rename sk_float_isNaN to sk_float_isnan to match related functions

add sk_float_isinf returning non-zero if the argument is +/- infinity



git-svn-id: http://skia.googlecode.com/svn/trunk@2813 2bbb7eff-a529-9590-31e7-b0007b416f81

3 files changed, 31 insertions, 9 deletions

diff --git a/bench/MathBench.cpp b/bench/MathBench.cpp
index ffee901545..9feb5afb32 100644
--- a/bench/MathBench.cpp
+++ b/bench/MathBench.cpp
@@ -186,7 +186,7 @@ static bool isfinite_plus_int(const float data[4]) {
 }
 
 static bool isfinite_plus_float(const float data[4]) {
-    return  !sk_float_isNaN(mulzeroadd(data));
+    return  !sk_float_isnan(mulzeroadd(data));
 }
 
 static bool isfinite_plus_mulzero(const float data[4]) {
@@ -212,11 +212,6 @@ static const struct {
 
 #undef MAKEREC
 
-static bool SkScalarIsNaN_new(SkScalar x) {
-    float y = x * 0;
-    return y == y;
-}
-
 static bool isFinite(const SkRect& r) {
     // x * 0 will be NaN iff x is infinity or NaN.
     // a + b will be NaN iff either a or b is NaN.
diff --git a/include/core/SkFloatingPoint.h b/include/core/SkFloatingPoint.h
index b204e48595..ee91cd9799 100644
--- a/include/core/SkFloatingPoint.h
+++ b/include/core/SkFloatingPoint.h
@@ -67,10 +67,15 @@ static inline float sk_float_copysign(float x, float y) {
 
 #ifdef SK_BUILD_FOR_WIN
     #define sk_float_isfinite(x)    _finite(x)
-    #define sk_float_isNaN(x)       _isnan(x)
+    #define sk_float_isnan(x)       _isnan(x)
+    static inline int sk_float_isinf(float x) {
+        int32_t bits = SkFloat2Bits(x);
+        return (bits << 1) == (0xFF << 24);
+    }
 #else
     #define sk_float_isfinite(x)    isfinite(x)
-    #define sk_float_isNaN(x)       isnan(x)
+    #define sk_float_isnan(x)       isnan(x)
+    #define sk_float_isinf(x)       isinf(x)
 #endif
 
 #ifdef SK_USE_FLOATBITS
diff --git a/tests/ScalarTest.cpp b/tests/ScalarTest.cpp
index 6c2df73199..2f0aa0bb5a 100644
--- a/tests/ScalarTest.cpp
+++ b/tests/ScalarTest.cpp
@@ -44,6 +44,20 @@ typedef bool (*IsFiniteProc2)(float, float, IsFiniteProc1);
 
 #endif
 
+enum FloatClass {
+    kFinite,
+    kInfinite,
+    kNaN
+};
+
+static void test_floatclass(skiatest::Reporter* reporter, float value, FloatClass fc) {
+    // our sk_float_is... function may return int instead of bool,
+    // hence the double ! to turn it into a bool
+    REPORTER_ASSERT(reporter, !!sk_float_isfinite(value) == (fc == kFinite));
+    REPORTER_ASSERT(reporter, !!sk_float_isinf(value) == (fc == kInfinite));
+    REPORTER_ASSERT(reporter, !!sk_float_isnan(value) == (fc == kNaN));
+}
+
 static void test_isfinite(skiatest::Reporter* reporter) {
 #ifdef SK_CAN_USE_FLOAT
     struct Rec {
@@ -53,7 +67,15 @@ static void test_isfinite(skiatest::Reporter* reporter) {
     
     float max = 3.402823466e+38f;
     float inf = max * max;
-    float nan = 1 / sk_float_sin(0);
+    float nan = inf * 0;
+
+    test_floatclass(reporter,    0, kFinite);
+    test_floatclass(reporter,  max, kFinite);
+    test_floatclass(reporter, -max, kFinite);
+    test_floatclass(reporter,  inf, kInfinite);
+    test_floatclass(reporter, -inf, kInfinite);
+    test_floatclass(reporter,  nan, kNaN);
+    test_floatclass(reporter, -nan, kNaN);
 
     const Rec data[] = {
         {   0,          true    },