Load vanilla feature stages and place ores

internal/world/placed_features_test.go

@@ -0,0 +1,45 @@
+package world
+
+import "testing"
+
+func TestPlacedOresUseStoneAndDeepslateTargets(t *testing.T) {
+	gen := NewVanillaGenerator(12345)
+	want := map[uint16]string{
+		131:  "iron ore",
+		132:  "deepslate iron ore",
+		5307: "diamond ore",
+		5308: "deepslate diamond ore",
+	}
+	counts := make(map[uint16]int)
+	for cx := int32(-8); cx <= 8; cx += 4 {
+		for cz := int32(-8); cz <= 8; cz += 4 {
+			chunk := gen(cx, cz)
+			for y := MinY; y < 128; y++ {
+				for x := 0; x < 16; x++ {
+					for z := 0; z < 16; z++ {
+						counts[chunk.GetBlock(x, y, z)]++
+					}
+				}
+			}
+		}
+	}
+	for state, name := range want {
+		if counts[state] == 0 {
+			t.Errorf("no %s generated by placed ore features", name)
+		}
+	}
+}
+
+func TestPlacedOresAreDeterministic(t *testing.T) {
+	gen := NewVanillaGenerator(4242)
+	a, b := gen(3, -2), gen(3, -2)
+	for y := MinY; y < MinY+WorldHeight; y++ {
+		for x := 0; x < 16; x++ {
+			for z := 0; z < 16; z++ {
+				if got, want := a.GetBlock(x, y, z), b.GetBlock(x, y, z); got != want {
+					t.Fatalf("block (%d,%d,%d): first %d second %d", x, y, z, got, want)
+				}
+			}
+		}
+	}
+}