cc: Use SkMScalar instead of doubles everywhere in cc

ui/gfx/transform_util.cc

Index: ui/gfx/transform_util.cc
diff --git a/ui/gfx/transform_util.cc b/ui/gfx/transform_util.cc
index 90c8b56e5547937f76686bfa6934064e74207112..d8e9e15e2785f7f214216d0192d62711496f6b9e 100644
--- a/ui/gfx/transform_util.cc
+++ b/ui/gfx/transform_util.cc
@@ -12,51 +12,52 @@ namespace gfx {
 
 namespace {
 
-double Length3(double v[3]) {
+SkMScalar Length3(SkMScalar v[3]) {
   return std::sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
 }
 
-void Scale3(double v[3], double scale) {
+void Scale3(SkMScalar v[3], SkMScalar scale) {
   for (int i = 0; i < 3; ++i)
     v[i] *= scale;
 }
 
 template <int n>
-double Dot(const double* a, const double* b) {
-  double toReturn = 0;
+SkMScalar Dot(const SkMScalar* a, const SkMScalar* b) {
+  SkMScalar toReturn = 0;
   for (int i = 0; i < n; ++i)
     toReturn += a[i] * b[i];
   return toReturn;
 }
 
 template <int n>
-void Combine(double* out,
-             const double* a,
-             const double* b,
-             double scale_a,
-             double scale_b) {
+void Combine(SkMScalar* out,
+             const SkMScalar* a,
+             const SkMScalar* b,
+             SkMScalar scale_a,
+             SkMScalar scale_b) {
   for (int i = 0; i < n; ++i)
     out[i] = a[i] * scale_a + b[i] * scale_b;
 }
 
-void Cross3(double out[3], double a[3], double b[3]) {
-  double x = a[1] * b[2] - a[2] * b[1];
-  double y = a[2] * b[0] - a[0] * b[2];
-  double z = a[0] * b[1] - a[1] * b[0];
+void Cross3(SkMScalar out[3], SkMScalar a[3], SkMScalar b[3]) {
+  SkMScalar x = a[1] * b[2] - a[2] * b[1];
+  SkMScalar y = a[2] * b[0] - a[0] * b[2];
+  SkMScalar z = a[0] * b[1] - a[1] * b[0];
   out[0] = x;
   out[1] = y;
   out[2] = z;
 }
 
 // Taken from http://www.w3.org/TR/css3-transforms/.
-bool Slerp(double out[4],
-           const double q1[4],
-           const double q2[4],
+bool Slerp(SkMScalar out[4],
+           const SkMScalar q1[4],
+           const SkMScalar q2[4],
            double progress) {
-  double product = Dot<4>(q1, q2);
+  SkMScalar product = Dot<4>(q1, q2);
 
   // Clamp product to -1.0 <= product <= 1.0.
-  product = std::min(std::max(product, -1.0), 1.0);
+  SkMScalar one(1);
+  product = std::min(std::max(product, -one), one);

[danakj, 2013/09/09 17:57:45]

SK_MScalar1?

[enne (OOO), 2013/09/10 22:32:32]

Done.

 
   // Interpolate angles along the shortest path. For example, to interpolate
   // between a 175 degree angle and a 185 degree angle, interpolate along the
@@ -65,25 +66,25 @@ bool Slerp(double out[4],
   // the current W3C spec. Fixing the spec to match this approach is discussed
   // at:
   // http://lists.w3.org/Archives/Public/www-style/2013May/0131.html
-  double scale1 = 1.0;
+  SkMScalar scale1 = 1.0;
   if (product < 0) {
     product = -product;
     scale1 = -1.0;
   }
 
-  const double epsilon = 1e-5;
+  const SkMScalar epsilon = 1e-5;
   if (std::abs(product - 1.0) < epsilon) {

[danakj, 2013/09/09 17:57:45]

should this be SK_MScalar1? or integer literal? or float literal? i see integer
literals down below here..

[enne (OOO), 2013/09/10 22:32:32]

Done.

     for (int i = 0; i < 4; ++i)
       out[i] = q1[i];
     return true;
   }
 
-  double denom = std::sqrt(1 - product * product);
-  double theta = std::acos(product);
-  double w = std::sin(progress * theta) * (1 / denom);
+  SkMScalar denom = std::sqrt(1 - product * product);
+  SkMScalar theta = std::acos(product);

[danakj, 2013/09/09 17:57:45]

Should |product| and |w| and all these variables above here be doubles to
preserve precision when doing acos() and sin?

[enne (OOO), 2013/09/10 22:32:32]

I think it's less important here.  The doubles for rotations were to help with
the 90/180/270 case.  This is slerping and will be accurate at the end points
because it's clamped to -1 or 1.

+  SkMScalar w = std::sin(progress * theta) * (1 / denom);
 
   scale1 *= std::cos(progress * theta) - product * w;
-  double scale2 = w;
+  SkMScalar scale2 = w;
   Combine<4>(out, q1, q2, scale1, scale2);
 
   return true;
@@ -91,14 +92,14 @@ bool Slerp(double out[4],
 
 // Returns false if the matrix cannot be normalized.
 bool Normalize(SkMatrix44& m) {
-  if (m.getDouble(3, 3) == 0.0)
+  if (m.get(3, 3) == 0.0)
     // Cannot normalize.
     return false;
 
-  double scale = 1.0 / m.getDouble(3, 3);
+  SkMScalar scale = 1.0 / m.get(3, 3);
   for (int i = 0; i < 4; i++)
     for (int j = 0; j < 4; j++)
-      m.setDouble(i, j, m.getDouble(i, j) * scale);
+      m.set(i, j, m.get(i, j) * scale);
 
   return true;
 }
@@ -152,18 +153,17 @@ bool DecomposeTransform(DecomposedTransform* decomp,
   SkMatrix44 perspectiveMatrix = matrix;
 
   for (int i = 0; i < 3; ++i)
-    perspectiveMatrix.setDouble(3, i, 0.0);
+    perspectiveMatrix.set(3, i, 0.0);
 
-  perspectiveMatrix.setDouble(3, 3, 1.0);
+  perspectiveMatrix.set(3, 3, 1.0);
 
   // If the perspective matrix is not invertible, we are also unable to
   // decompose, so we'll bail early. Constant taken from SkMatrix44::invert.
   if (std::abs(perspectiveMatrix.determinant()) < 1e-8)
     return false;
 
-  if (matrix.getDouble(3, 0) != 0.0 ||
-      matrix.getDouble(3, 1) != 0.0 ||
-      matrix.getDouble(3, 2) != 0.0) {
+  if (matrix.get(3, 0) != 0.0 || matrix.get(3, 1) != 0.0 ||
+      matrix.get(3, 2) != 0.0) {
     // rhs is the right hand side of the equation.
     SkMScalar rhs[4] = {
       matrix.get(3, 0),
@@ -195,12 +195,12 @@ bool DecomposeTransform(DecomposedTransform* decomp,
   }
 
   for (int i = 0; i < 3; i++)
-    decomp->translate[i] = matrix.getDouble(i, 3);
+    decomp->translate[i] = matrix.get(i, 3);
 
-  double row[3][3];
+  SkMScalar row[3][3];
   for (int i = 0; i < 3; i++)
     for (int j = 0; j < 3; ++j)
-      row[i][j] = matrix.getDouble(j, i);
+      row[i][j] = matrix.get(j, i);
 
   // Compute X scale factor and normalize first row.
   decomp->scale[0] = Length3(row[0]);
@@ -235,7 +235,7 @@ bool DecomposeTransform(DecomposedTransform* decomp,
   // At this point, the matrix (in rows) is orthonormal.
   // Check for a coordinate system flip.  If the determinant
   // is -1, then negate the matrix and the scaling factors.
-  double pdum3[3];
+  SkMScalar pdum3[3];
   Cross3(pdum3, row[1], row[2]);
   if (Dot<3>(row[0], pdum3) < 0) {
     for (int i = 0; i < 3; i++) {
@@ -268,16 +268,15 @@ bool DecomposeTransform(DecomposedTransform* decomp,
 Transform ComposeTransform(const DecomposedTransform& decomp) {
   SkMatrix44 matrix(SkMatrix44::kIdentity_Constructor);
   for (int i = 0; i < 4; i++)
-    matrix.setDouble(3, i, decomp.perspective[i]);
+    matrix.set(3, i, decomp.perspective[i]);
 
-  matrix.preTranslate(SkDoubleToMScalar(decomp.translate[0]),
-                      SkDoubleToMScalar(decomp.translate[1]),
-                      SkDoubleToMScalar(decomp.translate[2]));
+  matrix.preTranslate(
+      decomp.translate[0], decomp.translate[1], decomp.translate[2]);
 
-  double x = decomp.quaternion[0];
-  double y = decomp.quaternion[1];
-  double z = decomp.quaternion[2];
-  double w = decomp.quaternion[3];
+  SkMScalar x = decomp.quaternion[0];
+  SkMScalar y = decomp.quaternion[1];
+  SkMScalar z = decomp.quaternion[2];
+  SkMScalar w = decomp.quaternion[3];
 
   SkMatrix44 rotation_matrix(SkMatrix44::kUninitialized_Constructor);
   rotation_matrix.set3x3(1.0 - 2.0 * (y * y + z * z),
@@ -294,25 +293,23 @@ Transform ComposeTransform(const DecomposedTransform& decomp) {
 
   SkMatrix44 temp(SkMatrix44::kIdentity_Constructor);
   if (decomp.skew[2]) {
-    temp.setDouble(1, 2, decomp.skew[2]);
+    temp.set(1, 2, decomp.skew[2]);
     matrix.preConcat(temp);
   }
 
   if (decomp.skew[1]) {
-    temp.setDouble(1, 2, 0);
-    temp.setDouble(0, 2, decomp.skew[1]);
+    temp.set(1, 2, 0);
+    temp.set(0, 2, decomp.skew[1]);
     matrix.preConcat(temp);
   }
 
   if (decomp.skew[0]) {
-    temp.setDouble(0, 2, 0);
-    temp.setDouble(0, 1, decomp.skew[0]);
+    temp.set(0, 2, 0);
+    temp.set(0, 1, decomp.skew[0]);
     matrix.preConcat(temp);
   }
 
-  matrix.preScale(SkDoubleToMScalar(decomp.scale[0]),
-                  SkDoubleToMScalar(decomp.scale[1]),
-                  SkDoubleToMScalar(decomp.scale[2]));
+  matrix.preScale(decomp.scale[0], decomp.scale[1], decomp.scale[2]);
 
   Transform to_return;
   to_return.matrix() = matrix;