X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Flight.h;h=f1c458ad8bc42bfdadb4386995cfae9ec8980e78;hb=183c81b5ecf4f9350936737f5091073d81733d73;hp=b76ac3a5d7166371b08d6ff280993eed296c58a6;hpb=4e249fb3fbf75f0359758760d88e22aa5b14533c;p=oweals%2Fminetest.git

diff --git a/src/light.h b/src/light.h
index b76ac3a5d..f1c458ad8 100644
--- a/src/light.h
+++ b/src/light.h
@@ -1,10 +1,46 @@
+/*
+Minetest-c55
+Copyright (C) 2010 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+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.
+*/
+
 #ifndef LIGHT_HEADER
 #define LIGHT_HEADER
 
-#include "common_irrlicht.h"
+#include "irrlichttypes.h"
+#include "debug.h"
+
+/*
+	Day/night cache:
+	Meshes are cached for different day-to-night transition values
+*/
 
-// This directly sets the range of light
+/*#define DAYNIGHT_CACHE_COUNT 3
+// First one is day, last one is night.
+extern u32 daynight_cache_ratios[DAYNIGHT_CACHE_COUNT];*/
+
+/*
+	Lower level lighting stuff
+*/
+
+// This directly sets the range of light.
+// Actually this is not the real maximum, and this is not the
+// brightest. The brightest is LIGHT_SUN.
 #define LIGHT_MAX 14
+// Light is stored as 4 bits, thus 15 is the maximum.
 // This brightness is reserved for sunlight
 #define LIGHT_SUN 15
 
@@ -39,16 +75,55 @@ inline u8 undiminish_light(u8 light)
 
 extern u8 light_decode_table[LIGHT_MAX+1];
 
+// 0 <= light <= LIGHT_SUN
+// 0 <= return value <= 255
 inline u8 decode_light(u8 light)
 {
-	if(light == LIGHT_SUN)
-		return light_decode_table[LIGHT_MAX];
-	
 	if(light > LIGHT_MAX)
-		throw;
+		light = LIGHT_MAX;
 	
 	return light_decode_table[light];
 }
 
+// 0.0 <= light <= 1.0
+// 0.0 <= return value <= 1.0
+inline float decode_light_f(float light_f)
+{
+	s32 i = (u32)(light_f * LIGHT_MAX + 0.5);
+
+	if(i <= 0)
+		return (float)light_decode_table[0] / 255.0;
+	if(i >= LIGHT_MAX)
+		return (float)light_decode_table[LIGHT_MAX] / 255.0;
+
+	float v1 = (float)light_decode_table[i-1] / 255.0;
+	float v2 = (float)light_decode_table[i] / 255.0;
+	float f0 = (float)i - 0.5;
+	float f = light_f * LIGHT_MAX - f0;
+	return f * v2 + (1.0 - f) * v1;
+}
+
+// 0 <= daylight_factor <= 1000
+// 0 <= lightday, lightnight <= LIGHT_SUN
+// 0 <= return value <= LIGHT_SUN
+inline u8 blend_light(u32 daylight_factor, u8 lightday, u8 lightnight)
+{
+	u32 c = 1000;
+	u32 l = ((daylight_factor * lightday + (c-daylight_factor) * lightnight))/c;
+	if(l > LIGHT_SUN)
+		l = LIGHT_SUN;
+	return l;
+}
+
+// 0.0 <= daylight_factor <= 1.0
+// 0 <= lightday, lightnight <= LIGHT_SUN
+// 0 <= return value <= 255
+inline u8 blend_light_f1(float daylight_factor, u8 lightday, u8 lightnight)
+{
+	u8 l = ((daylight_factor * decode_light(lightday) +
+			(1.0-daylight_factor) * decode_light(lightnight)));
+	return l;
+}
+
 #endif