src/msw/xfspline.inc

   1 /*
   2  * File:        xfspline.cc
   3  * Purpose:
   4  * Author:      Julian Smart
   5  * Created:     1993
   6  * Updated:     August 1994
   7  * RCS_ID:      $Id$
   8  * Copyright:   (c) 1993, AIAI, University of Edinburgh
   9  */
  10
  11 // Must be a comment as this file is #include\'d by wb_dc.cc
  12 /* static const char sccsid[] = "@(#)xfspline.cc        1.3 5/9/94"; */
  13
  14 /*
  15  * FIG : Facility for Interactive Generation of figures
  16  * Copyright (c) 1985 by Supoj Sutanthavibul
  17  */
  18
  19
  20 #if USE_SPLINES
  21
  22 ////#define     wx_round(a)    (int)((a)+.5)
  23 //#define     wx_round(a)    (a)
  24
  25 class wxSpline: public wxObject
  26 {
  27  public:
  28   int type;
  29   wxList *points;
  30
  31   wxSpline(wxList *list);
  32   void DeletePoints(void);
  33
  34   // Doesn't delete points
  35   ~wxSpline(void);
  36 };
  37
  38 void wx_draw_open_spline(wxDC *dc, wxSpline *spline);
  39
  40 #if USE_POSTSCRIPT
  41 void wx_draw_open_spline_ps(wxPostScriptDC *dc, wxSpline *s);
  42 #endif
  43
  44 void wx_quadratic_spline(double a1, double b1, double a2, double b2,
  45                          double a3, double b3, double a4, double b4);
  46 void wx_clear_stack(void);
  47 int wx_spline_pop(double *x1, double *y1, double *x2, double *y2, double *x3,
  48         double *y3, double *x4, double *y4);
  49 void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3,
  50           double x4, double y4);
  51 static bool wx_spline_add_point(double x, double y);
  52 static void wx_spline_draw_point_array(wxDC *dc);
  53 wxSpline *wx_make_spline(int x1, int y1, int x2, int y2, int x3, int y3);
  54
  55 void wxDC::DrawSpline(int n, wxPoint points[])
  56 {
  57   wxList list;
  58   int i;
  59   for (i =0; i < n; i++)
  60     list.Append((wxObject*)&points[i]);
  61   DrawSpline((wxList *)&list);
  62 }
  63
  64 void wxDC::DrawSpline(wxList *list)
  65 {
  66   wxSpline spline(list);
  67
  68   wx_draw_open_spline(this, &spline);
  69 }
  70
  71
  72 wxList wx_spline_point_list;
  73
  74 void wx_draw_open_spline(wxDC *dc, wxSpline *spline)
  75 {
  76     wxPoint *p;
  77     double           cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4;
  78     double           x1, y1, x2, y2;
  79
  80     wxNode *node = spline->points->First();
  81     p = (wxPoint *)node->Data();
  82
  83     x1 = p->x;
  84     y1 = p->y;
  85
  86     node = node->Next();
  87     p = (wxPoint *)node->Data();
  88
  89     x2 = p->x;
  90     y2 = p->y;
  91     cx1 = (double)((x1 + x2) / 2);
  92     cy1 = (double)((y1 + y2) / 2);
  93     cx2 = (double)((cx1 + x2) / 2);
  94     cy2 = (double)((cy1 + y2) / 2);
  95
  96     wx_spline_add_point(x1, y1);
  97
  98     while ((node = node->Next()) != NULL)
  99     {
 100         p = (wxPoint *)node->Data();
 101         x1 = x2;
 102         y1 = y2;
 103         x2 = p->x;
 104         y2 = p->y;
 105         cx4 = (double)(x1 + x2) / 2;
 106         cy4 = (double)(y1 + y2) / 2;
 107         cx3 = (double)(x1 + cx4) / 2;
 108         cy3 = (double)(y1 + cy4) / 2;
 109
 110         wx_quadratic_spline(cx1, cy1, cx2, cy2, cx3, cy3, cx4, cy4);
 111
 112         cx1 = cx4;
 113         cy1 = cy4;
 114         cx2 = (double)(cx1 + x2) / 2;
 115         cy2 = (double)(cy1 + y2) / 2;
 116     }
 117
 118     wx_spline_add_point((double)wx_round(cx1), (double)wx_round(cy1));
 119     wx_spline_add_point(x2, y2);
 120
 121     wx_spline_draw_point_array(dc);
 122
 123 }
 124
 125 #if USE_POSTSCRIPT
 126 void wx_draw_open_spline_ps(wxPostScriptDC *dc, wxSpline *s)
 127 {
 128         double          a, b, c, d, x1, y1, x2, y2, x3, y3;
 129         wxPoint *p, *q;
 130         wxNode *node = s->points->First();
 131         p = (wxPoint *)node->Data();
 132
 133         x1 = p->x; y1 = p->y;
 134
 135         node = node->Next();
 136         p = (wxPoint *)node->Data();
 137         c = p->x; d = p->y;
 138         x3 = a = (double)(x1 + c) / 2;
 139         y3 = b = (double)(y1 + d) / 2;
 140
 141         *(dc->GetStream()) << "newpath " << x1 << " " << dc->GetYOrigin() - y1 << " moveto " << x3 << " " << dc->GetYOrigin() - y3;
 142         *(dc->GetStream()) << " lineto\n";
 143         dc->CalcBoundingBox((double)x1, (double)(dc->GetYOrigin() - y1));
 144         dc->CalcBoundingBox((double)x3, (double)(dc->GetYOrigin() - y3));
 145
 146         while ((node = node->Next()) != NULL)
 147         {
 148           q = (wxPoint *)node->Data();
 149
 150           x1 = x3; y1 = y3;
 151           x2 = c;  y2 = d;
 152           c = q->x; d = q->y;
 153           x3 = (double)(x2 + c) / 2;
 154           y3 = (double)(y2 + d) / 2;
 155           *(dc->GetStream()) << x1 << " " << dc->GetYOrigin() - y1 << " " << x2 << " " << dc->GetYOrigin() - y2 << " ";
 156           *(dc->GetStream()) << x3 << " " << dc->GetYOrigin() - y3 << " DrawSplineSection\n";
 157
 158           dc->CalcBoundingBox((double)x1, (double)(dc->GetYOrigin() - y1));
 159           dc->CalcBoundingBox((double)x3, (double)(dc->GetYOrigin() - y3));
 160         }
 161         /*
 162         * At this point, (x2,y2) and (c,d) are the position of the
 163         * next-to-last and last point respectively, in the point list
 164         */
 165         *(dc->GetStream()) << c << " " << dc->GetYOrigin() - d << " lineto stroke\n";
 166 }
 167 #endif
 168
 169 /********************* CURVES FOR SPLINES *****************************
 170
 171         The following spline drawing routine is from
 172
 173         "An Algorithm for High-Speed Curve Generation"
 174         by George Merrill Chaikin,
 175         Computer Graphics and Image Processing, 3, Academic Press,
 176         1974, 346-349.
 177
 178         and
 179
 180         "On Chaikin's Algorithm" by R. F. Riesenfeld,
 181         Computer Graphics and Image Processing, 4, Academic Press,
 182         1975, 304-310.
 183
 184 ***********************************************************************/
 185
 186 #define         half(z1, z2)    ((z1+z2)/2.0)
 187 #define         THRESHOLD       5
 188
 189 /* iterative version */
 190
 191 void wx_quadratic_spline(double a1, double b1, double a2, double b2, double a3, double b3, double a4,
 192                  double b4)
 193 {
 194     register double  xmid, ymid;
 195     double           x1, y1, x2, y2, x3, y3, x4, y4;
 196
 197     wx_clear_stack();
 198     wx_spline_push(a1, b1, a2, b2, a3, b3, a4, b4);
 199
 200     while (wx_spline_pop(&x1, &y1, &x2, &y2, &x3, &y3, &x4, &y4)) {
 201         xmid = (double)half(x2, x3);
 202         ymid = (double)half(y2, y3);
 203         if (fabs(x1 - xmid) < THRESHOLD && fabs(y1 - ymid) < THRESHOLD &&
 204             fabs(xmid - x4) < THRESHOLD && fabs(ymid - y4) < THRESHOLD) {
 205             wx_spline_add_point((double)wx_round(x1), (double)wx_round(y1));
 206             wx_spline_add_point((double)wx_round(xmid), (double)wx_round(ymid));
 207         } else {
 208             wx_spline_push(xmid, ymid, (double)half(xmid, x3), (double)half(ymid, y3),
 209                  (double)half(x3, x4), (double)half(y3, y4), x4, y4);
 210             wx_spline_push(x1, y1, (double)half(x1, x2), (double)half(y1, y2),
 211                  (double)half(x2, xmid), (double)half(y2, ymid), xmid, ymid);
 212         }
 213     }
 214 }
 215
 216
 217 /* utilities used by spline drawing routines */
 218
 219
 220 typedef struct wx_spline_stack_struct {
 221     double           x1, y1, x2, y2, x3, y3, x4, y4;
 222 }
 223                 Stack;
 224
 225 #define         SPLINE_STACK_DEPTH             20
 226 static Stack    wx_spline_stack[SPLINE_STACK_DEPTH];
 227 static Stack   *wx_stack_top;
 228 static int      wx_stack_count;
 229
 230 void wx_clear_stack(void)
 231 {
 232     wx_stack_top = wx_spline_stack;
 233     wx_stack_count = 0;
 234 }
 235
 236 void wx_spline_push(double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4)
 237 {
 238     wx_stack_top->x1 = x1;
 239     wx_stack_top->y1 = y1;
 240     wx_stack_top->x2 = x2;
 241     wx_stack_top->y2 = y2;
 242     wx_stack_top->x3 = x3;
 243     wx_stack_top->y3 = y3;
 244     wx_stack_top->x4 = x4;
 245     wx_stack_top->y4 = y4;
 246     wx_stack_top++;
 247     wx_stack_count++;
 248 }
 249
 250 int wx_spline_pop(double *x1, double *y1, double *x2, double *y2,
 251                   double *x3, double *y3, double *x4, double *y4)
 252 {
 253     if (wx_stack_count == 0)
 254         return (0);
 255     wx_stack_top--;
 256     wx_stack_count--;
 257     *x1 = wx_stack_top->x1;
 258     *y1 = wx_stack_top->y1;
 259     *x2 = wx_stack_top->x2;
 260     *y2 = wx_stack_top->y2;
 261     *x3 = wx_stack_top->x3;
 262     *y3 = wx_stack_top->y3;
 263     *x4 = wx_stack_top->x4;
 264     *y4 = wx_stack_top->y4;
 265     return (1);
 266 }
 267
 268 static bool wx_spline_add_point(double x, double y)
 269 {
 270   wxPoint *point = new wxPoint ;
 271   point->x = (int) x;
 272   point->y = (int) y;
 273   wx_spline_point_list.Append((wxObject*)point);
 274   return TRUE;
 275 }
 276
 277 static void wx_spline_draw_point_array(wxDC *dc)
 278 {
 279   dc->DrawLines(&wx_spline_point_list, (double)0.0, (double)0.0);
 280   wxNode *node = wx_spline_point_list.First();
 281   while (node)
 282   {
 283     wxPoint *point = (wxPoint *)node->Data();
 284     delete point;
 285     delete node;
 286     node = wx_spline_point_list.First();
 287   }
 288 }
 289
 290 wxSpline::wxSpline(wxList *list)
 291 {
 292   points = list;
 293 }
 294
 295 wxSpline::~wxSpline(void)
 296 {
 297 }
 298
 299 void wxSpline::DeletePoints(void)
 300 {
 301   for(wxNode *node = points->First(); node; node = points->First())
 302   {
 303     wxPoint *point = (wxPoint *)node->Data();
 304     delete point;
 305     delete node;
 306   }
 307   delete points;
 308 }
 309
 310 #if USE_POSTSCRIPT
 311
 312 // Make a 3-point spline
 313 void wxPostScriptDC::DrawSpline(long x1, long y1, long x2, long y2, long x3, long y3)
 314 {
 315   wxList *point_list = new wxList;
 316
 317   wxPoint *point1 = new wxPoint;
 318   point1->x = x1; point1->y = y1;
 319   point_list->Append((wxObject*)point1);
 320
 321   wxPoint *point2 = new wxPoint;
 322   point2->x = x2; point2->y = y2;
 323   point_list->Append((wxObject*)point2);
 324
 325   wxPoint *point3 = new wxPoint;
 326   point3->x = x3; point3->y = y3;
 327   point_list->Append((wxObject*)point3);
 328
 329   wxSpline spline(point_list);
 330
 331   wx_draw_open_spline_ps(this, &spline);
 332   spline.DeletePoints();
 333 }
 334
 335 void wxPostScriptDC::DrawSpline(wxList *list)
 336 {
 337   wxSpline spline(list);
 338
 339   wx_draw_open_spline_ps(this, &spline);
 340 }
 341
 342 void wxPostScriptDC::DrawSpline(int n, wxPoint points[])
 343 {
 344   wxList list;
 345   int i;
 346   for (i =0; i < n; i++)
 347     list.Append((wxObject*)&points[i]);
 348   DrawSpline((wxList *)&list);
 349 }
 350
 351
 352 #endif // USE_POSTSCRIPT
 353
 354 #endif // USE_SPLINES
 355