include/region.h

   1 /*
   2  * GDI region definitions
   3  * Mainly taken from the X11 distribution.
   4  * Modifications: Copyright 1998 Huw Davies
   5  */
   6
   7 /************************************************************************
   8
   9 Copyright (c) 1987  X Consortium
  10
  11 Permission is hereby granted, free of charge, to any person obtaining a copy
  12 of this software and associated documentation files (the "Software"), to deal
  13 in the Software without restriction, including without limitation the rights
  14 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15 copies of the Software, and to permit persons to whom the Software is
  16 furnished to do so, subject to the following conditions:
  17
  18 The above copyright notice and this permission notice shall be included in
  19 all copies or substantial portions of the Software.
  20
  21 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  24 X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  25 AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  26 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27
  28 Except as contained in this notice, the name of the X Consortium shall not be
  29 used in advertising or otherwise to promote the sale, use or other dealings
  30 in this Software without prior written authorization from the X Consortium.
  31
  32
  33 Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.
  34
  35                         All Rights Reserved
  36
  37 Permission to use, copy, modify, and distribute this software and its
  38 documentation for any purpose and without fee is hereby granted,
  39 provided that the above copyright notice appear in all copies and that
  40 both that copyright notice and this permission notice appear in
  41 supporting documentation, and that the name of Digital not be
  42 used in advertising or publicity pertaining to distribution of the
  43 software without specific, written prior permission.
  44
  45 DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
  46 ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
  47 DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
  48 ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  49 WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
  50 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  51 SOFTWARE.
  52
  53 ************************************************************************/
  54 #ifndef __WINE_REGION_H
  55 #define __WINE_REGION_H
  56
  57 #include "wingdi.h"
  58 #include "gdi.h"
  59
  60
  61 typedef struct {
  62     INT size;
  63     INT numRects;
  64     INT type; /* NULL, SIMPLE or COMPLEX */
  65     RECT *rects;
  66     RECT extents;
  67 } WINEREGION;
  68
  69   /* GDI logical region object */
  70 typedef struct
  71 {
  72     GDIOBJHDR   header;
  73     WINEREGION  *rgn;
  74 } RGNOBJ;
  75
  76 /*  1 if two RECTs overlap.
  77  *  0 if two RECTs do not overlap.
  78  */
  79 #define EXTENTCHECK(r1, r2) \
  80         ((r1)->right > (r2)->left && \
  81          (r1)->left < (r2)->right && \
  82          (r1)->bottom > (r2)->top && \
  83          (r1)->top < (r2)->bottom)
  84
  85 /*
  86  *   Check to see if there is enough memory in the present region.
  87  */
  88 #define MEMCHECK(reg, rect, firstrect){\
  89         if ((reg)->numRects >= ((reg)->size - 1)){\
  90           (firstrect) = HeapReAlloc( SystemHeap, 0, \
  91            (firstrect), (2 * (sizeof(RECT)) * ((reg)->size)));\
  92           if ((firstrect) == 0)\
  93             return;\
  94           (reg)->size *= 2;\
  95           (rect) = &(firstrect)[(reg)->numRects];\
  96          }\
  97        }
  98
  99 #define EMPTY_REGION(pReg) { \
 100     (pReg)->numRects = 0; \
 101     (pReg)->extents.left = (pReg)->extents.top = 0; \
 102     (pReg)->extents.right = (pReg)->extents.bottom = 0; \
 103     (pReg)->type = NULLREGION; \
 104  }
 105
 106 #define REGION_NOT_EMPTY(pReg) pReg->numRects
 107
 108 #define INRECT(r, x, y) \
 109       ( ( ((r).right >  x)) && \
 110         ( ((r).left <= x)) && \
 111         ( ((r).bottom >  y)) && \
 112         ( ((r).top <= y)) )
 113
 114
 115 /*
 116  * number of points to buffer before sending them off
 117  * to scanlines() :  Must be an even number
 118  */
 119 #define NUMPTSTOBUFFER 200
 120
 121 /*
 122  * used to allocate buffers for points and link
 123  * the buffers together
 124  */
 125
 126 typedef struct _POINTBLOCK {
 127     POINT pts[NUMPTSTOBUFFER];
 128     struct _POINTBLOCK *next;
 129 } POINTBLOCK;
 130
 131
 132
 133 /*
 134  *     This file contains a few macros to help track
 135  *     the edge of a filled object.  The object is assumed
 136  *     to be filled in scanline order, and thus the
 137  *     algorithm used is an extension of Bresenham's line
 138  *     drawing algorithm which assumes that y is always the
 139  *     major axis.
 140  *     Since these pieces of code are the same for any filled shape,
 141  *     it is more convenient to gather the library in one
 142  *     place, but since these pieces of code are also in
 143  *     the inner loops of output primitives, procedure call
 144  *     overhead is out of the question.
 145  *     See the author for a derivation if needed.
 146  */
 147
 148
 149 /*
 150  *  In scan converting polygons, we want to choose those pixels
 151  *  which are inside the polygon.  Thus, we add .5 to the starting
 152  *  x coordinate for both left and right edges.  Now we choose the
 153  *  first pixel which is inside the pgon for the left edge and the
 154  *  first pixel which is outside the pgon for the right edge.
 155  *  Draw the left pixel, but not the right.
 156  *
 157  *  How to add .5 to the starting x coordinate:
 158  *      If the edge is moving to the right, then subtract dy from the
 159  *  error term from the general form of the algorithm.
 160  *      If the edge is moving to the left, then add dy to the error term.
 161  *
 162  *  The reason for the difference between edges moving to the left
 163  *  and edges moving to the right is simple:  If an edge is moving
 164  *  to the right, then we want the algorithm to flip immediately.
 165  *  If it is moving to the left, then we don't want it to flip until
 166  *  we traverse an entire pixel.
 167  */
 168 #define BRESINITPGON(dy, x1, x2, xStart, d, m, m1, incr1, incr2) { \
 169     int dx;      /* local storage */ \
 170 \
 171     /* \
 172      *  if the edge is horizontal, then it is ignored \
 173      *  and assumed not to be processed.  Otherwise, do this stuff. \
 174      */ \
 175     if ((dy) != 0) { \
 176         xStart = (x1); \
 177         dx = (x2) - xStart; \
 178         if (dx < 0) { \
 179             m = dx / (dy); \
 180             m1 = m - 1; \
 181             incr1 = -2 * dx + 2 * (dy) * m1; \
 182             incr2 = -2 * dx + 2 * (dy) * m; \
 183             d = 2 * m * (dy) - 2 * dx - 2 * (dy); \
 184         } else { \
 185             m = dx / (dy); \
 186             m1 = m + 1; \
 187             incr1 = 2 * dx - 2 * (dy) * m1; \
 188             incr2 = 2 * dx - 2 * (dy) * m; \
 189             d = -2 * m * (dy) + 2 * dx; \
 190         } \
 191     } \
 192 }
 193
 194 #define BRESINCRPGON(d, minval, m, m1, incr1, incr2) { \
 195     if (m1 > 0) { \
 196         if (d > 0) { \
 197             minval += m1; \
 198             d += incr1; \
 199         } \
 200         else { \
 201             minval += m; \
 202             d += incr2; \
 203         } \
 204     } else {\
 205         if (d >= 0) { \
 206             minval += m1; \
 207             d += incr1; \
 208         } \
 209         else { \
 210             minval += m; \
 211             d += incr2; \
 212         } \
 213     } \
 214 }
 215
 216 /*
 217  *     This structure contains all of the information needed
 218  *     to run the bresenham algorithm.
 219  *     The variables may be hardcoded into the declarations
 220  *     instead of using this structure to make use of
 221  *     register declarations.
 222  */
 223 typedef struct {
 224     INT minor_axis;     /* minor axis        */
 225     INT d;              /* decision variable */
 226     INT m, m1;          /* slope and slope+1 */
 227     INT incr1, incr2;   /* error increments */
 228 } BRESINFO;
 229
 230
 231 #define BRESINITPGONSTRUCT(dmaj, min1, min2, bres) \
 232         BRESINITPGON(dmaj, min1, min2, bres.minor_axis, bres.d, \
 233                      bres.m, bres.m1, bres.incr1, bres.incr2)
 234
 235 #define BRESINCRPGONSTRUCT(bres) \
 236         BRESINCRPGON(bres.d, bres.minor_axis, bres.m, bres.m1, bres.incr1, bres.incr2)
 237
 238
 239
 240 /*
 241  *     These are the data structures needed to scan
 242  *     convert regions.  Two different scan conversion
 243  *     methods are available -- the even-odd method, and
 244  *     the winding number method.
 245  *     The even-odd rule states that a point is inside
 246  *     the polygon if a ray drawn from that point in any
 247  *     direction will pass through an odd number of
 248  *     path segments.
 249  *     By the winding number rule, a point is decided
 250  *     to be inside the polygon if a ray drawn from that
 251  *     point in any direction passes through a different
 252  *     number of clockwise and counter-clockwise path
 253  *     segments.
 254  *
 255  *     These data structures are adapted somewhat from
 256  *     the algorithm in (Foley/Van Dam) for scan converting
 257  *     polygons.
 258  *     The basic algorithm is to start at the top (smallest y)
 259  *     of the polygon, stepping down to the bottom of
 260  *     the polygon by incrementing the y coordinate.  We
 261  *     keep a list of edges which the current scanline crosses,
 262  *     sorted by x.  This list is called the Active Edge Table (AET)
 263  *     As we change the y-coordinate, we update each entry in
 264  *     in the active edge table to reflect the edges new xcoord.
 265  *     This list must be sorted at each scanline in case
 266  *     two edges intersect.
 267  *     We also keep a data structure known as the Edge Table (ET),
 268  *     which keeps track of all the edges which the current
 269  *     scanline has not yet reached.  The ET is basically a
 270  *     list of ScanLineList structures containing a list of
 271  *     edges which are entered at a given scanline.  There is one
 272  *     ScanLineList per scanline at which an edge is entered.
 273  *     When we enter a new edge, we move it from the ET to the AET.
 274  *
 275  *     From the AET, we can implement the even-odd rule as in
 276  *     (Foley/Van Dam).
 277  *     The winding number rule is a little trickier.  We also
 278  *     keep the EdgeTableEntries in the AET linked by the
 279  *     nextWETE (winding EdgeTableEntry) link.  This allows
 280  *     the edges to be linked just as before for updating
 281  *     purposes, but only uses the edges linked by the nextWETE
 282  *     link as edges representing spans of the polygon to
 283  *     drawn (as with the even-odd rule).
 284  */
 285
 286 /*
 287  * for the winding number rule
 288  */
 289 #define CLOCKWISE          1
 290 #define COUNTERCLOCKWISE  -1
 291
 292 typedef struct _EdgeTableEntry {
 293      INT ymax;           /* ycoord at which we exit this edge. */
 294      BRESINFO bres;        /* Bresenham info to run the edge     */
 295      struct _EdgeTableEntry *next;       /* next in the list     */
 296      struct _EdgeTableEntry *back;       /* for insertion sort   */
 297      struct _EdgeTableEntry *nextWETE;   /* for winding num rule */
 298      int ClockWise;        /* flag for winding number rule       */
 299 } EdgeTableEntry;
 300
 301
 302 typedef struct _ScanLineList{
 303      INT scanline;            /* the scanline represented */
 304      EdgeTableEntry *edgelist;  /* header node              */
 305      struct _ScanLineList *next;  /* next in the list       */
 306 } ScanLineList;
 307
 308
 309 typedef struct {
 310      INT ymax;               /* ymax for the polygon     */
 311      INT ymin;               /* ymin for the polygon     */
 312      ScanLineList scanlines;   /* header node              */
 313 } EdgeTable;
 314
 315
 316 /*
 317  * Here is a struct to help with storage allocation
 318  * so we can allocate a big chunk at a time, and then take
 319  * pieces from this heap when we need to.
 320  */
 321 #define SLLSPERBLOCK 25
 322
 323 typedef struct _ScanLineListBlock {
 324      ScanLineList SLLs[SLLSPERBLOCK];
 325      struct _ScanLineListBlock *next;
 326 } ScanLineListBlock;
 327
 328
 329 /*
 330  *
 331  *     a few macros for the inner loops of the fill code where
 332  *     performance considerations don't allow a procedure call.
 333  *
 334  *     Evaluate the given edge at the given scanline.
 335  *     If the edge has expired, then we leave it and fix up
 336  *     the active edge table; otherwise, we increment the
 337  *     x value to be ready for the next scanline.
 338  *     The winding number rule is in effect, so we must notify
 339  *     the caller when the edge has been removed so he
 340  *     can reorder the Winding Active Edge Table.
 341  */
 342 #define EVALUATEEDGEWINDING(pAET, pPrevAET, y, fixWAET) { \
 343    if (pAET->ymax == y) {          /* leaving this edge */ \
 344       pPrevAET->next = pAET->next; \
 345       pAET = pPrevAET->next; \
 346       fixWAET = 1; \
 347       if (pAET) \
 348          pAET->back = pPrevAET; \
 349    } \
 350    else { \
 351       BRESINCRPGONSTRUCT(pAET->bres); \
 352       pPrevAET = pAET; \
 353       pAET = pAET->next; \
 354    } \
 355 }
 356
 357
 358 /*
 359  *     Evaluate the given edge at the given scanline.
 360  *     If the edge has expired, then we leave it and fix up
 361  *     the active edge table; otherwise, we increment the
 362  *     x value to be ready for the next scanline.
 363  *     The even-odd rule is in effect.
 364  */
 365 #define EVALUATEEDGEEVENODD(pAET, pPrevAET, y) { \
 366    if (pAET->ymax == y) {          /* leaving this edge */ \
 367       pPrevAET->next = pAET->next; \
 368       pAET = pPrevAET->next; \
 369       if (pAET) \
 370          pAET->back = pPrevAET; \
 371    } \
 372    else { \
 373       BRESINCRPGONSTRUCT(pAET->bres); \
 374       pPrevAET = pAET; \
 375       pAET = pAET->next; \
 376    } \
 377 }
 378
 379 extern BOOL REGION_DeleteObject( HRGN hrgn, RGNOBJ * obj );
 380 extern BOOL REGION_UnionRectWithRgn( HRGN hrgn, const RECT *lpRect );
 381 extern HRGN REGION_CropRgn( HRGN hDst, HRGN hSrc, const RECT *lpRect, const POINT *lpPt );
 382 extern BOOL REGION_FrameRgn( HRGN dest, HRGN src, INT x, INT y );
 383 extern BOOL REGION_LPTODP( HDC hdc, HRGN hDest, HRGN hSrc );
 384
 385 #endif  /* __WINE_REGION_H */
 386
 387