unbias fy in the gpu glyphproc, since skia has pre-added 1/2 to the value

(assuming we would call floor to get a rounded value.)

apply finalFYMask not to the initial fy, but to the fyMask (so it is always
applied in the loop) in drawText.



git-svn-id: http://skia.googlecode.com/svn/trunk@1084 2bbb7eff-a529-9590-31e7-b0007b416f81

2 files changed, 12 insertions, 2 deletions

diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index 4cc068d609..14e5a803cb 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -1628,7 +1628,7 @@ void SkDraw::drawText(const char text[], size_t byteLength,
     // apply the bias here, so we don't have to add 1/2 in the loop
     fx += SK_FixedHalf;
     fy += SK_FixedHalf;
-    fy &= finalFYMask;
+    fyMask &= finalFYMask;
 
     SkAutoKern          autokern;
 	SkDraw1Glyph        d1g;
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 7b70b50c62..2d50c3652d 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -1261,8 +1261,18 @@ static void SkGPU_Draw1Glyph(const SkDraw1Glyph& state,
     if (NULL == procs->fFontScaler) {
         procs->fFontScaler = get_gr_font_scaler(state.fCache);
     }
+
+    /*
+     *  Skia calls us with fx,fy already biased by 1/2. It does this to speed
+     *  up rounding these, so that all of its procs (like us) can just call
+     *  SkFixedFloor and get the "rounded" value.
+     *
+     *  We take advantage of that for fx, where we pass a rounded value, but
+     *  we want the fractional fy, so we have to unbias it first.
+     */
     procs->fTextContext->drawPackedGlyph(GrGlyph::Pack(glyph.getGlyphID(), fx, 0),
-                                         SkIntToFixed(SkFixedFloor(fx)), fy,
+                                         SkIntToFixed(SkFixedFloor(fx)),
+                                         fy - SK_FixedHalf,
                                          procs->fFontScaler);
 }