minetest/src/light.h
Kahrl 157a4cf18c Node placement / mineral / serialization / iron freq / node_dig callback
- Node placement code moved to Lua
- Mineral system removed (added default:stone_with_coal and default:stone_with_iron).
- MapBlock and MapNode serialization updated.
- Mapgen: Frequency of iron increased.
- node_dig callback and related changes.
2012-01-22 17:24:50 +02:00

102 lines
2.4 KiB
C

/*
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 General Public License as published by
the Free Software Foundation; either version 2 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 General Public License for more details.
You should have received a copy of the GNU 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 "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.
#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
inline u8 diminish_light(u8 light)
{
if(light == 0)
return 0;
if(light >= LIGHT_MAX)
return LIGHT_MAX - 1;
return light - 1;
}
inline u8 diminish_light(u8 light, u8 distance)
{
if(distance >= light)
return 0;
return light - distance;
}
inline u8 undiminish_light(u8 light)
{
// We don't know if light should undiminish from this particular 0.
// Thus, keep it at 0.
if(light == 0)
return 0;
if(light == LIGHT_MAX)
return light;
return light + 1;
}
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_MAX)
light = LIGHT_MAX;
return light_decode_table[light];
}
// 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;
}
#endif