xorg-server-1.4/render/renderedge.c

   1 /*
   2  * Copyright © 2004 Keith Packard
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that
   7  * copyright notice and this permission notice appear in supporting
   8  * documentation, and that the name of Keith Packard not be used in
   9  * advertising or publicity pertaining to distribution of the software without
  10  * specific, written prior permission.  Keith Packard makes no
  11  * representations about the suitability of this software for any purpose.  It
  12  * is provided "as is" without express or implied warranty.
  13  *
  14  * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  16  * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  20  * PERFORMANCE OF THIS SOFTWARE.
  21  */
  22
  23 #ifdef HAVE_DIX_CONFIG_H
  24 #include <dix-config.h>
  25 #endif
  26
  27 #include "renderedge.h"
  28
  29 /*
  30  * Compute the smallest value no less than y which is on a
  31  * grid row
  32  */
  33
  34 _X_EXPORT xFixed
  35 RenderSampleCeilY (xFixed y, int n)
  36 {
  37     return pixman_sample_ceil_y (y, n);
  38 }
  39
  40 #define _div(a,b)    ((a) >= 0 ? (a) / (b) : -((-(a) + (b) - 1) / (b)))
  41
  42 /*
  43  * Compute the largest value no greater than y which is on a
  44  * grid row
  45  */
  46 _X_EXPORT xFixed
  47 RenderSampleFloorY (xFixed y, int n)
  48 {
  49     return pixman_sample_floor_y (y, n);
  50 }
  51
  52 /*
  53  * Step an edge by any amount (including negative values)
  54  */
  55 _X_EXPORT void
  56 RenderEdgeStep (RenderEdge *e, int n)
  57 {
  58     pixman_edge_step (e, n);
  59 }
  60
  61 /*
  62  * Initialize one edge structure given the line endpoints and a
  63  * starting y value
  64  */
  65 _X_EXPORT void
  66 RenderEdgeInit (RenderEdge      *e,
  67                 int             n,
  68                 xFixed          y_start,
  69                 xFixed          x_top,
  70                 xFixed          y_top,
  71                 xFixed          x_bot,
  72                 xFixed          y_bot)
  73 {
  74     pixman_edge_init (e, n, y_start, x_top, y_top, x_bot, y_bot);
  75 }
  76
  77 /*
  78  * Initialize one edge structure given a line, starting y value
  79  * and a pixel offset for the line
  80  */
  81 _X_EXPORT void
  82 RenderLineFixedEdgeInit (RenderEdge *e,
  83                          int        n,
  84                          xFixed     y,
  85                          xLineFixed *line,
  86                          int        x_off,
  87                          int        y_off)
  88 {
  89     pixman_line_fixed_edge_init (e, n, y, (pixman_line_fixed_t *)line, x_off, y_off);
  90 }
  91