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Torque/SDK/lib/maxsdk40/expr.h

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+/**********************************************************************
+ *<
+	FILE: expr.h
+
+	DESCRIPTION: expression object include file.
+
+	CREATED BY: Don Brittain
+
+	HISTORY:
+
+ *>	Copyright (c) 1994, All Rights Reserved.
+ **********************************************************************/
+
+#ifndef _EXPR_H_
+
+#define _EXPR_H_
+
+#include "export.h"
+
+#define SCALAR_EXPR		1
+#define VECTOR_EXPR		3
+
+#define SCALAR_VAR		SCALAR_EXPR
+#define VECTOR_VAR		VECTOR_EXPR
+
+class Expr;
+
+typedef int (*ExprFunc)(Expr *e, float f);
+
+class DllExport Inst {
+public:
+    ExprFunc	func;
+    float  		sVal;
+};
+
+class ExprVar {
+public:
+	TSTR		name;
+	int			type;
+	int			regNum;
+};
+
+MakeTab(float);
+MakeTab(Point3);
+MakeTab(Inst);
+MakeTab(ExprVar);
+
+class Expr {
+public:
+	Expr()	{ sValStk = vValStk = instStk = nextScalar = nextVector = 0; }
+	~Expr()	{ deleteAllVars(); }
+
+	DllExport int		load(char *s);
+	DllExport int		eval(float *ans, int sRegCt, float *sRegs, int vRegCt=0, Point3 *vRegs=NULL);
+	int					getExprType(void)	{ return exprType; }
+	TCHAR *				getExprStr(void)	{ return origStr; }
+	TCHAR *				getProgressStr(void){ return progressStr; }
+	DllExport int		defVar(int type, TCHAR *name);
+	DllExport int		getVarCount(int type);
+	DllExport TCHAR *	getVarName(int type, int i);
+	DllExport int		getVarRegNum(int type, int i);
+	DllExport BOOL		deleteAllVars();
+	DllExport BOOL		deleteVar(TCHAR *name);
+
+// pseudo-private: (only to be used by the "instruction" functions
+	void		setExprType(int type)	{ exprType = type; }
+	void		pushInst(ExprFunc fn, float f) 
+					{ if(instStk >= inst.Count()) inst.SetCount(instStk+30); 
+					inst[instStk].func = fn; inst[instStk++].sVal = f; }
+	void		pushSVal(float f)	{ if(sValStk>=sVal.Count())sVal.SetCount(sValStk+10);sVal[sValStk++]=f; }
+	float		popSVal()			{ return sVal[--sValStk]; }
+	void		pushVVal(Point3 &v)	{ if(vValStk>=vVal.Count())vVal.SetCount(vValStk+10);vVal[vValStk++]=v; }
+	Point3 &	popVVal()			{ return vVal[--vValStk]; }
+	int			getSRegCt(void)		{ return sRegCt; }
+	float		getSReg(int index)	{ return sRegPtr[index]; }
+	int			getVRegCt(void)		{ return vRegCt; }
+	Point3 &	getVReg(int index)	{ return vRegPtr[index]; }
+
+	ExprVarTab	vars;			// named variables
+private:
+	TCHAR *		exprPtr;		// pointer to current str pos during parsing
+	TCHAR *		exprStr;		// ptr to original expression string to parse
+	TSTR		origStr;		// original expression string that was loaded
+	TSTR		progressStr;	// string to hold part of expr successfully parsed
+	int			sRegCt;			// actual number of scalar registers passed to "eval"
+	float		*sRegPtr;		// pointer to the scalar register array
+	int			vRegCt;			// actual number of vector registers passed to "eval"
+	Point3		*vRegPtr;		// pointer to the vector register array
+	int			exprType;		// expression type: SCALAR_EXPR or VECTOR_EXPR (set by load)
+
+	int			sValStk;		// scalar value stack
+	floatTab	sVal;
+	int			vValStk;		// vector value stack
+	Point3Tab	vVal;
+	int			instStk;		// instruction stack
+	InstTab		inst;
+
+	int			nextScalar;		// next scalar slot
+	int			nextVector;		// next vector slot
+
+	friend		yylex();
+	friend		yyerror(char *);
+};
+
+#define EXPR_NORMAL			 0
+#define EXPR_INST_OVERFLOW	-1	// instruction stack overflow during parsing
+#define EXPR_UNKNOWN_TOKEN	-2  // unknown function, const, or reg during parsing
+#define EXPR_TOO_MANY_VARS	-3	// value stack overflow
+#define EXPR_TOO_MANY_REGS	-4	// register array overflow, or reg number too big
+#define EXPR_CANT_EVAL		-5	// function can't be evaluated with given arg
+#define EXPR_CANT_PARSE		-6	// expression can't be parsed (syntactically)
+
+#endif // _EXPR_H_