From 2ba8d90815a621d263cd198fe2da8579e46e732d Mon Sep 17 00:00:00 2001
From: Julien Dessaux
Date: Fri, 17 Sep 2021 00:45:07 +0200
Subject: Added function to calculate a next pointer step on the field

---
 pkg/field/step.go | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 pkg/field/step.go

(limited to 'pkg/field/step.go')

diff --git a/pkg/field/step.go b/pkg/field/step.go
new file mode 100644
index 0000000..50147d2
--- /dev/null
+++ b/pkg/field/step.go
@@ -0,0 +1,20 @@
+package field
+
+func (f Field) Step(x, y, dx, dy int) (int, int) {
+	x2, y2 := x+dx, y+dy
+	if f.IsIn(x2, y2) {
+		return x2, y2
+	}
+	// We are stepping outside, we need to wrap the Lahey-space
+	for {
+		x2, y2 := x-dx, y-dy
+		if !f.IsIn(x2, y2) {
+			return x, y
+		}
+		x, y = x2, y2
+	}
+}
+
+func (f Field) IsIn(x, y int) bool {
+	return x >= f.x && x < f.x+f.lx && y >= f.y && y < f.y+f.ly
+}
-- 
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