am_param.cpp

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 1992-2017 Jean-Pierre Charras <jp.charras at wanadoo.fr>
 * Copyright (C) 2010 SoftPLC Corporation, Dick Hollenbeck <[email protected]>
 * Copyright (C) 1992-2020 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under 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 program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */

#include <am_param.h>
#include <am_primitive.h>
#include <macros.h>

#include <wx/debug.h>


extern int ReadInt( char*& text, bool aSkipSeparator = true );
extern double ReadDouble( char*& text, bool aSkipSeparator = true );
extern double Evaluate( AM_PARAM_EVAL_STACK& aExp );

/* Class AM_PARAM
 * holds a parameter value for an "aperture macro" as defined within
 * standard RS274X. The parameter can be a constant, i.e. "immediate" parameter,
 * or depend on some defered values, defined in a D_CODE, by the ADD command.
 * Note the actual value could need an evaluation from an arithmetical expression
 * items in the expression are stored in .
 * A simple definition is just a value stored in one item in m_paramStack
 */
AM_PARAM::AM_PARAM( )
{
 m_index = -1;
}

bool AM_PARAM::IsImmediate() const
{
 bool is_immediate = true;
 for( unsigned ii = 0; ii < m_paramStack.size(); ii++ )
 {
 if( m_paramStack[ii].IsDefered() )
 { // a defered value is found in operand list,
 // so the parameter is not immediate
 is_immediate = false;
 break;
 }
 }
 return is_immediate;
}

double AM_PARAM::GetValue( const D_CODE* aDcode ) const
{
 // In macros, actual values are sometimes given by an expression like:
 // 0-$2/2-$4
 // Because arithmetic predence is used, the parameters (values (double) and operators)
 // are stored in a stack, with all numeric values converted to the actual values
 // when they are defered parameters
 // Each item is stored in a AM_PARAM_EVAL (a value or an operator)
 //
 // Then the stack with all values resolved is parsed and numeric values
 // calculated according to the precedence of operators
 double curr_value = 0.0;
 parm_item_type op_code;

 AM_PARAM_EVAL_STACK ops;

 for( unsigned ii = 0; ii < m_paramStack.size(); ii++ )
 {
 AM_PARAM_ITEM item = m_paramStack[ii];

 switch( item.GetType() )
 {
 case ADD:
 case SUB:
 case MUL:
 case DIV: // just an operator for next parameter value
 case OPEN_PAR:
 case CLOSE_PAR: // Priority modifiers: store in stack
 op_code = item.GetType();
 ops.push_back( AM_PARAM_EVAL( op_code ) );
 break;

 case PUSHPARM:
 // a defered value: get the actual parameter from the aDcode
 if( aDcode ) // should be always true here
 {
 if( item.GetIndex() <= aDcode->GetParamCount() )
 {
 curr_value = aDcode->GetParam( item.GetIndex() );
 }
 else // Get parameter from local param definition
 {
 const APERTURE_MACRO * am_parent = aDcode->GetMacro();
 curr_value = am_parent->GetLocalParam( aDcode, item.GetIndex() );
 }
 }
 else
 {
 wxFAIL_MSG( wxT( "AM_PARAM::GetValue(): NULL param aDcode" ) );
 }

 ops.push_back( AM_PARAM_EVAL( curr_value ) );
 break;

 case PUSHVALUE: // a value is on the stack:
 curr_value = item.GetValue();
 ops.push_back( AM_PARAM_EVAL( curr_value ) );
 break;

 default:
 wxFAIL_MSG( wxString::Format( wxT( "AM_PARAM::GetValue(): dcode %d prm %d/%d: "
 "unexpected type %d" ),
 aDcode ? aDcode->m_Num_Dcode : -1, ii,
 m_paramStack.size(), item.GetType() ) );
 break;
 }
 }

 double result = Evaluate( ops );

 return result;
}

void AM_PARAM::PushOperator( parm_item_type aType, double aValue )
{
 AM_PARAM_ITEM item( aType, aValue);
 m_paramStack.push_back( item );
}

void AM_PARAM::PushOperator( parm_item_type aType, int aValue )
{
 AM_PARAM_ITEM item( aType, aValue);
 m_paramStack.push_back( item );
}

bool AM_PARAM::ReadParam( char*& aText )
{
 bool found = false;
 int ivalue;
 double dvalue;
 bool end = false;

 while( !end )
 {
 switch( *aText )
 {
 case ',':
 aText++;

 if( !found ) // happens when a string starts by ',' before any param
 break; // just skip this separator

 KI_FALLTHROUGH;

 case '\n':
 case '\r':
 case 0: // EOL
 case '*': // Terminator in a gerber command
 end = true;
 break;

 case ' ':
 aText++;
 break;

 case '$':
 // defered value defined later, in ADD command which define defered parameters
 ++aText;
 ivalue = ReadInt( aText, false );
 if( m_index < 1 )
 SetIndex( ivalue );
 PushOperator( PUSHPARM, ivalue );
 found = true;
 break;

 case '/':
 PushOperator( DIV );
 aText++;
 break;

 case '(': // Open a block to evaluate an expression between '(' and ')'
 PushOperator( OPEN_PAR );
 aText++;
 break;

 case ')': // close a block between '(' and ')'
 PushOperator( CLOSE_PAR );
 aText++;
 break;

 case 'x':
 case 'X':
 PushOperator( MUL );
 aText++;
 break;

 case '-':
 case '+':
 // Test if this is an operator between 2 params, or the sign of a value
 if( m_paramStack.size() > 0 && !m_paramStack.back().IsOperator() )
 { // Seems an operator
 PushOperator( *aText == '+' ? ADD : SUB );
 aText++;
 }
 else
 { // seems the sign of a value
 dvalue = ReadDouble( aText, false );
 PushOperator( PUSHVALUE, dvalue );
 found = true;
 }
 break;

 case '=': // A local definition found like $4=$3/2
 // At this point, one defered parameter is expected to be read.
 // this parameter value (the index) is stored in m_index.
 // The list of items is cleared
 aText++;
 m_paramStack.clear();
 found = false;
 break;

 default:
 dvalue = ReadDouble( aText, false );
 PushOperator( PUSHVALUE, dvalue );
 found = true;
 break;
 }
 }

 return found;
}