+void wx_draw_open_spline(wxDC *dc, wxSpline *spline);
+
+void wx_quadratic_spline(double a1, double b1, double a2, double b2,
+ double a3, double b3, double a4, double b4);
+void wx_clear_stack(void);
+int wx_spline_pop(double *x1, double *y1, double *x2, double *y2, double *x3,
+ double *y3, double *x4, double *y4);
+void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3,
+ double x4, double y4);
+static bool wx_spline_add_point(double x, double y);
+static void wx_spline_draw_point_array(wxDC *dc);
+wxSpline *wx_make_spline(int x1, int y1, int x2, int y2, int x3, int y3);
+
+void wxDC::DrawSpline(wxList *list)
+{
+ wxSpline spline(list);
+
+ wx_draw_open_spline(this, &spline);
+}
+
+
+wxList wx_spline_point_list;
+
+void wx_draw_open_spline(wxDC *dc, wxSpline *spline)
+{
+ wxPoint *p;
+ double cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4;
+ double x1, y1, x2, y2;
+
+ wxNode *node = spline->points->First();
+ p = (wxPoint *)node->Data();
+
+ x1 = p->x;
+ y1 = p->y;
+
+ node = node->Next();
+ p = (wxPoint *)node->Data();
+
+ x2 = p->x;
+ y2 = p->y;
+ cx1 = (double)((x1 + x2) / 2);
+ cy1 = (double)((y1 + y2) / 2);
+ cx2 = (double)((cx1 + x2) / 2);
+ cy2 = (double)((cy1 + y2) / 2);
+
+ wx_spline_add_point(x1, y1);
+
+ while ((node = node->Next()) != NULL)
+ {
+ p = (wxPoint *)node->Data();
+ x1 = x2;
+ y1 = y2;
+ x2 = p->x;
+ y2 = p->y;
+ cx4 = (double)(x1 + x2) / 2;
+ cy4 = (double)(y1 + y2) / 2;
+ cx3 = (double)(x1 + cx4) / 2;
+ cy3 = (double)(y1 + cy4) / 2;
+
+ wx_quadratic_spline(cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4);
+
+ cx1 = cx4;
+ cy1 = cy4;
+ cx2 = (double)(cx1 + x2) / 2;
+ cy2 = (double)(cy1 + y2) / 2;
+ }
+
+ wx_spline_add_point((double)wx_round(cx1), (double)wx_round(cy1));
+ wx_spline_add_point(x2, y2);
+
+ wx_spline_draw_point_array(dc);
+
+}
+
+/********************* CURVES FOR SPLINES *****************************
+
+ The following spline drawing routine is from
+
+ "An Algorithm for High-Speed Curve Generation"
+ by George Merrill Chaikin,
+ Computer Graphics and Image Processing, 3, Academic Press,
+ 1974, 346-349.
+
+ and
+
+ "On Chaikin's Algorithm" by R. F. Riesenfeld,
+ Computer Graphics and Image Processing, 4, Academic Press,
+ 1975, 304-310.
+
+***********************************************************************/
+
+#define half(z1, z2) ((z1+z2)/2.0)
+#define THRESHOLD 5
+
+/* iterative version */
+
+void wx_quadratic_spline(double a1, double b1, double a2, double b2, double a3, double b3, double a4,
+ double b4)
+{
+ register double xmid, ymid;
+ double x1, y1, x2, y2, x3, y3, x4, y4;
+
+ wx_clear_stack();
+ wx_spline_push(a1, b1, a2, b2, a3, b3, a4, b4);
+
+ while (wx_spline_pop(&x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)) {
+ xmid = (double)half(x2, x3);
+ ymid = (double)half(y2, y3);
+ if (fabs(x1 - xmid) < THRESHOLD && fabs(y1 - ymid) < THRESHOLD &&
+ fabs(xmid - x4) < THRESHOLD && fabs(ymid - y4) < THRESHOLD) {
+ wx_spline_add_point((double)wx_round(x1), (double)wx_round(y1));
+ wx_spline_add_point((double)wx_round(xmid), (double)wx_round(ymid));
+ } else {
+ wx_spline_push(xmid, ymid, (double)half(xmid, x3), (double)half(ymid, y3),
+ (double)half(x3, x4), (double)half(y3, y4), x4, y4);
+ wx_spline_push(x1, y1, (double)half(x1, x2), (double)half(y1, y2),
+ (double)half(x2, xmid), (double)half(y2, ymid), xmid, ymid);
+ }
+ }
+}
+
+
+/* utilities used by spline drawing routines */
+
+
+typedef struct wx_spline_stack_struct {
+ double x1, y1, x2, y2, x3, y3, x4, y4;
+}
+Stack;
+
+#define SPLINE_STACK_DEPTH 20
+static Stack wx_spline_stack[SPLINE_STACK_DEPTH];
+static Stack *wx_stack_top;
+static int wx_stack_count;
+
+void wx_clear_stack(void)
+{
+ wx_stack_top = wx_spline_stack;
+ wx_stack_count = 0;
+}
+
+void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4)
+{
+ wx_stack_top->x1 = x1;
+ wx_stack_top->y1 = y1;
+ wx_stack_top->x2 = x2;
+ wx_stack_top->y2 = y2;
+ wx_stack_top->x3 = x3;
+ wx_stack_top->y3 = y3;
+ wx_stack_top->x4 = x4;
+ wx_stack_top->y4 = y4;
+ wx_stack_top++;
+ wx_stack_count++;
+}
+
+int wx_spline_pop(double *x1, double *y1, double *x2, double *y2,
+ double *x3, double *y3, double *x4, double *y4)
+{
+ if (wx_stack_count == 0)
+ return (0);
+ wx_stack_top--;
+ wx_stack_count--;
+ *x1 = wx_stack_top->x1;
+ *y1 = wx_stack_top->y1;
+ *x2 = wx_stack_top->x2;
+ *y2 = wx_stack_top->y2;
+ *x3 = wx_stack_top->x3;
+ *y3 = wx_stack_top->y3;
+ *x4 = wx_stack_top->x4;
+ *y4 = wx_stack_top->y4;
+ return (1);
+}
+
+static bool wx_spline_add_point(double x, double y)
+{
+ wxPoint *point = new wxPoint ;
+ point->x = (int) x;
+ point->y = (int) y;
+ wx_spline_point_list.Append((wxObject*)point);
+ return TRUE;
+}
+
+static void wx_spline_draw_point_array(wxDC *dc)
+{
+ dc->DrawLines(&wx_spline_point_list, 0, 0);
+ wxNode *node = wx_spline_point_list.First();
+ while (node)
+ {
+ wxPoint *point = (wxPoint *)node->Data();
+ delete point;
+ delete node;
+ node = wx_spline_point_list.First();
+ }
+}
+
+wxSpline::wxSpline(wxList *list)
+{
+ points = list;
+}
+
+wxSpline::~wxSpline(void)
+{
+}
+
+void wxSpline::DeletePoints(void)
+{
+ for(wxNode *node = points->First(); node; node = points->First())
+ {
+ wxPoint *point = (wxPoint *)node->Data();
+ delete point;
+ delete node;
+ }
+ delete points;
+}
+
+
+#endif // wxUSE_SPLINES
projects / wxWidgets.git / blobdiff