POLYWIN.CPP
/*
* POLYWIN.CPP
* Cosmo Chapter 18
*
* Window procedure for the polyline drawing window and support
* functions. This window is not complicated. On creation it
* allocates a block of memory for a POLYLINEDATA structure that
* contains 20 POINTs. We do not attempt to reallocate this
* array at all just to maintain simplicity.
*
* Copyright (c)1993-1995 Microsoft Corporation, All Rights Reserved
*
* Kraig Brockschmidt, Microsoft
* Internet : kraigb@microsoft.com
* Compuserve: >INTERNET:kraigb@microsoft.com
*/
#include "cosmo.h"
/*
* PolylineWndProc
*
* Purpose:
* Window procedure for the polyline drawing window.
*/
LRESULT APIENTRY PolylineWndProc(HWND hWnd, UINT iMsg
, WPARAM wParam, LPARAM lParam)
{
PCPolyline ppl;
PAINTSTRUCT ps;
HDC hDC;
POINTS pt;
RECT rc;
ppl=(PCPolyline)GetWindowLong(hWnd, PLWL_STRUCTURE);
switch (iMsg)
{
case WM_CREATE:
ppl=(PCPolyline)((LPCREATESTRUCT)lParam)->lpCreateParams;
SetWindowLong(hWnd, PLWL_STRUCTURE, (LONG)ppl);
ppl->m_hWnd=hWnd;
ppl->New();
break;
case WM_PAINT:
hDC=BeginPaint(hWnd, &ps);
ppl->Draw(hDC, FALSE, TRUE);
EndPaint(hWnd, &ps);
break;
case WM_LBUTTONDOWN:
//Stop if we are already at the limit.
if (CPOLYLINEPOINTS==ppl->m_pl.cPoints)
{
MessageBeep(0);
break;
}
//Convert the points into 0-32767 range
GetClientRect(hWnd, &rc);
pt=MAKEPOINTS(lParam);
ppl->PointScale(&rc, &pt, FALSE);
ppl->m_pl.rgpt[ppl->m_pl.cPoints++]=pt;
//Draw the lines to this new point only.
hDC=GetDC(hWnd);
ppl->Draw(hDC, FALSE, FALSE);
ReleaseDC(hWnd, hDC);
if (NULL!=ppl->m_pAdv)
ppl->m_pAdv->OnPointChange();
break;
default:
return DefWindowProc(hWnd, iMsg, wParam, lParam);
}
return 0L;
}
/*
* CPolyline::Draw
*
* Purpose:
* Paints the current line in the polyline window.
*
* Parameters:
* hDC HDC to draw on, could be metafile or printer DC.
* fMetafile BOOL indicating if hDC is a metafile or not, so
* we can avoid operations that RIP.
* fEntire BOOL indicating if we should draw the entire
* figure or not.
*
* Return Value:
* None
*/
void CPolyline::Draw(HDC hDC, BOOL fMetafile, BOOL fEntire)
{
HBRUSH hBrush;
HPEN hPen;
HGDIOBJ hObj1, hObj2;
UINT i, j;
UINT uMM;
POINTS pt1, pt2;
POINT rgpt[CPOLYLINEPOINTS];
RECT rc;
GetClientRect(m_hWnd, &rc);
/*
* Make a 32-bit copy of the points in the POLYLINE itself
* so we can use DPtoLP and LPtoDP.
*/
for (i=0; i < m_pl.cPoints; i++)
{
rgpt[i].x=m_pl.rgpt[i].x;
rgpt[i].y=m_pl.rgpt[i].y;
}
/*
* If the mapping mode is not MM_TEXT, convert the points to
* whatever mapping mode in in effect before drawing.
* This specifically supports metafiles in MM_ANISOTROPIC.
*/
uMM=fMetafile ? MM_TEXT : GetMapMode(hDC);
if (MM_TEXT!=uMM)
DPtoLP(hDC, rgpt, m_pl.cPoints);
hPen=CreatePen(m_pl.iLineStyle, 1, m_pl.rgbLine);
hObj1=SelectObject(hDC, hPen);
hBrush=CreateSolidBrush(m_pl.rgbBackground);
hObj2=SelectObject(hDC, hBrush);
SetBkColor(hDC, m_pl.rgbBackground);
/*
* Either draw the entire figure or just a single point. The
* entire figure also includes erasing the background
* completely,since hDC may be a metafile DC. Drawing a
* single point just updates the figure for that new point.
*/
if (fEntire || 0==m_pl.cPoints)
{
//Erase the background for bitmaps and metafiles.
SelectObject(hDC, GetStockObject(NULL_PEN));
Rectangle(hDC, rc.left, rc.top, rc.right+1, rc.bottom+1);
SelectObject(hDC, hPen);
/*
* If we are drawing the entire figure, then loop through
* each point drawing a line to each successive point.
*/
for (i=0; i < m_pl.cPoints; i++)
{
for (j=i; j < m_pl.cPoints; j++)
{
/*
* Not using POINTTOPOINTS since it unfortunately
* returns a LONG which doesn't equate to a POINTS.
*/
pt1.x=(short)rgpt[i].x;
pt1.y=(short)rgpt[i].y;
pt2.x=(short)rgpt[j].x;
pt2.y=(short)rgpt[j].y;
PointScale(&rc, &pt1, TRUE);
PointScale(&rc, &pt2, TRUE);
MoveToEx(hDC, pt1.x, pt1.y, NULL);
LineTo(hDC, pt2.x, pt2.y);
}
}
}
else
{
/*
* If we are only drawing the last point, just cycle once
* through previous points.
*/
//Get the last point entered in the array.
j=m_pl.cPoints-1;
pt1.x=(short)rgpt[j].x;
pt1.y=(short)rgpt[j].y;
PointScale(&rc, &pt1, TRUE);
for (i=0; i < j; i++)
{
pt2.x=(short)rgpt[i].x;
pt2.y=(short)rgpt[i].y;
PointScale(&rc, &pt2, TRUE);
MoveToEx(hDC, pt1.x, pt1.y, NULL);
LineTo(hDC, pt2.x, pt2.y);
}
}
//If we have one point, draw a dot to indicate it's position.
if (1==m_pl.cPoints)
{
pt1.x=(short)rgpt[0].x;
pt1.y=(short)rgpt[0].y;
PointScale(&rc, &pt1, TRUE);
SetPixel(hDC, pt1.x, pt1.y, m_pl.rgbLine);
}
//Note: m_pl.rgpt is unmodified in this code.
SelectObject(hDC, hObj1);
SelectObject(hDC, hObj2);
DeleteObject(hBrush);
DeleteObject(hPen);
return;
}
/*
* CPolyline::PointScale
*
* Purpose:
* Scales a point to or from a relative window coordinate to a
* 0-32767 coordinate.
*
* Parameters:
* pRect LPRECT of the window.
* ppt LPPOINTS to convert
* fScaleToWindow BOOL indicating direction of scaling.
*
* Return Value:
* None
*/
void CPolyline::PointScale(LPRECT pRect, LPPOINTS ppt
, BOOL fScaleToWindow)
{
DWORD cx, cy;
//Window size
cx=(DWORD)(pRect->right-pRect->left);
cy=(DWORD)(pRect->bottom-pRect->top);
//Prevent crashes
if (0L==cx) cx=1;
if (0L==cy) cy=1;
//Must use DWORD to insure proper scaling.
if (fScaleToWindow)
{
ppt->x=(UINT)(((DWORD)ppt->x*cx) >> 15);
ppt->y=(UINT)(((DWORD)ppt->y*cy) >> 15);
}
else
{
ppt->x=(UINT)(((DWORD)ppt->x << 15)/cx);
ppt->y=(UINT)(((DWORD)ppt->y << 15)/cy);
}
return;
}