Re: PolyLine and autoscrolling canvas

Hello again Joe and Stephen,

I've corrected whatever you suggested to, Joe, made a Create() method
to initialize, removed the OnCreate and the rest of stuffs...

Stephen, I modified also the OnPaint() thing as you said as you can
see below:

void CCaChart::OnPaint()
{
        CPaintDC dc(this); // device context for painting
        dc.SetBkColor(RGB(0,0,0));

        CRect rect;
        GetClientRect(&rect);

        int save = dc.SaveDC();

        if(bSetDraw)
        {
                CMemDC mDC(&dc);

                //mDC.SetBkColor(RGB(0,0,0));
                mDC.SetMapMode(MM_ANISOTROPIC);
                mDC.SetWindowOrg(rect.BottomRight());
                mDC.SetViewportOrg(0, 0);
                mDC.SetViewportExt(-1, -1);
                //mDC.SetViewportExt(-rect.right, -rect.bottom);
                mDC.SetWindowExt(1, 1);
                //mDC.SetWindowExt(rect.Width(), rect.Height());
                // ********** Background ***********
                // Grid
                if (bActivateGrid)
                {
                        CPen qLinePen(PS_SOLID, 1, RGB(0,139,0));
                        mDC.SelectObject(&qLinePen);

                        // Grid - Horizontal lines
                        mDC.MoveTo(1, 0);
                        mDC.LineTo(rect.Width(), 0);
                        int height = rect.Height();
                        int maxlines = height / (int)12.5;
                        for (int i=1;i<=maxlines;i++){
                                int y_axis = (int)((double)i * 12.5);
                                if (y_axis <= rect.Height()) {
                                        mDC.MoveTo(1, y_axis);
                                        mDC.LineTo(rect.Width(),
y_axis);
                                }
                        }

                        // Grid - Vertical lines
                        mDC.MoveTo(0, 0);
                        mDC.LineTo(0, rect.Height());
                        int width = rect.Width();
                        maxlines = width / (int)12.5;
                        for (int i=1;i<=maxlines;i++){
                                int x_axis = (int)(((double)i * 12.5)
- gridOffset);
                                if (x_axis <= rect.Width()) {
                                        mDC.MoveTo(x_axis, 1);
                                        mDC.LineTo(x_axis,
rect.Height());
                                }
                        }

                        qLinePen.DeleteObject();
                }
                // *********** graphic component ***********
                // based on choice of graph type
                CPen qPolylinePen(PS_SOLID, 1, RGB(0, 255, 0));
                switch (iGraphType)
                {
                case GRAPH_BARS:
                        break;

                case GRAPH_LINES:
                        {
                                if (vtPoints.capacity() == 1)
                                {
 
mDC.SelectObject(qPolylinePen);
                                        vectfPoints* pointsline =
&vtPoints[0];
                                        mDC.Polyline(&(*pointsline)
[0], (int)pointsline->size());
                                        //mDC->PolyPolyline()
                                        qPolylinePen.DeleteObject();
                                }
                        }
                        break;

                default:
                        break;
                }
                GDI_FLUSH();
        }

        dc.RestoreDC(save);
}

but when I resize window the vertical and horizontal lines are
repainted to the whole canvas but the Polyline stuff isn't rescaled; I
mean I have values in the vtPoints array which MM_ANISOTROPIC should
rescale automatically due having set SetViewportExt and SetWindowExt
respectively to -1, -1 and 1, 1 so I guess it should scale 1:1 and the
polyline graphic should be adjusted when resizing window....but it
doesn't... what I could have missed or made wrong in those
SetViewportExt and SetWindowExt?...

Thanks
Ciao
Luigi