Changeset 970 for cpp/common

Timestamp:

06/30/20 00:34:59 (4 years ago)

Author:

Maciej Komosinski

Message:

Added functions to properly round floating point values to specified precision

Location:

cpp/common

Files:

• nonstd_math.cpp (modified) (2 diffs)
• nonstd_math.h (modified) (1 diff)

cpp/common/nonstd_math.cpp

@@ -1 +1 @@
 // This file is a part of Framsticks SDK.  http://www.framsticks.com/
-// Copyright (C) 1999-2019  Maciej Komosinski and Szymon Ulatowski.
+// Copyright (C) 1999-2020  Maciej Komosinski and Szymon Ulatowski.
 // See LICENSE.txt for details.
 
 #include "nonstd_math.h"
+#ifdef USE_PRINTFLOAT_DRAGON4
+#include <PrintFloat/PrintFloat.h>
+#else
+#include <sstream>
+#endif
 
 RandomGenerator &rndGetInstance()
@@ -11 +16 @@
 }
 
+int doubleToString(double x, int precision, char *buffer, int bufferlen)
+{
+#ifdef USE_PRINTFLOAT_DRAGON4
+        return PrintFloat64(buffer, bufferlen, x,
+                ((x < -1e17) || (x > 1e17) || ((x < 1e-4) && (x > -1e-4) && (x != 0.0)))
+                ? PrintFloatFormat_Scientific : PrintFloatFormat_Positional,
+                precision); //http://www.ryanjuckett.com/programming/printing-floating-point-numbers/
+#else
+        char format[10];
+        sprintf(format, "%%.%dg", precision < 0 ? 17 : precision); //https://stackoverflow.com/questions/16839658/printf-width-specifier-to-maintain-precision-of-floating-point-value
+        return sprintf(buffer, format, x);
+#endif
+}
+
+
+double round(const double x, const int precision)
+{
+#ifdef USE_PRINTFLOAT_DRAGON4
+        char buffer[30];
+        doubleToString(x, precision, buffer, 30);
+        double rounded = strtod(buffer, NULL);
+#else
+        std::stringstream ss;
+        ss << std::fixed;
+        ss.precision(precision); // set the number of places after decimal
+        ss << x;
+        double rounded = stod(ss.str());
+#endif
+        //printf("%d  %20g \t %20g\n", precision, x, rounded); //for debugging
+        return rounded;
+}
 
 

cpp/common/nonstd_math.h

@@ -27 +27 @@
 inline void rndSetSeed(unsigned int seed) { rndGetInstance().setSeed(seed); }
 inline unsigned int rndRandomizeSeed() { return rndGetInstance().randomize(); }
+
+
+
+// precision==-1 for full precision, or positive values for the number of digits to print past the decimal point.
+// Allocated buffer with bufferlen=30 is OK.
+// Returns the number of chars actually used (not including the ending 0).
+int doubleToString(double x, int precision, char *buffer, int bufferlen);
+
+double round(const double x, const int precision);
+
+
+
+
 
 //floating point specific numbers