXZBy(horizon_position);
	centrum.rotateXYBy(day_position);
	centrum.rotateYZBy(m_sky_body_orbit_tilt);
	for (video::S3DVertex &vertex : vertices) {
		// Body is directed to -Z (south) by default
		vertex.Pos.rotateXZBy(horizon_position);
		vertex.Pos.rotateXYBy(day_position);
		vertex.Pos.Z += centrum.Z;
	}
}

void Sky::setSunTexture(const std::string &sun_texture,
		const std::string &sun_tonemap, ITextureSource *tsrc)
{
	// Ignore matching textures (with modifiers) entirely,
	// but lets at least update the tonemap before hand.
	m_sun_params.tonemap = sun_tonemap;
	m_sun_tonemap = tsrc->isKnownSourceImage(sun_tonemap) ?
		tsrc->getTexture(sun_tonemap) : nullptr;
	m_materials[3].Lighting = !!m_sun_tonemap;

	if (m_sun_params.texture == sun_texture && !m_first_update)
		return;
	m_sun_params.texture = sun_texture;

	m_sun_texture = nullptr;
	if (sun_texture == "sun.png") {
		// Dumb compatibility fix: sun.png transparently falls back to no texture
		m_sun_texture = tsrc->isKnownSourceImage(sun_texture) ?
			tsrc->getTexture(sun_texture) : nullptr;
	} else if (!sun_texture.empty()) {
		m_sun_texture = tsrc->getTextureForMesh(sun_texture);
	}

	if (m_sun_texture) {
		m_materials[3] = baseMaterial();
		m_materials[3].setTexture(0, m_sun_texture);
		m_materials[3].MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
		disableTextureFiltering(m_materials[3]);
		m_materials[3].Lighting = !!m_sun_tonemap;
	}
}

void Sky::setSunriseTexture(const std::string &sunglow_texture,
		ITextureSource* tsrc)
{
	// Ignore matching textures (with modifiers) entirely.
	if (m_sun_params.sunrise == sunglow_texture)
		return;
	m_sun_params.sunrise = sunglow_texture;
	m_materials[2].setTexture(0, tsrc->getTextureForMesh(
		sunglow_texture.empty() ? "sunrisebg.png" : sunglow_texture)
	);
}

void Sky::setMoonTexture(const std::string &moon_texture,
	const std::string &moon_tonemap, ITextureSource *tsrc)
{
	// Ignore matching textures (with modifiers) entirely,
	// but lets at least update the tonemap before hand.
	m_moon_params.tonemap = moon_tonemap;
	m_moon_tonemap = tsrc->isKnownSourceImage(moon_tonemap) ?
		tsrc->getTexture(moon_tonemap) : nullptr;
	m_materials[4].Lighting = !!m_moon_tonemap;

	if (m_moon_params.texture == moon_texture && !m_first_update)
		return;
	m_moon_params.texture = moon_texture;

	m_moon_texture = nullptr;
	if (moon_texture == "moon.png") {
		// Dumb compatibility fix: moon.png transparently falls back to no texture
		m_moon_texture = tsrc->isKnownSourceImage(moon_texture) ?
			tsrc->getTexture(moon_texture) : nullptr;
	} else if (!moon_texture.empty()) {
		m_moon_texture = tsrc->getTextureForMesh(moon_texture);
	}

	if (m_moon_texture) {
		m_materials[4] = baseMaterial();
		m_materials[4].setTexture(0, m_moon_texture);
		m_materials[4].MaterialType = video::EMT_TRANSPARENT_ALPHA_CHANNEL;
		disableTextureFiltering(m_materials[4]);
		m_materials[4].Lighting = !!m_moon_tonemap;
	}
}

void Sky::setStarCount(u16 star_count)
{
	// Allow force updating star count at game init.
	if (m_star_params.count != star_count || m_first_update) {
		m_star_params.count = star_count;
		updateStars();
	}
}

void Sky::updateStars()
{
	m_stars.reset(new scene::SMeshBuffer());
	// Stupid IrrLicht doesn’t allow non-indexed rendering, and indexed quad
	// rendering is slow due to lack of hardware support. So as indices are
	// 16-bit and there are 4 vertices per star... the limit is 2^16/4 = 0x4000.
	// That should be well enough actually.
	if (m_star_params.count > 0x4000) {
		warningstream << "Requested " << m_star_params.count << " stars but " << 0x4000 << " is the max\n";
		m_star_params.count = 0x4000;
	}
	m_stars->Vertices.reallocate(4 * m_star_params.count);
	m_stars->Indices.reallocate(6 * m_star_params.count);

	video::SColor fallback_color = m_star_params.starcolor; // used on GLES 2 “without shaders”
	PcgRandom rgen(m_seed);
	float d = (0.006 / 2) * m_star_params.scale;
	for (u16 i = 0; i < m_star_params.count; i++) {
		v3f r = v3f(
			rgen.range(-10000, 10000),
			rgen.range(-10000, 10000),
			rgen.range(-10000, 10000)
		);
		core::CMatrix4<f32> a;
		a.buildRotateFromTo(v3f(0, 1, 0), r);
		v3f p = v3f(-d, 1, -d);
		v3f p1 = v3f(d, 1, -d);
		v3f p2 = v3f(d, 1, d);
		v3f p3 = v3f(-d, 1, d);
		a.rotateVect(p);
		a.rotateVect(p1);
		a.rotateVect(p2);
		a.rotateVect(p3);
		m_stars->Vertices.push_back(video::S3DVertex(p, {}, fallback_color, {}));
		m_stars->Vertices.push_back(video::S3DVertex(p1, {}, fallback_color, {}));
		m_stars->Vertices.push_back(video::S3DVertex(p2, {}, fallback_color, {}));
		m_stars->Vertices.push_back(video::S3DVertex(p3, {}, fallback_color, {}));
	}
	for (u16 i = 0; i < m_star_params.count; i++) {
		m_stars->Indices.push_back(i * 4 + 0);
		m_stars->Indices.push_back(i * 4 + 1);
		m_stars->Indices.push_back(i * 4 + 2);
		m_stars->Indices.push_back(i * 4 + 2);
		m_stars->Indices.push_back(i * 4 + 3);
		m_stars->Indices.push_back(i * 4 + 0);
	}
	m_stars->setHardwareMappingHint(scene::EHM_STATIC);
}

void Sky::setSkyColors(const SkyColor &sky_color)
{
	m_sky_params.sky_color = sky_color;
}

void Sky::setHorizonTint(video::SColor sun_tint, video::SColor moon_tint,
	const std::string &use_sun_tint)
{
	// Change sun and moon tinting:
	m_sky_params.fog_sun_tint = sun_tint;
	m_sky_params.fog_moon_tint = moon_tint;
	// Faster than comparing strings every rendering frame
	if (use_sun_tint == "default")
		m_default_tint = true;
	else if (use_sun_tint == "custom")
		m_default_tint = false;
	else
		m_default_tint = true;
}

void Sky::addTextureToSkybox(const std::string &texture, int material_id,
		ITextureSource *tsrc)
{
	// Sanity check for more than six textures.
	if (material_id + 5 >= SKY_MATERIAL_COUNT)
		return;
	// Keep a list of texture names handy.
	m_sky_params.textures.emplace_back(texture);
	video::ITexture *result = tsrc->getTextureForMesh(texture);
	m_materials[material_id+5] = baseMaterial();
	m_materials[material_id+5].setTexture(0, result);
	m_materials[material_id+5].MaterialType = video::EMT_SOLID;
}

float getWickedTimeOfDay(float time_of_day)
{
	float nightlength = 0.415f;
	float wn = nightlength / 2;
	float wicked_time_of_day = 0;
	if (time_of_day > wn && time_of_day < 1.0f - wn)
		wicked_time_of_day = (time_of_day - wn) / (1.0f - wn * 2) * 0.5f + 0.25f;
	else if (time_of_day < 0.5f)
		wicked_time_of_day = time_of_day / wn * 0.25f;
	else
		wicked_time_of_day = 1.0f - ((1.0f - time_of_day) / wn * 0.25f);
	return wicked_time_of_day;
}
	Commit message (Collapse)	Author	Age
*	Fix formspec list spacing (#10861)	Vincent Robinson	2021-01-23
\|
*	FormSpec: Add list spacing, slot size, and noclip (#10083)	Vincent Robinson	2021-01-23
\| \| \| \| \| \| \| \| \|	* Add list spacing, slot size, and noclip * Simplify StyleSpec * Add test cases Co-authored-by: rubenwardy <rw@rubenwardy.com>
*	Remove dead code (#10845)	rubenwardy	2021-01-22
\|
*	Formspecs: Fix broken texture escaping with model[]	Jean-Patrick Guerrero	2021-01-01
\|
*	Fix item tooltip background color not working	Lars Mueller	2020-12-28
\|
*	Formspec: Allow to specify frame loop for model[] (#10679)	Thomas--S	2020-12-15
\| \| \|	Add the ability to specify an animation frame loop range for the model[] formspec element.
*	Revert "GUIFormSpecMenu: Shift+Click listring workaround for MacOS"	SmallJoker	2020-12-14
\| \| \| \| \| \| \| \|	The commit caused Shift-Clicking issues on Linux due to another Irrlicht bug where KeyInput.Shift released keys do not trigger OnEvent() MacOS users should build using a recent Irrlicht 1.8 development version. See also: https://sourceforge.net/p/irrlicht/patches/321/
*	GUIFormSpecMenu: Shift+Click listring workaround for MacOS	SmallJoker	2020-12-12
\| \| \| \|	event.MouseInput.Shift is not implemented for MacOS
*	Add sound to press event of some formspecs elements (#10402)	Pierre-Yves Rollo	2020-11-23
\|
*	Add model[] formspec element (#10320)	SmallJoker	2020-11-04
\| \| \| \| \| \|	Formspec element to display models, written by @kilbith, rebased and tweaked. Co-authored-by: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com> Co-authored-by: sfan5 <sfan5@live.de>
*	Avoid drawing clipped out formspec elements (#10095)	EvidenceB	2020-08-23
\|
*	Fix missing translation call in hypertext (#10296)	Pierre-Yves Rollo	2020-08-20
\|
*	Add gradients and borders to FormSpec boxes (#8676)	v-rob	2020-08-19
\|
*	Optimize formspec form size (#10144)	v-rob	2020-08-19
\|
*	Add font styling options to tables and textlists (#10203)	v-rob	2020-08-11
\|
*	Formspecs: volume and key settings windows can now be closed by ↵	Zughy	2020-07-14
\| \| \| \| \| \| \|	doubleclicking/tapping (#10128) Co-authored-by: Xx_Crazyminer_xX <carlo.digioia@hotmail.it> Co-authored-by: Marco <4279489-marco_a@users.noreply.gitlab.com>
*	Add FormSpec font styling options (#9763)	v-rob	2020-07-12
\| \| \| \| \| \| \|	* Add FormSpec font styling options * Change multiplication to stof * Remove extraneous check
*	Allow FormSpec elements to be focused with `set_focus` (#9353)	v-rob	2020-07-12
\| \| \|	This allows you to specify a FormSpec element to set the focus of with "set_focus[<name>;<always set>]".
*	Formspec: Make dropdowns optionally return event based on index, not value ↵	v-rob	2020-07-10
\| \| \| \|	(#9496)
*	Don't stop style parsing on unknown property (#10143)	v-rob	2020-07-03
\|
*	Hide tooltip after ETIE_LEFT_UP (for touch control)	MoNTE48	2020-06-09
\|
*	Always use same default tabheader height (#9319)	Paul Ouellette	2020-05-09
\| \| \| \| \|	Previously the default tabheader height was different when using real coordinates. This resulted in the height of tabs changing when switching tabs in sfinv if some tabs used real coordinates.
*	FormSpec: Add universal style selector `*` (#9718)	v-rob	2020-05-06
\|
*	Add `animated_image` to clickthrough elements (#9724)	v-rob	2020-04-25
\|
*	Simplify how parseElement splits element string (#9726)	Pierre-Yves Rollo	2020-04-25
\|
*	Formspec: allow lists to change size and existence while the formspec is ↵	DS	2020-04-18
\| \| \| \| \|	open (#9700) Fixes #9640.
*	Android: fix formspec input for AArch64 devices (#9685)	Maksim	2020-04-16
\|
*	Add scroll_container formspec element (redo) (#9101)	DS	2020-04-13
\| \| \| \| \| \| \| \| \|	New formspec elements: - `scroll_container[<X>,<Y>;<W>,<H>;<scrollbar name>;<orientation>;<scroll factor>]` - `scroll_container_end[]` Other elements can be embedded in this element. Scrollbar must be placed manually.
*	GUIFormSpecMenu: Add basic element highlighing debug feature (#9423)	SmallJoker	2020-04-12
\| \| \|	Activated using F5
*	Formspecs: Add state-selection to style elements (#9378)	Hugues Ross	2020-04-11
\|
*	Formspec: No spec ID for static text labels	SmallJoker	2020-04-11
\| \| \| \|	Fixes #9634
*	Fix GUI element click-through by changing visibility (#9534)	DS	2020-03-31
\| \| \| \| \|	This adds a vector that holds pointers to elements that should only be visible while being drawn. In the guifsmenu's draw func, all elements in this vector are made visible and invisible again. Apart from there, they are always invisible. (Well they are still visible before the first drawn, does this matter? If yes, it could be fixed easily with some lines of code everywhere.)
*	Fix mouse events sent to wrong GUI elements when dragging	sfan5	2020-03-16
\|
*	Formspecs: Add starting frame to `animated_image` (#9411)	v-rob	2020-03-16
\|
*	guiHyperText: Fix blinky cursor on link hover (#9392)	SmallJoker	2020-03-11
\| \| \| \|	Change legacy size/position calculations to 'textarea'
*	Fix memory leak in GUIHyperText (#9489)	DS	2020-03-10
\|
*	GUIFormSpecMenu: Remove field_close_on_enter warning (#9501)	SmallJoker	2020-03-10
\|
*	Add multiple element selection to `style` and `style_type` (#9380)	v-rob	2020-03-01
\|
*	Refactor Script API's log_deprecated	sfan5	2020-02-23
\|
*	Add animated_image[] formspec element (#9258)	Hugues Ross	2020-02-15
\|
*	Formspec: Create a new class for inventorylists (#9287)	DS	2020-02-01
\|
*	StaticText/EnrichedString: Styling support (#9187)	SmallJoker	2020-01-22
\| \| \| \| \| \| \| \|	* StaticText/EnrichedString: Styling support * Fix tooltip fg/bgcolor * Fix default color for substr(), add unittests
*	Replace stray tab with whitespace in guiFormSpecMenu.cpp (#9317)	ANAND	2020-01-18
\|
*	Make clipping of formspec elements more consistent (#9262)	Hugues Ross	2020-01-16
\|
*	Formspec: change the appeareance of the cursor on fields and co. (#8665)	DS	2020-01-11
\|
*	Formspec: Fix clicking on tooltip-obstructed elements (#9266)	DS	2020-01-04
\|
*	Don't override the FGIMG style property if the image parameter is null	Hugues Ross	2019-12-16
\|
*	GUIFormSpecMenu: Fix legacy sorting using std::stable_sort	SmallJoker	2019-12-14
\|
*	Fix spaces breaking formspec_version[] tag	rubenwardy	2019-12-09
\|
*	Refactor to centralize GUIButton styling/rendering code (#9090)	Hugues Ross	2019-12-09
\|