static cairo_status_t
_cairo_filler_curve_to (void *closure,
cairo_point_t *b,
cairo_point_t *c,
cairo_point_t *d)
{
int i;
cairo_status_t status = CAIRO_STATUS_SUCCESS;
cairo_filler_t *filler = closure;
cairo_polygon_t *polygon = &filler->polygon;
cairo_spline_t spline;
status = _cairo_spline_init (&spline, &filler->current_point, b, c, d);
if (status == CAIRO_INT_STATUS_DEGENERATE)
return CAIRO_STATUS_SUCCESS;
_cairo_spline_decompose (&spline, filler->tolerance);
if (status)
goto CLEANUP_SPLINE;
for (i = 1; i < spline.num_points; i++) {
status = _cairo_polygon_line_to (polygon, &spline.points[i]);
if (status)
break;
}
CLEANUP_SPLINE:
_cairo_spline_fini (&spline);
filler->current_point = *d;
return status;
}
/* Compute outline of a given spline using the pen.
The trapezoids needed to fill that outline will be added to traps
*/
cairo_status_t
_cairo_pen_stroke_spline (cairo_pen_t *pen,
cairo_spline_t *spline,
double tolerance,
cairo_traps_t *traps)
{
cairo_status_t status;
cairo_polygon_t polygon;
/* If the line width is so small that the pen is reduced to a
single point, then we have nothing to do. */
if (pen->num_vertices <= 1)
return CAIRO_STATUS_SUCCESS;
_cairo_polygon_init (&polygon);
status = _cairo_spline_decompose (spline, tolerance);
if (status)
return status;
status = _cairo_pen_stroke_spline_half (pen, spline, CAIRO_DIRECTION_FORWARD, &polygon);
if (status)
return status;
status = _cairo_pen_stroke_spline_half (pen, spline, CAIRO_DIRECTION_REVERSE, &polygon);
if (status)
return status;
_cairo_polygon_close (&polygon);
_cairo_traps_tessellate_polygon (traps, &polygon, CAIRO_FILL_RULE_WINDING);
_cairo_polygon_fini (&polygon);
return CAIRO_STATUS_SUCCESS;
}
static cairo_status_t
_cpf_curve_to (void *closure,
cairo_point_t *p1,
cairo_point_t *p2,
cairo_point_t *p3)
{
cpf_t *cpf = closure;
cairo_status_t status;
cairo_spline_t spline;
int i;
cairo_point_t *p0 = &cpf->current_point;
status = _cairo_spline_init (&spline, p0, p1, p2, p3);
if (status == CAIRO_INT_STATUS_DEGENERATE)
return CAIRO_STATUS_SUCCESS;
status = _cairo_spline_decompose (&spline, cpf->tolerance);
if (status)
goto out;
for (i=1; i < spline.num_points; i++) {
status = cpf->line_to (cpf->closure, &spline.points[i]);
if (status)
goto out;
}
cpf->current_point = *p3;
status = CAIRO_STATUS_SUCCESS;
out:
_cairo_spline_fini (&spline);
return status;
}
/* We're using two different algorithms here for dashed and un-dashed
* splines. The dashed algorithm uses the existing line dashing
* code. It's linear in path length, but gets subtly wrong results for
* self-intersecting paths (an outstanding but for self-intersecting
* non-curved paths as well). The non-dashed algorithm tessellates a
* single polygon for the whole curve. It handles the
* self-intersecting problem, but it's (unsurprisingly) not O(n) and
* more significantly, it doesn't yet handle dashes.
*
* The only reason we're doing split algorithms here is to
* minimize the impact of fixing the splines-aren't-dashed bug for
* 1.0.2. Long-term the right answer is to rewrite the whole pile
* of stroking code so that the entire result is computed as a
* single polygon that is tessellated, (that is, stroking can be
* built on top of filling). That will solve the self-intersecting
* problem. It will also increase the importance of implementing
* an efficient and more robust tessellator.
*/
static cairo_status_t
_cairo_stroker_curve_to_dashed (void *closure,
cairo_point_t *b,
cairo_point_t *c,
cairo_point_t *d)
{
cairo_status_t status = CAIRO_STATUS_SUCCESS;
cairo_stroker_t *stroker = closure;
cairo_spline_t spline;
cairo_point_t *a = &stroker->current_point;
cairo_line_join_t line_join_save;
int i;
status = _cairo_spline_init (&spline, a, b, c, d);
if (status == CAIRO_INT_STATUS_DEGENERATE)
return _cairo_stroker_line_to_dashed (closure, d);
/* If the line width is so small that the pen is reduced to a
single point, then we have nothing to do. */
if (stroker->pen.num_vertices <= 1)
goto CLEANUP_SPLINE;
/* Temporarily modify the stroker to use round joins to guarantee
* smooth stroked curves. */
line_join_save = stroker->style->line_join;
stroker->style->line_join = CAIRO_LINE_JOIN_ROUND;
status = _cairo_spline_decompose (&spline, stroker->tolerance);
if (status)
goto CLEANUP_GSTATE;
for (i = 1; i < spline.num_points; i++) {
if (stroker->dashed)
status = _cairo_stroker_line_to_dashed (stroker, &spline.points[i]);
else
status = _cairo_stroker_line_to (stroker, &spline.points[i]);
if (status)
break;
}
CLEANUP_GSTATE:
stroker->style->line_join = line_join_save;
CLEANUP_SPLINE:
_cairo_spline_fini (&spline);
return status;
}
static cairo_status_t
_cairo_filler_curve_to (void *closure,
const cairo_point_t *b,
const cairo_point_t *c,
const cairo_point_t *d)
{
cairo_filler_t *filler = closure;
cairo_spline_t spline;
if (! _cairo_spline_init (&spline,
_cairo_filler_line_to, filler,
&filler->polygon->current_point, b, c, d))
{
return _cairo_filler_line_to (closure, d);
}
return _cairo_spline_decompose (&spline, filler->tolerance);
}
static cairo_status_t
curve_to (void *closure,
const cairo_point_t *b,
const cairo_point_t *c,
const cairo_point_t *d)
{
struct stroker *stroker = closure;
cairo_spline_t spline;
cairo_stroke_face_t face;
if (stroker->has_limits) {
if (! _cairo_spline_intersects (&stroker->current_face.point, b, c, d,
&stroker->limit))
return line_to (closure, d);
}
if (! _cairo_spline_init (&spline, spline_to, stroker,
&stroker->current_face.point, b, c, d))
return line_to (closure, d);
compute_face (&stroker->current_face.point, &spline.initial_slope,
stroker, &face);
if (stroker->has_current_face) {
int clockwise = join_is_clockwise (&stroker->current_face, &face);
/* Join with final face from previous segment */
outer_join (stroker, &stroker->current_face, &face, clockwise);
inner_join (stroker, &stroker->current_face, &face, clockwise);
} else {
if (! stroker->has_first_face) {
/* Save sub path's first face in case needed for closing join */
stroker->first_face = face;
_cairo_tristrip_move_to (stroker->strip, &face.cw);
stroker->has_first_face = TRUE;
}
stroker->has_current_face = TRUE;
_cairo_tristrip_add_point (stroker->strip, &face.cw);
_cairo_tristrip_add_point (stroker->strip, &face.ccw);
}
stroker->current_face = face;
return _cairo_spline_decompose (&spline, stroker->tolerance);
}
static cairo_status_t
_cairo_in_fill_curve_to (void *closure,
const cairo_point_t *b,
const cairo_point_t *c,
const cairo_point_t *d)
{
cairo_in_fill_t *in_fill = closure;
cairo_spline_t spline;
cairo_fixed_t top, bot, left;
/* first reject based on bbox */
bot = top = in_fill->current_point.y;
if (b->y < top) top = b->y;
if (b->y > bot) bot = b->y;
if (c->y < top) top = c->y;
if (c->y > bot) bot = c->y;
if (d->y < top) top = d->y;
if (d->y > bot) bot = d->y;
if (bot < in_fill->y || top > in_fill->y) {
in_fill->current_point = *d;
return CAIRO_STATUS_SUCCESS;
}
left = in_fill->current_point.x;
if (b->x < left) left = b->x;
if (c->x < left) left = c->x;
if (d->x < left) left = d->x;
if (left > in_fill->x) {
in_fill->current_point = *d;
return CAIRO_STATUS_SUCCESS;
}
/* XXX Investigate direct inspection of the inflections? */
if (! _cairo_spline_init (&spline,
(cairo_spline_add_point_func_t)_cairo_in_fill_line_to,
in_fill,
&in_fill->current_point, b, c, d))
{
return CAIRO_STATUS_SUCCESS;
}
return _cairo_spline_decompose (&spline, in_fill->tolerance);
}
/* We're using two different algorithms here for dashed and un-dashed
* splines. The dashed algorithm uses the existing line dashing
* code. It's linear in path length, but gets subtly wrong results for
* self-intersecting paths (an outstanding but for self-intersecting
* non-curved paths as well). The non-dashed algorithm tessellates a
* single polygon for the whole curve. It handles the
* self-intersecting problem, but it's (unsurprisingly) not O(n) and
* more significantly, it doesn't yet handle dashes.
*
* The only reason we're doing split algorithms here is to
* minimize the impact of fixing the splines-aren't-dashed bug for
* 1.0.2. Long-term the right answer is to rewrite the whole pile
* of stroking code so that the entire result is computed as a
* single polygon that is tessellated, (that is, stroking can be
* built on top of filling). That will solve the self-intersecting
* problem. It will also increase the importance of implementing
* an efficient and more robust tessellator.
*/
static cairo_status_t
_cairo_stroker_curve_to_dashed (void *closure,
const cairo_point_t *b,
const cairo_point_t *c,
const cairo_point_t *d)
{
cairo_stroker_t *stroker = closure;
cairo_spline_t spline;
cairo_point_t *a = &stroker->current_point;
cairo_line_join_t line_join_save;
cairo_status_t status;
if (! _cairo_spline_init (&spline,
stroker->dashed ?
_cairo_stroker_line_to_dashed :
_cairo_stroker_line_to,
stroker,
a, b, c, d))
{
return _cairo_stroker_line_to_dashed (closure, d);
}
/* If the line width is so small that the pen is reduced to a
single point, then we have nothing to do. */
if (stroker->pen.num_vertices <= 1)
return CAIRO_STATUS_SUCCESS;
/* Temporarily modify the stroker to use round joins to guarantee
* smooth stroked curves. */
line_join_save = stroker->style->line_join;
stroker->style->line_join = CAIRO_LINE_JOIN_ROUND;
status = _cairo_spline_decompose (&spline, stroker->tolerance);
stroker->style->line_join = line_join_save;
return status;
}
static cairo_status_t
_cpf_curve_to (void *closure,
const cairo_point_t *p1,
const cairo_point_t *p2,
const cairo_point_t *p3)
{
cpf_t *cpf = closure;
cairo_spline_t spline;
cairo_point_t *p0 = &cpf->current_point;
if (! _cairo_spline_init (&spline,
cpf->line_to,
cpf->closure,
p0, p1, p2, p3))
{
return _cpf_line_to (closure, p3);
}
cpf->current_point = *p3;
return _cairo_spline_decompose (&spline, cpf->tolerance);
}
static cairo_status_t
_cairo_filler_curve_to (void *closure,
const cairo_point_t *p1,
const cairo_point_t *p2,
const cairo_point_t *p3)
{
cairo_filler_t *filler = closure;
cairo_spline_t spline;
if (filler->has_limits) {
if (! _cairo_spline_intersects (&filler->current_point, p1, p2, p3,
&filler->limit))
return _cairo_filler_line_to (filler, p3, NULL);
}
if (! _cairo_spline_init (&spline,
(cairo_spline_add_point_func_t)_cairo_filler_line_to, filler,
&filler->current_point, p1, p2, p3))
{
return _cairo_filler_line_to (closure, p3, NULL);
}
return _cairo_spline_decompose (&spline, filler->tolerance);
}
static cairo_status_t
_cairo_stroker_curve_to (void *closure,
const cairo_point_t *b,
const cairo_point_t *c,
const cairo_point_t *d)
{
cairo_stroker_t *stroker = closure;
cairo_spline_t spline;
cairo_line_join_t line_join_save;
cairo_stroke_face_t face;
double slope_dx, slope_dy;
cairo_path_fixed_line_to_func_t *line_to;
cairo_status_t status = CAIRO_STATUS_SUCCESS;
line_to = stroker->dash.dashed ?
_cairo_stroker_line_to_dashed :
_cairo_stroker_line_to;
if (! _cairo_spline_init (&spline,
(cairo_spline_add_point_func_t)line_to, stroker,
&stroker->current_point, b, c, d))
{
return line_to (closure, d);
}
/* If the line width is so small that the pen is reduced to a
single point, then we have nothing to do. */
if (stroker->pen.num_vertices <= 1)
return CAIRO_STATUS_SUCCESS;
/* Compute the initial face */
if (! stroker->dash.dashed || stroker->dash.dash_on) {
slope_dx = _cairo_fixed_to_double (spline.initial_slope.dx);
slope_dy = _cairo_fixed_to_double (spline.initial_slope.dy);
if (_compute_normalized_device_slope (&slope_dx, &slope_dy,
stroker->ctm_inverse, NULL))
{
_compute_face (&stroker->current_point,
&spline.initial_slope,
slope_dx, slope_dy,
stroker, &face);
}
if (stroker->has_current_face) {
status = _cairo_stroker_join (stroker,
&stroker->current_face, &face);
if (unlikely (status))
return status;
} else if (! stroker->has_first_face) {
stroker->first_face = face;
stroker->has_first_face = TRUE;
}
stroker->current_face = face;
stroker->has_current_face = TRUE;
}
/* Temporarily modify the stroker to use round joins to guarantee
* smooth stroked curves. */
line_join_save = stroker->style.line_join;
stroker->style.line_join = CAIRO_LINE_JOIN_ROUND;
status = _cairo_spline_decompose (&spline, stroker->tolerance);
if (unlikely (status))
return status;
/* And join the final face */
if (! stroker->dash.dashed || stroker->dash.dash_on) {
slope_dx = _cairo_fixed_to_double (spline.final_slope.dx);
slope_dy = _cairo_fixed_to_double (spline.final_slope.dy);
if (_compute_normalized_device_slope (&slope_dx, &slope_dy,
stroker->ctm_inverse, NULL))
{
_compute_face (&stroker->current_point,
&spline.final_slope,
slope_dx, slope_dy,
stroker, &face);
}
status = _cairo_stroker_join (stroker, &stroker->current_face, &face);
if (unlikely (status))
return status;
stroker->current_face = face;
}
stroker->style.line_join = line_join_save;
return CAIRO_STATUS_SUCCESS;
}