X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=src%2Flight.cpp;h=9b6f5c210ee7df4da84ff2208328a3b165eafe89;hb=115ef6c09c640598695d5d506a7a8e1ab928174b;hp=765c6303a97218ff27f31f2bf470bdb1c5f91710;hpb=22e186b4aa88b585e71500c4e9a03bf69b0b6191;p=dragonfireclient.git

diff --git a/src/light.cpp b/src/light.cpp
index 765c6303a..9b6f5c210 100644
--- a/src/light.cpp
+++ b/src/light.cpp
@@ -18,309 +18,69 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 */
 
 #include "light.h"
+#include <cmath>
+#include "util/numeric.h"
+#include "settings.h"
 
-#if 1
-// Middle-raised variation of a_n+1 = a_n * 0.786
-// Length of LIGHT_MAX+1 means LIGHT_MAX is the last value.
-// LIGHT_SUN is read as LIGHT_MAX from here.
-u8 light_decode_table[LIGHT_MAX+1] = 
-{
-8,
-11+2,
-14+7,
-18+10,
-22+15,
-29+20,
-37+20,
-47+15,
-60+10,
-76+7,
-97+5,
-123+2,
-157,
-200,
-255,
-};
-#endif
-
-#if 0
-/*
-Made using this and:
-- adding 220 as the second last one
-- replacing the third last one (212) with 195
+#ifndef SERVER
 
-#!/usr/bin/python
+static u8 light_LUT[LIGHT_SUN + 1];
 
-from math import *
-from sys import stdout
+// The const ref to light_LUT is what is actually used in the code
+const u8 *light_decode_table = light_LUT;
 
-# We want 0 at light=0 and 255 at light=LIGHT_MAX
-LIGHT_MAX = 14
-#FACTOR = 0.69
-#FACTOR = 0.75
-FACTOR = 0.83
-START_FROM_ZERO = False
-
-L = []
-if START_FROM_ZERO:
-    for i in range(1,LIGHT_MAX+1):
-        L.append(int(round(255.0 * FACTOR ** (i-1))))
-    L.append(0)
-else:
-    for i in range(1,LIGHT_MAX+1):
-        L.append(int(round(255.0 * FACTOR ** (i-1))))
-    L.append(255)
-
-L.reverse()
-for i in L:
-    stdout.write(str(i)+",\n")
-*/
-u8 light_decode_table[LIGHT_MAX+1] = 
-{
-23,
-27,
-33,
-40,
-48,
-57,
-69,
-83,
-100,
-121,
-146,
-176,
-195,
-220,
-255,
+struct LightingParams {
+	float a, b, c; // polynomial coefficients
+	float boost, center, sigma; // normal boost parameters
+	float gamma;
 };
-#endif
 
-#if 0
-// This is good
-// a_n+1 = a_n * 0.786
-// Length of LIGHT_MAX+1 means LIGHT_MAX is the last value.
-// LIGHT_SUN is read as LIGHT_MAX from here.
-u8 light_decode_table[LIGHT_MAX+1] = 
-{
-8,
-11,
-14,
-18,
-22,
-29,
-37,
-47,
-60,
-76,
-97,
-123,
-157,
-200,
-255,
-};
-#endif
+static LightingParams params;
 
-#if 0
-// Use for debugging in dark
-u8 light_decode_table[LIGHT_MAX+1] = 
+float decode_light_f(float x)
 {
-58,
-64,
-72,
-80,
-88,
-98,
-109,
-121,
-135,
-150,
-167,
-185,
-206,
-229,
-255,
-};
-#endif
-
-// This is reasonable with classic lighting with a light source
-/*u8 light_decode_table[LIGHT_MAX+1] = 
-{
-2,
-3,
-4,
-6,
-9,
-13,
-18,
-25,
-32,
-35,
-45,
-57,
-69,
-79,
-255
-};*/
-
-
-// As in minecraft, a_n+1 = a_n * 0.8
-// NOTE: This doesn't really work that well because this defines
-//       LIGHT_MAX as dimmer than LIGHT_SUN
-// NOTE: Uh, this has had 34 left out; forget this.
-/*u8 light_decode_table[LIGHT_MAX+1] = 
+	if (x >= 1.0f) // x is equal to 1.0f half the time
+		return 1.0f;
+	x = std::fmax(x, 0.0f);
+	float brightness = ((params.a * x + params.b) * x + params.c) * x;
+	brightness += params.boost * std::exp(-0.5f * sqr((x - params.center) / params.sigma));
+	if (brightness <= 0.0f) // may happen if parameters are insane
+		return 0.0f;
+	if (brightness >= 1.0f)
+		return 1.0f;
+	return powf(brightness, 1.0f / params.gamma);
+}
+
+// Initialize or update the light value tables using the specified gamma
+void set_light_table(float gamma)
 {
-8,
-11,
-14,
-17,
-21,
-27,
-42,
-53,
-66,
-83,
-104,
-130,
-163,
-204,
-255,
-};*/
+// Lighting curve derivatives
+	const float alpha = g_settings->getFloat("lighting_alpha");
+	const float beta  = g_settings->getFloat("lighting_beta");
+// Lighting curve coefficients
+	params.a = alpha + beta - 2.0f;
+	params.b = 3.0f - 2.0f * alpha - beta;
+	params.c = alpha;
+// Mid boost
+	params.boost = g_settings->getFloat("lighting_boost");
+	params.center = g_settings->getFloat("lighting_boost_center");
+	params.sigma = g_settings->getFloat("lighting_boost_spread");
+// Gamma correction
+	params.gamma = rangelim(gamma, 0.5f, 10.0f);
+
+// Boundary values should be fixed
+	light_LUT[0] = 0;
+	light_LUT[LIGHT_SUN] = 255;
+
+	for (size_t i = 1; i < LIGHT_SUN; i++) {
+		float brightness = decode_light_f((float)i / LIGHT_SUN);
+		// Strictly speaking, rangelim is not necessary here—if the implementation
+		// is conforming. But we don’t want problems in any case.
+		light_LUT[i] = rangelim((s32)(255.0f * brightness), 0, 255);
+		// Ensure light brightens with each level
+		if (i > 1 && light_LUT[i] <= light_LUT[i - 1])
+			light_LUT[i] = light_LUT[i - 1] + 1;
+	}
+}
 
-// This was a quick try of more light, manually quickly made
-/*u8 light_decode_table[LIGHT_MAX+1] = 
-{
-0,
-7,
-11,
-15,
-21,
-29,
-42,
-53,
-69,
-85,
-109,
-135,
-167,
-205,
-255,
-};*/
-
-// This was used for a long time, manually made
-/*u8 light_decode_table[LIGHT_MAX+1] = 
-{
-0,
-6,
-8,
-11,
-14,
-19,
-26,
-34,
-45,
-61,
-81,
-108,
-143,
-191,
-255,
-};*/
-
-/*u8 light_decode_table[LIGHT_MAX+1] = 
-{
-0,
-3,
-6,
-10,
-18,
-25,
-35,
-50,
-75,
-95,
-120,
-150,
-185,
-215,
-255,
-};*/
-/*u8 light_decode_table[LIGHT_MAX+1] = 
-{
-0,
-5,
-12,
-22,
-35,
-50,
-65,
-85,
-100,
-120,
-140,
-160,
-185,
-215,
-255,
-};*/
-// LIGHT_MAX is 14, 0-14 is 15 values
-/*u8 light_decode_table[LIGHT_MAX+1] = 
-{
-0,
-9,
-12,
-14,
-16,
-20,
-26,
-34,
-45,
-61,
-81,
-108,
-143,
-191,
-255,
-};*/
-
-#if 0
-/*
-#!/usr/bin/python
-
-from math import *
-from sys import stdout
-
-# We want 0 at light=0 and 255 at light=LIGHT_MAX
-LIGHT_MAX = 14
-#FACTOR = 0.69
-FACTOR = 0.75
-
-L = []
-for i in range(1,LIGHT_MAX+1):
-    L.append(int(round(255.0 * FACTOR ** (i-1))))
-L.append(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,
-};
 #endif
-
-