Bug 1272549 - Part 6: Use enum class for shear in decomposition functions. r=birtles

MozReview-Commit-ID: 4exovhbjHI3

--HG--
extra : rebase_source : 99705c1bb2c980be06f7c662698241dde5ee9ab9

layout/style/StyleAnimationValue.cpp

@@ -39,6 +39,7 @@ using namespace mozilla::css;
 using namespace mozilla::gfx;
 using nsStyleTransformMatrix::Decompose2DMatrix;
 using nsStyleTransformMatrix::Decompose3DMatrix;
+using nsStyleTransformMatrix::ShearType;
 
 // HELPER METHODS
 // --------------
@@ -1609,16 +1610,21 @@ StyleAnimationValue::InterpolateTransformMatrix(const Matrix4x4 &aMatrix1,
   // Decompose both matrices
 
   // TODO: What do we do if one of these returns false (singular matrix)
-
   Point3D scale1(1, 1, 1), translate1;
   Point4D perspective1(0, 0, 0, 1);
   gfxQuaternion rotate1;
-  float shear1[3] = { 0.0f, 0.0f, 0.0f};
+  nsStyleTransformMatrix::ShearArray shear1;
+  for (auto&& s : shear1) {
+    s = 0.0f;
+  }
 
   Point3D scale2(1, 1, 1), translate2;
   Point4D perspective2(0, 0, 0, 1);
   gfxQuaternion rotate2;
-  float shear2[3] = { 0.0f, 0.0f, 0.0f};
+  nsStyleTransformMatrix::ShearArray shear2;
+  for (auto&& s : shear2) {
+    s = 0.0f;
+  }
 
   Matrix matrix2d1, matrix2d2;
   if (aMatrix1.Is2D(&matrix2d1) && aMatrix2.Is2D(&matrix2d2)) {
@@ -1651,19 +1657,25 @@ StyleAnimationValue::InterpolateTransformMatrix(const Matrix4x4 &aMatrix1,
   // TODO: Would it be better to interpolate these as angles?
   //       How do we convert back to angles?
   float yzshear =
-    InterpolateNumerically(shear1[YZSHEAR], shear2[YZSHEAR], aProgress);
+    InterpolateNumerically(shear1[ShearType::YZSHEAR],
+                           shear2[ShearType::YZSHEAR],
+                           aProgress);
   if (yzshear != 0.0) {
     result.SkewYZ(yzshear);
   }
 
   float xzshear =
-    InterpolateNumerically(shear1[XZSHEAR], shear2[XZSHEAR], aProgress);
+    InterpolateNumerically(shear1[ShearType::XZSHEAR],
+                           shear2[ShearType::XZSHEAR],
+                           aProgress);
   if (xzshear != 0.0) {
     result.SkewXZ(xzshear);
   }
 
   float xyshear =
-    InterpolateNumerically(shear1[XYSHEAR], shear2[XYSHEAR], aProgress);
+    InterpolateNumerically(shear1[ShearType::XYSHEAR],
+                           shear2[ShearType::XYSHEAR],
+                           aProgress);
   if (xyshear != 0.0) {
     result.SkewXY(xyshear);
   }

layout/style/nsStyleTransformMatrix.cpp

@@ -876,7 +876,7 @@ ReadTransforms(const nsCSSValueList* aList,
 bool
 Decompose2DMatrix(const Matrix& aMatrix,
                   Point3D& aScale,
-                  float aShear[3],
+                  ShearArray& aShear,
                   gfxQuaternion& aRotate,
                   Point3D& aTranslate)
 {
@@ -916,7 +916,7 @@ Decompose2DMatrix(const Matrix& aMatrix,
 
   float rotate = atan2f(B, A);
   aRotate = gfxQuaternion(0, 0, sin(rotate/2), cos(rotate/2));
-  aShear[XYSHEAR] = XYshear;
+  aShear[ShearType::XYSHEAR] = XYshear;
   aScale.x = scaleX;
   aScale.y = scaleY;
   aTranslate.x = aMatrix._31;
@@ -937,7 +937,7 @@ Decompose2DMatrix(const Matrix& aMatrix,
 bool
 Decompose3DMatrix(const Matrix4x4& aMatrix,
                   Point3D& aScale,
-                  float aShear[3],
+                  ShearArray& aShear,
                   gfxQuaternion& aRotate,
                   Point3D& aTranslate,
                   Point4D& aPerspective)
@@ -994,26 +994,26 @@ Decompose3DMatrix(const Matrix4x4& aMatrix,
   local[0] /= aScale.x;
 
   /* Compute XY shear factor and make 2nd local orthogonal to 1st. */
-  aShear[XYSHEAR] = local[0].DotProduct(local[1]);
-  local[1] -= local[0] * aShear[XYSHEAR];
+  aShear[ShearType::XYSHEAR] = local[0].DotProduct(local[1]);
+  local[1] -= local[0] * aShear[ShearType::XYSHEAR];
 
   /* Now, compute Y scale and normalize 2nd local. */
   aScale.y = local[1].Length();
   local[1] /= aScale.y;
-  aShear[XYSHEAR] /= aScale.y;
+  aShear[ShearType::XYSHEAR] /= aScale.y;
 
   /* Compute XZ and YZ shears, make 3rd local orthogonal */
-  aShear[XZSHEAR] = local[0].DotProduct(local[2]);
-  local[2] -= local[0] * aShear[XZSHEAR];
-  aShear[YZSHEAR] = local[1].DotProduct(local[2]);
-  local[2] -= local[1] * aShear[YZSHEAR];
+  aShear[ShearType::XZSHEAR] = local[0].DotProduct(local[2]);
+  local[2] -= local[0] * aShear[ShearType::XZSHEAR];
+  aShear[ShearType::YZSHEAR] = local[1].DotProduct(local[2]);
+  local[2] -= local[1] * aShear[ShearType::YZSHEAR];
 
   /* Next, get Z scale and normalize 3rd local. */
   aScale.z = local[2].Length();
   local[2] /= aScale.z;
 
-  aShear[XZSHEAR] /= aScale.z;
-  aShear[YZSHEAR] /= aScale.z;
+  aShear[ShearType::XZSHEAR] /= aScale.z;
+  aShear[ShearType::YZSHEAR] /= aScale.z;
 
   /**
    * At this point, the matrix (in locals) is orthonormal.

layout/style/nsStyleTransformMatrix.h

@@ -10,6 +10,7 @@
 #ifndef nsStyleTransformMatrix_h_
 #define nsStyleTransformMatrix_h_
 
+#include "mozilla/EnumeratedArray.h"
 #include "nsCSSValue.h"
 
 class nsIFrame;
@@ -174,16 +175,21 @@ namespace nsStyleTransformMatrix {
                                          bool* aContains3dTransform);
 
   // Shear type for decomposition.
-  #define XYSHEAR 0
-  #define XZSHEAR 1
-  #define YZSHEAR 2
+  enum class ShearType {
+    XYSHEAR,
+    XZSHEAR,
+    YZSHEAR,
+    Count
+  };
+  using ShearArray =
+    mozilla::EnumeratedArray<ShearType, ShearType::Count, float>;
 
   /*
    * Implements the 2d transform matrix decomposition algorithm.
    */
   bool Decompose2DMatrix(const mozilla::gfx::Matrix& aMatrix,
                          mozilla::gfx::Point3D& aScale,
-                         float aShear[3],
+                         ShearArray& aShear,
                          gfxQuaternion& aRotate,
                          mozilla::gfx::Point3D& aTranslate);
   /*
@@ -191,7 +197,7 @@ namespace nsStyleTransformMatrix {
    */
   bool Decompose3DMatrix(const mozilla::gfx::Matrix4x4& aMatrix,
                          mozilla::gfx::Point3D& aScale,
-                         float aShear[3],
+                         ShearArray& aShear,
                          gfxQuaternion& aRotate,
                          mozilla::gfx::Point3D& aTranslate,
                          mozilla::gfx::Point4D& aPerspective);