xorg-server-1.4/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
  32 /*
  33  * Public definitions used for configuring basic pixelization aspects
  34  * of the sample implementation line-drawing routines provided in
  35  * {mfb,mi,cfb*} at run-time.
  36  */
  37
  38 #define XDECREASING     4
  39 #define YDECREASING     2
  40 #define YMAJOR          1
  41
  42 #define OCTANT1         (1 << (YDECREASING))
  43 #define OCTANT2         (1 << (YDECREASING|YMAJOR))
  44 #define OCTANT3         (1 << (XDECREASING|YDECREASING|YMAJOR))
  45 #define OCTANT4         (1 << (XDECREASING|YDECREASING))
  46 #define OCTANT5         (1 << (XDECREASING))
  47 #define OCTANT6         (1 << (XDECREASING|YMAJOR))
  48 #define OCTANT7         (1 << (YMAJOR))
  49 #define OCTANT8         (1 << (0))
  50
  51 #define XMAJOROCTANTS           (OCTANT1 | OCTANT4 | OCTANT5 | OCTANT8)
  52
  53 #define DEFAULTZEROLINEBIAS     (OCTANT2 | OCTANT3 | OCTANT4 | OCTANT5)
  54
  55 /*
  56  * Devices can configure the rendering of routines in mi, mfb, and cfb*
  57  * by specifying a thin line bias to be applied to a particular screen
  58  * using the following function.  The bias parameter is an OR'ing of
  59  * the appropriate OCTANT constants defined above to indicate which
  60  * octants to bias a line to prefer an axial step when the Bresenham
  61  * error term is exactly zero.  The octants are mapped as follows:
  62  *
  63  *   \    |    /
  64  *    \ 3 | 2 /
  65  *     \  |  /
  66  *    4 \ | / 1
  67  *       \|/
  68  *   -----------
  69  *       /|\
  70  *    5 / | \ 8
  71  *     /  |  \
  72  *    / 6 | 7 \
  73  *   /    |    \
  74  *
  75  * For more information, see "Ambiguities in Incremental Line Rastering,"
  76  * Jack E. Bresenham, IEEE CG&A, May 1987.
  77  */
  78
  79 extern void miSetZeroLineBias(
  80     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) \
 123     ((miZeroLineScreenIndex < 0) ? \
 124                 0 : ((_pScreen)->devPrivates[miZeroLineScreenIndex].uval))
 125
 126 #define CalcLineDeltas(_x1,_y1,_x2,_y2,_adx,_ady,_sx,_sy,_SX,_SY,_octant) \
 127     (_octant) = 0;                              \
 128     (_sx) = (_SX);                              \
 129     if (((_adx) = (_x2) - (_x1)) < 0) {         \
 130         (_adx) = -(_adx);                       \
 131         (_sx = -(_sx));                         \
 132         (_octant) |= XDECREASING;               \
 133     }                                           \
 134     (_sy) = (_SY);                              \
 135     if (((_ady) = (_y2) - (_y1)) < 0) {         \
 136         (_ady) = -(_ady);                       \
 137         (_sy = -(_sy));                         \
 138         (_octant) |= YDECREASING;               \
 139     }
 140
 141 #define SetYMajorOctant(_octant)        ((_octant) |= YMAJOR)
 142
 143 #define FIXUP_ERROR(_e, _octant, _bias) \
 144     (_e) -= (((_bias) >> (_octant)) & 1)
 145
 146 #define IsXMajorOctant(_octant)         (!((_octant) & YMAJOR))
 147 #define IsYMajorOctant(_octant)         ((_octant) & YMAJOR)
 148 #define IsXDecreasingOctant(_octant)    ((_octant) & XDECREASING)
 149 #define IsYDecreasingOctant(_octant)    ((_octant) & YDECREASING)
 150
 151 extern int miZeroLineScreenIndex;
 152
 153 extern int miZeroClipLine(
 154     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 */