solvespace/src/expr.h

141 lines
4.3 KiB
C++

//-----------------------------------------------------------------------------
// An expression in our symbolic algebra system, used to write, linearize,
// and solve our constraint equations.
//
// Copyright 2008-2013 Jonathan Westhues.
//-----------------------------------------------------------------------------
#ifndef SOLVESPACE_EXPR_H
#define SOLVESPACE_EXPR_H
class Expr {
public:
enum class Op : uint32_t {
// A parameter, by the hParam handle
PARAM = 0,
// A parameter, by a pointer straight in to the param table (faster,
// if we know that the param table won't move around)
PARAM_PTR = 1,
// Operands
CONSTANT = 20,
VARIABLE = 21,
// Binary ops
PLUS = 100,
MINUS = 101,
TIMES = 102,
DIV = 103,
// Unary ops
NEGATE = 104,
SQRT = 105,
SQUARE = 106,
SIN = 107,
COS = 108,
ASIN = 109,
ACOS = 110,
};
Op op;
Expr *a;
union {
double v;
hParam parh;
Param *parp;
Expr *b;
};
Expr() = default;
Expr(double val) : op(Op::CONSTANT) { v = val; }
static inline Expr *AllocExpr()
{ return (Expr *)AllocTemporary(sizeof(Expr)); }
static Expr *From(hParam p);
static Expr *From(double v);
Expr *AnyOp(Op op, Expr *b);
inline Expr *Plus (Expr *b_) { return AnyOp(Op::PLUS, b_); }
inline Expr *Minus(Expr *b_) { return AnyOp(Op::MINUS, b_); }
inline Expr *Times(Expr *b_) { return AnyOp(Op::TIMES, b_); }
inline Expr *Div (Expr *b_) { return AnyOp(Op::DIV, b_); }
inline Expr *Negate() { return AnyOp(Op::NEGATE, NULL); }
inline Expr *Sqrt () { return AnyOp(Op::SQRT, NULL); }
inline Expr *Square() { return AnyOp(Op::SQUARE, NULL); }
inline Expr *Sin () { return AnyOp(Op::SIN, NULL); }
inline Expr *Cos () { return AnyOp(Op::COS, NULL); }
inline Expr *ASin () { return AnyOp(Op::ASIN, NULL); }
inline Expr *ACos () { return AnyOp(Op::ACOS, NULL); }
Expr *PartialWrt(hParam p) const;
double Eval() const;
uint64_t ParamsUsed() const;
bool DependsOn(hParam p) const;
static bool Tol(double a, double b);
Expr *FoldConstants();
void Substitute(hParam oldh, hParam newh);
static const hParam NO_PARAMS, MULTIPLE_PARAMS;
hParam ReferencedParams(ParamList *pl) const;
void ParamsToPointers();
std::string Print() const;
// number of child nodes: 0 (e.g. constant), 1 (sqrt), or 2 (+)
int Children() const;
// total number of nodes in the tree
int Nodes() const;
// Make a simple copy
Expr *DeepCopy() const;
// Make a copy, with the parameters (usually referenced by hParam)
// resolved to pointers to the actual value. This speeds things up
// considerably.
Expr *DeepCopyWithParamsAsPointers(IdList<Param,hParam> *firstTry,
IdList<Param,hParam> *thenTry) const;
static Expr *Parse(const std::string &input, std::string *error);
static Expr *From(const std::string &input, bool popUpError);
};
class ExprVector {
public:
Expr *x, *y, *z;
static ExprVector From(Expr *x, Expr *y, Expr *z);
static ExprVector From(Vector vn);
static ExprVector From(hParam x, hParam y, hParam z);
static ExprVector From(double x, double y, double z);
ExprVector Plus(ExprVector b) const;
ExprVector Minus(ExprVector b) const;
Expr *Dot(ExprVector b) const;
ExprVector Cross(ExprVector b) const;
ExprVector ScaledBy(Expr *s) const;
ExprVector WithMagnitude(Expr *s) const;
Expr *Magnitude() const;
Vector Eval() const;
};
class ExprQuaternion {
public:
Expr *w, *vx, *vy, *vz;
static ExprQuaternion From(Expr *w, Expr *vx, Expr *vy, Expr *vz);
static ExprQuaternion From(Quaternion qn);
static ExprQuaternion From(hParam w, hParam vx, hParam vy, hParam vz);
ExprVector RotationU() const;
ExprVector RotationV() const;
ExprVector RotationN() const;
ExprVector Rotate(ExprVector p) const;
ExprQuaternion Times(ExprQuaternion b) const;
Expr *Magnitude() const;
};
#endif