diff --git a/res/shaders/simple.frag b/res/shaders/simple.frag index 8c95e34..5272811 100644 --- a/res/shaders/simple.frag +++ b/res/shaders/simple.frag @@ -36,6 +36,9 @@ const float la = 0.1, lb = 0.01, lc = 0.001; const float ballRadius = 1.0; +const float hardRadius = ballRadius; +const float softRadius = ballRadius * 2.0; + void main() { vec3 norm = normalize(normal); @@ -45,12 +48,10 @@ void main() vec3 result = ambient; for (int i = 0; i < 3; i++) { - vec3 lightVector = lights[i].position - worldPositions; - vec3 lightDir = normalize(lightVector); + vec3 fragToLight = lights[i].position - worldPositions; + vec3 lightDir = normalize(fragToLight); - vec3 fragToBall = lights[i].position - ballPosition; - - float d = length(lightVector); + float d = length(fragToLight); float attenuation = 1.0 / (la + d * lb + d * d * lc); float diff = max(dot(norm, lightDir), 0.0); @@ -60,15 +61,23 @@ void main() float spec = pow(max(dot(norm, halfwayDir), 0.0), shininess); vec3 specular = specularStrength * spec * lights[i].color; - // the ball's light is put inside it, thus it would cast a shadow all over the scene. - // to counter-act this, we can simply exclude it. i should instead move the light. - // either way, it makes for a cool light (shadow?) show. - bool shadow = false; - if (i != 2) { - shadow = length(lightVector) > length(fragToBall) && dot(lightVector, fragToBall) < 0.0; + // shadow stuff + vec3 fragToBall = ballPosition - worldPositions; + float projDist = dot(fragToBall, lightDir); + float r = length(fragToBall - projDist * lightDir); + bool inShadowRegion = (projDist > 0.0) && (projDist < d); + float shadowFactor = 1.0; + + // exclude ball light to avoid casting shadows everywhere + if (i != 2 && inShadowRegion) { + if (r <= hardRadius) { + shadowFactor = 0.0; + } else if (r < softRadius) { + shadowFactor = (r - hardRadius) / (softRadius - hardRadius); + } } - if (!shadow) - result += attenuation * (diffuse + specular) * objectColor; + + result += shadowFactor * attenuation * (diffuse + specular) * objectColor; } color = vec4(result + dither(textureCoordinates), 1.0);