- migrated to GZDoom's utility code.

source/common/thirdparty/math/cmath.h

@@ -0,0 +1,149 @@
+#ifndef __CMATH_H
+#define __CMATH_H
+
+#include "xs_Float.h"
+
+#define USE_CUSTOM_MATH	// we want repreducably reliable results, even at the cost of performance
+#define USE_FAST_MATH	// use faster table-based sin and cos variants with limited precision (sufficient for Doom gameplay)
+
+extern"C"
+{
+double c_asin(double);
+double c_acos(double);
+double c_atan(double);
+double c_atan2(double, double);
+double c_sin(double);
+double c_cos(double);
+double c_tan(double);
+double c_cot(double);
+double c_sqrt(double);
+double c_sinh(double);
+double c_cosh(double);
+double c_tanh(double);
+double c_exp(double);
+double c_log(double);
+double c_log10(double);
+double c_pow(double, double);
+}
+
+
+// This uses a sine table with linear interpolation
+// For in-game calculations this is precise enough
+// and this code is more than 10x faster than the
+// Cephes sin and cos function.
+
+struct FFastTrig
+{
+	static const int TBLPERIOD = 8192;
+	static const int BITSHIFT = 19;
+	static const int REMAINDER = (1 << BITSHIFT) - 1;
+	float sinetable[2049];
+
+	double sinq1(unsigned);
+	
+public:
+	FFastTrig();
+	double sin(unsigned);
+	double cos(unsigned);
+};
+
+extern FFastTrig fasttrig;
+
+// This must use xs_Float to guarantee proper integer wraparound.
+#define DEG2BAM(f)		((unsigned)xs_CRoundToInt((f) * (0x40000000/90.)))
+#define RAD2BAM(f)		((unsigned)xs_CRoundToInt((f) * (0x80000000/3.14159265358979323846)))
+
+
+inline double fastcosdeg(double v)
+{
+	return fasttrig.cos(DEG2BAM(v));
+}
+
+inline double fastsindeg(double v)
+{
+	return fasttrig.sin(DEG2BAM(v));
+}
+
+inline double fastcos(double v)
+{
+	return fasttrig.cos(RAD2BAM(v));
+}
+
+inline double fastsin(double v)
+{
+	return fasttrig.sin(RAD2BAM(v));
+}
+
+// these are supposed to be local to this file.
+#undef DEG2BAM
+#undef RAD2BAM
+
+inline double sindeg(double v)
+{
+#ifdef USE_CUSTOM_MATH
+	return c_sin(v * (3.14159265358979323846 / 180.));
+#else
+	return sin(v * (3.14159265358979323846 / 180.));
+#endif
+}
+
+inline double cosdeg(double v)
+{
+#ifdef USE_CUSTOM_MATH
+	return c_cos(v * (3.14159265358979323846 / 180.));
+#else
+	return cos(v * (3.14159265358979323846 / 180.));
+#endif
+}
+
+
+#ifndef USE_CUSTOM_MATH
+#define g_asin  asin
+#define g_acos  acos
+#define g_atan  atan
+#define g_atan2 atan2
+#define g_sin	sin
+#define g_cos	cos
+#define g_sindeg	sindeg
+#define g_cosdeg	cosdeg
+#define g_tan	tan
+#define g_cot	cot
+#define g_sqrt  sqrt
+#define g_sinh  sinh
+#define g_cosh  cosh
+#define g_tanh  tanh
+#define g_exp	exp
+#define g_log	log
+#define g_log10 log10
+#define g_pow	pow
+#else
+#define g_asin  c_asin
+#define g_acos  c_acos
+#define g_atan  c_atan
+#define g_atan2 c_atan2
+#ifndef USE_FAST_MATH
+#define g_sindeg	sindeg
+#define g_cosdeg	cosdeg
+#define g_sin	c_sin
+#define g_cos	c_cos
+#else
+#define g_sindeg	fastsindeg
+#define g_cosdeg	fastcosdeg
+#define g_sin	fastsin
+#define g_cos	fastcos
+#endif
+#define g_tan	c_tan
+#define g_cot	c_cot
+#define g_sqrt  c_sqrt
+#define g_sinh  c_sinh
+#define g_cosh  c_cosh
+#define g_tanh  c_tanh
+#define g_exp	c_exp
+#define g_log	c_log
+#define g_log10 c_log10
+#define g_pow	c_pow
+#endif
+
+
+
+#endif