Getting client coordinates after resizing

Code:

---

        case WM_SIZE:
                {
                        cxClient = LOWORD(lParam);
                        cyClient = HIWORD(lParam);

                        return 0;
                }

---

gives me width and height... I need to get coordinates rather (x.top, y.top, x.bottom, y.bottom)... Reason i need to use these to FillRect() the client window's background color every time the window is resize... My background is black because i use back-buffer (or memory DC), not sure why is that but yeah, that's the case i have. BTW what's the use of MoveWindow()? my thinking is whether or not i call MoveWindow, dragging or resizing the window will move/respond anyway!

Code:

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RECT rcClient;
GetClientRect(hwnd,&rcClient);

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As easy as that. :)

Quote:

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Originally Posted by maxorator

Code:

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RECT rcClient;
GetClientRect(hwnd,&rcClient);

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As easy as that. :)

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Mhh.. tried this already didn't work... Well then i guess my prob is not getting coordinates, is where i FillRect....

Here was my first attempt...

Code:

---

case WM_SIZE:
{
        GetClientRect(hwnd, &ctRect);
        return 0;
}

case WM_PAINT:
{
        hdc = BeginPaint(hwnd, &pntS);

        // Paint screen background grey
        hBrush = CreateSolidBrush( RGB(0xD3, 0xD3, 0xD3) );
        FillRect(hdc, &ctRect, hBrush);
        DeleteObject(hBrush);

        BitBlt(hdc, 0, 0, cScreenX, cScreenY, memDC, 0, 0, SRCCOPY);       

        EndPaint(hwnd, &pntS);

return 0;
}

---

note that i have two device contexts in red (hdc & memDC). Problem, if i FillRect on memDC

Code:

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        FillRect(memDC, &ctRect, hBrush);

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, then the background is painted once with the original size recalling that repaint does not update memDC, just copies whatever was on it by using bitblt (to avoid flickering)... So repainting with new sizes forces the color background to cover the memDC rectangle but not the new resized rectangle of client area... So i end up with a portion being colored, the rest (new area) becomes black...

Why are you using double buffering for a simple background? You don't even need to handle WM_SIZE actually.

Code:

---

case WM_PAINT:
    hdc = BeginPaint(hwnd, &pntS);
    hBrush = CreateSolidBrush( RGB(0xD3, 0xD3, 0xD3) );
    GetClientRect(hwnd, &ctRect);
    FillRect(hdc, &ctRect, hBrush);
    DeleteObject(hBrush);
    EndPaint(hwnd, &pntS);
    break;

---

Quote:

---

Originally Posted by maxorator

Why are you using double buffering for a simple background?

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Sho! this comes a long way (here), which i doubt you want to entertain now...

Code:

---

case WM_PAINT:
    hdc = BeginPaint(hwnd, &pntS);
    hBrush = CreateSolidBrush( RGB(0xD3, 0xD3, 0xD3) );
    GetClientRect(hwnd, &ctRect);
    FillRect(hdc, &ctRect, hBrush);
    DeleteObject(hBrush);
    EndPaint(hwnd, &pntS);
    break;

---

Calling GetClientRect within WM_PAINT causes flickers maybe has to do with timer...
Interesting thing is if i move GetClientRect to WM_SIZE and FillRect to WM_CREATE where i create and render to memDC, background remains black.. But then moving GetClientRect to WM_CREATE works, but then am back to my initial problem... (resizing)

/me sense yet another long thread

GetWindowRect() is giving me these coordinates [left: 66, top:87, right:1026, bottom:806]...

this is how my window is created

Code:

---

        hwnd=CreateWindowEx(WS_EX_OVERLAPPEDWINDOW,                       
                classname,                       
                _T("Radar FS Range Calculator"),                       
                WS_OVERLAPPEDWINDOW,               
                CW_USEDEFAULT,
                CW_USEDEFAULT,
                CW_USEDEFAULT,
                CW_USEDEFAULT,
                NULL,
                NULL,
                hInst,                                       
                NULL);

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with

Code:

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ShowWindow(hwnd,SW_SHOWDEFAULT);

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What's the default size of the window & what are these values references to?

GetWindowRect retrieves the coordinates of your window relative to the upper-left point of your screen.
So...
top is screen.size.top - window.pos.top
left is screen.size.left - window.pos.left
right is screen.size.right - window.pos.right
bottom is screen.size.bottom - window.pos.bottom
(Pseudo. Hope that makes sense.)

Quote:

---

Originally Posted by Elysia

GetWindowRect retrieves the coordinates of your window relative to the upper-left point of your screen.
So...
top is screen.size.top - window.pos.top
left is screen.size.left - window.pos.left
right is screen.size.right - window.pos.right
bottom is screen.size.bottom - window.pos.bottom
(Pseudo. Hope that makes sense.)

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does thnx.. though When i called FillRect with those coordinates, the filled aread was even smaller than client area (more like it referenced from client area than PC screen).. found that strange

Note that FillRect takes coordinates relative to the DC (I believe), not to the screen!
So the top-left pixel is 0 to FillRect. You must learn to differentiate between these types.
Use GetClientRect to get coordinates relative to your window.

Part of the issue is that the window has changed size and the memDC may now be too small/large.

You need to resize the DC, unless you created it the size of the full screen.

This is (similar) to how I do this.....

Code:

---


case WM_SIZE:
{
        GetClientRect(hwnd, &ctRect);//I use the lParam and fill in a RECT
        //add check for wParam==SIZE_MINIMISED ie has a size

        DrawScreen(hwnd,ctRect):
        return 0;
}

//a fast PAINT does nothing but a single BitBlt(), IMO it should NEVER do anything else
case WM_PAINT:
{
        hdc = BeginPaint(hwnd, &pntS);

        BitBlt(hdc, pntS.rcPaint.left, pntS.rcPaint.top, pntS.rcPaint.right-pntS.rcPaint.left, pntS.rcPaint.bottom-pntS.rcPaint.top, memDC, pntS.rcPaint.left, pntS.rcPaint.top, SRCCOPY);       

        EndPaint(hwnd, &pntS);

return 0;
}

void DrawScreen(HWND hwnd,RECT ctRect)
{

        //TODO
        //add check of OLD size to NEW size
        //if the new size is not the same as the old size
        //clearup the current HDC and BMP
        //create a new one the right size
        if(rectOLD!=ctRect)//NOTE: this is a placeholder, will not work
                CreateBuffer(hwnd,ctRect);

        // Paint screen background grey
        hBrush = CreateSolidBrush( RGB(0xD3, 0xD3, 0xD3) );
        FillRect(memDC, &ctRect, hBrush);
        DeleteObject(hBrush);
       
        //call for paint
        InvalidateRect(hwnd,ctRect);
        UpdateWindow(hwnd);
        return;
}

//other methods, also used in WM_CREATE and WM_DESTROY

void CreateBuffer(HWND , RECT);
{
        if(memDC)
                KillBuffers();

        //TODO
        //create new HDC and BMP based on HWND and RECT
        //remember to catch the original 1x1 monochrom bmp created in the HDC
        //as BMPs are not 100% of deleting if still selected into a DC

}
void KillBuffers()
{
        //check that DC has been created
        if(!memDC)
                return;

        SelectObject(memDC, hOriginalBMP);
        DeleteObject(hNewBMP);
        DeleteDC(memDC);
        memDC=NULL;//so our error check works
}

---

Quote:

---

Originally Posted by novacain

Part of the issue is that the window has changed size and the memDC may now be too small/large.

You need to resize the DC, unless you created it the size of the full screen.

This is (similar) to how I do this.....

Code:

---


case WM_SIZE:
{
        GetClientRect(hwnd, &ctRect);//I use the lParam and fill in a RECT
        //add check for wParam==SIZE_MINIMISED ie has a size

        DrawScreen(hwnd,ctRect):
        return 0;
}

//a fast PAINT does nothing but a single BitBlt(), IMO it should NEVER do anything else
case WM_PAINT:
{
        hdc = BeginPaint(hwnd, &pntS);

        BitBlt(hdc, pntS.rcPaint.left, pntS.rcPaint.top, pntS.rcPaint.right-pntS.rcPaint.left, pntS.rcPaint.bottom-pntS.rcPaint.top, memDC, pntS.rcPaint.left, pntS.rcPaint.top, SRCCOPY);       

        EndPaint(hwnd, &pntS);

return 0;
}

void DrawScreen(HWND hwnd,RECT ctRect)
{

        //TODO
        //add check of OLD size to NEW size
        //if the new size is not the same as the old size
        //clearup the current HDC and BMP
        //create a new one the right size
        if(rectOLD!=ctRect)//NOTE: this is a placeholder, will not work
                CreateBuffer(hwnd,ctRect);

        // Paint screen background grey
        hBrush = CreateSolidBrush( RGB(0xD3, 0xD3, 0xD3) );
        FillRect(memDC, &ctRect, hBrush);
        DeleteObject(hBrush);
       
        //call for paint
        InvalidateRect(hwnd,ctRect);
        UpdateWindow(hwnd);
        return;
}

//other methods, also used in WM_CREATE and WM_DESTROY

void CreateBuffer(HWND , RECT);
{
        if(memDC)
                KillBuffers();

        //TODO
        //create new HDC and BMP based on HWND and RECT
        //remember to catch the original 1x1 monochrom bmp created in the HDC
        //as BMPs are not 100% of deleting if still selected into a DC

}
void KillBuffers()
{
        //check that DC has been created
        if(!memDC)
                return;

        SelectObject(memDC, hOriginalBMP);
        DeleteObject(hNewBMP);
        DeleteDC(memDC);
        memDC=NULL;//so our error check works
}

---

---

opted for function PatBlt() instead, fills the entire background with no probs...

For a simple colour the background black that will work. It will not work well for any complex drawing.


This is what you were originally looking for.

Code:

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case WM_SIZE:

RECT DrawRect;

DrawRect.left=0;
DrawRect.top=0;
DrawRect.right=LOWORD(lParam);
DrawRect.bottom=HIWORD(lParam);

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As I pointed out, the BMP may not be big enough, depending on the size you created it.