113 lines
2.8 KiB
C
113 lines
2.8 KiB
C
/************************************************************************
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* Minetest-c55
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* Copyright (C) 2010 celeron55, Perttu Ahola <celeron55@gmail.com>
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*
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* light.h
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* voxelands - 3d voxel world sandbox game
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* Copyright (C) Lisa 'darkrose' Milne 2014 <lisa@ltmnet.com>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>
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*
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* License updated from GPLv2 or later to GPLv3 or later by Lisa Milne
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* for Voxelands.
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************************************************************************/
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#ifndef LIGHT_HEADER
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#define LIGHT_HEADER
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#include "common_irrlicht.h"
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#include "debug.h"
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/*
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Day/night cache:
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Meshes are cached for different day-to-night transition values
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*/
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/*#define DAYNIGHT_CACHE_COUNT 3
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// First one is day, last one is night.
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extern u32 daynight_cache_ratios[DAYNIGHT_CACHE_COUNT];*/
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/*
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Lower level lighting stuff
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*/
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// This directly sets the range of light.
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// Actually this is not the real maximum, and this is not the
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// brightest. The brightest is LIGHT_SUN.
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#define LIGHT_MAX 14
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// Light is stored as 4 bits, thus 15 is the maximum.
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// This brightness is reserved for sunlight
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#define LIGHT_SUN 15
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// these are used in mob spawning
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#define LIGHT_SPAWN_BRIGHT 10
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#define LIGHT_SPAWN_DARK 4
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inline u8 diminish_light(u8 light)
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{
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if(light == 0)
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return 0;
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if(light >= LIGHT_MAX)
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return LIGHT_MAX - 1;
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return light - 1;
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}
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inline u8 diminish_light(u8 light, u8 distance)
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{
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if(distance >= light)
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return 0;
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return light - distance;
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}
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inline u8 undiminish_light(u8 light)
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{
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// We don't know if light should undiminish from this particular 0.
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// Thus, keep it at 0.
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if(light == 0)
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return 0;
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if(light == LIGHT_MAX)
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return light;
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return light + 1;
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}
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extern u8 light_decode_table[LIGHT_MAX+1];
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inline u8 decode_light(u8 light)
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{
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if(light == LIGHT_SUN)
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return light_decode_table[LIGHT_MAX];
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if(light > LIGHT_MAX)
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light = LIGHT_MAX;
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return light_decode_table[light];
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}
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// 0 <= daylight_factor <= 1000
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// 0 <= lightday, lightnight <= LIGHT_SUN
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// 0 <= return value <= LIGHT_SUN
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inline u8 blend_light(u32 daylight_factor, u8 lightday, u8 lightnight)
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{
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u32 c = 1000;
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u32 l = ((daylight_factor * lightday + (c-daylight_factor) * lightnight))/c;
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if(l > LIGHT_SUN)
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l = LIGHT_SUN;
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return l;
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}
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#endif
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