mi/miline.h

   1
   2 /*
   3
   4 Copyright 1994, 1998  The Open Group
   5
   6 Permission to use, copy, modify, distribute, and sell this software and its
   7 documentation for any purpose is hereby granted without fee, provided that
   8 the above copyright notice appear in all copies and that both that
   9 copyright notice and this permission notice appear in supporting
  10 documentation.
  11
  12 The above copyright notice and this permission notice shall be included in
  13 all copies or substantial portions of the Software.
  14
  15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  18 OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  19 AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  20 CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21
  22 Except as contained in this notice, the name of The Open Group shall not be
  23 used in advertising or otherwise to promote the sale, use or other dealings
  24 in this Software without prior written authorization from The Open Group.
  25
  26 */
  27
  28 #ifndef MILINE_H
  29
  30 #include "screenint.h"
  31 #include "privates.h"
  32
  33 /*
  34  * Public definitions used for configuring basic pixelization aspects
  35  * of the sample implementation line-drawing routines provided in
  36  * {mfb,mi,cfb*} at run-time.
  37  */
  38
  39 #define XDECREASING     4
  40 #define YDECREASING     2
  41 #define YMAJOR          1
  42
  43 #define OCTANT1         (1 << (YDECREASING))
  44 #define OCTANT2         (1 << (YDECREASING|YMAJOR))
  45 #define OCTANT3         (1 << (XDECREASING|YDECREASING|YMAJOR))
  46 #define OCTANT4         (1 << (XDECREASING|YDECREASING))
  47 #define OCTANT5         (1 << (XDECREASING))
  48 #define OCTANT6         (1 << (XDECREASING|YMAJOR))
  49 #define OCTANT7         (1 << (YMAJOR))
  50 #define OCTANT8         (1 << (0))
  51
  52 #define XMAJOROCTANTS           (OCTANT1 | OCTANT4 | OCTANT5 | OCTANT8)
  53
  54 #define DEFAULTZEROLINEBIAS     (OCTANT2 | OCTANT3 | OCTANT4 | OCTANT5)
  55
  56 /*
  57  * Devices can configure the rendering of routines in mi, mfb, and cfb*
  58  * by specifying a thin line bias to be applied to a particular screen
  59  * using the following function.  The bias parameter is an OR'ing of
  60  * the appropriate OCTANT constants defined above to indicate which
  61  * octants to bias a line to prefer an axial step when the Bresenham
  62  * error term is exactly zero.  The octants are mapped as follows:
  63  *
  64  *   \    |    /
  65  *    \ 3 | 2 /
  66  *     \  |  /
  67  *    4 \ | / 1
  68  *       \|/
  69  *   -----------
  70  *       /|\
  71  *    5 / | \ 8
  72  *     /  |  \
  73  *    / 6 | 7 \
  74  *   /    |    \
  75  *
  76  * For more information, see "Ambiguities in Incremental Line Rastering,"
  77  * Jack E. Bresenham, IEEE CG&A, May 1987.
  78  */
  79
  80 extern _X_EXPORT void miSetZeroLineBias(ScreenPtr /* pScreen */ ,
  81                                         unsigned int    /* bias */
  82     );
  83
  84 /*
  85  * Private definitions needed for drawing thin (zero width) lines
  86  * Used by the mi, mfb, and all cfb* components.
  87  */
  88
  89 #define X_AXIS  0
  90 #define Y_AXIS  1
  91
  92 #define OUT_LEFT  0x08
  93 #define OUT_RIGHT 0x04
  94 #define OUT_ABOVE 0x02
  95 #define OUT_BELOW 0x01
  96
  97 #define OUTCODES(_result, _x, _y, _pbox) \
  98     if      ( (_x) <  (_pbox)->x1) (_result) |= OUT_LEFT; \
  99     else if ( (_x) >= (_pbox)->x2) (_result) |= OUT_RIGHT; \
 100     if      ( (_y) <  (_pbox)->y1) (_result) |= OUT_ABOVE; \
 101     else if ( (_y) >= (_pbox)->y2) (_result) |= OUT_BELOW;
 102
 103 #define MIOUTCODES(outcode, x, y, xmin, ymin, xmax, ymax) \
 104 {\
 105      if (x < xmin) outcode |= OUT_LEFT;\
 106      if (x > xmax) outcode |= OUT_RIGHT;\
 107      if (y < ymin) outcode |= OUT_ABOVE;\
 108      if (y > ymax) outcode |= OUT_BELOW;\
 109 }
 110
 111 #define SWAPINT(i, j) \
 112 {  int _t = i;  i = j;  j = _t; }
 113
 114 #define SWAPPT(i, j) \
 115 {  DDXPointRec _t; _t = i;  i = j; j = _t; }
 116
 117 #define SWAPINT_PAIR(x1, y1, x2, y2)\
 118 {   int t = x1;  x1 = x2;  x2 = t;\
 119         t = y1;  y1 = y2;  y2 = t;\
 120 }
 121
 122 #define miGetZeroLineBias(_pScreen) ((unsigned long) (unsigned long*)\
 123     dixLookupPrivate(&(_pScreen)->devPrivates, miZeroLineScreenKey))
 124
 125 #define CalcLineDeltas(_x1,_y1,_x2,_y2,_adx,_ady,_sx,_sy,_SX,_SY,_octant) \
 126     (_octant) = 0;                              \
 127     (_sx) = (_SX);                              \
 128     if (((_adx) = (_x2) - (_x1)) < 0) {         \
 129         (_adx) = -(_adx);                       \
 130         (_sx = -(_sx));                         \
 131         (_octant) |= XDECREASING;               \
 132     }                                           \
 133     (_sy) = (_SY);                              \
 134     if (((_ady) = (_y2) - (_y1)) < 0) {         \
 135         (_ady) = -(_ady);                       \
 136         (_sy = -(_sy));                         \
 137         (_octant) |= YDECREASING;               \
 138     }
 139
 140 #define SetYMajorOctant(_octant)        ((_octant) |= YMAJOR)
 141
 142 #define FIXUP_ERROR(_e, _octant, _bias) \
 143     (_e) -= (((_bias) >> (_octant)) & 1)
 144
 145 #define IsXMajorOctant(_octant)         (!((_octant) & YMAJOR))
 146 #define IsYMajorOctant(_octant)         ((_octant) & YMAJOR)
 147 #define IsXDecreasingOctant(_octant)    ((_octant) & XDECREASING)
 148 #define IsYDecreasingOctant(_octant)    ((_octant) & YDECREASING)
 149
 150 extern _X_EXPORT DevPrivateKeyRec miZeroLineScreenKeyRec;
 151
 152 #define miZeroLineScreenKey (&miZeroLineScreenKeyRec)
 153
 154 extern _X_EXPORT int miZeroClipLine(int /*xmin */ ,
 155                                     int /*ymin */ ,
 156                                     int /*xmax */ ,
 157                                     int /*ymax */ ,
 158                                     int * /*new_x1 */ ,
 159                                     int * /*new_y1 */ ,
 160                                     int * /*new_x2 */ ,
 161                                     int * /*new_y2 */ ,
 162                                     unsigned int /*adx */ ,
 163                                     unsigned int /*ady */ ,
 164                                     int * /*pt1_clipped */ ,
 165                                     int * /*pt2_clipped */ ,
 166                                     int /*octant */ ,
 167                                     unsigned int /*bias */ ,
 168                                     int /*oc1 */ ,
 169                                     int /*oc2 */
 170     );
 171
 172 #endif                          /* MILINE_H */