3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as published by
7 the Free Software Foundation; either version 2.1 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 #include "irrlichttypes.h"
25 Lower level lighting stuff
28 // This directly sets the range of light.
29 // Actually this is not the real maximum, and this is not the brightest, the
30 // brightest is LIGHT_SUN.
31 // If changed, this constant as defined in builtin/game/constants.lua must
34 // Light is stored as 4 bits, thus 15 is the maximum.
35 // This brightness is reserved for sunlight
43 * \warning DO NOT USE this directly; it is here simply so that decode_light()
46 * Array size is #LIGHTMAX+1
48 * The array is a lookup table to convert the internal representation of light
49 * (brightness) to the display brightness.
52 extern const u8 *light_decode_table;
54 // 0 <= light <= LIGHT_SUN
55 // 0 <= return value <= 255
56 inline u8 decode_light(u8 light)
58 // assert(light <= LIGHT_SUN);
59 if (light > LIGHT_SUN)
61 return light_decode_table[light];
64 // 0.0 <= light <= 1.0
65 // 0.0 <= return value <= 1.0
66 inline float decode_light_f(float light_f)
68 s32 i = (u32)(light_f * LIGHT_MAX + 0.5);
71 return (float)light_decode_table[0] / 255.0;
73 return (float)light_decode_table[LIGHT_SUN] / 255.0;
75 float v1 = (float)light_decode_table[i - 1] / 255.0;
76 float v2 = (float)light_decode_table[i] / 255.0;
77 float f0 = (float)i - 0.5;
78 float f = light_f * LIGHT_MAX - f0;
79 return f * v2 + (1.0 - f) * v1;
82 void set_light_table(float gamma);
84 #endif // ifndef SERVER
86 // 0 <= daylight_factor <= 1000
87 // 0 <= lightday, lightnight <= LIGHT_SUN
88 // 0 <= return value <= LIGHT_SUN
89 inline u8 blend_light(u32 daylight_factor, u8 lightday, u8 lightnight)
92 u32 l = ((daylight_factor * lightday + (c - daylight_factor) * lightnight)) / c;