diff options
| -rw-r--r-- | include/private/SkFixed.h | 36 | ||||
| -rw-r--r-- | tests/MathTest.cpp | 40 |
2 files changed, 67 insertions, 9 deletions
diff --git a/include/private/SkFixed.h b/include/private/SkFixed.h index 56821d4d82..c90d5e9ffd 100644 --- a/include/private/SkFixed.h +++ b/include/private/SkFixed.h @@ -9,6 +9,8 @@ #define SkFixed_DEFINED #include "SkScalar.h" +#include "math.h" + #include "SkTypes.h" /** \file SkFixed.h @@ -29,15 +31,18 @@ typedef int32_t SkFixed; #define SK_FixedRoot2Over2 (0xB505) #define SkFixedToFloat(x) ((x) * 1.52587890625e-5f) -#if 1 - #define SkFloatToFixed(x) ((SkFixed)((x) * SK_Fixed1)) -#else - // pins over/under flows to max/min int32 (slower than just a cast) - static inline SkFixed SkFloatToFixed(float x) { - int64_t n = x * SK_Fixed1; - return (SkFixed)n; - } -#endif +#define SkFloatToFixed(x) ((SkFixed)((x) * SK_Fixed1)) + +// Pins over/under flows to SK_FixedMax/SK_FixedMin (slower than just a cast). +static inline SkFixed SkFloatPinToFixed(float x) { + x *= SK_Fixed1; + // Casting float to int outside the range of the target type (int32_t) is undefined behavior. + if (x >= SK_FixedMax) return SK_FixedMax; + if (x <= SK_FixedMin) return SK_FixedMin; + const SkFixed result = static_cast<SkFixed>(x); + SkASSERT(truncf(x) == static_cast<float>(result)); + return result; +} #ifdef SK_DEBUG static inline SkFixed SkFloatToFixed_Check(float x) { @@ -53,6 +58,17 @@ typedef int32_t SkFixed; #define SkFixedToDouble(x) ((x) * 1.52587890625e-5) #define SkDoubleToFixed(x) ((SkFixed)((x) * SK_Fixed1)) +// Pins over/under flows to SK_FixedMax/SK_FixedMin (slower than just a cast). +static inline SkFixed SkDoublePinToFixed(double x) { + x *= SK_Fixed1; + // Casting double to int outside the range of the target type (int32_t) is undefined behavior. + if (x >= SK_FixedMax) return SK_FixedMax; + if (x <= SK_FixedMin) return SK_FixedMin; + const SkFixed result = static_cast<SkFixed>(x); + SkASSERT(trunc(x) == static_cast<double>(result)); + return result; +} + /** Converts an integer to a SkFixed, asserting that the result does not overflow a 32 bit signed integer */ @@ -147,11 +163,13 @@ inline SkFixed SkFixedMul_longlong(SkFixed a, SkFixed b) { #define SkFixedToScalar(x) SkFixedToFloat(x) #define SkScalarToFixed(x) SkFloatToFixed(x) +#define SkScalarPinToFixed(x) SkFloatPinToFixed(x) #else // SK_SCALAR_IS_DOUBLE #define SkFixedToScalar(x) SkFixedToDouble(x) #define SkScalarToFixed(x) SkDoubleToFixed(x) +#define SkScalarPinToFixed(x) SkDoublePinToFixed(x) #endif diff --git a/tests/MathTest.cpp b/tests/MathTest.cpp index 580cd941fa..9343277f8d 100644 --- a/tests/MathTest.cpp +++ b/tests/MathTest.cpp @@ -5,6 +5,8 @@ * found in the LICENSE file. */ +#include "float.h" + #include "SkColorPriv.h" #include "SkEndian.h" #include "SkFixed.h" @@ -697,3 +699,41 @@ DEF_TEST(divmod_s32, r) { DEF_TEST(divmod_s64, r) { test_divmod<int64_t>(r); } + +DEF_TEST(PinToFixed, reporter) { + // double + REPORTER_ASSERT(reporter, 0 == SkDoublePinToFixed(0.0)); + REPORTER_ASSERT(reporter, 0x10000 == SkDoublePinToFixed(1.0)); + REPORTER_ASSERT(reporter, 0x7FFFFFFE == SkDoublePinToFixed(32767.999984741)); + REPORTER_ASSERT(reporter, 0x7FFFFFFF == SkDoublePinToFixed(32767.999984742)); + REPORTER_ASSERT(reporter, 0x7FFFFFFF == SkDoublePinToFixed(32767.999999999)); + REPORTER_ASSERT(reporter, 0x7FFFFFFF == SkDoublePinToFixed(32768.0)); + REPORTER_ASSERT(reporter, 0x7FFFFFFF == SkDoublePinToFixed(5e10)); + REPORTER_ASSERT(reporter, 0x7FFFFFFF == SkDoublePinToFixed(DBL_MAX)); + REPORTER_ASSERT(reporter, -0x10000 == SkDoublePinToFixed(-1.0)); + // SK_FixedMin is defined to be -SK_FixedMax. + REPORTER_ASSERT(reporter, -0x7FFFFFFE == SkDoublePinToFixed(-32767.999984741)); + REPORTER_ASSERT(reporter, -0x7FFFFFFF == SkDoublePinToFixed(-32767.999984742)); + REPORTER_ASSERT(reporter, -0x7FFFFFFF == SkDoublePinToFixed(-32767.999999999)); + REPORTER_ASSERT(reporter, -0x7FFFFFFF == SkDoublePinToFixed(-32768.0)); + REPORTER_ASSERT(reporter, -0x7FFFFFFF == SkDoublePinToFixed(-5e10)); + REPORTER_ASSERT(reporter, -0x7FFFFFFF == SkDoublePinToFixed(-DBL_MAX)); + + // float + REPORTER_ASSERT(reporter, 0 == SkFloatPinToFixed(0.0f)); + REPORTER_ASSERT(reporter, 0x10000 == SkFloatPinToFixed(1.0f)); + // SkFixed has more precision than float near SK_FixedMax, so SkFloatPinToFixed will never + // produce output between 0x7FFFFF80 and 0x7FFFFFFF. + REPORTER_ASSERT(reporter, 0x7FFFFF80 == SkFloatPinToFixed(32767.9990f)); + REPORTER_ASSERT(reporter, 0x7FFFFFFF == SkFloatPinToFixed(32767.9991f)); + REPORTER_ASSERT(reporter, 0x7FFFFFFF == SkFloatPinToFixed(32768.0f)); + REPORTER_ASSERT(reporter, 0x7FFFFFFF == SkFloatPinToFixed(5e10f)); + REPORTER_ASSERT(reporter, 0x7FFFFFFF == SkFloatPinToFixed(FLT_MAX)); + REPORTER_ASSERT(reporter, -0x10000 == SkFloatPinToFixed(-1.0f)); + // SK_FixedMin is defined to be -SK_FixedMax. + REPORTER_ASSERT(reporter, -0x7FFFFF80 == SkFloatPinToFixed(-32767.9990f)); + REPORTER_ASSERT(reporter, -0x7FFFFFFF == SkFloatPinToFixed(-32767.9991f)); + REPORTER_ASSERT(reporter, -0x7FFFFFFF == SkFloatPinToFixed(-32768.0f)); + REPORTER_ASSERT(reporter, -0x7FFFFFFF == SkFloatPinToFixed(-5e10f)); + REPORTER_ASSERT(reporter, -0x7FFFFFFF == SkFloatPinToFixed(-FLT_MAX)); +} |