gfx/cairo/on-edge.patch

   1 commit a26655b3144ed273940486fc15ccdac12b0562ec
   2 Author: Jeff Muizelaar <jmuizelaar@mozilla.com>
   3 Date:   Tue Mar 17 15:08:50 2009 -0400
   4
   5     Jeff Muizelaar noted that the treatment of edges differed with firefox's
   6     canvas definition, which considers a point on any edge as inside. The
   7     current implementation has a similar definition to that of flash, for
   8     which the top and right edges are outside. Arguably, firefox has the more
   9     intuitive definition here...
  10
  11 diff --git a/src/cairo-path-in-fill.c b/src/cairo-path-in-fill.c
  12 index 21cd0bd..e641654 100644
  13 --- a/src/cairo-path-in-fill.c
  14 +++ b/src/cairo-path-in-fill.c
  15 @@ -41,6 +41,7 @@ typedef struct cairo_in_fill {
  16      int winding;
  17
  18      cairo_fixed_t x, y;
  19 +    cairo_bool_t on_edge;
  20
  21      cairo_bool_t has_current_point;
  22      cairo_point_t current_point;
  23 @@ -58,6 +59,7 @@ _cairo_in_fill_init (cairo_in_fill_t  *in_fill,
  24
  25      in_fill->x = _cairo_fixed_from_double (x);
  26      in_fill->y = _cairo_fixed_from_double (y);
  27 +    in_fill->on_edge = FALSE;
  28
  29      in_fill->has_current_point = FALSE;
  30      in_fill->current_point.x = 0;
  31 @@ -103,6 +105,9 @@ _cairo_in_fill_add_edge (cairo_in_fill_t *in_fill,
  32  {
  33      int dir;
  34
  35 +    if (in_fill->on_edge)
  36 +       return;
  37 +
  38      /* count the number of edge crossing to -∞ */
  39
  40      dir = 1;
  41 @@ -116,6 +121,18 @@ _cairo_in_fill_add_edge (cairo_in_fill_t *in_fill,
  42         dir = -1;
  43      }
  44
  45 +    /* First check whether the query is on an edge */
  46 +    if ((p1->x == in_fill->x && p1->x == in_fill->y) ||
  47 +       (p2->x == in_fill->x && p2->x == in_fill->y) ||
  48 +       (! (p2->y < in_fill->y || p1->y > in_fill->y) &&
  49 +        ! (p1->x > in_fill->x && p2->x > in_fill->x) &&
  50 +        ! (p1->x < in_fill->x && p2->x < in_fill->x) &&
  51 +        edge_compare_for_y_against_x (p1, p2, in_fill->y, in_fill->x) == 0))
  52 +    {
  53 +       in_fill->on_edge = TRUE;
  54 +       return;
  55 +    }
  56 +
  57      /* edge is entirely above or below, note the shortening rule */
  58      if (p2->y <= in_fill->y || p1->y > in_fill->y)
  59         return;
  60 @@ -246,7 +263,9 @@ _cairo_path_fixed_in_fill (cairo_path_fixed_t       *path,
  61
  62      _cairo_in_fill_close_path (&in_fill);
  63
  64 -    switch (fill_rule) {
  65 +    if (in_fill.on_edge) {
  66 +       *is_inside = TRUE;
  67 +    } else switch (fill_rule) {
  68      case CAIRO_FILL_RULE_EVEN_ODD:
  69         *is_inside = in_fill.winding & 1;
  70         break;