Add platform/transforms pretty printers for logging and testing

third_party/WebKit/Source/platform/transforms/TransformationMatrix.cpp

 /*
  * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2009 Torch Mobile, Inc.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 19 matching lines @@
 #include "platform/geometry/FloatBox.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/transforms/AffineTransform.h"
 #include "platform/transforms/Rotation.h"
 
 #include "wtf/Assertions.h"
 #include "wtf/MathExtras.h"
+#include "wtf/text/WTFString.h"
 
 #include <cmath>
 #include <cstdlib>
 
 #if CPU(X86_64)
 #include <emmintrin.h>
 #endif
 
 namespace blink {
 
@@ skipping 1541 matching lines @@
     ret.setDouble(2, 1, matrix.m23());
     ret.setDouble(2, 2, matrix.m33());
     ret.setDouble(2, 3, matrix.m43());
     ret.setDouble(3, 0, matrix.m14());
     ret.setDouble(3, 1, matrix.m24());
     ret.setDouble(3, 2, matrix.m34());
     ret.setDouble(3, 3, matrix.m44());
     return ret;
 }
 
+String TransformationMatrix::toString(bool asMatrix) const
+{
+    if (asMatrix) {
+        // Return as a matrix in row-major order.
+        return String::format("[%lg,%lg,%lg,%lg,\n%lg,%lg,%lg,%lg,\n%lg,%lg,%lg,%lg,\n%lg,%lg,%lg,%lg]",
+            m11(), m21(), m31(), m41(),
+            m12(), m22(), m32(), m42(),
+            m13(), m23(), m33(), m43(),
+            m14(), m24(), m34(), m44());
+    }
+
+    TransformationMatrix::DecomposedType decomposition;
+    if (!decompose(decomposition))
+        return "degenerate";

[jbroman, 2016/08/21 16:21:07]

nit: maybe the matrix representation above would be more helpful in this case.
Or possibly even both:

return toString(true) + " (degenerate)";

[pdr., 2016/08/22 17:27:35]

Good idea, done.

+
+    if (isIdentityOrTranslation()) {
+        if (decomposition.translateX == 0 && decomposition.translateY == 0 && decomposition.translateZ == 0)
+            return "identity";
+        return String::format("translation(%lg,%lg,%lg)", decomposition.translateX, decomposition.translateY, decomposition.translateZ);
+    }
+
+    return String::format("translation(%lg,%lg,%lg), scale(%lg,%lg,%lg), skew(%lg,%lg,%lg), quaternion(%lg,%lg,%lg,%lg), perspective(%lg,%lg,%lg,%lg)",
+        decomposition.translateX, decomposition.translateY, decomposition.translateZ,
+        decomposition.scaleX, decomposition.scaleY, decomposition.scaleZ,
+        decomposition.skewXY, decomposition.skewXZ, decomposition.skewYZ,
+        decomposition.quaternionX, decomposition.quaternionY, decomposition.quaternionZ, decomposition.quaternionW,
+        decomposition.perspectiveX, decomposition.perspectiveY, decomposition.perspectiveZ, decomposition.perspectiveW);
+}
+
 } // namespace blink