Tune caves

[oweals/minetest.git] / src / light.h

diff --git a/src/light.h b/src/light.h
index 888b6da50108aa5131cea024c2cbe291da7f489e..238acce43d2d73c52e0762f395e244c68a4ccb16 100644 (file)
--- a/src/light.h
+++ b/src/light.h
@@ -36,7 +36,9 @@ extern u32 daynight_cache_ratios[DAYNIGHT_CACHE_COUNT];*/
        Lower level lighting stuff
 */
 
-// This directly sets the range of light
+// 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
@@ -73,16 +75,27 @@ 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)
                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