Use explicit constructor-enums for SkMatrix44, either kUninitialized or kIdentity

for clarity, and to take advantage of the fact that most of the time, we actually
want kUninitialized, which is free (doesn't call setIdentity()) and we set the entire
matrix right after it comes into scope (e.g. set3x3, setTranslate). The plan is to
hide/remove the default constructor in Skia soon.
Review URL: https://codereview.chromium.org/11931017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@177163 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 29 insertions, 33 deletions

diff --git a/ui/gfx/transform.cc b/ui/gfx/transform.cc
index df3ed9f..5e87998 100644
--- a/ui/gfx/transform.cc
+++ b/ui/gfx/transform.cc
@@ -83,7 +83,7 @@ void Transform::RotateAboutXAxis(double degrees) {
                      0, cosTheta, sinTheta,
                      0, -sinTheta, cosTheta);
   } else {
-    SkMatrix44 rot;
+    SkMatrix44 rot(SkMatrix44::kUninitialized_Constructor);
     rot.set3x3(1, 0, 0,
                0, cosTheta, sinTheta,
                0, -sinTheta, cosTheta);
@@ -102,7 +102,7 @@ void Transform::RotateAboutYAxis(double degrees) {
                      0, 1, 0,
                      sinTheta, 0, cosTheta);
   } else {
-    SkMatrix44 rot;
+    SkMatrix44 rot(SkMatrix44::kUninitialized_Constructor);
     rot.set3x3(cosTheta, 0, -sinTheta,
                0, 1, 0,
                sinTheta, 0, cosTheta);
@@ -119,7 +119,7 @@ void Transform::RotateAboutZAxis(double degrees) {
                      -sinTheta, cosTheta, 0,
                      0, 0, 1);
   } else {
-    SkMatrix44 rot;
+    SkMatrix44 rot(SkMatrix44::kUninitialized_Constructor);
     rot.set3x3(cosTheta, sinTheta, 0,
                -sinTheta, cosTheta, 0,
                0, 0, 1);
@@ -134,7 +134,7 @@ void Transform::RotateAbout(const Vector3dF& axis, double degrees) {
                                   SkDoubleToMScalar(axis.z()),
                                   SkDoubleToMScalar(degrees));
   } else {
-    SkMatrix44 rot;
+    SkMatrix44 rot(SkMatrix44::kUninitialized_Constructor);
     rot.setRotateDegreesAbout(SkDoubleToMScalar(axis.x()),
                               SkDoubleToMScalar(axis.y()),
                               SkDoubleToMScalar(axis.z()),
@@ -167,7 +167,7 @@ void Transform::SkewX(double angle_x) {
   if (matrix_.isIdentity())
     matrix_.setDouble(0, 1, TanDegrees(angle_x));
   else {
-    SkMatrix44 skew;
+    SkMatrix44 skew(SkMatrix44::kIdentity_Constructor);
     skew.setDouble(0, 1, TanDegrees(angle_x));
     matrix_.preConcat(skew);
   }
@@ -177,7 +177,7 @@ void Transform::SkewY(double angle_y) {
   if (matrix_.isIdentity())
     matrix_.setDouble(1, 0, TanDegrees(angle_y));
   else {
-    SkMatrix44 skew;
+    SkMatrix44 skew(SkMatrix44::kIdentity_Constructor);
     skew.setDouble(1, 0, TanDegrees(angle_y));
     matrix_.preConcat(skew);
   }
@@ -189,7 +189,7 @@ void Transform::ApplyPerspectiveDepth(double depth) {
   if (matrix_.isIdentity())
     matrix_.setDouble(3, 2, -1.0 / depth);
   else {
-    SkMatrix44 m;
+    SkMatrix44 m(SkMatrix44::kIdentity_Constructor);
     m.setDouble(3, 2, -1.0 / depth);
     matrix_.preConcat(m);
   }
@@ -321,7 +321,7 @@ void Transform::TransformPoint(Point3F& point) const {
 
 bool Transform::TransformPointReverse(Point& point) const {
   // TODO(sad): Try to avoid trying to invert the matrix.
-  SkMatrix44 inverse;
+  SkMatrix44 inverse(SkMatrix44::kUninitialized_Constructor);
   if (!matrix_.invert(&inverse))
     return false;
 
@@ -331,7 +331,7 @@ bool Transform::TransformPointReverse(Point& point) const {
 
 bool Transform::TransformPointReverse(Point3F& point) const {
   // TODO(sad): Try to avoid trying to invert the matrix.
-  SkMatrix44 inverse;
+  SkMatrix44 inverse(SkMatrix44::kUninitialized_Constructor);
   if (!matrix_.invert(&inverse))
     return false;
 
@@ -353,7 +353,7 @@ bool Transform::TransformRectReverse(RectF* rect) const {
   if (matrix_.isIdentity())
     return true;
 
-  SkMatrix44 inverse;
+  SkMatrix44 inverse(SkMatrix44::kUninitialized_Constructor);
   if (!matrix_.invert(&inverse))
     return false;
 
diff --git a/ui/gfx/transform_util.cc b/ui/gfx/transform_util.cc
index c8ef573..9db41c3 100644
--- a/ui/gfx/transform_util.cc
+++ b/ui/gfx/transform_util.cc
@@ -166,7 +166,7 @@ bool DecomposeTransform(DecomposedTransform* decomp,
 
     // Solve the equation by inverting perspectiveMatrix and multiplying
     // rhs by the inverse.
-    SkMatrix44 inversePerspectiveMatrix;
+    SkMatrix44 inversePerspectiveMatrix(SkMatrix44::kUninitialized_Constructor);
     if (!perspectiveMatrix.invert(&inversePerspectiveMatrix))
       return false;
 
@@ -258,35 +258,33 @@ bool DecomposeTransform(DecomposedTransform* decomp,
 
 // Taken from http://www.w3.org/TR/css3-transforms/.
 Transform ComposeTransform(const DecomposedTransform& decomp) {
-  SkMatrix44 matrix;
+  SkMatrix44 matrix(SkMatrix44::kIdentity_Constructor);
   for (int i = 0; i < 4; i++)
     matrix.setDouble(3, i, decomp.perspective[i]);
 
-  SkMatrix44 tempTranslation;
-  tempTranslation.setTranslate(SkDoubleToMScalar(decomp.translate[0]),
-                               SkDoubleToMScalar(decomp.translate[1]),
-                               SkDoubleToMScalar(decomp.translate[2]));
-  matrix.preConcat(tempTranslation);
+  matrix.preTranslate(SkDoubleToMScalar(decomp.translate[0]),
+                      SkDoubleToMScalar(decomp.translate[1]),
+                      SkDoubleToMScalar(decomp.translate[2]));
 
   double x = decomp.quaternion[0];
   double y = decomp.quaternion[1];
   double z = decomp.quaternion[2];
   double w = decomp.quaternion[3];
 
-  SkMatrix44 rotation_matrix;
-  rotation_matrix.setDouble(0, 0, 1.0 - 2.0 * (y * y + z * z));
-  rotation_matrix.setDouble(0, 1, 2.0 * (x * y - z * w));
-  rotation_matrix.setDouble(0, 2, 2.0 * (x * z + y * w));
-  rotation_matrix.setDouble(1, 0, 2.0 * (x * y + z * w));
-  rotation_matrix.setDouble(1, 1, 1.0 - 2.0 * (x * x + z * z));
-  rotation_matrix.setDouble(1, 2, 2.0 * (y * z - x * w));
-  rotation_matrix.setDouble(2, 0, 2.0 * (x * z - y * w));
-  rotation_matrix.setDouble(2, 1, 2.0 * (y * z + x * w));
-  rotation_matrix.setDouble(2, 2, 1.0 - 2.0 * (x * x + y * y));
+  SkMatrix44 rotation_matrix(SkMatrix44::kUninitialized_Constructor);
+  rotation_matrix.set3x3(1.0 - 2.0 * (y * y + z * z),
+                         2.0 * (x * y + z * w),
+                         2.0 * (x * z - y * w),
+                         2.0 * (x * y - z * w),
+                         1.0 - 2.0 * (x * x + z * z),
+                         2.0 * (y * z + x * w),
+                         2.0 * (x * z + y * w),
+                         2.0 * (y * z - x * w),
+                         1.0 - 2.0 * (x * x + y * y));
 
   matrix.preConcat(rotation_matrix);
 
-  SkMatrix44 temp;
+  SkMatrix44 temp(SkMatrix44::kIdentity_Constructor);
   if (decomp.skew[2]) {
     temp.setDouble(1, 2, decomp.skew[2]);
     matrix.preConcat(temp);
@@ -304,11 +302,9 @@ Transform ComposeTransform(const DecomposedTransform& decomp) {
     matrix.preConcat(temp);
   }
 
-  SkMatrix44 tempScale;
-  tempScale.setScale(SkDoubleToMScalar(decomp.scale[0]),
-                     SkDoubleToMScalar(decomp.scale[1]),
-                     SkDoubleToMScalar(decomp.scale[2]));
-  matrix.preConcat(tempScale);
+  matrix.preScale(SkDoubleToMScalar(decomp.scale[0]),
+                  SkDoubleToMScalar(decomp.scale[1]),
+                  SkDoubleToMScalar(decomp.scale[2]));
 
   Transform to_return;
   to_return.matrix() = matrix;