Expose getPointedThing to Lua

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

diff --git a/src/light.cpp b/src/light.cpp
index 95bb37a8d55e58975f787e492c5b5a632b9dd8f8..4a3ca5a60767c8388429f59e0a025935f80e7375 100644 (file)
--- a/src/light.cpp
+++ b/src/light.cpp
@@ -1,85 +1,85 @@
-#include "light.h"
-
 /*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
 
-#!/usr/bin/python
+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
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
 
-from math import *
-from sys import stdout
+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 Lesser General Public License for more details.
 
-# We want 0 at light=0 and 255 at light=LIGHT_MAX
-LIGHT_MAX = 15
+You should have received a copy of the GNU Lesser 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.
+*/
 
-L = []
-for i in range(1,LIGHT_MAX+1):
-    L.append(int(round(255.0 * 0.69 ** (i-1))))
-       L.append(0)
+#include "light.h"
+#include <math.h>
+#include "util/numeric.h"
 
-L.reverse()
-for i in L:
-       stdout.write(str(i)+",\n")
+#ifndef SERVER
 
-*/
+// Length of LIGHT_MAX+1 means LIGHT_MAX is the last value.
+// LIGHT_SUN is read as LIGHT_MAX from here.
 
-/*
-       The first value should be 0, the last value should be 255.
-*/
-/*u8 light_decode_table[LIGHT_MAX+1] = 
-{
-0,
-2,
-3,
-4,
-6,
-9,
-13,
-19,
-28,
-40,
-58,
-84,
-121,
-176,
-255,
-};*/
+u8 light_LUT[LIGHT_MAX+1];
 
-/*
-#!/usr/bin/python
+// the const ref to light_LUT is what is actually used in the code.
+const u8 *light_decode_table = light_LUT;
 
-from math import *
-from sys import stdout
+/** Initialize or update the light value tables using the specified \p gamma.
+ *  If \p gamma == 1.0 then the light table is linear.  Typically values for
+ *  gamma range between 1.8 and 2.2.
+ *
+ *  @note The value for gamma will be restricted to the range 1.1 <= gamma <= 3.0.
+ *
+ *  @note This function is not, currently, a simple linear to gamma encoding
+ *        because adjustments are made so that a gamma of 1.8 gives the same
+ *        results as those hardcoded for use by the server.
+ */
+void set_light_table(float gamma)
+{
+       static const float brightness_step = 255.0f / (LIGHT_MAX + 1);
 
-# We want 0 at light=0 and 255 at light=LIGHT_MAX
-LIGHT_MAX = 14
-#FACTOR = 0.69
-FACTOR = 0.75
+       // this table is pure arbitrary values, made so that
+       // at gamma 2.2 the game looks not too dark at light=1,
+       // and mostly linear for the rest of the scale.
+       // we could try to inverse the gamma power function, but this
+       // is simpler and quicker.
+       static const int adjustments[LIGHT_MAX + 1] = {
+               -67,
+               -91,
+               -125,
+               -115,
+               -104,
+               -85,
+               -70,
+               -63,
+               -56,
+               -49,
+               -42,
+               -35,
+               -28,
+               -22,
+               0
+       };
 
-L = []
-for i in range(1,LIGHT_MAX+1):
-    L.append(int(round(255.0 * FACTOR ** (i-1))))
-L.append(0)
+       gamma = rangelim(gamma, 1.0, 3.0);
 
-L.reverse()
-for i in L:
-    stdout.write(str(i)+",\n")
-*/
-u8 light_decode_table[LIGHT_MAX+1] = 
-{
-0,
-6,
-8,
-11,
-14,
-19,
-26,
-34,
-45,
-61,
-81,
-108,
-143,
-191,
-255,
-};
+       float brightness = brightness_step;
 
+       for (size_t i = 0; i < LIGHT_MAX; i++) {
+               light_LUT[i] = (u8)(255 * powf(brightness / 255.0f, 1.0 / gamma));
+               light_LUT[i] = rangelim(light_LUT[i] + adjustments[i], 0, 255);
+               if (i > 1 && light_LUT[i] < light_LUT[i - 1])
+                       light_LUT[i] = light_LUT[i - 1] + 1;
+               brightness += brightness_step;
+       }
+       light_LUT[LIGHT_MAX] = 255;
+}
+#endif