www.pudn.com > GdiplusTest16.zip > GdiPlusMetaHeader.h
/**************************************************************************\
*
* Copyright (c) 1998-2001, Microsoft Corp. All Rights Reserved.
*
* Module Name:
*
* Metafile headers
*
* Abstract:
*
* GDI+ Metafile Related Structures
*
\**************************************************************************/
#ifndef _GDIPLUSMETAHEADER_H
#define _GDIPLUSMETAHEADER_H
typedef struct
{
DWORD iType; // Record type EMR_HEADER
DWORD nSize; // Record size in bytes. This may be greater
// than the sizeof(ENHMETAHEADER).
RECTL rclBounds; // Inclusive-inclusive bounds in device units
RECTL rclFrame; // Inclusive-inclusive Picture Frame .01mm unit
DWORD dSignature; // Signature. Must be ENHMETA_SIGNATURE.
DWORD nVersion; // Version number
DWORD nBytes; // Size of the metafile in bytes
DWORD nRecords; // Number of records in the metafile
WORD nHandles; // Number of handles in the handle table
// Handle index zero is reserved.
WORD sReserved; // Reserved. Must be zero.
DWORD nDescription; // Number of chars in the unicode desc string
// This is 0 if there is no description string
DWORD offDescription; // Offset to the metafile description record.
// This is 0 if there is no description string
DWORD nPalEntries; // Number of entries in the metafile palette.
SIZEL szlDevice; // Size of the reference device in pels
SIZEL szlMillimeters; // Size of the reference device in millimeters
} ENHMETAHEADER3;
// Placeable WMFs
// Placeable Metafiles were created as a non-standard way of specifying how
// a metafile is mapped and scaled on an output device.
// Placeable metafiles are quite wide-spread, but not directly supported by
// the Windows API. To playback a placeable metafile using the Windows API,
// you will first need to strip the placeable metafile header from the file.
// This is typically performed by copying the metafile to a temporary file
// starting at file offset 22 (0x16). The contents of the temporary file may
// then be used as input to the Windows GetMetaFile(), PlayMetaFile(),
// CopyMetaFile(), etc. GDI functions.
// Each placeable metafile begins with a 22-byte header,
// followed by a standard metafile:
#include // set structure packing to 2
typedef struct
{
INT16 Left;
INT16 Top;
INT16 Right;
INT16 Bottom;
} PWMFRect16;
typedef struct
{
UINT32 Key; // GDIP_WMF_PLACEABLEKEY
INT16 Hmf; // Metafile HANDLE number (always 0)
PWMFRect16 BoundingBox; // Coordinates in metafile units
INT16 Inch; // Number of metafile units per inch
UINT32 Reserved; // Reserved (always 0)
INT16 Checksum; // Checksum value for previous 10 WORDs
} WmfPlaceableFileHeader;
#include
// Key contains a special identification value that indicates the presence
// of a placeable metafile header and is always 0x9AC6CDD7.
// Handle is used to stored the handle of the metafile in memory. When written
// to disk, this field is not used and will always contains the value 0.
// Left, Top, Right, and Bottom contain the coordinates of the upper-left
// and lower-right corners of the image on the output device. These are
// measured in twips.
// A twip (meaning "twentieth of a point") is the logical unit of measurement
// used in Windows Metafiles. A twip is equal to 1/1440 of an inch. Thus 720
// twips equal 1/2 inch, while 32,768 twips is 22.75 inches.
// Inch contains the number of twips per inch used to represent the image.
// Normally, there are 1440 twips per inch; however, this number may be
// changed to scale the image. A value of 720 indicates that the image is
// double its normal size, or scaled to a factor of 2:1. A value of 360
// indicates a scale of 4:1, while a value of 2880 indicates that the image
// is scaled down in size by a factor of two. A value of 1440 indicates
// a 1:1 scale ratio.
// Reserved is not used and is always set to 0.
// Checksum contains a checksum value for the previous 10 WORDs in the header.
// This value can be used in an attempt to detect if the metafile has become
// corrupted. The checksum is calculated by XORing each WORD value to an
// initial value of 0.
// If the metafile was recorded with a reference Hdc that was a display.
#define GDIP_EMFPLUSFLAGS_DISPLAY 0x00000001
class MetafileHeader
{
public:
MetafileType Type;
UINT Size; // Size of the metafile (in bytes)
UINT Version; // EMF+, EMF, or WMF version
UINT EmfPlusFlags;
REAL DpiX;
REAL DpiY;
INT X; // Bounds in device units
INT Y;
INT Width;
INT Height;
union
{
METAHEADER WmfHeader;
ENHMETAHEADER3 EmfHeader;
};
INT EmfPlusHeaderSize; // size of the EMF+ header in file
INT LogicalDpiX; // Logical Dpi of reference Hdc
INT LogicalDpiY; // usually valid only for EMF+
public:
MetafileType GetType() const { return Type; }
UINT GetMetafileSize() const { return Size; }
// If IsEmfPlus, this is the EMF+ version; else it is the WMF or EMF ver
UINT GetVersion() const { return Version; }
// Get the EMF+ flags associated with the metafile
UINT GetEmfPlusFlags() const { return EmfPlusFlags; }
REAL GetDpiX() const { return DpiX; }
REAL GetDpiY() const { return DpiY; }
VOID GetBounds (OUT Rect *rect) const
{
rect->X = X;
rect->Y = Y;
rect->Width = Width;
rect->Height = Height;
}
// Is it any type of WMF (standard or Placeable Metafile)?
BOOL IsWmf() const
{
return ((Type == MetafileTypeWmf) || (Type == MetafileTypeWmfPlaceable));
}
// Is this an Placeable Metafile?
BOOL IsWmfPlaceable() const { return (Type == MetafileTypeWmfPlaceable); }
// Is this an EMF (not an EMF+)?
BOOL IsEmf() const { return (Type == MetafileTypeEmf); }
// Is this an EMF or EMF+ file?
BOOL IsEmfOrEmfPlus() const { return (Type >= MetafileTypeEmf); }
// Is this an EMF+ file?
BOOL IsEmfPlus() const { return (Type >= MetafileTypeEmfPlusOnly); }
// Is this an EMF+ dual (has dual, down-level records) file?
BOOL IsEmfPlusDual() const { return (Type == MetafileTypeEmfPlusDual); }
// Is this an EMF+ only (no dual records) file?
BOOL IsEmfPlusOnly() const { return (Type == MetafileTypeEmfPlusOnly); }
// If it's an EMF+ file, was it recorded against a display Hdc?
BOOL IsDisplay() const
{
return (IsEmfPlus() &&
((EmfPlusFlags & GDIP_EMFPLUSFLAGS_DISPLAY) != 0));
}
// Get the WMF header of the metafile (if it is a WMF)
const METAHEADER * GetWmfHeader() const
{
if (IsWmf())
{
return &WmfHeader;
}
return NULL;
}
// Get the EMF header of the metafile (if it is an EMF)
const ENHMETAHEADER3 * GetEmfHeader() const
{
if (IsEmfOrEmfPlus())
{
return &EmfHeader;
}
return NULL;
}
};
#endif