Analytic AntiAlias for Convex Shapes

include/private/SkFixed.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 SkFixed_DEFINED
 #define SkFixed_DEFINED
 
@@ skipping 70 matching lines @@
     SkToS32(SkTPin<int64_t>((SkLeftShift((int64_t)(numer), 16) / (denom)), SK_MinS32, SK_MaxS32))
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////
 // Now look for ASM overrides for our portable versions (should consider putting this in its own file)
 
 inline SkFixed SkFixedMul_longlong(SkFixed a, SkFixed b) {
     return (SkFixed)((int64_t)a * b >> 16);
 }
 #define SkFixedMul(a,b)     SkFixedMul_longlong(a,b)
 
+inline SkFixed SkFixedMul_lowprec(SkFixed a, SkFixed b) {
+    return (a >> 8) * (b >> 8);
+}
+
 
 #if defined(SK_CPU_ARM32)
     /* This guy does not handle NaN or other obscurities, but is faster than
        than (int)(x*65536).  When built on Android with -Os, needs forcing
        to inline or we lose the speed benefit.
     */
     SK_ALWAYS_INLINE SkFixed SkFloatToFixed_arm(float x)
     {
         int32_t y, z;
         asm("movs    %1, %3, lsl #1         \n"
@@ skipping 49 matching lines @@
 
 #define SkIntToFixed3232(x)       (SkLeftShift((SkFixed3232)(x), 32))
 #define SkFixed3232ToInt(x)       ((int)((x) >> 32))
 #define SkFixedToFixed3232(x)     (SkLeftShift((SkFixed3232)(x), 16))
 #define SkFixed3232ToFixed(x)     ((SkFixed)((x) >> 16))
 #define SkFloatToFixed3232(x)     ((SkFixed3232)((x) * (65536.0f * 65536.0f)))
 
 #define SkScalarToFixed3232(x)    SkFloatToFixed3232(x)
 
 #endif