GeometryInterface: Add DOMMatrixInit and fromMatrix().

third_party/WebKit/Source/core/dom/DOMMatrixReadOnly.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/dom/DOMMatrix.h"
+#include "core/dom/DOMMatrixInit.h"
 
 namespace blink {
+namespace {
+
+void setDictionaryMembers(DOMMatrixInit& other)
+{
+    if (!other.hasM11()) {
+        if (other.hasA())
+            other.setM11(other.a());
+        else
+            other.setM11(1);
+    }
+    if (!other.hasM12()) {
+        if (other.hasB())
+            other.setM12(other.b());
+        else
+            other.setM12(0);
+    }
+    if (!other.hasM21()) {
+        if (other.hasC())
+            other.setM21(other.c());
+        else
+            other.setM21(0);
+    }
+    if (!other.hasM22()) {
+        if (other.hasD())
+            other.setM22(other.d());
+        else
+            other.setM22(1);
+    }
+    if (!other.hasM41()) {
+        if (other.hasE())
+            other.setM41(other.e());
+        else
+            other.setM41(0);
+    }
+    if (!other.hasM42()) {
+        if (other.hasF())
+            other.setM42(other.f());
+        else
+            other.setM42(0);
+    }
+}
+
+} // namespace
+
+void DOMMatrixReadOnly::validateAndFixup(DOMMatrixInit& other, ExceptionState& exceptionState)

[dominicc (has gone to gerrit), 2016/08/30 02:13:43]

Please add tests for NaN. The note about NaN bit patterns at
https://drafts.fxtf.org/geometry/#validate-and-fixup is interesting.

[zino, 2016/09/10 10:18:15]

Done.

+{
+    if ((other.hasA() && other.hasM11() && other.a() != other.m11())
+        || (other.hasB() && other.hasM12() && other.b() != other.m12())
+        || (other.hasC() && other.hasM21() && other.c() != other.m21())
+        || (other.hasD() && other.hasM22() && other.d() != other.m22())
+        || (other.hasE() && other.hasM41() && other.e() != other.m41())
+        || (other.hasF() && other.hasM42() && other.f() != other.m42())) {
+        exceptionState.throwTypeError("[a, b, c, d, e, f] members should equals [m11, m12, m21, m22, m41, m42].");

[dominicc (has gone to gerrit), 2016/08/30 02:13:43]

Grammar: should equals -> should equal

It's a bit awkward to refer to [a, b, ...] *members* and then talk about [m11,
m12, ...] without mentioning members. Is member some jargon for matrices? Be
consistent.

I'm also not sure about 'member' at all. JavaScript doesn't have 'members' but
properties.

[zino, 2016/09/10 10:18:15]

Done.

+        return;
+    }
+
+    if (other.hasIs2D() && other.is2D() && (other.m31() || other.m32()
+        || other.m13() || other.m23() || other.m43() || other.m14()
+        || other.m24() || other.m34() || other.m33() != 1 || other.m44() != 1)) {
+        exceptionState.throwTypeError("The is2D member is set to true but the input matrix is 3d matrix.");
+        return;
+    }
+
+    setDictionaryMembers(other);
+    if (!other.hasIs2D()) {
+        if (other.m31() || other.m32() || other.m13() || other.m23()
+            || other.m43() || other.m14() || other.m24() || other.m34()
+            || other.m33() != 1 || other.m44() != 1)
+            other.setIs2D(false);

[dominicc (has gone to gerrit), 2016/08/30 02:13:43]

Why not save that expression in a variable with a good, descriptive name, and
then do one line:

other.setIs2D(niceNameYouFound);

It's simpler and clearer.

[zino, 2016/09/10 10:18:15]

Done.

+        else
+            other.setIs2D(true);
+    }
+}
 
 DOMMatrixReadOnly* DOMMatrixReadOnly::create(Vector<double> sequence, ExceptionState& exceptionState)
 {
     if (sequence.size() != 6 && sequence.size() != 16) {
         exceptionState.throwTypeError("An invalid number sequence is specified. The sequence must contain 6 elements for 2D matrix and 16 elements for 3D matrix.");
         return nullptr;
     }
     return new DOMMatrixReadOnly(sequence);
 }
 
+DOMMatrixReadOnly* DOMMatrixReadOnly::fromMatrix(DOMMatrixInit& other, ExceptionState& exceptionState)
+{
+    validateAndFixup(other, exceptionState);

[dominicc (has gone to gerrit), 2016/08/30 02:13:43]

The common pattern seems to be

validateAndFixUp
check whether there was an exception
  return early.

What do you think about having validateAndFixUp return a boolean and simplify
that to two lines?

[zino, 2016/09/10 10:18:15]

Done.

+    if (exceptionState.hadException())
+        return nullptr;
+
+    if (other.is2D()) {
+        return new DOMMatrixReadOnly({
+            other.m11(), other.m12(), other.m21(),
+            other.m22(), other.m41(), other.m42()});
+    }
+    return new DOMMatrixReadOnly({
+        other.m11(), other.m12(), other.m13(), other.m14(),
+        other.m21(), other.m22(), other.m23(), other.m24(),
+        other.m31(), other.m32(), other.m33(), other.m34(),
+        other.m41(), other.m42(), other.m43(), other.m44()});
+}
+
 DOMMatrixReadOnly::DOMMatrixReadOnly(Vector<double> sequence)
 {
     if (sequence.size() == 6) {
         m_matrix = TransformationMatrix::create(
             sequence[0], sequence[1], sequence[2], sequence[3],
             sequence[4], sequence[5]);
         m_is2D = true;
     } else if (sequence.size() == 16) {
         m_matrix = TransformationMatrix::create(
             sequence[0], sequence[1], sequence[2], sequence[3],
@@ skipping 13 matching lines @@
 bool DOMMatrixReadOnly::is2D() const
 {
     return m_is2D;
 }
 
 bool DOMMatrixReadOnly::isIdentity() const
 {
     return m_matrix->isIdentity();
 }
 
-DOMMatrix* DOMMatrixReadOnly::multiply(DOMMatrix* other)
+DOMMatrix* DOMMatrixReadOnly::multiply(DOMMatrixInit& other, ExceptionState& exceptionState)
 {
-    return DOMMatrix::create(this)->multiplySelf(other);
+    return DOMMatrix::create(this)->multiplySelf(other, exceptionState);
 }
 
 DOMMatrix* DOMMatrixReadOnly::translate(double tx, double ty, double tz)
 {
     return DOMMatrix::create(this)->translateSelf(tx, ty, tz);
 }
 
 DOMMatrix* DOMMatrixReadOnly::scale(double scale, double ox, double oy)
 {
     return DOMMatrix::create(this)->scaleSelf(scale, ox, oy);
@@ skipping 77 matching lines @@
         << m21() << ", " << m22() << ", " << m23() << ", " << m24() << ", "
         << m31() << ", " << m32() << ", " << m33() << ", " << m34() << ", "
         << m41() << ", " << m42() << ", " << m43() << ", " << m44();
     }
     stream << ")";
 
     return String(stream.str().c_str());
 }
 
 } // namespace blink