Revert of Repeating SkBitmapProcState rounding bias (patchset #6 id:100001 of https://codereview.chromium.org/1529833003/ )

Reason for revert:
We need a SkFractionalInt auto mapper flavor, otherwise we're losing precision for some procs => seaming artifacs

(https://gold.skia.org/diff?test=giantbitmap_mirror_point_rotate&left=0dd7a412fce81586e6a142e039ec2de9&top=a706d4bb2b8e994b936445b87115b07e)

Original issue's description:
> Repeating SkBitmapProcState rounding bias
>
> Observe the bias in repeat matrix procs also.
>
> Introduce a utility class to handle device space -> bitmap space
> mapping.
>
> BUG=skia:4680,skia:4649
> R=reed@google.com
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1529833003
>
> Committed: https://skia.googlesource.com/skia/+/5ae7fdcc3d7712da3193c39a751e88b092aa82db

TBR=reed@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:4680,skia:4649

Review URL: https://codereview.chromium.org/1531423003

1 files changed, 13 insertions, 7 deletions

diff --git a/src/core/SkBitmapProcState_matrix_template.h b/src/core/SkBitmapProcState_matrix_template.h
index 9d639b8a04..468013c30d 100644
--- a/src/core/SkBitmapProcState_matrix_template.h
+++ b/src/core/SkBitmapProcState_matrix_template.h
@@ -22,10 +22,13 @@ void NoFilterProc_Scale(const SkBitmapProcState& s, uint32_t xy[],
     const unsigned maxX = s.fPixmap.width() - 1;
     SkFractionalInt fx;
     {
-        const SkBitmapProcStateAutoMapper mapper(s, x ,y);
+        SkPoint pt;
+        s.fInvProc(s.fInvMatrix, SkIntToScalar(x) + SK_ScalarHalf,
+                                  SkIntToScalar(y) + SK_ScalarHalf, &pt);
+        fx = SkScalarToFractionalInt(pt.fY);
         const unsigned maxY = s.fPixmap.height() - 1;
-        *xy++ = TileProc::Y(s, mapper.y(), maxY);
-        fx = SkFixedToFractionalInt(mapper.x());
+        *xy++ = TileProc::Y(s, SkFractionalIntToFixed(fx), maxY);
+        fx = SkScalarToFractionalInt(pt.fX);
     }
 
     if (0 == maxX) {
@@ -77,9 +80,13 @@ void NoFilterProc_Affine(const SkBitmapProcState& s, uint32_t xy[],
                              SkMatrix::kScale_Mask |
                              SkMatrix::kAffine_Mask)) == 0);
 
-    const SkBitmapProcStateAutoMapper mapper(s, x ,y);
-    SkFractionalInt fx = SkFixedToFractionalInt(mapper.x());
-    SkFractionalInt fy = SkFixedToFractionalInt(mapper.y());
+    SkPoint srcPt;
+    s.fInvProc(s.fInvMatrix,
+               SkIntToScalar(x) + SK_ScalarHalf,
+               SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
+
+    SkFractionalInt fx = SkScalarToFractionalInt(srcPt.fX);
+    SkFractionalInt fy = SkScalarToFractionalInt(srcPt.fY);
     SkFractionalInt dx = s.fInvSxFractionalInt;
     SkFractionalInt dy = s.fInvKyFractionalInt;
     int maxX = s.fPixmap.width() - 1;
@@ -100,7 +107,6 @@ void NoFilterProc_Persp(const SkBitmapProcState& s, uint32_t* SK_RESTRICT xy,
     int maxX = s.fPixmap.width() - 1;
     int maxY = s.fPixmap.height() - 1;
 
-    // TODO: inv bias support
     SkPerspIter   iter(s.fInvMatrix,
                        SkIntToScalar(x) + SK_ScalarHalf,
                        SkIntToScalar(y) + SK_ScalarHalf, count);