From 9c8fec83af2c94791865cd82ee18abdc54f913a1 Mon Sep 17 00:00:00 2001 From: Vitaliy Date: Thu, 17 Aug 2017 01:23:20 +0300 Subject: [PATCH] New lighting curve (#5279) * New lighting curve * Make polynomial lighting curve * Update default lighting settings --- builtin/settingtypes.txt | 6 +++- minetest.conf.example | 10 ++++-- src/defaultsettings.cpp | 4 ++- src/light.cpp | 56 +++++++++---------------------- src/settings_translation_file.cpp | 2 ++ 5 files changed, 34 insertions(+), 44 deletions(-) diff --git a/builtin/settingtypes.txt b/builtin/settingtypes.txt index 395f98290..2ee8f5e2c 100644 --- a/builtin/settingtypes.txt +++ b/builtin/settingtypes.txt @@ -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. # 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. texture_path (Texture path) path diff --git a/minetest.conf.example b/minetest.conf.example index d314577cb..f163965ba 100644 --- a/minetest.conf.example +++ b/minetest.conf.example @@ -702,8 +702,14 @@ # 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. -# type: float min: 1 max: 3 -# display_gamma = 2.2 +# type: float min: 0.5 max: 3.0 +# 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. # type: path diff --git a/src/defaultsettings.cpp b/src/defaultsettings.cpp index e5b2c8da4..5bdb5e14c 100644 --- a/src/defaultsettings.cpp +++ b/src/defaultsettings.cpp @@ -168,7 +168,9 @@ void set_default_settings(Settings *settings) settings->setDefault("leaves_style", "fancy"); settings->setDefault("connected_glass", "false"); 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("shader_path", ""); settings->setDefault("video_driver", "opengl"); diff --git a/src/light.cpp b/src/light.cpp index 4a3ca5a60..b269f6233 100644 --- a/src/light.cpp +++ b/src/light.cpp @@ -20,6 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc., #include "light.h" #include #include "util/numeric.h" +#include "settings.h" #ifndef SERVER @@ -32,52 +33,27 @@ u8 light_LUT[LIGHT_MAX+1]; const u8 *light_decode_table = light_LUT; /** 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); - - // 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 - }; - - gamma = rangelim(gamma, 1.0, 3.0); - - float brightness = brightness_step; +// lighting curve derivatives + const float alpha = g_settings->getFloat("lighting_alpha"); + const float beta = g_settings->getFloat("lighting_beta"); +// lighting curve coefficients + const float a = alpha + beta - 2; + const float b = 3 - 2 * alpha - beta; + const float c = alpha; +// gamma correction + gamma = rangelim(gamma, 0.5, 3.0); 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]) + float x = i; + x /= LIGHT_MAX; + 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; - brightness += brightness_step; } light_LUT[LIGHT_MAX] = 255; } diff --git a/src/settings_translation_file.cpp b/src/settings_translation_file.cpp index d472852b8..a7fa67a74 100644 --- a/src/settings_translation_file.cpp +++ b/src/settings_translation_file.cpp @@ -245,6 +245,8 @@ fake_function() { gettext("Field of view while zooming in degrees.\nThis requires the \"zoom\" privilege on the server."); 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("Darkness sharpness"); + gettext("Lightness sharpness"); gettext("Texture path"); gettext("Path to texture directory. All textures are first searched from here."); gettext("Video driver"); -- 2.25.1