Extrahování souřadnic z souboru autocad dxf pomocí funkce explodovat php

Funkce explode () je poměrně jednoduchá, ale velmi užitečná a používá se nepřetržitě při kódování. Pokud tato funkce není použitelná, používají se regulární výrazy, ale pracují pomaleji, takže je užitečné pracovat s připravenými funkcemi php, které urychlí váš program.

Explode php: popis funkce a její praktická aplikace

Funkce vezme řetězec jako vstup, rozdělí jej dělitel a přiřadí hodnoty pole s číselnými klávesami.

Použijeme-li jako příklad soubor dxf autocad, pokusme se extrahovat souřadnice a nakreslit výkres pomocí GD Library php.

Soubor dxf je v podstatě dokument prostého textu, ve kterém jsou zaznamenány souřadnice všech výkresů. Vypadá to takto:

ENTITIES jsou entity, LWPOLYLINE je uzavřený polygon, číslo 10 označuje souřadnici x, následuje hodnota (tj. X = 0.0), číslo 20 označuje y, jeho hodnota je od dalšího řádku (tj. Y = 500.0 ), nic složitého.

Najděte potřebné informace v souboru dxf. K tomu používáme funkci strchr (), která nalezne entity (ENTITIES) a polygony (LWPOLYLINE):

 $content = file_get_contents('stairs.dxf');$entities = strchr($content, "ENTITIES");$endsec = strchr($entities, "ENDSEC", true);$entitie_string = $endsec; 

Funkce exploduje php pomáhá extrahovat souřadnice. V tomto příkladu používáme pouze mnohoúhelník, ale na výkresech je mnoho dalších čísel, takže je přidáváme do pole. Zvažujeme pouze LWPOLYLINE:

 $entities_array = array("LWPOLYLINE"); 

Následující příklad najde polohy všech položek LWPOLYLINE v dokumentu dxf text:

 $lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else } {$positions_entities[$lastPos] = $entitie;$lastPos = $lastPos + strlen($entitie);} $lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else } {$entities_string_array[$positions_entities[$array_keys_positions[$i]]][$array_keys_positions[$i]] = substr($entitie_string, $array_keys_positions[$i], $array_keys_positions[$i+1] - $array_keys_positions[$i] );} $lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else } {$entities_string_array[$positions_entities[$array_keys_positions[$i]]][$array_keys_positions[$i]] = substr($first_entitie_string, $array_keys_positions[$i] );} $lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else } 

Všechny řádky polygonů jsou nyní v poli, tzn. Máme tři polygony, což znamená tři klíče a tři hodnoty. Hodnoty obsahují řádky s informacemi z souboru dxf o těchto polygonech. Nyní je třeba rozdělit tyto čáry na výběr souřadnic z nich. Chcete-li to provést, použijte funkci explode ():

 foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) } {$explode_value_e[$key_ent][$key_val] = explode(PHP_EOL,  $value_e);} foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) } 

Z získaného vícerozměrného pole získáváme hodnoty, které následují značky 10 (x) a 20 (y):

 $lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y); {$coordinates[$k][] = $coordinates_db[] = $coordinates_x[] = (float)$explode_key[$key+1];} $lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y); {$coordinates[$k][] = $coordinates_db[] = $coordinates_y[] = (float)$explode_key[$key+1];} $lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y); 

$ Souřadnice pole obsahuje souřadnice polygonů, $ coordinates_db se použije pro zápis hodnot x a y do databáze a $ coordinates_x a $ coordinates_y jsou potřebné k určení šířky a výšky našeho výkresu v knihovně GD php.

Kombinace dat do řetězce pomocí implode () pro kompaktní ukládání informací v MySQL

Pro uložení do databáze shromáždíme souřadnice do řetězce pomocí implode (), t. Pokud uložíte každý bod do samostatné buňky, bude databáze postupně narůstat na obrovskou velikost. Vytvoření tabulky v MySQL nebude tak, aby komplikuje kód.

 $implode_coordinates_db[$k] = implode(';',$coordinates_db); 

Zbývá napsat funkci, která nakreslí obrázek v knihovně GD:

 $image_array = array($implode_coordinates_db, $width, $height); 

Chcete-li vytvořit obrázek, potřebujeme souřadnice (použijeme řetězec se souřadnicemi, které lze načíst z databáze $ implode_coordinates_db), šířku a výšku.

Volání funkce:

 $image_base64 = image_create($image_array); 

A samotná funkce:

 function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;} {$implode_coordinates = $image_array[0];$width = $image_array[1];$height = $image_array[2];$im = imagecreatetruecolor($width+1, $height+1);$white=imagecolorallocate($im,255,255,255);$black = imagecolorallocate($im, 0, 0, 0);imagefilledrectangle($im, 0, 0, $width, $height, $white);foreach( $implode_coordinates as $key =>$coordinates_string ){$coordinates[$key] = explode(';', $coordinates_string);$polygon_arrays_count[$key]=count($coordinates[$key])/2;imagepolygon($im, $coordinates[$key], $polygon_arrays_count[$key] , $black);} function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;} 

Rozdělení řetězce získané z MySQL pomocí explode ()

Funkce získává souřadnice řetězce z databáze, pak se řetězec rozdělí pomocí exploze php, po níž imagepolygon () nakreslí naše polygony.

 $coordinates[$key] = explode(';', $coordinates_string);imagepolygon($im, $coordinates[$key], $polygon_arrays_count[$key] , $black); 

V tomto příkladu byl obrázek vytvořen ve formátu imagepng base64_encode, ale obrázek můžete uložit do formátu jpg nebo png.

Nyní můžete zobrazit obrázek v prohlížeči:

 $image_array = array($implode_coordinates_db, $width, $height);$image_base64 = image_create($image_array);$image_src="'data:image/png;base64,'.$image_base64;echo" "  "; 

Obrázky na pozadí budou vypadat takto:

Pokud je možné použít namísto regulárních výrazů vestavěné funkce, proces provádění bude trvat o něco méně času, takže vždycky dává smysl nejprve pokusit se o dosažení cíle pomocí hotových řešení v php.

Celý kód:

 $content = file_get_contents('stairs.dxf');$entities = strchr($content, "ENTITIES");$endsec = strchr($entities, "ENDSEC", true);$entitie_string = $endsec;$entities_array = array("LWPOLYLINE");$lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else }foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) }$lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y);function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;}$image_array = array($implode_coordinates_db, $width, $height);$image_base64 = image_create($image_array);$image_src="'data:image/png;base64,'.$image_base64;echo" "  "; {$positions_entities[$lastPos] = $entitie;$lastPos = $lastPos + strlen($entitie);} $content = file_get_contents('stairs.dxf');$entities = strchr($content, "ENTITIES");$endsec = strchr($entities, "ENDSEC", true);$entitie_string = $endsec;$entities_array = array("LWPOLYLINE");$lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else }foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) }$lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y);function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;}$image_array = array($implode_coordinates_db, $width, $height);$image_base64 = image_create($image_array);$image_src='data:image/png;base64,'.$image_base64;echo "  "; {$entities_string_array[$positions_entities[$array_keys_positions[$i]]][$array_keys_positions[$i]] = substr($entitie_string, $array_keys_positions[$i], $array_keys_positions[$i+1] - $array_keys_positions[$i] );} $content = file_get_contents('stairs.dxf');$entities = strchr($content, "ENTITIES");$endsec = strchr($entities, "ENDSEC", true);$entitie_string = $endsec;$entities_array = array("LWPOLYLINE");$lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else }foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) }$lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y);function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;}$image_array = array($implode_coordinates_db, $width, $height);$image_base64 = image_create($image_array);$image_src='data:image/png;base64,'.$image_base64;echo "  "; {$entities_string_array[$positions_entities[$array_keys_positions[$i]]][$array_keys_positions[$i]] = substr($entitie_string, $array_keys_positions[$i] );} $content = file_get_contents('stairs.dxf');$entities = strchr($content, "ENTITIES");$endsec = strchr($entities, "ENDSEC", true);$entitie_string = $endsec;$entities_array = array("LWPOLYLINE");$lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else }foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) }$lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y);function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;}$image_array = array($implode_coordinates_db, $width, $height);$image_base64 = image_create($image_array);$image_src='data:image/png;base64,'.$image_base64;echo "  "; {$explode_value_e[$key_ent][$key_val] = explode(PHP_EOL,  $value_e);} $content = file_get_contents('stairs.dxf');$entities = strchr($content, "ENTITIES");$endsec = strchr($entities, "ENDSEC", true);$entitie_string = $endsec;$entities_array = array("LWPOLYLINE");$lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else }foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) }$lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y);function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;}$image_array = array($implode_coordinates_db, $width, $height);$image_base64 = image_create($image_array);$image_src='data:image/png;base64,'.$image_base64;echo "  "; {$coordinates[$k][] = $coordinates_db[] = $coordinates_x[] = (float)$explode_key[$key+1];} $content = file_get_contents('stairs.dxf');$entities = strchr($content, "ENTITIES");$endsec = strchr($entities, "ENDSEC", true);$entitie_string = $endsec;$entities_array = array("LWPOLYLINE");$lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else }foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) }$lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y);function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;}$image_array = array($implode_coordinates_db, $width, $height);$image_base64 = image_create($image_array);$image_src='data:image/png;base64,'.$image_base64;echo "  "; {$coordinates[$k][] = $coordinates_db[] = $coordinates_y[] = (float)$explode_key[$key+1];} $content = file_get_contents('stairs.dxf');$entities = strchr($content, "ENTITIES");$endsec = strchr($entities, "ENDSEC", true);$entitie_string = $endsec;$entities_array = array("LWPOLYLINE");$lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else }foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) }$lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y);function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;}$image_array = array($implode_coordinates_db, $width, $height);$image_base64 = image_create($image_array);$image_src='data:image/png;base64,'.$image_base64;echo "  "; {$implode_coordinates = $image_array[0];$width = $image_array[1];$height = $image_array[2];$im = imagecreatetruecolor($width+1, $height+1);$white=imagecolorallocate($im,255,255,255);$black = imagecolorallocate($im, 0, 0, 0);imagefilledrectangle($im, 0, 0, $width, $height, $white);foreach( $implode_coordinates as $key =>$coordinates_string ){$coordinates[$key] = explode(';', $coordinates_string);$polygon_arrays_count[$key]=count($coordinates[$key])/2;imagepolygon($im, $coordinates[$key], $polygon_arrays_count[$key] , $black);} $content = file_get_contents('stairs.dxf');$entities = strchr($content, "ENTITIES");$endsec = strchr($entities, "ENDSEC", true);$entitie_string = $endsec;$entities_array = array("LWPOLYLINE");$lastPos = 0;$positions_entities = array();foreach($entities_array as $key_needle =>$entitie){while (($lastPos = strpos($entitie_string, $entitie, $lastPos))!== false) }$array_keys_positions = array_keys($positions_entities);$sizeof_array_positions = sizeof($array_keys_positions);for($i=0; $i< $sizeof_array_positions; $i++){if(isset($array_keys_positions[$i+1])) else }foreach( $entities_string_array as $key_ent =>$value_ent){foreach( $value_ent as $key_val =>$value_e ) }$lwpolyline_array = $explode_value_e["LWPOLYLINE"];$k = 0;foreach( $lwpolyline_array as $lw_key => $explode_key ){foreach( $explode_key as $key => $lwpolyline_value){if( $lwpolyline_value == '10' ) else if( $lwpolyline_value == '20' ) }$implode_coordinates_db[$k] = implode(';',$coordinates_db);$k++;}$width = max($coordinates_x) - min($coordinates_x);$height = max($coordinates_y) - min($coordinates_y);function image_create( $image_array ) ob_start();imagepng($im);$buffer = ob_get_clean();//ob_end_clean();$img = base64_encode($buffer);imagedestroy($im);return $img;}$image_array = array($implode_coordinates_db, $width, $height);$image_base64 = image_create($image_array);$image_src='data:image/png;base64,'.$image_base64;echo "  ";