From 6e04839bd5e0189e99d72a20d7dce6d918fb4439 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=A9my=20Zurcher?= <jeremy@asynk.ch>
Date: Mon, 29 Sep 2014 23:49:27 +0200
Subject: SearchBoard: add List<Node> lineOfSight()
---
.../ch/asynk/tankontank/engine/SearchBoard.java | 106 ++++++++++++++++++++-
1 file changed, 105 insertions(+), 1 deletion(-)
diff --git a/core/src/ch/asynk/tankontank/engine/SearchBoard.java b/core/src/ch/asynk/tankontank/engine/SearchBoard.java
index 6131a69..bd1ce2b 100644
--- a/core/src/ch/asynk/tankontank/engine/SearchBoard.java
+++ b/core/src/ch/asynk/tankontank/engine/SearchBoard.java
@@ -283,5 +283,109 @@ public class SearchBoard
return result;
}
-}
+ public List<Node> lineOfSight(int x0, int y0, int x1, int y1)
+ {
+ return lineOfSight(x0, y0, x1, y1, true);
+ }
+
+ public List<Node> lineOfSight(int x0, int y0, int x1, int y1, boolean check)
+ {
+ result.clear();
+
+ // orthogonal axis
+ int ox0 = x0 - ((y0 +1) / 2);
+ int ox1 = x1 - ((y1 +1) / 2);
+
+ int dy = y1 - y0;
+ int dx = ox1 - ox0;
+
+ int xs = 1;
+ int ys = 1;
+ if (dx < 0) xs = -1;
+ if (dy < 0) ys = -1;
+ boolean sig = !(((dx < 0) && (dy >= 0)) || ((dx >= 0) && (dy < 0)));
+
+ dy = Math.abs(dy);
+ dx = Math.abs(2 * dx);
+ if ((dy % 2) == 1) {
+ if ((y0 % 2) == 0) dx += xs;
+ else {
+ dx -= xs;
+ Math.abs(dx);
+ }
+ }
+ if (dx == 0)
+ return verticalLineOfSight(x0, y0, x1, y1, check);
+
+ int dx3 = 3 * dx;
+ int dy3 = 3 * dy;
+
+ int x = x0;
+ int y = y0;
+ int e = -2 * dx;
+
+ boolean vert = (dx == 0);
+ boolean flat = (dx > (3 * dy));
+ boolean diag = (dx == (3 * dy));
+
+ int step = 0;
+ result.add(getNode(x, y));
+ while((x != x1) || (y != y1)) {
+ if (e > 0) {
+ e -= (dy3 + dx3);
+ y += ys;
+ if (!sig)
+ x -= xs;
+ } else {
+ e += dy3;
+ if ((e > -dx) || (!flat && (e == -dx))) {
+ e -= dx3;
+ y += ys;
+ if (sig)
+ x += xs;
+ } else if ((e < -dx3) || (diag && (e == -dx3))) {
+ e += dx3;
+ y -= ys;
+ if (!sig)
+ x += xs;
+ } else {
+ e += dy3;
+ x += xs;
+ }
+ }
+ result.add(getNode(x, y));
+ step += 1;
+ if (step > 20) {
+ return result;
+ }
+ }
+
+ return result;
+ }
+
+ private List<Node> verticalLineOfSight(int x0, int y0, int x1, int y1, boolean check)
+ {
+ int d = ( (y1 > y0) ? 1 : -1);
+ int x = x0;
+ int y = y0;
+
+ Tile t = null;
+ result.add(getNode(x, y));
+ while((x != x1) || (y != y1)) {
+ y += d;
+ t = board.getTile(x, y);
+ if (!t.isOffMap()) result.add(getNode(x, y));
+
+ x += d;
+ t = board.getTile(x, y);
+ if (!t.isOffMap()) result.add(getNode(x, y));
+
+ y += d;
+ t = board.getTile(x, y);
+ if (!t.isOffMap()) result.add(getNode(x, y));
+ }
+
+ return result;
+ }
+}
--
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