saving the processor

Quote:

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Originally posted by Marc G
NOTE: There's still a bug when using big sizes like 6400x4800: the scrollbars start to overflow because the range is too big.

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the max size gonna be entered is 640 x 480 only..

Quote:

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Originally posted by Marc G
The code above works rather fast even when you enter something like 6400x4800 at startup of the program, but when you do, startup of the program itself is a bit slow because of memory allocation and stuff. But once it has started it works fast.
NOTE: There's still a bug when using big sizes like 6400x4800: the scrollbars start to overflow because the range is too big.

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i did what all you wrote/....but the app became slower ibnstead of faster...what i mean is that when i scroll after adding your the Invalidate(FALSE) and adding the scrolPos in OnDraw...the scroll has become slower...actually it doesnt allow me top scroll...and shows a blank screen when i pres sthe scroll once..:(:confused:

When i get back home, i'll send you my project files.

hi...i got your proj....tks a lot for your help and effort..
but the display always shows EMPTY SPACE between the right scroll bar and the grid even when i am in the center of the grid...:(
and space between the bottom scroll bar and the grdi even when i am in the middle of the screen....:(
also i cant draw on the last bottom line of the grid...:(:confused::eek:

thisis what i have come up iwth,.,,,but now i got FLASHING problem...........pls help...:(

To solve the white space you got:

Code:

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    CRect rcClient;
    GetClientRect(&rcClient);
    // Add the following 2 lines after you've set the mapping mode to MM_LOENGLISH
    pDC->DPtoLP(&rcClient);
    rcClient.bottom *= -1;

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If you've got everything working then you can try to remove the flickering with a memory DC.

Create a memory DC, do all your drawing in this mem dc and blit the final result to the screen.

If you do this, do not forget to add a handler for WM_ERASEBKGND and just return TRUE.

Quote:

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Originally posted by Marc G

If you've got everything working then you can try to remove the flickering with a memory DC.

Create a memory DC, do all your drawing in this mem dc and blit the final result to the screen.

If you do this, do not forget to add a handler for WM_ERASEBKGND and just return TRUE.

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but i don't wanna use the memdc...as Mr. gsterken said..if i use it...all is hidden and i dont know what happens inside/...:(
is ther anyway i can do it myself???
tks a lot..:)

I think Mr. gsterken meant not to use a memdc BEFORE everything is drawn correctly, but once everything is drawn correctly to the screen, then you can start using a memory DC to prevent flickering. AFAIK memory DC is the only solution to this problem.

Quote:

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Originally posted by Marc G
I think Mr. gsterken meant not to use a memdc BEFORE everything is drawn correctly, but once everything is drawn correctly to the screen, then you can start using a memory DC to prevent flickering.

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Yes, that's what I meant. But I also said that a memory DC would not be needed at all for this app in order to remove flicker.

Quote:

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Originally posted by Marc G
AFAIK memory DC is the only solution to this problem.

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No, as there are no overlapping objects. All drawing objects (the grid lines and the changing filled squares) sit side by side, so there is no point in using a memory DC. Flicker can be removed completely by invalidating only the required areas, and the whole drawing can be sped up by limiting all drawing to the visible region.

Quote:

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Originally posted by gstercken
Yes, that's what I meant. But I also said that a memory DC would not be needed at all for this app in order to remove flicker.

No, as there are no overlapping objects. All drawing objects (the grid lines and the changing filled squares) sit side by side, so there is no point in using a memory DC. Flicker can be removed completely by invalidating only the required areas, and the whole drawing can be sped up by limiting all drawing to the visible region.

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hi mr.gstercken... so can u pls elaborate for me what else i need to do to get the proj working pls??
i think i have some probs in synchronizing the preview area and the drawingg area too....:( :confused:
hope you can help....
tks a lot....

hi mr.gstercken..
i have done as u told me, now there is no coversion of rect and point to a rect and then back on UpdateAllViews.

hi...i have managed to stop the blinking of my EditorView..but i lost th edraing on th ePeekView..now i have to minimize and maximize my window to see the drawing on PeekView..:(
CAn someone pls help me???
i have made PeekView just liek Editor View for easy coding..later i will take off the grid and everything should be fine...
but now the grid in my peek view is giving me probs as when i change the size of the PeekView by dragging the border between EditorView and PeekView the peekView grids change:eek:
i have no idea why this is happening or how to stop this...pls help...
tks a lot...

any ideas???:confused: :(

First change your void CPeekView::OnUpdate(CView* pSender, LPARAM lHint, CObject* pHint), instead of "InvalidateRect(rect)" use "Invalidate(0)", because there's something wrong with the calculated rect and thus you don't see anything being updated. For the moment change it to "Invalidate(0)".

Then change your OnDraw to something like:

Code:

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void CPeekView::OnDraw(CDC* pDC)
{
    CEditorDoc* pDoc = GetDocument();
    ASSERT_VALID(pDoc);

        //
        //Set the mapping mode to LOENGLISH
        //
        pDC->SetMapMode(MM_LOENGLISH);

        CRect rect( 9, 9, 10+pDoc->GetGridX()+1, 10+pDoc->GetGridY()+1);
        pDC->DPtoLP(&rect);
        pDC->Rectangle(rect);

    int nGridX = pDoc->GetGridX();
    int nGridY = pDoc->GetGridY();

        for(int i = 0 ; i < nGridY; ++i) {
        for(int j = 0 ; j < nGridX; ++j) {
                        COLORREF color = pDoc->GetSquareColor(i, j);
                        POINT pt;
                        pt.x = j+10;
                        pt.y = -i-10;
                        pDC->DPtoLP(&pt);
                        pDC->SetPixel(pt,color);
        }
    }
}

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should work, but it will be slow.

SetPixel will always be slow. You should take a look at CreateDIBSection to create a bitmap in memory and then blit it to screen which will be much faster. You can even create a DIB section when your program starts and then update it in CEditorDoc::SetSquareColor. Then the only thing you have to do to draw the little preview is blit this DIB to the screen which is fast.

tks a lot for your kind help.

Quote:

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Originally posted by Marc G
First change your void CPeekView::OnUpdate(CView* pSender, LPARAM lHint, CObject* pHint), instead of "InvalidateRect(rect)" use "Invalidate(0)", because there's something wrong with the calculated rect and thus you don't see anything being updated. For the moment change it to "Invalidate(0)".

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ok...i did this...now i can see the drawing but the preview window flahes :(

Quote:

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Originally posted by Marc G
Then change your OnDraw to something like:

Code:

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void CPeekView::OnDraw(CDC* pDC)
{
    CEditorDoc* pDoc = GetDocument();
    ASSERT_VALID(pDoc);

        //
        //Set the mapping mode to LOENGLISH
        //
        pDC->SetMapMode(MM_LOENGLISH);

        CRect rect( 9, 9, 10+pDoc->GetGridX()+1, 10+pDoc->GetGridY()+1);
        pDC->DPtoLP(&rect);
        pDC->Rectangle(rect);

    int nGridX = pDoc->GetGridX();
    int nGridY = pDoc->GetGridY();

        for(int i = 0 ; i < nGridY; ++i) {
        for(int j = 0 ; j < nGridX; ++j) {
                        COLORREF color = pDoc->GetSquareColor(i, j);
                        POINT pt;
                        pt.x = j+10;
                        pt.y = -i-10;
                        pDC->DPtoLP(&pt);
                        pDC->SetPixel(pt,color);
        }
    }
}

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should work, but it will be slow.

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when i did this now my preview window stopped working again :(
i have attached the proj again.. i have commented out all the code in my PeekView::OnDraw()
and substituted with your code already but doesnt work :(
hope u can pls throw some more light
tks a lot
appreciate your help

Oops, i made a copy-paste error.

Code:

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pt.y = -i-10;

should be

pt.y = i+10;

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But again, this method is very slow for a 640x480 bitmap. You need to read up a bit on CreateDIBSection like I said in my previous post.