-// ---------------------------------------------------------------------------
-// spline drawing code
-// ---------------------------------------------------------------------------
-
-#if wxUSE_SPLINES
-
-class wxSpline: public wxObject
-{
-public:
- int type;
- wxList *points;
-
- wxSpline(wxList *list);
- void DeletePoints();
-
- // Doesn't delete points
- ~wxSpline();
-};
-
-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();
-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::DoDrawSpline(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()
-{
- 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 wxSpline::DeletePoints()
-{
- 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