diff options
Diffstat (limited to 'lodepng_util.cpp')
| -rw-r--r-- | lodepng_util.cpp | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/lodepng_util.cpp b/lodepng_util.cpp index 574138a..1d76b35 100644 --- a/lodepng_util.cpp +++ b/lodepng_util.cpp @@ -273,15 +273,12 @@ void* lodepng_malloc(size_t size); void lodepng_free(void* ptr); #endif /*LODEPNG_COMPILE_ALLOCATORS*/ -/* avoid needing <float.h> for FLT_MAX. This assumes IEEE 32-bit float. */ -static const float lodepng_flt_max = 3.40282346638528859811704183484516925e38f; - /* define infinity and NaN in a way compatible with ANSI C90 (no INFINITY or NAN macros) yet also with visual studio */ -/* visual studio doesn't allow division through a zero literal, but allows it through non-const variable set to zero */ +/* visual studio doesn't allow division through a zero literal, but allows it through public non-const variable set to zero */ float lodepng_flt_zero_ = 0.0f; static const float lodepng_flt_inf = 1.0f / lodepng_flt_zero_; /* infinity */ static const float lodepng_flt_nan = 0.0f / lodepng_flt_zero_; /* not a number */ - +static const float lodepng_flt_max = 3.40282346638528859811704183484516925e38f; /* avoid needing <float.h> for FLT_MAX. This assumes IEEE 32-bit float. */ /* powf polyfill, 5-6 digits accurate, 33-80% slower than powf, assumes IEEE 32-bit float, but other than that multiplatform and no math lib needed @@ -291,15 +288,14 @@ static float lodepng_powf(float x, float y) { int i = 0; /* handle all the special floating point rules */ if(x == 1 || y == 0) return 1; /*these cases return 1 even if the other value is NaN, as specified*/ - if(y == 1) return x; - if(!(x > 0 && x <= lodepng_flt_max && y == y && y <= lodepng_flt_max && y >= -lodepng_flt_max)) { - if(y == 1) return x; /* preserves negative-0 */ + if(y == 1) return x; /* preserves negative-0 */ + if(!(x > 0 && x <= lodepng_flt_max && y >= -lodepng_flt_max && y <= lodepng_flt_max)) { /*all special cases*/ if(x != x || y != y) return x + y; /* nan */ if(x > 0) { if(x > lodepng_flt_max) return y <= 0 ? (y == 0 ? 1 : 0) : x; /* x = +infinity */ } else { if(!(y < -1073741824.0f || y > 1073741824.0f)) { /* large y always even integer, but cast would overflow */ - i = (int)y; + i = (int)y; /* not using floor: not using math lib */ if(i != y) { return (x < -lodepng_flt_max) ? (y < 0 ? 0 : lodepng_flt_inf) : (x == 0 ? (y < 0 ? lodepng_flt_inf : 0) : lodepng_flt_nan); @@ -312,7 +308,7 @@ static float lodepng_powf(float x, float y) { -lodepng_flt_inf : lodepng_flt_inf); } x = -x; - if(x == 1) return 1; + if(x == 1) return 1; /* under the C++ rules, pow(-1, +/- infinity) also returns 1 */ } if(y < -lodepng_flt_max || y > lodepng_flt_max) return ((x < 1) != (y > 0)) ? (y < 0 ? -y : y) : 0; } |