New lighting curve (#5279)

* New lighting curve

* Make polynomial lighting curve

* Update default lighting settings
This commit is contained in:
Vitaliy 2017-08-17 01:23:20 +03:00 committed by Loïc Blot
parent 1d8d01074f
commit 9c8fec83af
5 changed files with 34 additions and 44 deletions

@ -602,7 +602,11 @@ zoom_fov (Field of view for zoom) int 15 7 160
# Adjust the gamma encoding for the light tables. Higher numbers are brighter. # Adjust the gamma encoding for the light tables. Higher numbers are brighter.
# This setting is for the client only and is ignored by the server. # This setting is for the client only and is ignored by the server.
display_gamma (Gamma) float 2.2 1.0 3.0 display_gamma (Gamma) float 1.0 0.5 3.0
lighting_alpha (Darkness sharpness) float 0.0 0.0 4.0
lighting_beta (Lightness sharpness) float 0.0 0.0 4.0
# Path to texture directory. All textures are first searched from here. # Path to texture directory. All textures are first searched from here.
texture_path (Texture path) path texture_path (Texture path) path

@ -702,8 +702,14 @@
# Adjust the gamma encoding for the light tables. Higher numbers are brighter. # Adjust the gamma encoding for the light tables. Higher numbers are brighter.
# This setting is for the client only and is ignored by the server. # This setting is for the client only and is ignored by the server.
# type: float min: 1 max: 3 # type: float min: 0.5 max: 3.0
# display_gamma = 2.2 # display_gamma = 1.0
# type: float min: 0.0 max: 4.0
# lighting_alpha = 0.0
# type: float min: 0.0 max: 4.0
# lighting_beta = 0.0
# Path to texture directory. All textures are first searched from here. # Path to texture directory. All textures are first searched from here.
# type: path # type: path

@ -168,7 +168,9 @@ void set_default_settings(Settings *settings)
settings->setDefault("leaves_style", "fancy"); settings->setDefault("leaves_style", "fancy");
settings->setDefault("connected_glass", "false"); settings->setDefault("connected_glass", "false");
settings->setDefault("smooth_lighting", "true"); settings->setDefault("smooth_lighting", "true");
settings->setDefault("display_gamma", "2.2"); settings->setDefault("lighting_alpha", "0.0");
settings->setDefault("lighting_beta", "0.0");
settings->setDefault("display_gamma", "1.0");
settings->setDefault("texture_path", ""); settings->setDefault("texture_path", "");
settings->setDefault("shader_path", ""); settings->setDefault("shader_path", "");
settings->setDefault("video_driver", "opengl"); settings->setDefault("video_driver", "opengl");

@ -20,6 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
#include "light.h" #include "light.h"
#include <math.h> #include <math.h>
#include "util/numeric.h" #include "util/numeric.h"
#include "settings.h"
#ifndef SERVER #ifndef SERVER
@ -32,52 +33,27 @@ u8 light_LUT[LIGHT_MAX+1];
const u8 *light_decode_table = light_LUT; const u8 *light_decode_table = light_LUT;
/** Initialize or update the light value tables using the specified \p gamma. /** 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) void set_light_table(float gamma)
{ {
static const float brightness_step = 255.0f / (LIGHT_MAX + 1); // lighting curve derivatives
const float alpha = g_settings->getFloat("lighting_alpha");
// this table is pure arbitrary values, made so that const float beta = g_settings->getFloat("lighting_beta");
// at gamma 2.2 the game looks not too dark at light=1, // lighting curve coefficients
// and mostly linear for the rest of the scale. const float a = alpha + beta - 2;
// we could try to inverse the gamma power function, but this const float b = 3 - 2 * alpha - beta;
// is simpler and quicker. const float c = alpha;
static const int adjustments[LIGHT_MAX + 1] = { // gamma correction
-67, gamma = rangelim(gamma, 0.5, 3.0);
-91,
-125,
-115,
-104,
-85,
-70,
-63,
-56,
-49,
-42,
-35,
-28,
-22,
0
};
gamma = rangelim(gamma, 1.0, 3.0);
float brightness = brightness_step;
for (size_t i = 0; i < LIGHT_MAX; i++) { for (size_t i = 0; i < LIGHT_MAX; i++) {
light_LUT[i] = (u8)(255 * powf(brightness / 255.0f, 1.0 / gamma)); float x = i;
light_LUT[i] = rangelim(light_LUT[i] + adjustments[i], 0, 255); x /= LIGHT_MAX;
if (i > 1 && light_LUT[i] < light_LUT[i - 1]) float brightness = a * x * x * x + b * x * x + c * x;
brightness = powf(brightness, 1.0 / gamma);
light_LUT[i] = rangelim((u32)(255 * brightness), 0, 255);
if (i > 1 && light_LUT[i] <= light_LUT[i - 1])
light_LUT[i] = light_LUT[i - 1] + 1; light_LUT[i] = light_LUT[i - 1] + 1;
brightness += brightness_step;
} }
light_LUT[LIGHT_MAX] = 255; light_LUT[LIGHT_MAX] = 255;
} }

@ -245,6 +245,8 @@ fake_function() {
gettext("Field of view while zooming in degrees.\nThis requires the \"zoom\" privilege on the server."); gettext("Field of view while zooming in degrees.\nThis requires the \"zoom\" privilege on the server.");
gettext("Gamma"); gettext("Gamma");
gettext("Adjust the gamma encoding for the light tables. Higher numbers are brighter.\nThis setting is for the client only and is ignored by the server."); gettext("Adjust the gamma encoding for the light tables. Higher numbers are brighter.\nThis setting is for the client only and is ignored by the server.");
gettext("Darkness sharpness");
gettext("Lightness sharpness");
gettext("Texture path"); gettext("Texture path");
gettext("Path to texture directory. All textures are first searched from here."); gettext("Path to texture directory. All textures are first searched from here.");
gettext("Video driver"); gettext("Video driver");