+#if wxUSE_SPLINES
+void wxDC::DoDrawSpline(wxList *points)
+{
+#ifdef __WXWINCE__
+ // WinCE does not support ::PolyBezier so use generic version
+ wxDCBase::DoDrawSpline(points);
+#else
+ // quadratic b-spline to cubic bezier spline conversion
+ //
+ // quadratic spline with control points P0,P1,P2
+ // P(s) = P0*(1-s)^2 + P1*2*(1-s)*s + P2*s^2
+ //
+ // bezier spline with control points B0,B1,B2,B3
+ // B(s) = B0*(1-s)^3 + B1*3*(1-s)^2*s + B2*3*(1-s)*s^2 + B3*s^3
+ //
+ // control points of bezier spline calculated from b-spline
+ // B0 = P0
+ // B1 = (2*P1 + P0)/3
+ // B2 = (2*P1 + P2)/3
+ // B3 = P2
+
+ WXMICROWIN_CHECK_HDC
+
+ wxASSERT_MSG( points, wxT("NULL pointer to spline points?") );
+
+ const size_t n_points = points->GetCount();
+ wxASSERT_MSG( n_points > 2 , wxT("incomplete list of spline points?") );
+
+ const size_t n_bezier_points = n_points * 3 + 1;
+ POINT *lppt = (POINT *)malloc(n_bezier_points*sizeof(POINT));
+ size_t bezier_pos = 0;
+ wxCoord x1, y1, x2, y2, cx1, cy1, cx4, cy4;
+
+ wxList::compatibility_iterator node = points->GetFirst();
+ wxPoint *p = (wxPoint *)node->GetData();
+ lppt[ bezier_pos ].x = x1 = p->x;
+ lppt[ bezier_pos ].y = y1 = p->y;
+ bezier_pos++;
+ lppt[ bezier_pos ] = lppt[ bezier_pos-1 ];
+ bezier_pos++;
+
+ node = node->GetNext();
+ p = (wxPoint *)node->GetData();
+
+ x2 = p->x;
+ y2 = p->y;
+ cx1 = ( x1 + x2 ) / 2;
+ cy1 = ( y1 + y2 ) / 2;
+ lppt[ bezier_pos ].x = XLOG2DEV(cx1);
+ lppt[ bezier_pos ].y = YLOG2DEV(cy1);
+ bezier_pos++;
+ lppt[ bezier_pos ] = lppt[ bezier_pos-1 ];
+ bezier_pos++;
+
+#if !wxUSE_STL
+ while ((node = node->GetNext()) != NULL)
+#else
+ while ((node = node->GetNext()))
+#endif // !wxUSE_STL
+ {
+ p = (wxPoint *)node->GetData();
+ x1 = x2;
+ y1 = y2;
+ x2 = p->x;
+ y2 = p->y;
+ cx4 = (x1 + x2) / 2;
+ cy4 = (y1 + y2) / 2;
+ // B0 is B3 of previous segment
+ // B1:
+ lppt[ bezier_pos ].x = XLOG2DEV((x1*2+cx1)/3);
+ lppt[ bezier_pos ].y = YLOG2DEV((y1*2+cy1)/3);
+ bezier_pos++;
+ // B2:
+ lppt[ bezier_pos ].x = XLOG2DEV((x1*2+cx4)/3);
+ lppt[ bezier_pos ].y = YLOG2DEV((y1*2+cy4)/3);
+ bezier_pos++;
+ // B3:
+ lppt[ bezier_pos ].x = XLOG2DEV(cx4);
+ lppt[ bezier_pos ].y = YLOG2DEV(cy4);
+ bezier_pos++;
+ cx1 = cx4;
+ cy1 = cy4;
+ }
+
+ lppt[ bezier_pos ] = lppt[ bezier_pos-1 ];
+ bezier_pos++;
+ lppt[ bezier_pos ].x = XLOG2DEV(x2);
+ lppt[ bezier_pos ].y = YLOG2DEV(y2);
+ bezier_pos++;
+ lppt[ bezier_pos ] = lppt[ bezier_pos-1 ];
+ bezier_pos++;
+
+ ::PolyBezier( GetHdc(), lppt, bezier_pos );
+
+ free(lppt);
+#endif
+}
+#endif
+
projects / wxWidgets.git / blobdiff