Add pinned versions of *ToFixed.
BUG=skia:4632
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1707023002
Review URL: https://codereview.chromium.org/1707023002
diff --git a/include/private/SkFixed.h b/include/private/SkFixed.h
index 56821d4..c90d5e9 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 @@
#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 @@
#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 @@
#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