oss/luanti
oss/luanti
1
0
Fork 0
mirror of https://github.com/luanti-org/luanti.git synced 2025-06-27 16:36:03 +00:00
Code Wiki Activity

Light curve: Add and tune mid boost gaussian

Browse source 
Create a closer match to the light curve of 0.4.16 stable.
Results in darker shadows while maintaining the 'brightness' and light
spread.
This commit is contained in:
paramat 2017-11-18 00:22:15 +00:00 • committed by paramat
parent 76eb3f2b7a
commit 03c11a73d8
3 changed files with 34 additions and 17 deletions
Download patch file Download diff file Expand all files Collapse all files

32
src/light.cpp
View file

@ -24,38 +24,40 @@ with this program; if not, write to the Free Software Foundation, Inc.,
#ifndef SERVER
// Length of LIGHT_MAX+1 means LIGHT_MAX is the last value.
// Length of LIGHT_MAX + 1 means LIGHT_MAX is the last value.
// LIGHT_SUN is read as LIGHT_MAX from here.
u8 light_LUT[LIGHT_MAX + 1];
u8 light_LUT[LIGHT_MAX+1];
// the const ref to light_LUT is what is actually used in the code.
// The const ref to light_LUT is what is actually used in the code
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 gamma
void set_light_table(float gamma)
{
// lighting curve derivatives
// 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;
// Lighting curve coefficients
const float a = alpha + beta - 2.0f;
const float b = 3.0f - 2.0f * alpha - beta;
const float c = alpha;
// gamma correction
gamma = rangelim(gamma, 0.5, 3.0);
// Mid boost
const float d = g_settings->getFloat("lighting_boost");
const float e = g_settings->getFloat("lighting_boost_center");
const float f = g_settings->getFloat("lighting_boost_spread");
// Gamma correction
gamma = rangelim(gamma, 0.5f, 3.0f);
for (size_t i = 0; i < LIGHT_MAX; i++) {
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);
float boost = d * std::exp(-((x - e) * (x - e)) / (2.0f * f * f));
brightness = powf(brightness + boost, 1.0f / gamma);
light_LUT[i] = rangelim((u32)(255.0f * brightness), 0, 255);
if (i > 1 && light_LUT[i] <= light_LUT[i - 1])
light_LUT[i] = light_LUT[i - 1] + 1;
}
light_LUT[LIGHT_MAX] = 255;
}
#endif