gifimage.pas

TGIFiMAGE 2.2 支持D7等 Changed 2007.01.18 This is a version of Anders Melander s TGIFImage ported t

// Delphi 1.x
{$IFDEF VER80}
  'Error: TGIFImage does not support Delphi 1.x'
{$ENDIF}

// Delphi 2.x
{$IFDEF VER90}
  {$DEFINE VER9x}
{$ENDIF}

// C++ Builder 1.x
{$IFDEF VER93}
  // Good luck...
  {$DEFINE VER9x}
{$ENDIF}

// Delphi 3.x
{$IFDEF VER100}
  {$DEFINE VER10_PLUS}
  {$DEFINE D3_BCB3}
{$ENDIF}

// C++ Builder 3.x
{$IFDEF VER110}
  {$DEFINE VER10_PLUS}
  {$DEFINE VER11_PLUS}
  {$DEFINE D3_BCB3}
  {$DEFINE BAD_STACK_ALIGNMENT}
{$ENDIF}

// Delphi 4.x
{$IFDEF VER120}
  {$DEFINE VER10_PLUS}
  {$DEFINE VER11_PLUS}
  {$DEFINE VER12_PLUS}
  {$DEFINE BAD_STACK_ALIGNMENT}
{$ENDIF}

// C++ Builder 4.x
{$IFDEF VER125}
  {$DEFINE VER10_PLUS}
  {$DEFINE VER11_PLUS}
  {$DEFINE VER12_PLUS}
  {$DEFINE VER125_PLUS}
  {$DEFINE BAD_STACK_ALIGNMENT}
{$ENDIF}

// Delphi 5.x
{$IFDEF VER130}
  {$DEFINE VER10_PLUS}
  {$DEFINE VER11_PLUS}
  {$DEFINE VER12_PLUS}
  {$DEFINE VER125_PLUS}
  {$DEFINE VER13_PLUS}
  {$DEFINE BAD_STACK_ALIGNMENT}
{$ENDIF}

// Delphi 6.x
{$IFDEF VER140}
{$WARN SYMBOL_PLATFORM OFF}
  {$DEFINE VER10_PLUS}
  {$DEFINE VER11_PLUS}
  {$DEFINE VER12_PLUS}
  {$DEFINE VER125_PLUS}
  {$DEFINE VER13_PLUS}
  {$DEFINE VER14_PLUS}
  {$DEFINE BAD_STACK_ALIGNMENT}
{$ENDIF}

// Delphi 7.x
{$IFDEF VER150}
{$WARN SYMBOL_PLATFORM OFF}
  {$DEFINE VER10_PLUS}
  {$DEFINE VER11_PLUS}
  {$DEFINE VER12_PLUS}
  {$DEFINE VER125_PLUS}
  {$DEFINE VER13_PLUS}
  {$DEFINE VER14_PLUS}
  {$DEFINE VER15_PLUS}
  {$DEFINE BAD_STACK_ALIGNMENT}
{$ENDIF}

// 2003.03.09 ->
// Unknown compiler version - assume D4 compatible
//{$IFNDEF VER9x}
//  {$IFNDEF VER10_PLUS}
//    {$DEFINE VER10_PLUS}
//    {$DEFINE VER11_PLUS}
//    {$DEFINE VER12_PLUS}
//    {$DEFINE BAD_STACK_ALIGNMENT}
//  {$ENDIF}
//{$ENDIF}
// 2003.03.09 <-

// 2003.03.09 ->
// Unknown compiler version - assume D7 compatible
{$IFNDEF VER9x}
{$IFNDEF VER10_PLUS}
{$WARN SYMBOL_PLATFORM OFF}
  {$DEFINE VER10_PLUS}
  {$DEFINE VER11_PLUS}
  {$DEFINE VER12_PLUS}
  {$DEFINE VER125_PLUS}
  {$DEFINE VER13_PLUS}
  {$DEFINE VER14_PLUS}
  {$DEFINE VER15_PLUS}
  {$DEFINE BAD_STACK_ALIGNMENT}
{$ENDIF}
{$ENDIF}
// 2003.03.09 <-

////////////////////////////////////////////////////////////////////////////////
//
//		Compiler Options required to compile this library
//
////////////////////////////////////////////////////////////////////////////////
{$A+,B-,H+,J+,K-,M-,T-,X+}

// Debug control - You can safely change these settings
{$IFDEF DEBUG}
  {$C+}	// ASSERTIONS
  {$O-}	// OPTIMIZATION
  {$Q+}	// OVERFLOWCHECKS
  {$R+}	// RANGECHECKS
{$ELSE}
  {$C-}	// ASSERTIONS
  {$IFDEF GIF_NOSAFETY}
    {$Q-}// OVERFLOWCHECKS
    {$R-}// RANGECHECKS
  {$ENDIF}
{$ENDIF}

// Special options for Time2Help parser
{$ifdef TIME2HELP}
{$UNDEF PIXELFORMAT_TOO_SLOW}
{$endif}

////////////////////////////////////////////////////////////////////////////////
//
//			External dependecies
//
////////////////////////////////////////////////////////////////////////////////
uses
  sysutils,
  Windows,
  Graphics,
  Classes;

////////////////////////////////////////////////////////////////////////////////
//
//			TGIFImage library version
//
////////////////////////////////////////////////////////////////////////////////
const
  GIFVersion		= $0202;
  GIFVersionMajor	= 2;
  GIFVersionMinor	= 2;
  GIFVersionRelease	= 5;

////////////////////////////////////////////////////////////////////////////////
//
//			Misc constants and support types
//
////////////////////////////////////////////////////////////////////////////////
const
  GIFMaxColors	= 256;			// Max number of colors supported by GIF
  					// Don't bother changing this value!

  BitmapAllocationThreshold = 500000;	// Bitmap pixel count limit at which
  					// a newly allocated bitmap will be
                                        // converted to 1 bit format before
                                        // being resized and converted to 8 bit.

var
{$IFDEF FAST_AS_HELL}
  GIFDelayExp: integer = 10;		// Delay multiplier in mS.
{$ELSE}
  GIFDelayExp: integer = 12;		// Delay multiplier in mS. Tweaked.
{$ENDIF}
					// * GIFDelayExp:
  					// The following delay values should all
                                        // be multiplied by this value to
                                        // calculate the effective time (in mS).
                                        // According to the GIF specs, this
                                        // value should be 10.
                                        // Since our paint routines are much
                                        // faster than Mozilla's, you might need
                                        // to increase this value if your
                                        // animations loops too fast. The
                                        // optimal value is impossible to
                                        // determine since it depends on the
                                        // speed of the CPU, the viceo card,
                                        // memory and many other factors.

  GIFDefaultDelay: integer = 10;	// * GIFDefaultDelay:
  					// Default animation delay.
  					// This value is used if no GCE is
                                        // defined.
                                        // (10 = 100 mS)

{$IFDEF FAST_AS_HELL}
  GIFMinimumDelay: integer = 1;		// Minimum delay (from Mozilla source).
  					// (1 = 10 mS)
{$ELSE}
  GIFMinimumDelay: integer = 3;		// Minimum delay - Tweaked.
{$ENDIF}
					// * GIFMinimumDelay:
					// The minumum delay used in the Mozilla
                                        // source is 10mS. This corresponds to a
                                        // value of 1. However, since our paint
                                        // routines are much faster than
                                        // Mozilla's, a value of 3 or 4 gives
                                        // better results.

  GIFMaximumDelay: integer = 1000;	// * GIFMaximumDelay:
  					// Maximum delay when painter is running
  					// in main thread (goAsync is not set).
                                        // This value guarantees that a very
                                        // long and slow GIF does not hang the
                                        // system.
                                        // (1000 = 10000 mS = 10 Seconds)

type
  TGIFVersion = (gvUnknown, gv87a, gv89a);
  TGIFVersionRec = array[0..2] of char;

const
  GIFVersions : array[gv87a..gv89a] of TGIFVersionRec = ('87a', '89a');

type
  // TGIFImage mostly throws exceptions of type GIFException
  GIFException = class(EInvalidGraphic);

  // Severity level as indicated in the Warning methods and the OnWarning event
  TGIFSeverity = (gsInfo, gsWarning, gsError);

////////////////////////////////////////////////////////////////////////////////
//
//			Delphi 2.x support
//
////////////////////////////////////////////////////////////////////////////////
{$IFDEF VER9x}
// Delphi 2 doesn't support TBitmap.PixelFormat
{$DEFINE PIXELFORMAT_TOO_SLOW}
type
  // TThreadList from Delphi 3 classes.pas
  TThreadList = class
  private
    FList: TList;
    FLock: TRTLCriticalSection;
  public
    constructor Create;
    destructor Destroy; override;
    procedure Add(Item: Pointer);
    procedure Clear;
    function  LockList: TList;
    procedure Remove(Item: Pointer);
    procedure UnlockList;
  end;

  // From Delphi 3 sysutils.pas
  EOutOfMemory = class(Exception);

  // From Delphi 3 classes.pas
  EOutOfResources = class(EOutOfMemory);

  // From Delphi 3 windows.pas
  PMaxLogPalette = ^TMaxLogPalette;
  TMaxLogPalette = packed record
    palVersion: Word;
    palNumEntries: Word;
    palPalEntry: array [Byte] of TPaletteEntry;
  end; { TMaxLogPalette }

  // From Delphi 3 graphics.pas. Used by the D3 TGraphic class.
  TProgressStage = (psStarting, psRunning, psEnding);
  TProgressEvent = procedure (Sender: TObject; Stage: TProgressStage;
    PercentDone: Byte; RedrawNow: Boolean; const R: TRect; const Msg: string) of object;

  // From Delphi 3 windows.pas
  PRGBTriple = ^TRGBTriple;
{$ENDIF}

////////////////////////////////////////////////////////////////////////////////
//
//			Forward declarations
//
////////////////////////////////////////////////////////////////////////////////
type
  TGIFImage = class;
  TGIFSubImage = class;