From 6e958e4ff611dd7ade1049f9c66dc39e5f8bf3a7 Mon Sep 17 00:00:00 2001
From: "Sascha L. Teichmann" <sascha.teichmann@intevation.de>
Date: Sun, 7 Sep 2014 00:18:28 +0200
Subject: [PATCH] Be more clever in testing BigMin. This shows that the
 interleaving code has shift all values to be positive, so it's broken atm.
 :-/

---
 common/coords_test.go | 50 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 38 insertions(+), 12 deletions(-)

diff --git a/common/coords_test.go b/common/coords_test.go
index 556d279..e34f640 100644
--- a/common/coords_test.go
+++ b/common/coords_test.go
@@ -153,9 +153,36 @@ func TestTransforms(t *testing.T) {
 	})
 }
 
+func outsiders(zmin, zmax int64) chan int64 {
+
+	outs := make(chan int64)
+
+	go func() {
+		defer close(outs)
+		c1 := InterleavedToCoord(zmin)
+		c2 := InterleavedToCoord(zmax)
+		cub := Cuboid{P1: c1, P2: c2}
+		var c Coord
+		for c.X = c1.X; c.X <= c2.X; c.X++ {
+			for c.Y = c1.Y; c.Y <= c2.Y; c.Y++ {
+				for c.Z = c1.Z; c.Z <= c2.Z; c.Z++ {
+					code := CoordToInterleaved(c) + 1
+					if code < zmin || code > zmax {
+						continue
+					}
+					c3 := InterleavedToCoord(code)
+					if !cub.Contains(c3) {
+						outs <- code
+					}
+				}
+			}
+		}
+	}()
+	return outs
+}
+
 func TestBigMin(t *testing.T) {
-	const tries = 1
-	errors, success := 0, 0
+	const tries = 10
 	for i := 0; i < tries; i++ {
 		x1 := rand.Intn(4000) - 2000
 		y1 := rand.Intn(4000) - 2000
@@ -169,16 +196,12 @@ func TestBigMin(t *testing.T) {
 
 		c1 := Coord{X: int16(x1), Y: int16(y1), Z: int16(z1)}
 		c2 := Coord{X: int16(x2), Y: int16(y2), Z: int16(z2)}
-		cub := Cuboid{P1: c1, P2: c2}
-		//fmt.Printf("Cuboid: %s\n", cub)
 
 		zmin := CoordToInterleaved(c1)
 		zmax := CoordToInterleaved(c2)
 
-		for zcode := zmin + 1; zcode < zmax; zcode++ {
-			if cub.Contains(InterleavedToCoord(zcode)) {
-				continue
-			}
+		errors, success := 0, 0
+		for zcode := range outsiders(zmin, zmax) {
 			nbm := NaiveBigMin(zmin, zmax, zcode)
 			cbm := BigMin(zmin, zmax, zcode)
 			//fmt.Printf("nbm: %b\n", nbm)
@@ -189,9 +212,12 @@ func TestBigMin(t *testing.T) {
 				success++
 			}
 		}
-	}
-	if errors > 0 {
-		t.Errorf("BigMin: %d errors out of %d (%f)\n",
-			errors, errors+success, float64(errors)/float64(errors+success))
+		if errors > 0 {
+			cub := Cuboid{P1: c1, P2: c2}
+			t.Errorf("BigMin: %s %d errors out of %d (%f)\n",
+				cub,
+				errors, errors+success,
+				float64(errors)/float64(errors+success))
+		}
 	}
 }