mi/miwideline.h

   1 /*
   2
   3 Copyright 1988, 1998  The Open Group
   4
   5 Permission to use, copy, modify, distribute, and sell this software and its
   6 documentation for any purpose is hereby granted without fee, provided that
   7 the above copyright notice appear in all copies and that both that
   8 copyright notice and this permission notice appear in supporting
   9 documentation.
  10
  11 The above copyright notice and this permission notice shall be included
  12 in all copies or substantial portions of the Software.
  13
  14 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  15 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  16 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  17 IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20 OTHER DEALINGS IN THE SOFTWARE.
  21
  22 Except as contained in this notice, the name of The Open Group shall
  23 not be used in advertising or otherwise to promote the sale, use or
  24 other dealings in this Software without prior written authorization
  25 from The Open Group.
  26
  27 */
  28
  29 /* Author:  Keith Packard, MIT X Consortium */
  30
  31 #include "mispans.h"
  32 #include "mifpoly.h"            /* for ICEIL */
  33
  34 /*
  35  * Polygon edge description for integer wide-line routines
  36  */
  37
  38 typedef struct _PolyEdge {
  39     int height;                 /* number of scanlines to process */
  40     int x;                      /* starting x coordinate */
  41     int stepx;                  /* fixed integral dx */
  42     int signdx;                 /* variable dx sign */
  43     int e;                      /* initial error term */
  44     int dy;
  45     int dx;
  46 } PolyEdgeRec, *PolyEdgePtr;
  47
  48 #define SQSECANT 108.856472512142       /* 1/sin^2(11/2) - miter limit constant */
  49
  50 /*
  51  * types for general polygon routines
  52  */
  53
  54 typedef struct _PolyVertex {
  55     double x, y;
  56 } PolyVertexRec, *PolyVertexPtr;
  57
  58 typedef struct _PolySlope {
  59     int dx, dy;
  60     double k;                   /* x0 * dy - y0 * dx */
  61 } PolySlopeRec, *PolySlopePtr;
  62
  63 /*
  64  * Line face description for caps/joins
  65  */
  66
  67 typedef struct _LineFace {
  68     double xa, ya;
  69     int dx, dy;
  70     int x, y;
  71     double k;
  72 } LineFaceRec, *LineFacePtr;
  73
  74 /*
  75  * macros for polygon fillers
  76  */
  77
  78 #define MILINESETPIXEL(pDrawable, pGC, pixel, oldPixel) { \
  79     oldPixel = pGC->fgPixel; \
  80     if (pixel != oldPixel) { \
  81         ChangeGCVal gcval; \
  82         gcval.val = pixel; \
  83         ChangeGC (NullClient, pGC, GCForeground, &gcval); \
  84         ValidateGC (pDrawable, pGC); \
  85     } \
  86 }
  87 #define MILINERESETPIXEL(pDrawable, pGC, pixel, oldPixel) { \
  88     if (pixel != oldPixel) { \
  89         ChangeGCVal gcval; \
  90         gcval.val = oldPixel; \
  91         ChangeGC (NullClient, pGC, GCForeground, &gcval); \
  92         ValidateGC (pDrawable, pGC); \
  93     } \
  94 }
  95
  96 extern _X_EXPORT void miRoundJoinClip(LineFacePtr /*pLeft */ ,
  97                                       LineFacePtr /*pRight */ ,
  98                                       PolyEdgePtr /*edge1 */ ,
  99                                       PolyEdgePtr /*edge2 */ ,
 100                                       int * /*y1 */ ,
 101                                       int * /*y2 */ ,
 102                                       Bool * /*left1 */ ,
 103                                       Bool *    /*left2 */
 104     );
 105
 106 extern _X_EXPORT int miRoundCapClip(LineFacePtr /*face */ ,
 107                                     Bool /*isInt */ ,
 108                                     PolyEdgePtr /*edge */ ,
 109                                     Bool *      /*leftEdge */
 110     );
 111
 112 extern _X_EXPORT int miPolyBuildEdge(double x0, double y0, double k, int dx,
 113                                      int dy, int xi, int yi, int left,
 114                                      PolyEdgePtr edge);
 115 extern _X_EXPORT int miPolyBuildPoly(PolyVertexPtr vertices,
 116                                      PolySlopePtr slopes, int count, int xi,
 117                                      int yi, PolyEdgePtr left,
 118                                      PolyEdgePtr right, int *pnleft,
 119                                      int *pnright, int *h);