Add platform/transforms pretty printers for logging and testing

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

 /*
  * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
  *               2010 Dirk Schulze <krit@webkit.org>
  * 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 14 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "platform/transforms/AffineTransform.h"
 
 #include "platform/FloatConversion.h"
 #include "platform/geometry/FloatQuad.h"
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/IntRect.h"
 #include "wtf/MathExtras.h"
+#include "wtf/text/WTFString.h"
 
 namespace blink {
 
 AffineTransform::AffineTransform()
 {
     const Transform identity = IDENTITY_TRANSFORM;
     setMatrix(identity);
 }
 
 AffineTransform::AffineTransform(double a, double b, double c, double d, double e, double f)
@@ skipping 348 matching lines @@
     this->setA(decomp.remainderA);
     this->setB(decomp.remainderB);
     this->setC(decomp.remainderC);
     this->setD(decomp.remainderD);
     this->setE(decomp.translateX);
     this->setF(decomp.translateY);
     this->rotateRadians(decomp.angle);
     this->scale(decomp.scaleX, decomp.scaleY);
 }
 
+String AffineTransform::toString(bool asMatrix) const
+{
+    if (asMatrix) {
+        // Return as a matrix in row-major order.
+        return String::format("[%lg,%lg,%lg,\n%lg,%lg,%lg]",
+            a(), c(), e(),
+            b(), d(), f());
+    }
+
+    if (isIdentity())
+        return "identity";
+
+    AffineTransform::DecomposedType decomposition;
+    decompose(decomposition);
+
+    if (isIdentityOrTranslation())
+        return String::format("translation(%lg,%lg)", decomposition.translateX, decomposition.translateY);
+
+    return String::format("translation(%lg,%lg), scale(%lg,%lg), angle(%lgrad), remainder(%lg,%lg,%lg,%lg)",
+        decomposition.translateX,
+        decomposition.translateY,
+        decomposition.scaleX,
+        decomposition.scaleY,
+        decomposition.angle,

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

super-nit: up to you, but I'd expect deg to be more useful in practice (as I
think it's more common in the web and in our unit tests), but up to you.
(rad2deg in wtf/MathExtras.h if you agree)

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

begrudgingly done. Radians are the one true way but you're right that we mostly
use degrees. When in wrong Rome..

+        decomposition.remainderA,
+        decomposition.remainderB,
+        decomposition.remainderC,
+        decomposition.remainderD);
+}
+
 } // namespace blink