Use SkScalar when aligning glyphs in user space.

Drawing text from paths is done in user space and not in device space.
All operations in user space should be performed with SkScalars.

BUG=327031
R=reed@google.com

Review URL: https://codereview.chromium.org/113123005

git-svn-id: http://skia.googlecode.com/svn/trunk/src@12682 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 34 insertions, 11 deletions

diff --git a/core/SkDraw.cpp b/core/SkDraw.cpp
index 52891ea5..ccab56ca 100644
--- a/core/SkDraw.cpp
+++ b/core/SkDraw.cpp
@@ -1841,19 +1841,16 @@ void SkDraw::drawText(const char text[], size_t byteLength,
 //   e.g. subpixel doesn't round
 typedef void (*AlignProc)(const SkPoint&, const SkGlyph&, SkIPoint*);
 
-static void leftAlignProc(const SkPoint& loc, const SkGlyph& glyph,
-                          SkIPoint* dst) {
+static void leftAlignProc(const SkPoint& loc, const SkGlyph& glyph, SkIPoint* dst) {
     dst->set(SkScalarToFixed(loc.fX), SkScalarToFixed(loc.fY));
 }
 
-static void centerAlignProc(const SkPoint& loc, const SkGlyph& glyph,
-                            SkIPoint* dst) {
+static void centerAlignProc(const SkPoint& loc, const SkGlyph& glyph, SkIPoint* dst) {
     dst->set(SkScalarToFixed(loc.fX) - (glyph.fAdvanceX >> 1),
              SkScalarToFixed(loc.fY) - (glyph.fAdvanceY >> 1));
 }
 
-static void rightAlignProc(const SkPoint& loc, const SkGlyph& glyph,
-                           SkIPoint* dst) {
+static void rightAlignProc(const SkPoint& loc, const SkGlyph& glyph, SkIPoint* dst) {
     dst->set(SkScalarToFixed(loc.fX) - glyph.fAdvanceX,
              SkScalarToFixed(loc.fY) - glyph.fAdvanceY);
 }
@@ -1868,6 +1865,32 @@ static AlignProc pick_align_proc(SkPaint::Align align) {
     return gProcs[align];
 }
 
+typedef void (*AlignProc_scalar)(const SkPoint&, const SkGlyph&, SkPoint*);
+
+static void leftAlignProc_scalar(const SkPoint& loc, const SkGlyph& glyph, SkPoint* dst) {
+    dst->set(loc.fX, loc.fY);
+}
+
+static void centerAlignProc_scalar(const SkPoint& loc, const SkGlyph& glyph, SkPoint* dst) {
+    dst->set(loc.fX - SkFixedToScalar(glyph.fAdvanceX >> 1),
+             loc.fY - SkFixedToScalar(glyph.fAdvanceY >> 1));
+}
+
+static void rightAlignProc_scalar(const SkPoint& loc, const SkGlyph& glyph, SkPoint* dst) {
+    dst->set(loc.fX - SkFixedToScalar(glyph.fAdvanceX),
+             loc.fY - SkFixedToScalar(glyph.fAdvanceY));
+}
+
+static AlignProc_scalar pick_align_proc_scalar(SkPaint::Align align) {
+    static const AlignProc_scalar gProcs[] = {
+        leftAlignProc_scalar, centerAlignProc_scalar, rightAlignProc_scalar
+    };
+
+    SkASSERT((unsigned)align < SK_ARRAY_COUNT(gProcs));
+
+    return gProcs[align];
+}
+
 class TextMapState {
 public:
     mutable SkPoint fLoc;
@@ -1944,7 +1967,7 @@ void SkDraw::drawPosText_asPaths(const char text[], size_t byteLength,
     SkGlyphCache*       cache = autoCache.getCache();
 
     const char*        stop = text + byteLength;
-    AlignProc          alignProc = pick_align_proc(paint.getTextAlign());
+    AlignProc_scalar   alignProc = pick_align_proc_scalar(paint.getTextAlign());
     TextMapState       tms(SkMatrix::I(), constY);
     TextMapState::Proc tmsProc = tms.pickProc(scalarsPerPosition);
 
@@ -1954,11 +1977,11 @@ void SkDraw::drawPosText_asPaths(const char text[], size_t byteLength,
             const SkPath* path = cache->findPath(glyph);
             if (path) {
                 tmsProc(tms, pos);
-                SkIPoint fixedLoc;
-                alignProc(tms.fLoc, glyph, &fixedLoc);
+                SkPoint loc;
+                alignProc(tms.fLoc, glyph, &loc);
 
-                matrix[SkMatrix::kMTransX] = SkFixedToScalar(fixedLoc.fX);
-                matrix[SkMatrix::kMTransY] = SkFixedToScalar(fixedLoc.fY);
+                matrix[SkMatrix::kMTransX] = loc.fX;
+                matrix[SkMatrix::kMTransY] = loc.fY;
                 if (fDevice) {
                     fDevice->drawPath(*this, *path, paint, &matrix, false);
                 } else {