X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Flight.h;h=f8c4b83c33dd221363a0aa8ea92f20f0fdf7c3a7;hb=6c9df2ffa7ee81a05b28fdd6123a926abd284c72;hp=218af348e1a21419add94aecc622cd9051a4c50d;hpb=9f031a67594162a53b07acbfbc65faf8c4938e99;p=minetest.git

diff --git a/src/light.h b/src/light.h
index 218af348e..f8c4b83c3 100644
--- a/src/light.h
+++ b/src/light.h
@@ -1,6 +1,6 @@
 /*
-Minetest-c55
-Copyright (C) 2010 celeron55, Perttu Ahola <celeron55@gmail.com>
+Minetest
+Copyright (C) 2013 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
@@ -17,28 +17,19 @@ 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
-
+#pragma once
+#include <cassert>
 #include "irrlichttypes.h"
-#include "debug.h"
-
-/*
-	Day/night cache:
-	Meshes are cached for different day-to-night transition values
-*/
-
-/*#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.
+// Actually this is not the real maximum, and this is not the brightest, the
+// brightest is LIGHT_SUN.
+// If changed, this constant as defined in builtin/game/constants.lua must
+// also be changed.
 #define LIGHT_MAX 14
 // Light is stored as 4 bits, thus 15 is the maximum.
 // This brightness is reserved for sunlight
@@ -46,56 +37,90 @@ extern u32 daynight_cache_ratios[DAYNIGHT_CACHE_COUNT];*/
 
 inline u8 diminish_light(u8 light)
 {
-	if(light == 0)
+	if (light == 0)
 		return 0;
-	if(light >= LIGHT_MAX)
+	if (light >= LIGHT_MAX)
 		return LIGHT_MAX - 1;
-		
+
 	return light - 1;
 }
 
 inline u8 diminish_light(u8 light, u8 distance)
 {
-	if(distance >= light)
+	if (distance >= light)
 		return 0;
-	return  light - distance;
+	return light - distance;
 }
 
 inline u8 undiminish_light(u8 light)
 {
+	assert(light <= LIGHT_SUN);
 	// We don't know if light should undiminish from this particular 0.
 	// Thus, keep it at 0.
-	if(light == 0)
+	if (light == 0)
 		return 0;
-	if(light == LIGHT_MAX)
+	if (light >= LIGHT_MAX)
 		return light;
-	
+
 	return light + 1;
 }
 
-extern u8 light_decode_table[LIGHT_MAX+1];
+#ifndef SERVER
+
+/**
+ * \internal
+ *
+ * \warning DO NOT USE this directly; it is here simply so that decode_light()
+ * can be inlined.
+ *
+ * Array size is #LIGHTMAX+1
+ *
+ * The array is a lookup table to convert the internal representation of light
+ * (brightness) to the display brightness.
+ *
+ */
+extern const u8 *light_decode_table;
 
 // 0 <= light <= LIGHT_SUN
 // 0 <= return value <= 255
 inline u8 decode_light(u8 light)
 {
-	if(light > LIGHT_MAX)
-		light = LIGHT_MAX;
-	
+	// assert(light <= LIGHT_SUN);
+	if (light > LIGHT_SUN)
+		light = LIGHT_SUN;
 	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_SUN)
+		return (float)light_decode_table[LIGHT_SUN] / 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;
+}
+
+void set_light_table(float gamma);
+
+#endif // ifndef SERVER
+
 // 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)
+	u32 l = ((daylight_factor * lightday + (c - daylight_factor) * lightnight)) / c;
+	if (l > LIGHT_SUN)
 		l = LIGHT_SUN;
 	return l;
 }
-
-#endif
-