Privatization:

move SkFDot.h to private
move parts of SkMath.h into SkMathPriv.h
Review URL: https://codereview.appspot.com/6461045

git-svn-id: http://skia.googlecode.com/svn/trunk@4997 2bbb7eff-a529-9590-31e7-b0007b416f81

12 files changed, 163 insertions, 12 deletions

diff --git a/src/core/Sk64.cpp b/src/core/Sk64.cpp
index f3506564a5..c530ed866f 100644
--- a/src/core/Sk64.cpp
+++ b/src/core/Sk64.cpp
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2006 The Android Open Source Project
  *
@@ -7,7 +6,7 @@
  */
 
 #include "Sk64.h"
-#include "SkMath.h"
+#include "SkMathPriv.h"
 
 #define shift_left(hi, lo)          \
     hi = (hi << 1) | (lo >> 31);    \
diff --git a/src/core/SkBitmapProcState_matrix.h b/src/core/SkBitmapProcState_matrix.h
index 469cbf3ad4..317c98437e 100644
--- a/src/core/SkBitmapProcState_matrix.h
+++ b/src/core/SkBitmapProcState_matrix.h
@@ -7,6 +7,7 @@
  */
 
 #include "SkMath.h"
+#include "SkMathPriv.h"
 
 #define SCALE_NOFILTER_NAME     MAKENAME(_nofilter_scale)
 #define SCALE_FILTER_NAME       MAKENAME(_filter_scale)
diff --git a/src/core/SkBitmapProcState_shaderproc.h b/src/core/SkBitmapProcState_shaderproc.h
index a3a8a99c0d..ead57f123e 100644
--- a/src/core/SkBitmapProcState_shaderproc.h
+++ b/src/core/SkBitmapProcState_shaderproc.h
@@ -6,7 +6,7 @@
  * found in the LICENSE file.
  */
 
-
+#include "SkMathPriv.h"
 
 #define SCALE_FILTER_NAME       MAKENAME(_filter_DX_shaderproc)
 
diff --git a/src/core/SkBlitRow_D16.cpp b/src/core/SkBlitRow_D16.cpp
index c815468bb6..5e675e5493 100644
--- a/src/core/SkBlitRow_D16.cpp
+++ b/src/core/SkBlitRow_D16.cpp
@@ -8,6 +8,7 @@
 #include "SkBlitRow.h"
 #include "SkColorPriv.h"
 #include "SkDither.h"
+#include "SkMathPriv.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/src/core/SkConfig8888.cpp b/src/core/SkConfig8888.cpp
index 10a1b36614..f889f20744 100644
--- a/src/core/SkConfig8888.cpp
+++ b/src/core/SkConfig8888.cpp
@@ -1,4 +1,5 @@
 #include "SkConfig8888.h"
+#include "SkMathPriv.h"
 
 namespace {
 
diff --git a/src/core/SkCordic.cpp b/src/core/SkCordic.cpp
index 14d34fb9fd..56cb4606c5 100644
--- a/src/core/SkCordic.cpp
+++ b/src/core/SkCordic.cpp
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2006 The Android Open Source Project
  *
@@ -6,9 +5,8 @@
  * found in the LICENSE file.
  */
 
-
 #include "SkCordic.h"
-#include "SkMath.h"
+#include "SkMathPriv.h"
 #include "Sk64.h"
 
 // 0x20000000 equals pi / 4
diff --git a/src/core/SkFDot6.h b/src/core/SkFDot6.h
new file mode 100644
index 0000000000..aa588572f8
--- /dev/null
+++ b/src/core/SkFDot6.h
@@ -0,0 +1,58 @@
+
+/*
+ * 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 SkFDot6_DEFINED
+#define SkFDot6_DEFINED
+
+#include "SkMath.h"
+
+typedef int32_t SkFDot6;
+
+#define SK_FDot6One         (64)
+#define SK_FDot6Half        (32)
+
+#ifdef SK_DEBUG
+    inline SkFDot6 SkIntToFDot6(S16CPU x) {
+        SkASSERT(SkToS16(x) == x);
+        return x << 6;
+    }
+#else
+    #define SkIntToFDot6(x) ((x) << 6)
+#endif
+
+#define SkFDot6Floor(x)     ((x) >> 6)
+#define SkFDot6Ceil(x)      (((x) + 63) >> 6)
+#define SkFDot6Round(x)     (((x) + 32) >> 6)
+
+#define SkFixedToFDot6(x)   ((x) >> 10)
+
+inline SkFixed SkFDot6ToFixed(SkFDot6 x) {
+    SkASSERT((x << 10 >> 10) == x);
+
+    return x << 10;
+}
+
+#ifdef SK_SCALAR_IS_FLOAT
+    #define SkScalarToFDot6(x)  (SkFDot6)((x) * 64)
+#else
+    #define SkScalarToFDot6(x)  ((x) >> 10)
+#endif
+
+inline SkFixed SkFDot6Div(SkFDot6 a, SkFDot6 b) {
+    SkASSERT(b != 0);
+
+    if (a == (int16_t)a) {
+        return (a << 16) / b;
+    } else {
+        return SkFixedDiv(a, b);
+    }
+}
+
+#endif
+
diff --git a/src/core/SkFloat.cpp b/src/core/SkFloat.cpp
index ec785f320b..dffb0d7803 100644
--- a/src/core/SkFloat.cpp
+++ b/src/core/SkFloat.cpp
@@ -8,7 +8,7 @@
 
 
 #include "SkFloat.h"
-#include "SkMath.h"
+#include "SkMathPriv.h"
 
 #define EXP_BIAS    (127+23)
 
diff --git a/src/core/SkFloatBits.cpp b/src/core/SkFloatBits.cpp
index 378f98db43..fe4a1b9ab8 100644
--- a/src/core/SkFloatBits.cpp
+++ b/src/core/SkFloatBits.cpp
@@ -1,12 +1,12 @@
-
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+
 #include "SkFloatBits.h"
-#include "SkMath.h"
+#include "SkMathPriv.h"
 
 /******************************************************************************
     SkFloatBits_toInt[Floor, Round, Ceil] are identical except for what they
diff --git a/src/core/SkMath.cpp b/src/core/SkMath.cpp
index 7b753057cc..a149625297 100644
--- a/src/core/SkMath.cpp
+++ b/src/core/SkMath.cpp
@@ -1,4 +1,3 @@
-
 /*
  * Copyright 2008 The Android Open Source Project
  *
@@ -6,8 +5,7 @@
  * found in the LICENSE file.
  */
 
-
-#include "SkMath.h"
+#include "SkMathPriv.h"
 #include "SkCordic.h"
 #include "SkFloatBits.h"
 #include "SkFloatingPoint.h"
diff --git a/src/core/SkMathPriv.h b/src/core/SkMathPriv.h
new file mode 100644
index 0000000000..055acc4ebd
--- /dev/null
+++ b/src/core/SkMathPriv.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkMathPriv_DEFINED
+#define SkMathPriv_DEFINED
+
+#include "SkMath.h"
+
+/** Returns -1 if n < 0, else returns 0
+ */
+#define SkExtractSign(n)    ((int32_t)(n) >> 31)
+
+/** If sign == -1, returns -n, else sign must be 0, and returns n.
+ Typically used in conjunction with SkExtractSign().
+ */
+static inline int32_t SkApplySign(int32_t n, int32_t sign) {
+    SkASSERT(sign == 0 || sign == -1);
+    return (n ^ sign) - sign;
+}
+
+/** Return x with the sign of y */
+static inline int32_t SkCopySign32(int32_t x, int32_t y) {
+    return SkApplySign(x, SkExtractSign(x ^ y));
+}
+
+/** Given a positive value and a positive max, return the value
+ pinned against max.
+ Note: only works as long as max - value doesn't wrap around
+ @return max if value >= max, else value
+ */
+static inline unsigned SkClampUMax(unsigned value, unsigned max) {
+#ifdef SK_CPU_HAS_CONDITIONAL_INSTR
+    if (value > max) {
+        value = max;
+    }
+    return value;
+#else
+    int diff = max - value;
+    // clear diff if diff is positive
+    diff &= diff >> 31;
+    
+    return value + diff;
+#endif
+}
+
+/** Computes the 64bit product of a * b, and then shifts the answer down by
+ shift bits, returning the low 32bits. shift must be [0..63]
+ e.g. to perform a fixedmul, call SkMulShift(a, b, 16)
+ */
+int32_t SkMulShift(int32_t a, int32_t b, unsigned shift);
+
+/** Return the integer square root of n, treated as a SkFixed (16.16)
+ */
+#define SkSqrt32(n)         SkSqrtBits(n, 15)
+
+/** Return the integer cube root of value, with a bias of bitBias
+ */
+int32_t SkCubeRootBits(int32_t value, int bitBias);
+
+///////////////////////////////////////////////////////////////////////////////
+
+/** Return a*b/255, truncating away any fractional bits. Only valid if both
+ a and b are 0..255
+ */
+static inline U8CPU SkMulDiv255Trunc(U8CPU a, U8CPU b) {
+    SkASSERT((uint8_t)a == a);
+    SkASSERT((uint8_t)b == b);
+    unsigned prod = SkMulS16(a, b) + 1;
+    return (prod + (prod >> 8)) >> 8;
+}
+
+/** Return (a*b)/255, taking the ceiling of any fractional bits. Only valid if
+ both a and b are 0..255. The expected result equals (a * b + 254) / 255.
+ */
+static inline U8CPU SkMulDiv255Ceiling(U8CPU a, U8CPU b) {
+    SkASSERT((uint8_t)a == a);
+    SkASSERT((uint8_t)b == b);
+    unsigned prod = SkMulS16(a, b) + 255;
+    return (prod + (prod >> 8)) >> 8;
+}
+
+/** Just the rounding step in SkDiv255Round: round(value / 255)
+ */
+static inline unsigned SkDiv255Round(unsigned prod) {
+    prod += 128;
+    return (prod + (prod >> 8)) >> 8;
+}
+
+#endif
+
diff --git a/src/core/SkXfermode.cpp b/src/core/SkXfermode.cpp
index 74097be67b..aeed9cc26e 100644
--- a/src/core/SkXfermode.cpp
+++ b/src/core/SkXfermode.cpp
@@ -10,6 +10,7 @@
 #include "SkXfermode.h"
 #include "SkColorPriv.h"
 #include "SkFlattenableBuffers.h"
+#include "SkMathPriv.h"
 
 SK_DEFINE_INST_COUNT(SkXfermode)