qzdoom-gpl/src/thingdef/thingdef_exp.cpp
Christoph Oelckers b9afb78523 - Added native variables to expression evaluator and replaced the previous
handling of actor variables in expressions with it.
- Added support for floating point constants to DECORATE expression evaluator.

SVN r1271 (trunk)
2008-10-19 21:43:36 +00:00

572 lines
14 KiB
C++

/*
** thingdef_exp.cpp
**
** Expression parsing / runtime evaluating support
**
**---------------------------------------------------------------------------
** Copyright 2005 Jan Cholasta
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
** derived from this software without specific prior written permission.
** 4. When not used as part of ZDoom or a ZDoom derivative, this code will be
** covered by the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or (at
** your option) any later version.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/
#include "actor.h"
#include "sc_man.h"
#include "tarray.h"
#include "templates.h"
#include "cmdlib.h"
#include "i_system.h"
#include "m_random.h"
#include "a_pickups.h"
#include "thingdef.h"
#include "p_lnspec.h"
#include "doomstat.h"
#include "thingdef_exp.h"
FRandom pr_exrandom ("EX_Random");
//
// ParseExpression
// [GRB] Parses an expression and stores it into Expression array
//
static FxExpression *ParseExpressionM (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionL (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionK (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionJ (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionI (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionH (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionG (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionF (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionE (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionD (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionC (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionB (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpressionA (FScanner &sc, const PClass *cls);
static FxExpression *ParseExpression0 (FScanner &sc, const PClass *cls);
FxExpression *ParseExpression (FScanner &sc, PClass *cls)
{
FxExpression *data = ParseExpressionM (sc, cls);
FCompileContext ctx;
ctx.cls = cls;
ctx.lax = true;
data = data->Resolve(ctx);
return data;
}
int ParseExpression (FScanner &sc, bool _not, PClass *cls)
{
return AddExpression(ParseExpression (sc, cls));
}
static FxExpression *ParseExpressionM (FScanner &sc, const PClass *cls)
{
FxExpression *condition = ParseExpressionL (sc, cls);
if (sc.CheckToken('?'))
{
FxExpression *truex = ParseExpressionM (sc, cls);
sc.MustGetToken(':');
FxExpression *falsex = ParseExpressionM (sc, cls);
return new FxConditional(condition, truex, falsex);
}
else
{
return condition;
}
}
static FxExpression *ParseExpressionL (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionK (sc, cls);
while (sc.CheckToken(TK_OrOr))
{
FxExpression *right = ParseExpressionK (sc, cls);
tmp = new FxBinaryLogical(TK_OrOr, tmp, right);
}
return tmp;
}
static FxExpression *ParseExpressionK (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionJ (sc, cls);
while (sc.CheckToken(TK_AndAnd))
{
FxExpression *right = ParseExpressionJ (sc, cls);
tmp = new FxBinaryLogical(TK_AndAnd, tmp, right);
}
return tmp;
}
static FxExpression *ParseExpressionJ (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionI (sc, cls);
while (sc.CheckToken('|'))
{
FxExpression *right = ParseExpressionI (sc, cls);
tmp = new FxBinaryInt('|', tmp, right);
}
return tmp;
}
static FxExpression *ParseExpressionI (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionH (sc, cls);
while (sc.CheckToken('^'))
{
FxExpression *right = ParseExpressionH (sc, cls);
tmp = new FxBinaryInt('^', tmp, right);
}
return tmp;
}
static FxExpression *ParseExpressionH (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionG (sc, cls);
while (sc.CheckToken('&'))
{
FxExpression *right = ParseExpressionG (sc, cls);
tmp = new FxBinaryInt('&', tmp, right);
}
return tmp;
}
static FxExpression *ParseExpressionG (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionF (sc, cls);
while (sc.GetToken() && (sc.TokenType == TK_Eq || sc.TokenType == TK_Neq))
{
int token = sc.TokenType;
FxExpression *right = ParseExpressionF (sc, cls);
tmp = new FxCompareEq(token, tmp, right);
}
if (!sc.End) sc.UnGet();
return tmp;
}
static FxExpression *ParseExpressionF (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionE (sc, cls);
while (sc.GetToken() && (sc.TokenType == '<' || sc.TokenType == '>' || sc.TokenType == TK_Leq || sc.TokenType == TK_Geq))
{
int token = sc.TokenType;
FxExpression *right = ParseExpressionE (sc, cls);
tmp = new FxCompareRel(token, tmp, right);
}
if (!sc.End) sc.UnGet();
return tmp;
}
static FxExpression *ParseExpressionE (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionD (sc, cls);
while (sc.GetToken() && (sc.TokenType == TK_LShift || sc.TokenType == TK_RShift || sc.TokenType == TK_URShift))
{
int token = sc.TokenType;
FxExpression *right = ParseExpressionD (sc, cls);
tmp = new FxBinaryInt(token, tmp, right);
}
if (!sc.End) sc.UnGet();
return tmp;
}
static FxExpression *ParseExpressionD (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionC (sc, cls);
while (sc.GetToken() && (sc.TokenType == '+' || sc.TokenType == '-'))
{
int token = sc.TokenType;
FxExpression *right = ParseExpressionC (sc, cls);
tmp = new FxAddSub(token, tmp, right);
}
if (!sc.End) sc.UnGet();
return tmp;
}
static FxExpression *ParseExpressionC (FScanner &sc, const PClass *cls)
{
FxExpression *tmp = ParseExpressionB (sc, cls);
while (sc.GetToken() && (sc.TokenType == '*' || sc.TokenType == '/' || sc.TokenType == '%'))
{
int token = sc.TokenType;
FxExpression *right = ParseExpressionB (sc, cls);
tmp = new FxMulDiv(token, tmp, right);
}
if (!sc.End) sc.UnGet();
return tmp;
}
static FxExpression *ParseExpressionB (FScanner &sc, const PClass *cls)
{
sc.GetToken();
switch(sc.TokenType)
{
case '~':
return new FxUnaryNotBitwise(ParseExpressionA (sc, cls));
case '!':
return new FxUnaryNotBoolean(ParseExpressionA (sc, cls));
case '-':
return new FxMinusSign(ParseExpressionA (sc, cls));
case '+':
return new FxPlusSign(ParseExpressionA (sc, cls));
default:
sc.UnGet();
return ParseExpressionA (sc, cls);
}
}
//==========================================================================
//
// ParseExpressionB
//
//==========================================================================
static FxExpression *ParseExpressionA (FScanner &sc, const PClass *cls)
{
FxExpression *base_expr = ParseExpression0 (sc, cls);
while(1)
{
FScriptPosition pos(sc);
#if 0
if (sc.CheckToken('.'))
{
if (sc.CheckToken(TK_Default))
{
sc.MustGetToken('.');
base_expr = new FxClassDefaults(base_expr, pos);
}
sc.MustGetToken(TK_Identifier);
FName FieldName = sc.String;
pos = sc;
/* later!
if (SC_CheckToken('('))
{
if (base_expr->IsDefaultObject())
{
SC_ScriptError("Cannot call methods for default.");
}
base_expr = ParseFunctionCall(base_expr, FieldName, false, false, pos);
}
else
*/
{
base_expr = new FxDotIdentifier(base_expr, FieldName, pos);
}
}
else
#endif
if (sc.CheckToken('['))
{
FxExpression *index = ParseExpressionM(sc, cls);
sc.MustGetToken(']');
base_expr = new FxArrayElement(base_expr, index);
}
else break;
}
return base_expr;
}
static FxExpression *ParseExpression0 (FScanner &sc, const PClass *cls)
{
FScriptPosition scpos(sc);
if (sc.CheckToken('('))
{
FxExpression *data = ParseExpressionM (sc, cls);
sc.MustGetToken(')');
return data;
}
else if (sc.CheckToken(TK_True))
{
return new FxConstant(1, scpos);
}
else if (sc.CheckToken(TK_False))
{
return new FxConstant(0, scpos);
}
else if (sc.CheckToken(TK_IntConst))
{
return new FxConstant(sc.Number, scpos);
}
else if (sc.CheckToken(TK_FloatConst))
{
return new FxConstant(sc.Float, scpos);
}
else if (sc.CheckToken(TK_Identifier))
{
FName identifier = FName(sc.String);
switch (identifier)
{
case NAME_Random:
{
FRandom *rng;
if (sc.CheckToken('['))
{
sc.MustGetToken(TK_Identifier);
rng = FRandom::StaticFindRNG(sc.String);
sc.MustGetToken(']');
}
else
{
rng = &pr_exrandom;
}
sc.MustGetToken('(');
FxExpression *min = ParseExpressionM (sc, cls);
sc.MustGetToken(',');
FxExpression *max = ParseExpressionM (sc, cls);
sc.MustGetToken(')');
return new FxRandom(rng, min, max, sc);
}
break;
case NAME_Random2:
{
FRandom *rng;
if (sc.CheckToken('['))
{
sc.MustGetToken(TK_Identifier);
rng = FRandom::StaticFindRNG(sc.String);
sc.MustGetToken(']');
}
else
{
rng = &pr_exrandom;
}
sc.MustGetToken('(');
FxExpression *mask = NULL;
if (!sc.CheckToken(')'))
{
mask = ParseExpressionM(sc, cls);
sc.MustGetToken(')');
}
return new FxRandom2(rng, mask, sc);
}
break;
case NAME_Abs:
{
sc.MustGetToken('(');
FxExpression *x = ParseExpressionM (sc, cls);
sc.MustGetToken(')');
return new FxAbs(x);
}
default:
if (sc.CheckToken('('))
{
if (identifier == NAME_Sin)
{
FxExpression *data = new FxExpression;
data->Type = EX_Sin;
data->ValueType = VAL_Float;
data->Children[0] = ParseExpressionM (sc, cls);
sc.MustGetToken(')');
return data;
}
else if (identifier == NAME_Cos)
{
FxExpression *data = new FxExpression;
data->Type = EX_Cos;
data->ValueType = VAL_Float;
data->Children[0] = ParseExpressionM (sc, cls);
sc.MustGetToken(')');
return data;
}
else
{
int specnum, min_args, max_args;
// Check if this is an action special
specnum = P_FindLineSpecial (sc.String, &min_args, &max_args);
if (specnum != 0 && min_args >= 0)
{
int i;
FxExpression *data = new FxExpression, **left;
data->Type = EX_ActionSpecial;
data->Value.Int = specnum;
data->ValueType = VAL_Int;
data->Children[0] = ParseExpressionM (sc, cls);
left = &data->Children[1];
for (i = 1; i < 5 && sc.CheckToken(','); ++i)
{
FxExpression *right = new FxExpression;
right->Type = EX_Right;
right->Children[0] = ParseExpressionM (sc, cls);
*left = right;
left = &right->Children[1];
}
*left = NULL;
sc.MustGetToken(')');
if (i < min_args)
sc.ScriptError ("Not enough arguments to action special");
if (i > max_args)
sc.ScriptError ("Too many arguments to action special");
return data;
}
else
{
sc.ScriptError("Unknown function '%s'", identifier.GetChars());
}
}
}
else
{
return new FxIdentifier(identifier, sc);
}
}
}
else
{
FString tokname = sc.TokenName(sc.TokenType, sc.String);
sc.ScriptError ("Unexpected token %s", tokname.GetChars());
}
return NULL;
}
ExpVal FxExpression::EvalExpression (AActor *self)
{
ExpVal val;
val.Type = VAL_Int; // Placate GCC
switch (Type)
{
case EX_NOP:
assert (Type != EX_NOP);
val = Value;
break;
case EX_Sin:
{
ExpVal a = Children[0]->EvalExpression (self);
angle_t angle = (a.Type == VAL_Int) ? (a.Int * ANGLE_1) : angle_t(a.Float * ANGLE_1);
val.Type = VAL_Float;
val.Float = FIXED2FLOAT (finesine[angle>>ANGLETOFINESHIFT]);
}
break;
case EX_Cos:
{
ExpVal a = Children[0]->EvalExpression (self);
angle_t angle = (a.Type == VAL_Int) ? (a.Int * ANGLE_1) : angle_t(a.Float * ANGLE_1);
val.Type = VAL_Float;
val.Float = FIXED2FLOAT (finecosine[angle>>ANGLETOFINESHIFT]);
}
break;
case EX_ActionSpecial:
{
int parms[5] = { 0, 0, 0, 0 };
int i = 0;
FxExpression *parm = this;
while (parm != NULL && i < 5)
{
ExpVal val = parm->Children[0]->EvalExpression (self);
if (val.Type == VAL_Int)
{
parms[i] = val.Int;
}
else
{
parms[i] = (int)val.Float;
}
i++;
parm = parm->Children[1];
}
val.Type = VAL_Int;
val.Int = LineSpecials[Value.Int] (NULL, self, false,
parms[0], parms[1], parms[2], parms[3], parms[4]);
}
break;
case EX_Right:
// This should never be a top-level expression.
assert (Type != EX_Right);
break;
}
return val;
}
bool FxExpression::isConstant() const
{
return false;
}
FxExpression *FxExpression::Resolve(FCompileContext &ctx)
{
if (Children[0]) Children[0] = Children[0]->Resolve(ctx);
if (Children[1]) Children[1] = Children[1]->Resolve(ctx);
return this;
}