class RectangleLight

extends Light › LightEvaluation › Shader

@:directlyUsed@:src({ @param var lightDir:Vec3; @param var lightPos:Vec3; @param var p0:Vec3; @param var p1:Vec3; @param var p2:Vec3; @param var p3:Vec3; @param var width:Float; @param var height:Float; @param var horizontalAngle:Float; @param var verticalAngle:Float; @param var verticalFallOff:Float; @param var horizontalFallOff:Float; @param var range:Float; @param var invLightRange4:Float; var view:Vec3; var normal:Vec3; function getIntersectionPoint(rayOrigin:Vec3, rayDirection:Vec3, p0:Vec3, p1:Vec3, p2:Vec3):Vec3 { var planeNormal = cross(p1 - p0, p2 - p1).normalize(); return tracePlane(rayOrigin, rayDirection, p0, planeNormal); }; function closestPointOnSegment(a:Vec3, b:Vec3, c:Vec3):Vec3 { var ab = b - a; var t = dot(c - a, ab) / dot(ab, ab); return a + saturate(t) * ab; }; function tracePlane(rayOrigin:Vec3, rayDirection:Vec3, planeOrigin:Vec3, planeNormal:Vec3):Vec3 { var distanceToPlane = dot(planeNormal, (planeOrigin - rayOrigin) / dot(planeNormal, rayDirection)); return rayOrigin + rayDirection * distanceToPlane; }; function traceTriangle(rayOrigin:Vec3, rayDirection:Vec3, p0:Vec3, p1:Vec3, p2:Vec3):Bool { var p = getIntersectionPoint(rayOrigin, rayDirection, p0, p1, p2); var n1 = cross(p1 - p0, p - p1).normalize(); var n2 = cross(p2 - p1, p - p2).normalize(); var n3 = cross(p0 - p2, p - p0).normalize(); var d0 = dot(n1, n2); var d1 = dot(n2, n3); return (d0 > 0.1) && (d1 > 0.1); }; function getClosestPointOnRectangle(rayOrigin:Vec3, rayDirection:Vec3, p0:Vec3, p1:Vec3, p2:Vec3, p3:Vec3):Vec3 { var int = getIntersectionPoint(rayOrigin, rayDirection, p0, p1, p3); var closestPoint = vec3(0, 0, 0); if (traceTriangle(rayOrigin, rayDirection, p0, p3, p2)) { closestPoint = getIntersectionPoint(rayOrigin, rayDirection, p0, p3, p2); } else if (traceTriangle(rayOrigin, rayDirection, p0, p1, p3)) { closestPoint = getIntersectionPoint(rayOrigin, rayDirection, p0, p1, p3); } else { var p = int - lightPos; var right = (p1 - p0).normalize(); var up = (p2 - p0).normalize(); var intRight = clamp(dot(p, right), -width * 0.5, width * 0.5) * right; var intUp = clamp(dot(p, up), -height * 0.5, height * 0.5) * up; closestPoint = lightPos + intRight + intUp; }; return closestPoint; }; function fragment() { pbrOcclusionFactor = occlusionFactor; var right = (p1 - p0).normalize(); var up = (p2 - p0).normalize(); var invLightDir = -lightDir; var closestPointDiffuse = getClosestPointOnRectangle(transformedPosition, normal, p0, p1, p2, p3); var delta = closestPointDiffuse - transformedPosition; pbrLightDirection = normalize(delta); var xyEpsilon = horizontalFallOff - horizontalAngle; var xyLightDir = invLightDir - dot(invLightDir, up) * up; var xyDelta = delta - dot(delta, up) * up; var xyTheta = dot(xyDelta.normalize(), xyLightDir.normalize()); var horizontalFalloff = saturate((xyTheta - horizontalAngle) / xyEpsilon); var xzEpsilon = verticalFallOff - verticalAngle; var xzLightDir = invLightDir - dot(invLightDir, right) * right; var xzDelta = delta - dot(delta, right) * right; var xzTheta = dot(xzDelta.normalize(), xzLightDir.normalize()); var verticalFalloff = saturate((xzTheta - verticalAngle) / xzEpsilon); var falloff = verticalFalloff * horizontalFalloff * pointLightIntensity(delta, range, invLightRange4); pbrLightColor = falloff * lightColor; var r = reflect(-view, normal); var closestPointSpec = getClosestPointOnRectangle(transformedPosition, r, p0, p1, p2, p3); var delta = normalize(closestPointSpec - transformedPosition); pbrSpecularLightDirection = delta; }; })@:build(hxsl.Macros.buildShader())@:autoBuild(hxsl.Macros.buildShader())