From 81cbec5348a444a1d9e394b8c2ae668ac85063a8 Mon Sep 17 00:00:00 2001
From: punchready <marlin.gorsleben@gmail.com>
Date: Mon, 7 Jun 2021 00:27:58 +0200
Subject: [PATCH] fix: mind stone creates an infinite ray

---
 .../gamelibrary/gamelogic/GameLogic.java      | 66 ++++++++++++++++++-
 1 file changed, 64 insertions(+), 2 deletions(-)

diff --git a/src/main/java/uulm/teamname/marvelous/gamelibrary/gamelogic/GameLogic.java b/src/main/java/uulm/teamname/marvelous/gamelibrary/gamelogic/GameLogic.java
index e982da6..f513ba9 100644
--- a/src/main/java/uulm/teamname/marvelous/gamelibrary/gamelogic/GameLogic.java
+++ b/src/main/java/uulm/teamname/marvelous/gamelibrary/gamelogic/GameLogic.java
@@ -176,6 +176,10 @@ public class GameLogic {
                                 throw new InvalidRequestException("Invalid soul stone target (same as origin)");
                             }
 
+                            if(data.originField.distanceChebyshev(data.targetField) != 1) {
+                                throw new InvalidRequestException("Invalid soul stone target distance");
+                            }
+
                             if(target.isAlive()) {
                                 throw new InvalidRequestException("Invalid soul stone target (already alive)");
                             }
@@ -403,8 +407,7 @@ public class GameLogic {
                         }
                         case MindStone -> {
                             EntityType target = data.originEntity.type == EntityType.P1 ? EntityType.P2 : EntityType.P1;
-                            //todo: extend to infinity
-                            for(IntVector2 pos: rasterize(data.originField, data.targetField, false, true)) {
+                            for(IntVector2 pos: rasterizeInfinity(data.originField, data.targetField, state.mapSize, false)) {
                                 for(Entity entity: state.entities.findByPosition(pos)) {
                                     if(entity.id.isSameType(target)) {
                                         result.add(new EventBuilder(EventType.TakenDamageEvent)
@@ -1292,6 +1295,62 @@ public class GameLogic {
         return result;
     }
 
+    /**
+     * Computes all fields which intersect the ray between the center points of the given two fields extending past the second one.
+     * @param size The size of the map
+     * @param includeA Whether to include point a in the result
+     * @return The list of intersecting positions
+     */
+    public static ArrayList<IntVector2> rasterizeInfinity(IntVector2 a, IntVector2 b, IntVector2 size, boolean includeA) {
+        ArrayList<IntVector2> result = new ArrayList<>();
+
+        if(includeA) {
+            result.add(a);
+        }
+
+        int x1 = a.getX();
+        int y1 = a.getY();
+        int x2 = b.getX();
+        int y2 = b.getY();
+
+        Line2D line = new Line2D.Float(x1 + 0.5f, y1 + 0.5f, x2 + 0.5f, y2 + 0.5f);
+        double l = line.getP1().distance(line.getP2());
+
+        for(int i = 0; i < size.getX(); i++) {
+            for(int j = 0; j < size.getY(); j++) {
+                HashSet<Point2D.Float> intersections = new HashSet<>();
+                for(Line2D.Float part: getWireframe(new Rectangle.Float(i, j, 1, 1))) {
+                    Point2D.Float intersection = calculateInterceptionPoint(line.getP1(), line.getP2(), part.getP1(), part.getP2());
+                    if(intersection != null) {
+                        double dPa = intersection.distance(part.getP1());
+                        double dPb = intersection.distance(part.getP2());
+                        // sum of distances to points of the rectangle part == 1 => point lies on line segment
+                        // -----a---x----b-----
+                        // --x--a--------b-----
+                        if(dPa + dPb == 1) {
+                            double da = intersection.distance(line.getP1());
+                            double db = intersection.distance(line.getP2());
+                            // distance to a greater than to b => point lies on the ray from a over b
+                            // sum of distances analog to rectangle part => point lies between a and b
+                            // 0.000000005 because computers suck (missing precision)
+                            if(da > db || da + db <= l + 0.000000005) {
+                                intersections.add(intersection);
+                                if(intersections.size() > 1) {
+                                    break;
+                                }
+                            }
+                        }
+                    }
+                }
+                if(intersections.size() > 1) {
+                    result.add(new IntVector2(i, j));
+                }
+            }
+        }
+
+        return result;
+    }
+
     //https://rosettacode.org/wiki/Find_the_intersection_of_two_lines#Java
     public static Point2D.Float calculateInterceptionPoint(Point2D s1, Point2D s2, Point2D d1, Point2D d2) {
         double a1 = s2.getY() - s1.getY();
@@ -1303,6 +1362,9 @@ public class GameLogic {
         double c2 = a2 * d1.getX() + b2 * d1.getY();
 
         double delta = a1 * b2 - a2 * b1;
+        if(delta == 0) {
+            return null;
+        }
         return new Point2D.Float((float) ((b2 * c1 - b1 * c2) / delta), (float) ((a1 * c2 - a2 * c1) / delta));
     }