I shall give it a try...

Among them, CreateWindowExW(0, GDImageClassName, Resource((WCHAR*) L"paintbrush.png"), ...), is the one used by every GDImage container.
Resource((WCHAR*) L"paintbrush.png"), means use this image to paint the background of the control, it works like the desktop wallpaper background in Windows.

You hack the WindowName to load an image as a background. Is there a way to specify a starting coordinate to display the image?

Hello Shao Voon

I shall use WinMerge to see the code difference, and will let you know here, once done.

Added:

Here is the code for ZI_LoadFromResource

HBITMAP ZI_LoadFromResource (IN HWND hWnd, IN WCHAR* sName) { // dllexport
    HBITMAP hbmReturn = 0;
    HRSRC hResource = FindResource(zInstance(), (LPCWSTR) sName, RT_RCDATA);
    if (hResource) {
        DWORD resourceSize = SizeofResource(zInstance(), hResource);
        if (resourceSize) {
            HGLOBAL hGlobal = LoadResource(zInstance(), hResource);
            if (hGlobal) {
                LPVOID pResourceData = LockResource(hGlobal);
                if (pResourceData) {
                    HGLOBAL hMemory = GlobalAlloc(GMEM_MOVEABLE | GMEM_NODISCARD, resourceSize);
                    if (hMemory) {
                        LPVOID pBuffer = GlobalLock(hMemory);
                        if (pBuffer) {
                            memcpy(pBuffer, pResourceData, resourceSize);
                            LPSTREAM pStream = 0;
                            if (CreateStreamOnHGlobal(hMemory, FALSE, &pStream) == 0) {
                                LONG_PTR hImage;
                                if (GdipCreateBitmapFromStream(pStream, hImage) == 0) {
                                    if (hWnd) {
                                        if (zSetGdipImageHandle(hWnd, hImage)) { ZI_UpdateWindow(hWnd, TRUE); }
                                    } else { // Return a standard bitmap
                                        long background = 0;
                                        GdipCreateHBITMAPFromBitmap(hImage, hbmReturn, background);
                                        GdipDisposeImage(hImage); // Delete image
                                    }
                                }
                                //IUnknown_Release(pStream);
                                ReleaseObject((PFUNKNOWN*) pStream);
                            }
                        }
                        GlobalUnlock(hMemory);
                    }
                    GlobalFree(hMemory);
                }
                FreeResource(hGlobal);
            }
        }
    }
    return hbmReturn;
}

In order to use RT_RCDATA, you must put your resource image in the correct folder location to embed it inside of your binary EXE.

RT_RCDATA is the only way to embed any RAW_DATA, including, audio, dll, png images, etc.

Example of Resource.rc file used in PowerBASIC, that should be almost the same in C/C++

PROGRAM ICON ZAP.ICO

REDMASK RCDATA DISCARDABLE REDMASK.GIF
ZMAGIC  RCDATA DISCARDABLE ZMAGIE.GIF
STAR    CURSOR STAR.CUR

// Manifest info for WinXP theme support
#define CREATEPROCESS_MANIFEST_RESOURCE_ID   1
#define RT_MANIFEST                         24
#define CONTROL_PANEL_RESOURCE_ID          123

CREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST "gdw.man"

See this link
https://learn.microsoft.com/en-us/windows/win32/menurc/rcdata-resource

Asside of skinning existing Windows controls.

WinLIFT has its own set of buttons, based on a custom "button" superclass.

This project is using the "Sony" skin theme.

It is provided with several wallpapers stored in the "Background" folder.
To change them, click with the left or right mouse button on the top left icon.

You can click on the Help button to view the WinLIFT.chm file.

Fifth post of a series, translated from the "WinDev tutorial",
to explain the use of GDImage64 in procedural* programming mode with Visual Studio 2022.

About Tutor_05
This tutor introduces the use of sprite graphic controls to mimic the behavior of the standard Windows controls.

The Play/Pause buttons, and the audio track slider, send events to the ProcessMessage() procedure, to process the command flow.
 
REAL TIME PROCESSING:
The Oscillo() procedure is used by the timer to process the audio signal in real time.
The Bass.dll from Ian Luck is used for playing/decoding the audio channel.
Use Drag & Drop from the explorer to play a new audio file, stream and music tracker extensions are supported:
.mp3, .wav, .ogg, .aif, .mo3, .it, .xm, .s3m, .mtm, .mod, .umx.
Several effects are synchronized on the audio pulse to perform rotation, scalling, and color change.

PROGRESS GAUGE:
Display the percentage progression.

SEEK TRACKER:
Sets playback position of the audio file.

PRIVATE FONT:
The text name of the playing audio file is using a private font.
A private font do not need to be installed first, and the text always look the same whatever the computer used.
GDImage does all the hard work for you, the only thing you have to do, is to specify a .ttf extension when using the font name.

TOOLTIP:
Each sprite object is able to display a tooltip, using the friendly name label property.

WINDOW STYLE
The GDImage control is using the WS_BORDER style to let you see its client size inside of the main window.

BACKGROUND:
The GDImage graphic control, and the main window share the same bitmap wallpaper,
see the GDImageUpdateBackround() procedure and the ZI_CreateSkinBackground(...) API.
The bitmap is also updated while processing the WM_SIZE message, with the ResizeGDImageCtrl() procedure.

Last but not least,
the size of the standalone binary EXE is only 29 Kb.


   
* procedural programming mode, is based on direct use of the FLAT API (Windows SDK) that is the core meat of the OS.