initial commit

1 files changed, 78 insertions, 0 deletions

diff --git a/src/ExtMath.h b/src/ExtMath.h
new file mode 100644
index 0000000..b05289d
--- /dev/null
+++ b/src/ExtMath.h
@@ -0,0 +1,78 @@
+#ifndef CC_MATH_H
+#define CC_MATH_H
+#include "Core.h"
+/* Simple math functions and constants. Also implements a RNG algorithm, based on 
+      Java's implementation from https://docs.oracle.com/javase/7/docs/api/java/util/Random.html
+   Copyright 2014-2023 ClassiCube | Licensed under BSD-3
+*/
+
+#define MATH_PI 3.1415926535897931f
+#define MATH_DEG2RAD (MATH_PI / 180.0f)
+#define MATH_RAD2DEG (180.0f / MATH_PI)
+#define MATH_LARGENUM 1000000000.0f
+
+#define Math_Deg2Packed(x) ((cc_uint8)((x) * 256.0f / 360.0f))
+#define Math_Packed2Deg(x) ((x) * 360.0f / 256.0f)
+
+#if defined __GNUC__ && !defined CC_PLAT_PS1
+/* fabsf/sqrtf are single intrinsic instructions in gcc/clang */
+/* (sqrtf is only when -fno-math-errno though) */
+#define Math_AbsF(x) __builtin_fabsf(x)
+#define Math_SqrtF(x) __builtin_sqrtf(x)
+#else
+float Math_AbsF(float x);
+float Math_SqrtF(float x);
+#endif
+
+float Math_Mod1(float x);
+int   Math_AbsI(int x);
+
+CC_API double Math_Sin(double x);
+CC_API double Math_Cos(double x);
+CC_API float Math_SinF(float x);
+CC_API float Math_CosF(float x);
+/* Computes atan2(y, x), intended primarily for angle calculation*/
+/*  Note that accuracy is only up to around 4 decimal places */
+float Math_Atan2f(float x, float y);
+
+/* Computes log2(x). Can also be used to approximate log_y(x). */
+/*   e.g. for log3(x), use: log2(x)/log2(3) */
+double Math_Log2(double x);
+/* Computes 2^x. Can also be used to approximate y^x. */
+/*   e.g. for 3^x, use: exp2(log2(3)*x) */
+double Math_Exp2(double x);
+
+int Math_Floor(float value);
+int Math_Ceil(float value);
+int Math_ilog2(cc_uint32 value);
+int Math_CeilDiv(int a, int b);
+int Math_Sign(float value);
+
+/* Clamps the given angle so it lies between [0, 360) */
+float Math_ClampAngle(float degrees);
+/* Linearly interpolates between a and b */
+float Math_Lerp(float a, float b, float t);
+/* Linearly interpolates between a given angle range, adjusting if necessary. */
+float Math_LerpAngle(float leftAngle, float rightAngle, float t);
+
+int Math_NextPowOf2(int value);
+cc_bool Math_IsPowOf2(int value);
+#define Math_Clamp(val, min, max) val = val < (min) ? (min) : val;  val = val > (max) ? (max) : val;
+
+typedef cc_uint64 RNGState;
+/* Initialises RNG using seed from current UTC time. */
+void Random_SeedFromCurrentTime(RNGState* rnd);
+/* Initialised RNG using the given seed. */
+CC_API  void Random_Seed(      RNGState* rnd, int seed);
+typedef void (*FP_Random_Seed)(RNGState* rnd, int seed);
+
+/* Returns integer from 0 inclusive to n exclusive */
+CC_API  int Random_Next(      RNGState* rnd, int n);
+typedef int (*FP_Random_Next)(RNGState* rnd, int n);
+/* Returns real from 0 inclusive to 1 exclusive */
+CC_API float Random_Float(RNGState* rnd);
+/* Returns integer from min inclusive to max exclusive */
+static CC_INLINE int Random_Range(RNGState* rnd, int min, int max) {
+	return min + Random_Next(rnd, max - min);
+}
+#endif