libShaderFile/header/ulibShaderFile.pas

unit ulibShaderFile;

{$mode objfpc}{$H+}

interface

uses
  Classes, SysUtils;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
const
  LSF_LOGLEVEL_DEBUG                      = 0;
  LSF_LOGLEVEL_INFO                       = 1;
  LSF_LOGLEVEL_WARNING                    = 2;
  LSF_LOGLEVEL_ERROR                      = 3;

  LSF_ERR_NONE                            = $00000000;
  LSF_ERR_NOT_INIT                        = $00000001;
  LSF_ERR_INVALID_HANDLE_SHADER_FILE      = $00000002;
  LSF_ERR_UNKNOWN_IDENTFIFIER             = $00001000;
  LSF_ERR_DUPLICATE_IDENTIFIER            = $00001001;
  LSF_ERR_OUT_OF_RANGE                    = $00001002;
  LSF_ERR_INVALID_IDENTIFIER              = $00001003;
  LSF_ERR_INVALID_PARAMTER_COUNT          = $00001004;
  LSF_ERR_INVALID_PARAMTER                = $00001005;
  LSF_ERR_UNEXPECTED_TOKEN                = $00001006;
  LSF_ERR_INVALID_TOKEN                   = $00001007;
  LSF_ERR_EXPRESSION_INTERNAL             = $00001008;
  LSF_ERR_EXPRESSION                      = $00001009;
  LSF_ERR_SHADER_PART_INTERNAL            = $0000100A;
  LSF_ERR_SHADER_PART                     = $0000100B;
  LSF_ERR_UNKNOWN                         = $FFFFFFFF;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
type
  TlsfErrorCode = Cardinal;
  TlsfLogLevel = Cardinal;
  TlsfShaderFileHandle = Pointer;
  TlsfShaderFileLogEvent = procedure(const aLogLevel: TlsfLogLevel; const aMsg: PAnsiChar);

  Tlsf_ShaderFile_create          = function: TlsfShaderFileHandle; stdcall;
  Tlsf_ShaderFile_setLogCallback  = function(const aHandle: TlsfShaderFileHandle; const aCallback: TlsfShaderFileLogEvent): TlsfErrorCode; stdcall;
  Tlsf_ShaderFile_loadFromFile    = function(const aHandle: TlsfShaderFileHandle; const aFilename: PAnsiChar): TlsfErrorCode; stdcall;
  Tlsf_ShaderFile_saveToFile      = function(const aHandle: TlsfShaderFileHandle; const aFilename: PAnsiChar): TlsfErrorCode; stdcall;
  Tlsf_ShaderFile_destroy         = function(const aHandle: TlsfShaderFileHandle): TlsfErrorCode; stdcall;

  Tlsf_init                       = function : TlsfErrorCode; stdcall;
  Tlsf_getLastErrorCode           = function : TlsfErrorCode; stdcall;
  Tlsf_getLastErrorMsg            = function : PAnsiChar; stdcall;
  Tlsf_getLastErrorTrace          = function : PAnsiChar; stdcall;
  Tlsf_finish                     = function: TlsfErrorCode; stdcall;

var
  lsf_ShaderFile_create:          Tlsf_ShaderFile_create;
  lsf_ShaderFile_setLogCallback:  Tlsf_ShaderFile_setLogCallback;
  lsf_ShaderFile_loadFromFile:    Tlsf_ShaderFile_loadFromFile;
  lsf_ShaderFile_saveToFile:      Tlsf_ShaderFile_saveToFile;
  lsf_ShaderFile_destroy:         Tlsf_ShaderFile_destroy;

  lsf_getLastErrorCode:           Tlsf_getLastErrorCode;
  lsf_getLastErrorMsg:            Tlsf_getLastErrorMsg;
  lsf_getLastErrorTrace:          Tlsf_getLastErrorTrace;

procedure lsf_init(const aLibName: String);
procedure lsf_finish;

implementation

uses
  dynlibs;

var
  libHandle: TLibHandle;
  lsf_init_intern: Tlsf_init;
  lsf_finish_intern: Tlsf_finish;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
procedure lsf_init(const aLibName: String);

  function LoadProc(const aName: AnsiString): Pointer;
  begin
    result := GetProcedureAddress(libHandle, aName);
    if not Assigned(result) then
      raise Exception.CreateFmt('unable to load ''%s'' from ''%s''', [aName, aLibName]);
  end;

begin
  libHandle := LoadLibrary(aLibName);
  if (libHandle = 0) then
    raise Exception.CreateFmt('unable to load library: %s', [aLibName]);
  lsf_ShaderFile_create         := Tlsf_ShaderFile_create(        LoadProc('lsf_ShaderFile_create'));
  lsf_ShaderFile_setLogCallback := Tlsf_ShaderFile_setLogCallback(LoadProc('lsf_ShaderFile_setLogCallback'));
  lsf_ShaderFile_loadFromFile   := Tlsf_ShaderFile_loadFromFile(  LoadProc('lsf_ShaderFile_loadFromFile'));
  lsf_ShaderFile_saveToFile     := Tlsf_ShaderFile_saveToFile(    LoadProc('lsf_ShaderFile_saveToFile'));
  lsf_ShaderFile_destroy        := Tlsf_ShaderFile_destroy(       LoadProc('lsf_ShaderFile_destroy'));

  lsf_init_intern               := Tlsf_init(                     LoadProc('lsf_init'));
  lsf_getLastErrorCode          := Tlsf_getLastErrorCode(         LoadProc('lsf_getLastErrorCode'));
  lsf_getLastErrorMsg           := Tlsf_getLastErrorMsg(          LoadProc('lsf_getLastErrorMsg'));
  lsf_getLastErrorTrace         := Tlsf_getLastErrorTrace(        LoadProc('lsf_getLastErrorTrace'));
  lsf_finish_intern             := Tlsf_finish(                   LoadProc('lsf_finish'));

  if (lsf_init_intern() <> LSF_ERR_NONE) then
    raise Exception.Create('error while initializing library: ' + lsf_getLastErrorMsg());
end;

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
procedure lsf_finish;
begin
  lsf_finish_intern();
  lsf_ShaderFile_create         := nil;
  lsf_ShaderFile_setLogCallback := nil;
  lsf_ShaderFile_loadFromFile   := nil;
  lsf_ShaderFile_saveToFile     := nil;
  lsf_ShaderFile_destroy        := nil;
  lsf_getLastErrorCode          := nil;
  lsf_getLastErrorMsg           := nil;
  lsf_getLastErrorTrace         := nil;
  if (libHandle <> 0) then begin
    FreeLibrary(libHandle);
    libHandle := 0;
  end;
end;

end.