tilemap_index.c

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/*****************************************************************************
 * ugBASIC - an isomorphic BASIC language compiler for retrocomputers        *
 *****************************************************************************
 * Copyright 2021-2026 Marco Spedaletti (asimov@mclink.it)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
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 * Unless required by applicable law or agreed to in writing, software
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 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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/****************************************************************************
 * INCLUDE SECTION 
 ****************************************************************************/
 
#include "../../ugbc.h"
 
/****************************************************************************
 * CODE SECTION 
 ****************************************************************************/
 
extern char DATATYPE_AS_STRING[][16];
 
/* <usermanual>
@keyword TILEMAP INDEX
 
@english
 
The ''TILEMAP INDEX'' allows you to know the identifier of the tile located 
in correspondence with the given set of coordinates. In particular, given a 
tile map as parameter, you can know what the tile is at the x, y position and, 
if present and given, at the given layer.
 
@italian
 
L'istruzione ''TILEMAP INDEX'' consente di conoscere l'identificativo della 
tile che si trova in corrispondenza del set di coordinate date. In particolare, 
data una mappa di tiles come parametro, si può conoscere quale sia il tile alla 
posizione x, y e, se presente, al layer dato. 
 
@syntax = TILEMAP INDEX( column, row [, layer] )
 
@example index = TILEMAP INDEX( 0, 0 )
@example index = TILEMAP INDEX( 0, 0, 1 )
 
@seeAlso TILEMAP TILE AT
 
@target all
@verified
</usermanual> */
/* <usermanual>
@keyword TILEMAP TILE AT
 
@english
 
@italian
 
@syntax = TILEMAP TILE AT( column, row [, layer] )
 
@example index = TILEMAP TILE AT( 0, 0 )
@example index = TILEMAP TILE AT( 0, 0, 1 )
 
@alias TILEMAP INDEX
 
@target all
@verified
</usermanual> */
 
Variable * tilemap_index_vars( Environment * _environment, char * _tilemap, char * _column, char * _row, char * _layer  ) {
 
    MAKE_LABEL
 
    Variable * tilemap = NULL;
    Variable * column = NULL;
    Variable * row = NULL;
    Variable * layer = NULL;
 
    if ( _column ) {
        column = variable_retrieve( _environment, _column );
    }
    
    if ( _row ) {
        row = variable_retrieve( _environment, _row );
    }
 
    if ( _layer ) {
        layer = variable_retrieve( _environment, _layer );
    }
 
    tilemap = variable_retrieve( _environment, _tilemap );
    if ( tilemap->type != VT_TILEMAP ) {
        CRITICAL_TILEMAP_INDEX_INVALID_TILEMAP( _tilemap );
    }
 
    Variable * tileset = variable_retrieve( _environment, tilemap->tileset->name );
 
    int size = tilemap->mapWidth * tilemap->mapHeight;
 
    Variable * index = NULL;
 
    if ( tilemap->size > 255 ) {
        index = variable_temporary( _environment, VT_WORD, "(index)" );
    } else {
        index = variable_temporary( _environment, VT_BYTE, "(index)" );
    }
 
    variable_store( _environment, index->name, 0 );
 
    if ( row && column ) {
        Variable * mapWidth = variable_temporary( _environment, VT_BYTE, "(map width)");
        variable_store( _environment, mapWidth->name, tilemap->mapWidth );
        index = variable_add( _environment, index->name, variable_mul( _environment, row->name, mapWidth->name )->name );
        index = variable_add( _environment, index->name, column->name );
    }
 
    if ( layer ) {
        Variable * sizeSize = variable_temporary( _environment, VT_WORD, "(size)");
        variable_store( _environment, sizeSize->name, size );
        index = variable_add( _environment, index->name, variable_mul( _environment, layer->name, sizeSize->name )->name );
    }
 
    Variable * frame = variable_temporary( _environment, VT_BYTE, "(frame)" );
 
    if ( tilemap->size > 255 ) {
        cpu_move_8bit_indirect2_16bit( _environment, tilemap->realName, index->realName, frame->realName );
    } else {
        cpu_move_8bit_indirect2_8bit( _environment, tilemap->realName, index->realName, frame->realName );
    }
 
    return frame;
 
}