unit uengShaderFileHelper;

{$mode objfpc}{$H+}
{$I uengShaderFile.inc}

interface

uses
  uengShaderPart, uengShaderFileParser;

function IsValidIdentifier(const aIdent: String): Boolean;
function CheckEndToken(const aArgs: TengParseArgs; const aShaderPart: TengShaderPart): String;

implementation

uses
  sysutils,
  uengShaderFileConstants, uengShaderFileTypes;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function IsValidIdentifier(const aIdent: String): Boolean;
var
  i, len: Integer;
begin
  len := Length(aIdent);
  result := false;
  for i := 1 to len do
    if not (aIdent[i] in VALID_IDENT_CHARS) then
      exit;
  result := true;
end;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
function CheckEndToken(const aArgs: TengParseArgs; const aShaderPart: TengShaderPart): String;
var
  oldLine, oldCol: Integer;
  param: TengTokenParameterList;
begin
  param := TengTokenParameterList.Create('');
  try
    oldLine := aArgs.Line;
    oldCol  := aArgs.Col;
    if not aArgs.ExtractToken(param) then
      raise EengUnexpectedToken.Create(TOKEN_NONE, TOKEN_END, oldLine, oldCol, aShaderPart.Filename);
    if (param[0].Name <> TOKEN_END) then
      raise EengUnexpectedToken.Create(param[0].Name, TOKEN_END, oldLine, oldCol, aShaderPart.Filename);
    if (param.Count <> 1) then
      raise EengInvalidParamterCount.Create(TOKEN_END, 1, oldLine, oldCol, aShaderPart.Filename);
    result := '';
  finally
    FreeAndNil(param);
  end;
end;

end.