1 files changed, 150 insertions, 0 deletions
diff --git a/skia/include/corecg/SkFloatBits.h b/skia/include/corecg/SkFloatBits.h
new file mode 100644
index 0000000..1628f6e
--- /dev/null
+++ b/skia/include/corecg/SkFloatBits.h
@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SkFloatBits_DEFINED
+#define SkFloatBits_DEFINED
+
+#include "SkTypes.h"
+
+/** Convert a sign-bit int (i.e. float interpreted as int) into a 2s compliement
+    int. This also converts -0 (0x80000000) to 0. Doing this to a float allows
+    it to be compared using normal C operators (<, <=, etc.)
+*/
+static inline int32_t SkSignBitTo2sCompliment(int32_t x) {
+    if (x < 0) {
+        x &= 0x7FFFFFFF;
+        x = -x;
+    }
+    return x;
+}
+
+/** Convert a 2s compliment int to a sign-bit (i.e. int interpreted as float).
+    This undoes the result of SkSignBitTo2sCompliment().
+ */
+static inline int32_t Sk2sComplimentToSignBit(int32_t x) {
+    int sign = x >> 31;
+    // make x positive
+    x = (x ^ sign) - sign;
+    // set the sign bit as needed
+    x |= sign << 31;
+    return x;
+}
+
+/** Given the bit representation of a float, return its value cast to an int.
+    If the value is out of range, or NaN, return return +/- SK_MaxS32
+*/
+int32_t SkFloatBits_toIntCast(int32_t floatBits);
+
+/** Given the bit representation of a float, return its floor as an int.
+    If the value is out of range, or NaN, return return +/- SK_MaxS32
+ */
+int32_t SkFloatBits_toIntFloor(int32_t floatBits);
+
+/** Given the bit representation of a float, return it rounded to an int.
+    If the value is out of range, or NaN, return return +/- SK_MaxS32
+ */
+int32_t SkFloatBits_toIntRound(int32_t floatBits);
+
+/** Given the bit representation of a float, return its ceiling as an int.
+    If the value is out of range, or NaN, return return +/- SK_MaxS32
+ */
+int32_t SkFloatBits_toIntCeil(int32_t floatBits);
+
+
+#ifdef SK_CAN_USE_FLOAT
+
+union SkFloatIntUnion {
+    float   fFloat;
+    int32_t fSignBitInt;
+};
+
+// Helper to see a float as its bit pattern (w/o aliasing warnings)
+static inline int32_t SkFloat2Bits(float x) {
+    SkFloatIntUnion data;
+    data.fFloat = x;
+    return data.fSignBitInt;
+}
+
+// Helper to see a bit pattern as a float (w/o aliasing warnings)
+static inline float SkBits2Float(int32_t floatAsBits) {
+    SkFloatIntUnion data;
+    data.fSignBitInt = floatAsBits;
+    return data.fFloat;
+}
+
+/** Return the float as a 2s compliment int. Just to be used to compare floats
+    to each other or against positive float-bit-constants (like 0). This does
+    not return the int equivalent of the float, just something cheaper for
+    compares-only.
+ */
+static inline int32_t SkFloatAs2sCompliment(float x) {
+    return SkSignBitTo2sCompliment(SkFloat2Bits(x));
+}
+
+/** Return the 2s compliment int as a float. This undos the result of
+    SkFloatAs2sCompliment
+ */
+static inline float Sk2sComplimentAsFloat(int32_t x) {
+    return SkBits2Float(Sk2sComplimentToSignBit(x));
+}
+
+/** Return x cast to a float (i.e. (float)x)
+*/
+float SkIntToFloatCast(int x);
+float SkIntToFloatCast_NoOverflowCheck(int x);
+
+/** Return the float cast to an int.
+    If the value is out of range, or NaN, return +/- SK_MaxS32
+*/
+static inline int32_t SkFloatToIntCast(float x) {
+    return SkFloatBits_toIntCast(SkFloat2Bits(x));
+}
+
+/** Return the floor of the float as an int.
+    If the value is out of range, or NaN, return +/- SK_MaxS32
+*/
+static inline int32_t SkFloatToIntFloor(float x) {
+    return SkFloatBits_toIntFloor(SkFloat2Bits(x));
+}
+
+/** Return the float rounded to an int.
+    If the value is out of range, or NaN, return +/- SK_MaxS32
+*/
+static inline int32_t SkFloatToIntRound(float x) {
+    return SkFloatBits_toIntRound(SkFloat2Bits(x));
+}
+
+/** Return the ceiling of the float as an int.
+    If the value is out of range, or NaN, return +/- SK_MaxS32
+*/
+static inline int32_t SkFloatToIntCeil(float x) {
+    return SkFloatBits_toIntCeil(SkFloat2Bits(x));
+}
+
+#endif
+
+//  Scalar wrappers for float-bit routines
+
+#ifdef SK_SCALAR_IS_FLOAT
+    #define SkScalarAs2sCompliment(x)    SkFloatAs2sCompliment(x)
+    #define Sk2sComplimentAsScalar(x)    Sk2sComplimentAsFloat(x)
+#else
+    #define SkScalarAs2sCompliment(x)    (x)
+    #define Sk2sComplimentAsScalar(x)    (x)
+#endif
+
+#endif
+