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30 #include "screenint.h"
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.
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))
52 #define XMAJOROCTANTS (OCTANT1 | OCTANT4 | OCTANT5 | OCTANT8)
54 #define DEFAULTZEROLINEBIAS (OCTANT2 | OCTANT3 | OCTANT4 | OCTANT5)
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:
76 * For more information, see "Ambiguities in Incremental Line Rastering,"
77 * Jack E. Bresenham, IEEE CG&A, May 1987.
80 extern _X_EXPORT void miSetZeroLineBias(
81 ScreenPtr /* pScreen */,
82 unsigned int /* bias */
86 * Private definitions needed for drawing thin (zero width) lines
87 * Used by the mi, mfb, and all cfb* components.
94 #define OUT_RIGHT 0x04
95 #define OUT_ABOVE 0x02
96 #define OUT_BELOW 0x01
98 #define OUTCODES(_result, _x, _y, _pbox) \
99 if ( (_x) < (_pbox)->x1) (_result) |= OUT_LEFT; \
100 else if ( (_x) >= (_pbox)->x2) (_result) |= OUT_RIGHT; \
101 if ( (_y) < (_pbox)->y1) (_result) |= OUT_ABOVE; \
102 else if ( (_y) >= (_pbox)->y2) (_result) |= OUT_BELOW;
104 #define MIOUTCODES(outcode, x, y, xmin, ymin, xmax, ymax) \
106 if (x < xmin) outcode |= OUT_LEFT;\
107 if (x > xmax) outcode |= OUT_RIGHT;\
108 if (y < ymin) outcode |= OUT_ABOVE;\
109 if (y > ymax) outcode |= OUT_BELOW;\
112 #define SWAPINT(i, j) \
113 { int _t = i; i = j; j = _t; }
115 #define SWAPPT(i, j) \
116 { DDXPointRec _t; _t = i; i = j; j = _t; }
118 #define SWAPINT_PAIR(x1, y1, x2, y2)\
119 { int t = x1; x1 = x2; x2 = t;\
120 t = y1; y1 = y2; y2 = t;\
123 #define miGetZeroLineBias(_pScreen) ((unsigned long) (unsigned long*)\
124 dixLookupPrivate(&(_pScreen)->devPrivates, miZeroLineScreenKey))
126 #define CalcLineDeltas(_x1,_y1,_x2,_y2,_adx,_ady,_sx,_sy,_SX,_SY,_octant) \
129 if (((_adx) = (_x2) - (_x1)) < 0) { \
132 (_octant) |= XDECREASING; \
135 if (((_ady) = (_y2) - (_y1)) < 0) { \
138 (_octant) |= YDECREASING; \
141 #define SetYMajorOctant(_octant) ((_octant) |= YMAJOR)
143 #define FIXUP_ERROR(_e, _octant, _bias) \
144 (_e) -= (((_bias) >> (_octant)) & 1)
146 #define IsXMajorOctant(_octant) (!((_octant) & YMAJOR))
147 #define IsYMajorOctant(_octant) ((_octant) & YMAJOR)
148 #define IsXDecreasingOctant(_octant) ((_octant) & XDECREASING)
149 #define IsYDecreasingOctant(_octant) ((_octant) & YDECREASING)
151 extern _X_EXPORT DevPrivateKeyRec miZeroLineScreenKeyRec;
152 #define miZeroLineScreenKey (&miZeroLineScreenKeyRec)
154 extern _X_EXPORT int miZeroClipLine(
163 unsigned int /*adx*/,
164 unsigned int /*ady*/,
165 int * /*pt1_clipped*/,
166 int * /*pt2_clipped*/,
168 unsigned int /*bias*/,
173 #endif /* MILINE_H */