mirror of
https://github.com/tanema/light_world.lua.git
synced 2024-12-24 20:24:19 +00:00
81 lines
3.5 KiB
GLSL
81 lines
3.5 KiB
GLSL
/*
|
|
Copyright (c) 2014 Tim Anema
|
|
light shadow, shine and normal shader all in one
|
|
*/
|
|
#define PI 3.1415926535897932384626433832795
|
|
|
|
extern Image shadowMap; //a canvas containing shadow data only
|
|
extern vec3 lightPosition; //the light position on the screen(not global)
|
|
extern vec3 lightColor; //the rgb color of the light
|
|
extern float lightRange; //the range of the light
|
|
extern float lightSmooth; //smoothing of the lights attenuation
|
|
extern vec2 lightGlow; //how brightly the light bulb part glows
|
|
extern float lightAngle; //if set, the light becomes directional to a slice lightAngle degrees wide
|
|
extern float lightDirection; //which direction to shine the light in if directional in degrees
|
|
extern bool invert_normal; //if the light should invert normals
|
|
|
|
//calculate if a pixel is within the light slice
|
|
bool not_in_slice(vec2 pixel_coords){
|
|
float angle = atan(lightPosition.x - pixel_coords.x, pixel_coords.y - lightPosition.y) + PI;
|
|
bool pastRightSide = angle < mod(lightDirection + lightAngle, PI * 2);
|
|
bool pastLeftSide = angle > mod(lightDirection - lightAngle, PI * 2);
|
|
bool lightUp = lightDirection - lightAngle > 0 && lightDirection + lightAngle < PI * 2;
|
|
return (lightUp && (pastRightSide && pastLeftSide)) || (!lightUp && (pastRightSide || pastLeftSide));
|
|
}
|
|
|
|
vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords) {
|
|
vec4 pixelColor = Texel(texture, texture_coords);
|
|
vec4 shadowColor = Texel(shadowMap, texture_coords);
|
|
|
|
float dist = distance(lightPosition, vec3(pixel_coords, 1.0));
|
|
//if the pixel is within this lights range
|
|
if(dist > lightRange) {
|
|
//not in range draw in shadows
|
|
return vec4(0.0, 0.0, 0.0, 1.0);
|
|
}else{
|
|
//if the light is a slice and the pixel is not inside
|
|
if(lightAngle > 0.0 && not_in_slice(pixel_coords)) {
|
|
return vec4(0.0, 0.0, 0.0, 1.0);
|
|
}
|
|
|
|
vec3 normal;
|
|
if(pixelColor.a > 0.0) {
|
|
//if on the normal map ie there is normal map data
|
|
//so get the normal data
|
|
if(invert_normal) {
|
|
normal = normalize(vec3(pixelColor.r, 1 - pixelColor.g, pixelColor.b) * 2.0 - 1.0);
|
|
} else {
|
|
normal = normalize(pixelColor.rgb * 2.0 - 1.0);
|
|
}
|
|
} else {
|
|
// not on the normal map so it is the floor with a normal point strait up
|
|
normal = vec3(0.0, 0.0, 1.0);
|
|
}
|
|
//calculater attenuation of light based on the distance
|
|
float att = clamp((1.0 - dist / lightRange) / lightSmooth, 0.0, 1.0);
|
|
// if not on the normal map draw attenuated shadows
|
|
if(pixelColor.a == 0.0) {
|
|
//start with a dark color and add in the light color and shadow color
|
|
vec4 pixel = vec4(0.0, 0.0, 0.0, 1.0);
|
|
if (lightGlow.x < 1.0 && lightGlow.y > 0.0) {
|
|
pixel.rgb = clamp(lightColor * pow(att, lightSmooth) + pow(smoothstep(lightGlow.x, 1.0, att), lightSmooth) * lightGlow.y, 0.0, 1.0);
|
|
} else {
|
|
pixel.rgb = lightColor * pow(att, lightSmooth);
|
|
}
|
|
//If on the shadow map add the shadow color
|
|
if(shadowColor.a > 0.0) {
|
|
pixel.rgb = pixel.rgb * shadowColor.rgb;
|
|
}
|
|
return pixel;
|
|
} else {
|
|
//on the normal map, draw normal shadows
|
|
vec3 dir = vec3((lightPosition.xy - pixel_coords.xy) / love_ScreenSize.xy, lightPosition.z);
|
|
dir.x *= love_ScreenSize.x / love_ScreenSize.y;
|
|
vec3 diff = lightColor * max(dot(normalize(normal), normalize(dir)), 0.0);
|
|
//return the light that is effected by the normal and attenuation
|
|
return vec4(diff * att, 1.0);
|
|
}
|
|
}
|
|
}
|
|
|