The BiDisp DLL or OCX include functions or methods to zoom the image with user interaction. The user can select a rectangle on the image for zooming.
[C++]
#include “BiDisp.h”
/* You have to redefine some functions in CView class for zooming */
void CMyView::OnLButtonDown(UINT nFlags, CPoint point)
{
…
ZOOMFLAG zmflg = ZOOM_SELECT_LARGE;
if(nFlags & MK_CONTROL)
zmflg = ZOOM_SELECT_MOVE;
if(nFlags & MK_SHIFT)
zmflg = ZOOM_SELECT_PLUS;
// Inicialize zoom
// 1. parameter (HWND): Window handle to display image
// 2. parameter (LPPOINT): Coordinates of the mouse pointer
// 3. parameter (LPRECT): X, Y scaling factor
// 4. parameter (ZOOMFLAG): Determines the operation of zoom.
// 5. parameter (LPZOOMSTRUCT): Zoom structure
// 6. parameter (BOOL): Inerpretation of mouse pointer coordanates
BZoomStart(m_hWnd, &point, &rScale, zmflg, &m_zm, FALSE);
m_zoom_select = TRUE;
…
}
void CMyView::OnMouseMove(UINT nFlags, CPoint point)
{
…
if (m_zoom_select)
// 1. parameter (HWND): Window handle to display image
// 2. parameter (LPPOINT): Coordinates of the mouse pointer
// 3. parameter (LPZOOMSTRUCT): Zoom structure
BZoomUpdate(m_hWnd, &point, &m_zm);
…
}
void CVtiffView::OnLButtonUp(UINT nFlags, CPoint point)
{
…
if(m_zoom_select)
{
// 1. parameter (HWND): Window handle to display image
// 2. parameter (LPPOINT): Coordinates of the mouse pointer
// 3. parameter (LPZOOMSTRUCT): Zoom structure
// 4. parameter (DISPLAYSTRUCT): Display information structure
BZoomEnd(m_hWnd, &point, &m_zm, &sDisplay);
DispZoom();
}
…
}
void CMyView::DispZoom()
{
CopyRect(&rScale, &m_zm.rScaleOut);
SetRect(&sDisplay.rOrigo, 0, 0, 0, 0);
sDisplay.rOrigo.left = m_zm.pOrigoOut.x;
sDisplay.rOrigo.top = m_zm.pOrigoOut.y;
if(hDib)
{
DisplayDIBStart(m_hWnd, hDib, &sDisplay.rOrigo,
&rScale, wDisplayMode, &sDisplay);
}
}
[VB]
Private Sub mnuZoom_Click()
‘ Set Zoom property to True
BiDisp.Zoom = 1
End Sub
[C#]
private void ZoomImage()
{
// Set Zoom property to true
BiDisp.Zoom = BIDISPLib.enum2State.tif2sEnable;
}