static cairo_status_t
_cairo_stroker_add_sub_edge (cairo_stroker_t *stroker,
const cairo_point_t *p1,
const cairo_point_t *p2,
cairo_slope_t *dev_slope,
double slope_dx, double slope_dy,
cairo_stroke_face_t *start,
cairo_stroke_face_t *end)
{
cairo_point_t rectangle[4];
_compute_face (p1, dev_slope, slope_dx, slope_dy, stroker, start);
/* XXX: This could be optimized slightly by not calling
_compute_face again but rather translating the relevant
fields from start. */
_compute_face (p2, dev_slope, slope_dx, slope_dy, stroker, end);
if (p1->x == p2->x && p1->y == p2->y)
return CAIRO_STATUS_SUCCESS;
rectangle[0] = start->cw;
rectangle[1] = start->ccw;
rectangle[2] = end->ccw;
rectangle[3] = end->cw;
return _cairo_traps_tessellate_convex_quad (stroker->traps, rectangle);
}
static cairo_status_t
_cairo_stroker_add_caps (cairo_stroker_t *stroker)
{
cairo_status_t status;
/* check for a degenerative sub_path */
if (stroker->has_initial_sub_path
&& ! stroker->has_first_face
&& ! stroker->has_current_face
&& stroker->style.line_cap == CAIRO_LINE_CAP_ROUND)
{
/* pick an arbitrary slope to use */
double dx = 1.0, dy = 0.0;
cairo_slope_t slope = { CAIRO_FIXED_ONE, 0 };
cairo_stroke_face_t face;
_compute_normalized_device_slope (&dx, &dy,
stroker->ctm_inverse, NULL);
/* arbitrarily choose first_point
* first_point and current_point should be the same */
_compute_face (&stroker->first_point, &slope, dx, dy, stroker, &face);
status = _cairo_stroker_add_leading_cap (stroker, &face);
if (unlikely (status))
return status;
status = _cairo_stroker_add_trailing_cap (stroker, &face);
if (unlikely (status))
return status;
}
if (stroker->has_first_face) {
status = _cairo_stroker_add_leading_cap (stroker,
&stroker->first_face);
if (unlikely (status))
return status;
}
if (stroker->has_current_face) {
status = _cairo_stroker_add_trailing_cap (stroker,
&stroker->current_face);
if (unlikely (status))
return status;
}
return CAIRO_STATUS_SUCCESS;
}
static cairo_status_t
_cairo_stroker_add_sub_edge (cairo_stroker_t *stroker,
const cairo_point_t *p1,
const cairo_point_t *p2,
cairo_slope_t *dev_slope,
double slope_dx, double slope_dy,
cairo_stroke_face_t *start,
cairo_stroke_face_t *end)
{
_compute_face (p1, dev_slope, slope_dx, slope_dy, stroker, start);
*end = *start;
if (p1->x == p2->x && p1->y == p2->y)
return CAIRO_STATUS_SUCCESS;
end->point = *p2;
end->ccw.x += p2->x - p1->x;
end->ccw.y += p2->y - p1->y;
end->cw.x += p2->x - p1->x;
end->cw.y += p2->y - p1->y;
if (stroker->add_external_edge != NULL) {
cairo_status_t status;
status = stroker->add_external_edge (stroker->closure,
&end->cw, &start->cw);
if (unlikely (status))
return status;
status = stroker->add_external_edge (stroker->closure,
&start->ccw, &end->ccw);
if (unlikely (status))
return status;
return CAIRO_STATUS_SUCCESS;
} else {
cairo_point_t quad[4];
quad[0] = start->cw;
quad[1] = end->cw;
quad[2] = end->ccw;
quad[3] = start->ccw;
return stroker->add_convex_quad (stroker->closure, quad);
}
}
static cairo_status_t
_cairo_stroker_spline_to (void *closure,
const cairo_point_t *point,
const cairo_slope_t *tangent)
{
cairo_stroker_t *stroker = closure;
cairo_stroke_face_t new_face;
double slope_dx, slope_dy;
cairo_point_t points[3];
stroker->has_initial_sub_path = TRUE;
if (stroker->current_point.x == point->x &&
stroker->current_point.y == point->y)
return CAIRO_STATUS_SUCCESS;
slope_dx = _cairo_fixed_to_double (tangent->dx);
slope_dy = _cairo_fixed_to_double (tangent->dy);
if (! _compute_normalized_device_slope (&slope_dx, &slope_dy,
stroker->ctm_inverse, NULL))
return CAIRO_STATUS_SUCCESS;
_compute_face (point, tangent,
slope_dx, slope_dy,
stroker, &new_face);
assert(stroker->has_current_face);
points[0] = stroker->current_face.cw;
points[1] = stroker->current_face.ccw;
points[2] = new_face.cw;
stroker->add_triangle (stroker->closure, points);
points[0] = stroker->current_face.ccw;
points[1] = new_face.cw;
points[2] = new_face.ccw;
stroker->add_triangle (stroker->closure, points);
stroker->current_face = new_face;
stroker->has_current_face = TRUE;
stroker->current_point = *point;
return CAIRO_STATUS_SUCCESS;
}
/*
* Dashed lines. Cap each dash end, join around turns when on
*/
static cairo_status_t
_cairo_stroker_line_to_dashed (void *closure,
const cairo_point_t *p2)
{
cairo_stroker_t *stroker = closure;
double mag, remain, step_length = 0;
double slope_dx, slope_dy;
double dx2, dy2;
cairo_stroke_face_t sub_start, sub_end;
cairo_point_t *p1 = &stroker->current_point;
cairo_slope_t dev_slope;
cairo_line_t segment;
cairo_bool_t fully_in_bounds;
cairo_status_t status;
stroker->has_initial_sub_path = stroker->dash.dash_starts_on;
if (p1->x == p2->x && p1->y == p2->y)
return CAIRO_STATUS_SUCCESS;
fully_in_bounds = TRUE;
if (stroker->has_bounds &&
(! _cairo_box_contains_point (&stroker->bounds, p1) ||
! _cairo_box_contains_point (&stroker->bounds, p2)))
{
fully_in_bounds = FALSE;
}
_cairo_slope_init (&dev_slope, p1, p2);
slope_dx = _cairo_fixed_to_double (p2->x - p1->x);
slope_dy = _cairo_fixed_to_double (p2->y - p1->y);
if (! _compute_normalized_device_slope (&slope_dx, &slope_dy,
stroker->ctm_inverse, &mag))
{
return CAIRO_STATUS_SUCCESS;
}
remain = mag;
segment.p1 = *p1;
while (remain) {
step_length = MIN (stroker->dash.dash_remain, remain);
remain -= step_length;
dx2 = slope_dx * (mag - remain);
dy2 = slope_dy * (mag - remain);
cairo_matrix_transform_distance (stroker->ctm, &dx2, &dy2);
segment.p2.x = _cairo_fixed_from_double (dx2) + p1->x;
segment.p2.y = _cairo_fixed_from_double (dy2) + p1->y;
if (stroker->dash.dash_on &&
(fully_in_bounds ||
(! stroker->has_first_face && stroker->dash.dash_starts_on) ||
_cairo_box_intersects_line_segment (&stroker->bounds, &segment)))
{
status = _cairo_stroker_add_sub_edge (stroker,
&segment.p1, &segment.p2,
&dev_slope,
slope_dx, slope_dy,
&sub_start, &sub_end);
if (unlikely (status))
return status;
if (stroker->has_current_face)
{
/* Join with final face from previous segment */
status = _cairo_stroker_join (stroker,
&stroker->current_face,
&sub_start);
if (unlikely (status))
return status;
stroker->has_current_face = FALSE;
}
else if (! stroker->has_first_face &&
stroker->dash.dash_starts_on)
{
/* Save sub path's first face in case needed for closing join */
stroker->first_face = sub_start;
stroker->has_first_face = TRUE;
}
else
{
/* Cap dash start if not connecting to a previous segment */
status = _cairo_stroker_add_leading_cap (stroker, &sub_start);
if (unlikely (status))
return status;
}
if (remain) {
/* Cap dash end if not at end of segment */
status = _cairo_stroker_add_trailing_cap (stroker, &sub_end);
if (unlikely (status))
return status;
} else {
stroker->current_face = sub_end;
stroker->has_current_face = TRUE;
}
} else {
if (stroker->has_current_face) {
/* Cap final face from previous segment */
status = _cairo_stroker_add_trailing_cap (stroker,
&stroker->current_face);
if (unlikely (status))
return status;
stroker->has_current_face = FALSE;
}
}
_cairo_stroker_dash_step (&stroker->dash, step_length);
segment.p1 = segment.p2;
}
if (stroker->dash.dash_on && ! stroker->has_current_face) {
/* This segment ends on a transition to dash_on, compute a new face
* and add cap for the beginning of the next dash_on step.
*
* Note: this will create a degenerate cap if this is not the last line
* in the path. Whether this behaviour is desirable or not is debatable.
* On one side these degenerate caps can not be reproduced with regular
* path stroking.
* On the other hand, Acroread 7 also produces the degenerate caps.
*/
_compute_face (p2, &dev_slope,
slope_dx, slope_dy,
stroker,
&stroker->current_face);
status = _cairo_stroker_add_leading_cap (stroker,
&stroker->current_face);
if (unlikely (status))
return status;
stroker->has_current_face = TRUE;
}
stroker->current_point = *p2;
return CAIRO_STATUS_SUCCESS;
}
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;
}
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_pen_stroke_spline_t spline_pen;
cairo_stroke_face_t start, end;
cairo_point_t extra_points[4];
cairo_point_t *a = &stroker->current_point;
double initial_slope_dx, initial_slope_dy;
double final_slope_dx, final_slope_dy;
cairo_status_t status;
status = _cairo_pen_stroke_spline_init (&spline_pen,
&stroker->pen,
a, b, c, d);
if (status == CAIRO_INT_STATUS_DEGENERATE)
return _cairo_stroker_line_to (closure, d);
else if (unlikely (status))
return status;
initial_slope_dx = _cairo_fixed_to_double (spline_pen.spline.initial_slope.dx);
initial_slope_dy = _cairo_fixed_to_double (spline_pen.spline.initial_slope.dy);
final_slope_dx = _cairo_fixed_to_double (spline_pen.spline.final_slope.dx);
final_slope_dy = _cairo_fixed_to_double (spline_pen.spline.final_slope.dy);
if (_compute_normalized_device_slope (&initial_slope_dx, &initial_slope_dy,
stroker->ctm_inverse, NULL))
{
_compute_face (a,
&spline_pen.spline.initial_slope,
initial_slope_dx, initial_slope_dy,
stroker, &start);
}
if (_compute_normalized_device_slope (&final_slope_dx, &final_slope_dy,
stroker->ctm_inverse, NULL))
{
_compute_face (d,
&spline_pen.spline.final_slope,
final_slope_dx, final_slope_dy,
stroker, &end);
}
if (stroker->has_current_face) {
status = _cairo_stroker_join (stroker, &stroker->current_face, &start);
if (unlikely (status))
goto CLEANUP_PEN;
} else if (! stroker->has_first_face) {
stroker->first_face = start;
stroker->has_first_face = TRUE;
}
stroker->current_face = end;
stroker->has_current_face = TRUE;
extra_points[0] = start.cw;
extra_points[0].x -= start.point.x;
extra_points[0].y -= start.point.y;
extra_points[1] = start.ccw;
extra_points[1].x -= start.point.x;
extra_points[1].y -= start.point.y;
extra_points[2] = end.cw;
extra_points[2].x -= end.point.x;
extra_points[2].y -= end.point.y;
extra_points[3] = end.ccw;
extra_points[3].x -= end.point.x;
extra_points[3].y -= end.point.y;
status = _cairo_pen_add_points (&spline_pen.pen, extra_points, 4);
if (unlikely (status))
goto CLEANUP_PEN;
status = _cairo_pen_stroke_spline (&spline_pen,
stroker->tolerance,
stroker->traps);
CLEANUP_PEN:
_cairo_pen_stroke_spline_fini (&spline_pen);
stroker->current_point = *d;
return status;
}
