michael@0: 
michael@0: /*
michael@0:  * Copyright 2006 The Android Open Source Project
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #ifndef SkAutoKern_DEFINED
michael@0: #define SkAutoKern_DEFINED
michael@0: 
michael@0: #include "SkGlyph.h"
michael@0: 
michael@0: #define SkAutoKern_AdjustF(prev, next)    (((next) - (prev) + 32) >> 6 << 16)
michael@0: #define SkAutoKern_AdjustS(prev, next)    SkIntToScalar(((next) - (prev) + 32) >> 6)
michael@0: 
michael@0: /* this is a helper class to perform auto-kerning
michael@0:  * the adjust() method returns a SkFixed corresponding
michael@0:  * to a +1/0/-1 pixel adjustment
michael@0:  */
michael@0: 
michael@0: class SkAutoKern {
michael@0: public:
michael@0:     SkAutoKern() : fPrevRsbDelta(0) {}
michael@0: 
michael@0:     SkFixed  adjust(const SkGlyph&  glyph)
michael@0:     {
michael@0: //        if (SkAbs32(glyph.fLsbDelta) > 47 || SkAbs32(glyph.fRsbDelta) > 47)
michael@0: //            printf("------- %d> L %d R %d\n", glyph.f_GlyphID, glyph.fLsbDelta, glyph.fRsbDelta);
michael@0: 
michael@0: #if 0
michael@0:         int  distort = fPrevRsbDelta - glyph.fLsbDelta;
michael@0: 
michael@0:         fPrevRsbDelta = glyph.fRsbDelta;
michael@0: 
michael@0:         if (distort >= 32)
michael@0:             return -SK_Fixed1;
michael@0:         else if (distort < -32)
michael@0:             return +SK_Fixed1;
michael@0:         else
michael@0:             return 0;
michael@0: #else
michael@0:         SkFixed adjust = SkAutoKern_AdjustF(fPrevRsbDelta, glyph.fLsbDelta);
michael@0:         fPrevRsbDelta = glyph.fRsbDelta;
michael@0:         return adjust;
michael@0: #endif
michael@0:     }
michael@0: private:
michael@0:     int   fPrevRsbDelta;
michael@0: };
michael@0: 
michael@0: #endif