add blitter api for aa-hairlines

src/core/SkBlitter.h

-
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
-
 #ifndef SkBlitter_DEFINED
 #define SkBlitter_DEFINED
 
 #include "SkBitmap.h"
 #include "SkBitmapProcShader.h"
 #include "SkMask.h"
 #include "SkMatrix.h"
 #include "SkPaint.h"
 #include "SkRefCnt.h"
 #include "SkRegion.h"
@@ skipping 28 matching lines @@
     /// Blit a pattern of pixels defined by a rectangle-clipped mask;
     /// typically used for text.
     virtual void blitMask(const SkMask&, const SkIRect& clip);
 
     /** If the blitter just sets a single value for each pixel, return the
         bitmap it draws into, and assign value. If not, return NULL and ignore
         the value parameter.
     */
     virtual const SkBitmap* justAnOpaqueColor(uint32_t* value);
 
+    // (x, y), (x + 1, y)
+    void blitAntiH2(int x, int y, U8CPU a0, U8CPU a1) {
+        int16_t runs[3];
+        uint8_t aa[2];
+        
+        runs[0] = 1;
+        runs[1] = 1;
+        runs[2] = 0;
+        aa[0] = SkToU8(a0);
+        aa[1] = SkToU8(a1);
+        this->blitAntiH(x, y, aa, runs);
+    }
+
+    // (x, y), (x, y + 1)
+    void blitAntiV2(int x, int y, U8CPU a0, U8CPU a1) {
+        int16_t runs[2];
+        uint8_t aa[1];
+        
+        runs[0] = 1;
+        runs[1] = 0;
+        aa[0] = SkToU8(a0);
+        this->blitAntiH(x, y, aa, runs);
+        // reset in case the clipping blitter modified runs
+        runs[0] = 1;
+        runs[1] = 0;
+        aa[0] = SkToU8(a1);
+        this->blitAntiH(x, y + 1, aa, runs);
+    }
+    
     /**
      *  Special method just to identify the null blitter, which is returned
      *  from Choose() if the request cannot be fulfilled. Default impl
      *  returns false.
      */
     virtual bool isNullBlitter() const;
 
     /**
      *  Special methods for SkShaderBlitter. On all other classes this is a no-op.
      */
@@ skipping 140 matching lines @@
     SkBlitter*  apply(SkBlitter* blitter, const SkRegion* clip,
                       const SkIRect* bounds = NULL);
 
 private:
     SkNullBlitter       fNullBlitter;
     SkRectClipBlitter   fRectBlitter;
     SkRgnClipBlitter    fRgnBlitter;
 };
 
 #endif