GDI+

[Gintaras]

For QM 2.3.2.2 and later.

Macro Gdip help

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;Several classes that make easier to use GDI+.

;__________________________________________________


;ABOUT GDI+

;GDI+ is a Windows graphics library.
;Available on Windows XP and later.
;For Windows 2000, need to add gdiplus.dll to the system folder. Can download from Microsoft or take from XP or 7.

;GDI+ is documented in MSDN Library.
;The documentation is for GDI+ C++ classes. We cannot use them in QM. But we can use GDI+ flat API. The C++ classes internally use the flat API too, and are open-source.
;The flat API are not documented, but you can understand almost everything from the documentation of the C++ classes. What is possible with C++ classes, also is possible with flat API.

;GDI+ can load files of these formats: BMP, GIF, JPEG, PNG, TIFF, ICON, WMF, EMF, EXIF.
;Can save in these formats: BMP, GIF, JPEG, PNG, TIFF.

;__________________________________________________


;ABOUT THE QM CLASSES

;Each class holds a pointer to a GDI+ native object of corresponding type (GpGraphics*, GpPen*, etc). See declarations in macro "__Gdip".
;The GDI+ native object is automatically deleted when the class variable dies or a creation function called again. Or you can call Delete.

;Most of the classes have only object creation functions. Some classes can load/save image files.
;To draw, etc, use GDI+ flat API. It is easy when using these classes. Look in "examples" folder.
;A class variable can be passed to GDI+ flat API functions where need pointer to GDI+ native object of corresponding type.

;To initialize variables of these classes, use the member functions.
;Or you can create GDI+ native object using GDI+ flat API and do: classVar.Delete; classVar=nativePointer.
;Copying of variables is not supported. Never do classVar=classVar. To copy bitmap: b2.FromBitmapArea(b1 0 0 b1.width b1.height).

;All the creation functions return pointer to the GDI+ native object. Don't delete the object. The variable will automatically delete it.
;Other functions return 1 or other value.
;If a function fails, it returns 0. There are no functions throwing errors.
;If a function fails, it assigns a GDI+ error code to _hresult (it's a special variable having thread scope, also used with COM functions). On success _hresult will be 0.
;GDI+ error codes are documented in MSDN Library, in "Status Enumeration" topic.
;_hresult will be -1 if gdiplus.dll in unavailable (Windows 2000).

;You don't have to initialize GDI+ when using these classes. The creation functions initialize it automatically. GDI+ version 1.0.
;If you use GDI+ flat API without these classes, call GdipInit before.

;The GDI+ flat API declarations are in reference file GDIP (gdiplus.txt). The file is installed with QM.
;It's scope is not global, so you have to always prepend "GDIP." to the GDI+ flat API functions, types and constants.
;The file contains everything from GDI+ C++ headers (Windows 7 SDK).
;The file contains even such classes as Bitmap, Graphics etc that are not useful because don't have member functions in QM.
;Some other classes, such as RectF, also don't have member functions in QM, but can be used with GDI+ flat API as simple types.

;Also there are several related global functions in Functions folder.

;This can be used in exe too. Just remember that Windows 2000 doesn't have gdiplus.dll. You can take it together with exe.

  GDI+.qml (Size: 20.2 KB / Downloads: 1,282)

tags: dialog draw paint gradient transparent color alpha blend bitmap brush pen font picture file plus rectangle ellipse texture hatch convert

Note: this also is included in Archive.qml, with one or two new functions: Collected QM apps, functions, samples

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