Direct2D

Hello I have two questions regarding Direct2D, the answers are probably a resounding no but I must ask.

it is possible to draw something and preserve the background as we do with GDI, for example if in the form I have an image and I want to draw a text with Direct2 in some part of the form, without the background being a fixed color and without having to repaint the image.

the other, is it possible to paint only a part and not the whole form?

I know it is different from GDI but maybe someone understands what my intention is.

Code:

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Private Sub Form_Paint()
    Dim sText  As String
    'font "Segoe UI Emoji"
    Const D2D1_DRAW_TEXT_OPTIONS_ENABLE_COLOR_FONT = 4
    sText = ChrW2(&H2638) & "Hello World!" & ChrW2(&H2639)
   
    cTarget.BeginDraw
   
    cTarget.Clear D2D1.ColorF(Ivory)
   
    cTarget.DrawText sText, Len(sText), ByVal cTextFormat, D2D1.RectF(20, 20, 220, 120), cBrush, D2D1_DRAW_TEXT_OPTIONS_ENABLE_COLOR_FONT

    cTarget.EndDraw ByVal 0&, ByVal 0&
   
End Sub

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use ID2D1BitmapRenderTarget (cTarget)
this is how my render function looks like:

Code:

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Sub Rendering()
    On Error GoTo error
    cTarget.EndDraw ByVal 0&, ByVal 0&
    If SoftWare Then D3DKMTWaitForVerticalBlankEvent tWaitVSync
    hTarget.BeginDraw
    hTarget.DrawBitmap cTarget.GetBitmap, ResizeRect, 1, InterPolationMode, GameRect
    hTarget.EndDraw ByVal 0&, ByVal 0&

    cTarget.BeginDraw
    cTarget.Clear bcolor
error:
    If err.Number <> 0 Then Running = 99
End Sub

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this is the "end" function, so theres a lot before this function where I draw to cTarget.
hTarget is used to draw to a picturebox. and lastly it will clear cTarget for another circle.
this is inside a loop, so it will render 60 frames a second, but you can easily change that to work with events.

instead u can use the paint_event and call:

Code:

---

    hTarget.BeginDraw
    hTarget.DrawBitmap cTarget.GetBitmap, ResizeRect, 1, InterPolationMode, GameRect
    hTarget.EndDraw ByVal 0&, ByVal 0&

---

alone, as cTarget you already created beforehand.

and if you use

Code:

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.presentOptions =D2D1_PRESENT_OPTIONS_IMMEDIATELY

---

it will draw when u call it instead of the wait-for sync.

also, important to set the DPI (when u initialize)
call

Code:

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cTarget.SetDpi 96, 96
hTarget.SetDpi 96, 96

---

maybe theres other ways, to draw directly into a DC and make it persistent somehow.
but Im unsure the refresh autoredraw works. unlikely as u have tried that already I assume.

to render is superfast, so its not that the vb6 autoredraw is faster. contrary slower.

about drawing a part. u can draw to a picturebox, so its not that you need to draw to the form.

Code:

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HwndRenderTargetProperties.hWnd = .hWnd

---

so it can be any hwnd not just to form.

not sure theres a way to use the form.hwnd and just draw a specific position.
but at least with a picturebox u can select the left/top position.

Thanks Baka, I will have to study a little more about Direct2D there are many things to learn, I appreciate your time