mirror of
https://github.com/tanema/light_world.lua.git
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51 lines
2.2 KiB
GLSL
51 lines
2.2 KiB
GLSL
/*
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Copyright (c) 2014 Tim Anema
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light shadow, shine and normal shader all in one
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*/
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#define PI 3.1415926535897932384626433832795
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extern Image normalMap; //a canvas containing shadow data only
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extern vec3 lightPosition; //the light position on the screen(not global)
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extern vec3 lightColor; //the rgb color of the light
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extern float lightRange; //the range of the light
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extern float lightSmooth; //smoothing of the lights attenuation
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extern vec2 lightGlow; //how brightly the light bulb part glows
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extern bool invert_normal; //if the light should invert normals
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vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords) {
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float dist = distance(lightPosition, vec3(pixel_coords, 1.0));
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if(dist > lightRange) { //not in range draw in shadows
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return vec4(0.0, 0.0, 0.0, 1.0);
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}else{
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vec4 shadowColor = Texel(texture, texture_coords);
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vec4 normalColor = Texel(normalMap, texture_coords);
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vec4 pixel;
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//calculate attenuation of light based on the distance
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float att = clamp((1.0 - dist / lightRange) / lightSmooth, 0.0, 1.0);
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// if not on the normal map draw attenuated shadows
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if(normalColor.a <= 0.0) {
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//start with a dark color and add in the light color and shadow color
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pixel = vec4(0.0, 0.0, 0.0, 1.0);
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if (lightGlow.x < 1.0 && lightGlow.y > 0.0) {
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pixel.rgb = clamp(lightColor * pow(att, lightSmooth) + pow(smoothstep(lightGlow.x, 1.0, att), lightSmooth) * lightGlow.y, 0.0, 1.0);
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} else {
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pixel.rgb = lightColor * pow(att, lightSmooth);
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}
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} else {
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vec3 normal = normalize(vec3(normalColor.r,invert_normal ? 1 - normalColor.g : normalColor.g, normalColor.b) * 2.0 - 1.0);
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//on the normal map, draw normal shadows
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vec3 dir = vec3((lightPosition.xy - pixel_coords.xy) / love_ScreenSize.xy, lightPosition.z);
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dir.x *= love_ScreenSize.x / love_ScreenSize.y;
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vec3 diff = lightColor * max(dot(normalize(normal), normalize(dir)), 0.0);
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//return the light that is effected by the normal and attenuation
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pixel = vec4(diff * att, 1.0);
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}
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if(shadowColor.a > 0.0) {
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pixel.rgb = pixel.rgb * shadowColor.rgb;
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}
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return pixel;
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}
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}
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