net.minestom.server.collision.RayUtils Maven / Gradle / Ivy
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1.20.4 Lightweight Minecraft server
package net.minestom.server.collision;
import net.minestom.server.coordinate.Point;
import net.minestom.server.coordinate.Pos;
import net.minestom.server.coordinate.Vec;
final class RayUtils {
/**
* Check if a bounding box intersects a ray
*
* @param rayStart Ray start position
* @param rayDirection Ray to check
* @param collidableStatic Bounding box
* @param finalResult
* @return true if an intersection between the ray and the bounding box was found
*/
public static boolean BoundingBoxIntersectionCheck(BoundingBox moving, Point rayStart, Point rayDirection, BoundingBox collidableStatic, Point staticCollidableOffset, SweepResult finalResult) {
Point bbCentre = new Vec(moving.minX() + moving.width() / 2, moving.minY() + moving.height() / 2, moving.minZ() + moving.depth() / 2);
Point rayCentre = rayStart.add(bbCentre);
// Translate bounding box
Vec bbOffMin = new Vec(collidableStatic.minX() - rayCentre.x() + staticCollidableOffset.x() - moving.width() / 2, collidableStatic.minY() - rayCentre.y() + staticCollidableOffset.y() - moving.height() / 2, collidableStatic.minZ() - rayCentre.z() + staticCollidableOffset.z() - moving.depth() / 2);
Vec bbOffMax = new Vec(collidableStatic.maxX() - rayCentre.x() + staticCollidableOffset.x() + moving.width() / 2, collidableStatic.maxY() - rayCentre.y() + staticCollidableOffset.y() + moving.height() / 2, collidableStatic.maxZ() - rayCentre.z() + staticCollidableOffset.z() + moving.depth() / 2);
// This check is done in 2d. it can be visualised as a rectangle (the face we are checking), and a point.
// If the point is within the rectangle, we know the vector intersects the face.
double signumRayX = Math.signum(rayDirection.x());
double signumRayY = Math.signum(rayDirection.y());
double signumRayZ = Math.signum(rayDirection.z());
boolean isHit = false;
double percentage = Double.MAX_VALUE;
int collisionFace = -1;
// Intersect X
// Left side of bounding box
if (rayDirection.x() > 0) {
double xFac = epsilon(bbOffMin.x() / rayDirection.x());
if (xFac < percentage) {
double yix = rayDirection.y() * xFac + rayCentre.y();
double zix = rayDirection.z() * xFac + rayCentre.z();
// Check if ray passes through y/z plane
if (((yix - rayCentre.y()) * signumRayY) >= 0
&& ((zix - rayCentre.z()) * signumRayZ) >= 0
&& yix >= collidableStatic.minY() + staticCollidableOffset.y() - moving.height() / 2
&& yix <= collidableStatic.maxY() + staticCollidableOffset.y() + moving.height() / 2
&& zix >= collidableStatic.minZ() + staticCollidableOffset.z() - moving.depth() / 2
&& zix <= collidableStatic.maxZ() + staticCollidableOffset.z() + moving.depth() / 2) {
isHit = true;
percentage = xFac;
collisionFace = 0;
}
}
}
// Right side of bounding box
if (rayDirection.x() < 0) {
double xFac = epsilon(bbOffMax.x() / rayDirection.x());
if (xFac < percentage) {
double yix = rayDirection.y() * xFac + rayCentre.y();
double zix = rayDirection.z() * xFac + rayCentre.z();
if (((yix - rayCentre.y()) * signumRayY) >= 0
&& ((zix - rayCentre.z()) * signumRayZ) >= 0
&& yix >= collidableStatic.minY() + staticCollidableOffset.y() - moving.height() / 2
&& yix <= collidableStatic.maxY() + staticCollidableOffset.y() + moving.height() / 2
&& zix >= collidableStatic.minZ() + staticCollidableOffset.z() - moving.depth() / 2
&& zix <= collidableStatic.maxZ() + staticCollidableOffset.z() + moving.depth() / 2) {
isHit = true;
percentage = xFac;
collisionFace = 0;
}
}
}
// Intersect Z
if (rayDirection.z() > 0) {
double zFac = epsilon(bbOffMin.z() / rayDirection.z());
if (zFac < percentage) {
double xiz = rayDirection.x() * zFac + rayCentre.x();
double yiz = rayDirection.y() * zFac + rayCentre.y();
if (((yiz - rayCentre.y()) * signumRayY) >= 0
&& ((xiz - rayCentre.x()) * signumRayX) >= 0
&& xiz >= collidableStatic.minX() + staticCollidableOffset.x() - moving.width() / 2
&& xiz <= collidableStatic.maxX() + staticCollidableOffset.x() + moving.width() / 2
&& yiz >= collidableStatic.minY() + staticCollidableOffset.y() - moving.height() / 2
&& yiz <= collidableStatic.maxY() + staticCollidableOffset.y() + moving.height() / 2) {
isHit = true;
percentage = zFac;
collisionFace = 1;
}
}
}
if (rayDirection.z() < 0) {
double zFac = epsilon(bbOffMax.z() / rayDirection.z());
if (zFac < percentage) {
double xiz = rayDirection.x() * zFac + rayCentre.x();
double yiz = rayDirection.y() * zFac + rayCentre.y();
if (((yiz - rayCentre.y()) * signumRayY) >= 0
&& ((xiz - rayCentre.x()) * signumRayX) >= 0
&& xiz >= collidableStatic.minX() + staticCollidableOffset.x() - moving.width() / 2
&& xiz <= collidableStatic.maxX() + staticCollidableOffset.x() + moving.width() / 2
&& yiz >= collidableStatic.minY() + staticCollidableOffset.y() - moving.height() / 2
&& yiz <= collidableStatic.maxY() + staticCollidableOffset.y() + moving.height() / 2) {
isHit = true;
percentage = zFac;
collisionFace = 1;
}
}
}
// Intersect Y
if (rayDirection.y() > 0) {
double yFac = epsilon(bbOffMin.y() / rayDirection.y());
if (yFac < percentage) {
double xiy = rayDirection.x() * yFac + rayCentre.x();
double ziy = rayDirection.z() * yFac + rayCentre.z();
if (((ziy - rayCentre.z()) * signumRayZ) >= 0
&& ((xiy - rayCentre.x()) * signumRayX) >= 0
&& xiy >= collidableStatic.minX() + staticCollidableOffset.x() - moving.width() / 2
&& xiy <= collidableStatic.maxX() + staticCollidableOffset.x() + moving.width() / 2
&& ziy >= collidableStatic.minZ() + staticCollidableOffset.z() - moving.depth() / 2
&& ziy <= collidableStatic.maxZ() + staticCollidableOffset.z() + moving.depth() / 2) {
isHit = true;
percentage = yFac;
collisionFace = 2;
}
}
}
if (rayDirection.y() < 0) {
double yFac = epsilon(bbOffMax.y() / rayDirection.y());
if (yFac < percentage) {
double xiy = rayDirection.x() * yFac + rayCentre.x();
double ziy = rayDirection.z() * yFac + rayCentre.z();
if (((ziy - rayCentre.z()) * signumRayZ) >= 0
&& ((xiy - rayCentre.x()) * signumRayX) >= 0
&& xiy >= collidableStatic.minX() + staticCollidableOffset.x() - moving.width() / 2
&& xiy <= collidableStatic.maxX() + staticCollidableOffset.x() + moving.width() / 2
&& ziy >= collidableStatic.minZ() + staticCollidableOffset.z() - moving.depth() / 2
&& ziy <= collidableStatic.maxZ() + staticCollidableOffset.z() + moving.depth() / 2) {
isHit = true;
percentage = yFac;
collisionFace = 2;
}
}
}
percentage *= 0.99999;
if (isHit && percentage >= 0 && percentage <= finalResult.res) {
finalResult.res = percentage;
finalResult.normalX = 0;
finalResult.normalY = 0;
finalResult.normalZ = 0;
if (collisionFace == 0) finalResult.normalX = 1;
if (collisionFace == 1) finalResult.normalZ = 1;
if (collisionFace == 2) finalResult.normalY = 1;
return true;
}
return false;
}
private static double epsilon(double value) {
return Math.abs(value) < Vec.EPSILON ? 0 : value;
}
public static boolean BoundingBoxRayIntersectionCheck(Vec start, Vec direction, BoundingBox boundingBox, Pos position) {
return BoundingBoxIntersectionCheck(BoundingBox.ZERO, start, direction, boundingBox, position, new SweepResult(Double.MAX_VALUE, 0, 0, 0, null, 0, 0, 0, 0, 0, 0));
}
}