CIJLBitmap v1.22

Welcome to CIJLBitmap, A freeware MFC class based in part on CBitmap and CPalette which provides support for loading Device Independent Bitmaps (DIBS) and jpegs from disk. Support is provided for Loading BMP's from file and resource, loading Jpeg files and saving to BMP's on file.

Features

• Code is UNICODE enabled and build configurations are provided.
• All code compiles cleanly at level 4.
• Small footprint, total size amounts to just c. 300 lines of code.

Usage

• To use the class in your code simply include IJLBitmap.cpp in your project and #include "IJLBitmap.h" in which ever of your modules needs to make calls to the class.
• Your code will need to include MFC either statically or dynamically.
• To see the class in action, have a look at the usage of the code in the modules "testIJLView.cpp" and "testIJLDoc.cpp".
• Since the code as of v1.2 uses COM, don't forget to initialize OLE (AfxOleInit) in your apps normal initialization routine.

History

V1.0 (3 April 2000)

• Initial public release.

V1.1 (10 April 2000)

• Now includes full support for palettes.

V1.2 (30 July 2000)

• Now supports loading of .gif and .ico. This is accomplished via the IPicture COM interface. Please note that to release code which uses the GIF format, you will need to obtain a license from Unisys. 
• I have also removed the dependence on the Intel Jpeg Library as the IPicture interface supports loading Jpegs. This means that the sample app is now just 23 K in size and only depends on the normal Win32 DLLs (including OLE) as well as the MFC runtimes.

V1.21 (31 July 2000)

• Class is now derived from CBitmap as before, Dropped support for ICO format as it was producing a separate code path.

V1.22 (1 August 2001)

• Now includes support for saving back to a bmp file.

API Reference

The API consists of the following class members

CIJLBitmap::Load
CIJLBitmap::LoadBmp
CIJLBitmap::Rect
CIJLBitmap::Size
CIJLBitmap::Draw
CIJLBitmap::DeleteObject
CIJLBitmap::Palette
CIJLBitmap::Save

CIJLBitmap::Load

BOOL Load(LPCTSTR lpszPathName);

Return Value

TRUE if the file was loaded successfully otherwise FALSE.

Parameters

lpszPathName The name of the image file to load.

Remarks

Loads an image from disk. The type supported are DIB (*.bmp, *.DIB), Jpeg (*.jpg, *.jpeg).

CIJLBitmap::LoadBmp

BOOL LoadBmp(HINSTANCE hInst, LPCTSTR lpResourceName);
BOOL LoadBmp(HINSTANCE hInst, UNINT uID);

Return Value

TRUE if the bitmap file was loaded successfully otherwise FALSE.

Parameters

hInst The instance handle to load from 

uID The resource ID of the resource to load.

lpResourceName The resource ID of the resource to load.

Remarks

This function loads a DIB from a resource. 

CIJLBitmap::Rect

CRect Rect();

CIJLBitmap::Size()

CSize Size()

Remarks

These methods are simple accessors for the size of the bitmap expressed as a CRect or a CSize. 

CIJLBitmap::Draw

BOOL Draw(CDC* pDC, DWORD dwRop = SRCCOPY, BOOL bBackground = FALSE, const CRect* rcDst = NULL, const CRect* rcSrc = NULL, CPalette* pPal = NULL);

Return Value

TRUE if the bitmap was successfully drawn otherwise FALSE.

Parameters

pDC The device context where the bitmap is to be drawn to.

dwRop The Raster operation code to use when drawing the bitmap.

bBackground TRUE if the palette should be realized in the background otherwise FALSE if normal realization.

rcDst The destination rectangle of the bitmap. Leave NULL if you want the bitmap to be drawn 100% sized at offset point 0,0.

rcSrc The source rectangle of the bitmap. Leave NULL if you want all the bitmap drawn.

pPal The palette to use when drawing the bitmap. Leave NULL if you want the palette associated with the bitmap to be used

Remarks

This function draws the bitmap to a device context. 

CIJLBitmap::DeleteObject

BOOL DeleteObject();

Return Value

Nonzero if the object was successfully deleted; otherwise 0.

Remarks

Deletes any associated resources which the bitmap has. Internally all that is done is that the IPicture interface is released.

CIJLBitmap::Palette

CPalette& Palette();

Remarks

This method provides access to the palette associated with this DIB. This is sometimes required externally if you need to implement palette handling code in your classes. 

CIJLBitmap::Save

BOOL Save(LPCTSTR lpszPathName);

Return Value

TRUE if the file was successfully saved otherwise FALSE.

Parameters

lpszPathName The name of the image file to save as.

Remarks

Saves an image to disk. The type written will always be a DIB i.e. *.bmp or *.DIB.

PLANNED ENHANCEMENTS

• If you have any other suggested improvements, please let me know so that I can incorporate them into the next release.

CONTACTING THE AUTHOR

PJ Naughter
Email: pjna@naughter.com
Web: http://www.naughter.com
1 August 2001