Address Issue #2115, Aztec grid (#2116)

1 files changed, 30 insertions, 0 deletions

diff --git a/core/src/test/java/com/google/zxing/aztec/encoder/EncoderTest.java b/core/src/test/java/com/google/zxing/aztec/encoder/EncoderTest.java
index 280018d6d..61a74d745 100644
--- a/core/src/test/java/com/google/zxing/aztec/encoder/EncoderTest.java
+++ b/core/src/test/java/com/google/zxing/aztec/encoder/EncoderTest.java
@@ -477,6 +477,36 @@ public final class EncoderTest extends Assert {
     assertEquals(4, aztecCode.getLayers());
   }
 
+  @Test
+  public void testEncodeReferenceGridComplete() {
+    // Regression test for https://github.com/zxing/zxing/issues/2115
+    // A 12-layer full Aztec symbol is 67x67 modules and, per ISO/IEC 24778, must carry a
+    // complete reference grid with lines every 16 modules. Previously the outermost grid
+    // lines (one module in from each edge) were dropped because the drawing loop stopped one
+    // iteration short whenever (baseMatrixSize / 2 - 1) was an exact multiple of 15.
+    AztecCode aztec = Encoder.encode("Hello world", Encoder.DEFAULT_EC_PERCENT, 12);
+    assertFalse("Expected a full (non-compact) symbol", aztec.isCompact());
+    assertEquals("Unexpected nr. of layers", 12, aztec.getLayers());
+    BitMatrix matrix = aztec.getMatrix();
+    int size = matrix.getWidth();
+    assertEquals("Unexpected symbol size", 67, size);
+
+    // The outermost reference grid lines lie at coordinate 1 and size - 2. Along a grid line
+    // the encoder draws dark modules on every other position (matching the parity of the
+    // symbol centre); the interleaving positions stay light. A grid line is an exclusive
+    // reference column/row, so no data modules land on it.
+    int parity = (size / 2) & 1;
+    for (int coord : new int[] {1, size - 2}) {
+      for (int k = 0; k < size; k++) {
+        boolean expectedDark = (k & 1) == parity;
+        assertEquals("reference grid column x=" + coord + ", y=" + k,
+            expectedDark, matrix.get(coord, k));
+        assertEquals("reference grid row y=" + coord + ", x=" + k,
+            expectedDark, matrix.get(k, coord));
+      }
+    }
+  }
+
   // Helper routines
 
   private static void testEncode(String data, boolean compact, int layers, String expected) {