graphics单元的几个图像函数

r   :=   GetRvalue(ColorToRGB(clred));
g   :=   GetGvalue(ColorToRGB(clred));
b   :=   GetBvalue(ColorToRGB(clred));

color := Windows.RGB(r,g,b);//反向转化

//另外，这个有用么
R:=longx   and   $FF;
longx:=longx   shr   8;
G:=longx   and   $FF;
longx:=longx   shr   8;
B:=long   and   $FF;(正常情况下，这儿不需要and   $FF)

function GraphicFilter(GraphicClass: TGraphicClass): string;
function GraphicExtension(GraphicClass: TGraphicClass): string;
function GraphicFileMask(GraphicClass: TGraphicClass): string;

function ColorToRGB(Color: TColor): Longint;
function ColorToString(Color: TColor): string;
function StringToColor(const S: string): TColor;
procedure GetColorValues(Proc: TGetStrProc);
function ColorToIdent(Color: Longint; var Ident: string): Boolean;
function IdentToColor(const Ident: string; var Color: Longint): Boolean;
procedure GetCharsetValues(Proc: TGetStrProc);
function CharsetToIdent(Charset: Longint; var Ident: string): Boolean;
function IdentToCharset(const Ident: string; var Charset: Longint): Boolean;

procedure GetDIBSizes(Bitmap: HBITMAP; var InfoHeaderSize: DWORD;
var ImageSize: DWORD);
function GetDIB(Bitmap: HBITMAP; Palette: HPALETTE; var BitmapInfo; var Bits): Boolean;

function CopyPalette(Palette: HPALETTE): HPALETTE;

procedure PaletteChanged;
procedure FreeMemoryContexts;

function GetDefFontCharSet: TFontCharSet;

function TransparentStretchBlt(DstDC: HDC; DstX, DstY, DstW, DstH: Integer;
SrcDC: HDC; SrcX, SrcY, SrcW, SrcH: Integer; MaskDC: HDC; MaskX,
MaskY: Integer): Boolean;

function CreateMappedBmp(Handle: HBITMAP; const OldColors, NewColors: array of TColor): HBITMAP;
function CreateMappedRes(Instance: THandle; ResName: PChar; const OldColors, NewColors: array of TColor): HBITMAP;
function CreateGrayMappedBmp(Handle: HBITMAP): HBITMAP;
function CreateGrayMappedRes(Instance: THandle; ResName: PChar): HBITMAP;

function AllocPatternBitmap(BkColor, FgColor: TColor): TBitmap;

// Alignment must be a power of 2.  Color BMPs require DWORD alignment (32).
function BytesPerScanline(PixelsPerScanline, BitsPerPixel, Alignment: Longint): Longint;