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path: Compute coarse bounds upon construction.
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Frequently we only need the coarse path bounds, so avoid walking over
the list of points once more as we can cheaply track the extents during
construction.
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Chris Wilson committed Jan 22, 2010
1 parent 6bfcf3e commit 6b77567
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Showing 7 changed files with 184 additions and 100 deletions.
6 changes: 6 additions & 0 deletions src/cairo-debug.c
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Original file line number Diff line number Diff line change
Expand Up @@ -221,6 +221,12 @@ _cairo_debug_print_path (FILE *stream, cairo_path_fixed_t *path)
{
cairo_status_t status;

printf ("path: extents=(%f, %f), (%f, %f)\n",
_cairo_fixed_to_double (path->extents.p1.x),
_cairo_fixed_to_double (path->extents.p1.y),
_cairo_fixed_to_double (path->extents.p2.x),
_cairo_fixed_to_double (path->extents.p2.y));

status = _cairo_path_fixed_interpret (path,
CAIRO_DIRECTION_FORWARD,
_print_move_to,
Expand Down
21 changes: 16 additions & 5 deletions src/cairo-gstate.c
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Original file line number Diff line number Diff line change
Expand Up @@ -806,14 +806,25 @@ _cairo_gstate_path_extents (cairo_gstate_t *gstate,
double *x1, double *y1,
double *x2, double *y2)
{
cairo_box_t box;
double px1, py1, px2, py2;

_cairo_path_fixed_bounds (path,
&px1, &py1, &px2, &py2);
if (_cairo_path_fixed_extents (path, &box)) {
px1 = _cairo_fixed_to_double (box.p1.x);
py1 = _cairo_fixed_to_double (box.p1.y);
px2 = _cairo_fixed_to_double (box.p2.x);
py2 = _cairo_fixed_to_double (box.p2.y);

_cairo_gstate_backend_to_user_rectangle (gstate,
&px1, &py1, &px2, &py2,
NULL);
} else {
px1 = 0.0;
py1 = 0.0;
px2 = 0.0;
py2 = 0.0;
}

_cairo_gstate_backend_to_user_rectangle (gstate,
&px1, &py1, &px2, &py2,
NULL);
if (x1)
*x1 = px1;
if (y1)
Expand Down
159 changes: 77 additions & 82 deletions src/cairo-path-bounds.c
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Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@
*/

#include "cairoint.h"
#include "cairo-path-fixed-private.h"

typedef struct cairo_path_bounder {
cairo_point_t current_point;
Expand Down Expand Up @@ -134,26 +135,6 @@ _cairo_path_bounder_curve_to (void *closure,
}
}

static cairo_status_t
_cairo_path_bounder_curve_to_cp (void *closure,
const cairo_point_t *b,
const cairo_point_t *c,
const cairo_point_t *d)
{
cairo_path_bounder_t *bounder = closure;

if (bounder->has_initial_point) {
_cairo_path_bounder_add_point (bounder, &bounder->current_point);
bounder->has_initial_point = FALSE;
}

_cairo_path_bounder_add_point (bounder, b);
_cairo_path_bounder_add_point (bounder, c);
_cairo_path_bounder_add_point (bounder, d);

return CAIRO_STATUS_SUCCESS;
}

static cairo_status_t
_cairo_path_bounder_close_path (void *closure)
{
Expand All @@ -168,21 +149,8 @@ void
_cairo_path_fixed_approximate_clip_extents (const cairo_path_fixed_t *path,
cairo_rectangle_int_t *extents)
{
cairo_path_bounder_t bounder;
cairo_status_t status;

_cairo_path_bounder_init (&bounder);

status = _cairo_path_fixed_interpret (path, CAIRO_DIRECTION_FORWARD,
_cairo_path_bounder_move_to,
_cairo_path_bounder_line_to,
_cairo_path_bounder_curve_to_cp,
_cairo_path_bounder_close_path,
&bounder);
assert (status == CAIRO_STATUS_SUCCESS);

if (bounder.has_point) {
_cairo_box_round_to_rectangle (&bounder.extents, extents);
if (path->extents.p1.x < path->extents.p2.x) {
_cairo_box_round_to_rectangle (&path->extents, extents);
} else {
extents->x = extents->y = 0;
extents->width = extents->height = 0;
Expand All @@ -199,15 +167,20 @@ _cairo_path_fixed_approximate_fill_extents (const cairo_path_fixed_t *path,
cairo_path_bounder_t bounder;
cairo_status_t status;

_cairo_path_bounder_init (&bounder);

status = _cairo_path_fixed_interpret (path, CAIRO_DIRECTION_FORWARD,
_cairo_path_bounder_move_to,
_cairo_path_bounder_line_to,
_cairo_path_bounder_curve_to,
_cairo_path_bounder_close_path,
&bounder);
assert (status == CAIRO_STATUS_SUCCESS);
if (! path->has_curve_to) {
bounder.extents = path->extents;
bounder.has_point = path->extents.p1.x < path->extents.p2.x;
} else {
_cairo_path_bounder_init (&bounder);

status = _cairo_path_fixed_interpret (path, CAIRO_DIRECTION_FORWARD,
_cairo_path_bounder_move_to,
_cairo_path_bounder_line_to,
_cairo_path_bounder_curve_to,
_cairo_path_bounder_close_path,
&bounder);
assert (status == CAIRO_STATUS_SUCCESS);
}

if (bounder.has_point) {
_cairo_box_round_to_rectangle (&bounder.extents, extents);
Expand All @@ -226,14 +199,19 @@ _cairo_path_fixed_fill_extents (const cairo_path_fixed_t *path,
cairo_path_bounder_t bounder;
cairo_status_t status;

_cairo_path_bounder_init (&bounder);

status = _cairo_path_fixed_interpret_flat (path, CAIRO_DIRECTION_FORWARD,
_cairo_path_bounder_move_to,
_cairo_path_bounder_line_to,
_cairo_path_bounder_close_path,
&bounder, tolerance);
assert (status == CAIRO_STATUS_SUCCESS);
if (! path->has_curve_to) {
bounder.extents = path->extents;
bounder.has_point = path->extents.p1.x < path->extents.p2.x;
} else {
_cairo_path_bounder_init (&bounder);

status = _cairo_path_fixed_interpret_flat (path, CAIRO_DIRECTION_FORWARD,
_cairo_path_bounder_move_to,
_cairo_path_bounder_line_to,
_cairo_path_bounder_close_path,
&bounder, tolerance);
assert (status == CAIRO_STATUS_SUCCESS);
}

if (bounder.has_point) {
_cairo_box_round_to_rectangle (&bounder.extents, extents);
Expand All @@ -247,21 +225,43 @@ _cairo_path_fixed_fill_extents (const cairo_path_fixed_t *path,
void
_cairo_path_fixed_approximate_stroke_extents (const cairo_path_fixed_t *path,
const cairo_stroke_style_t *style,
const const cairo_matrix_t *ctm,
const cairo_matrix_t *ctm,
cairo_rectangle_int_t *extents)
{
cairo_path_bounder_t bounder;
cairo_status_t status;

_cairo_path_bounder_init (&bounder);
if (! path->has_curve_to) {
bounder.extents = path->extents;

status = _cairo_path_fixed_interpret (path, CAIRO_DIRECTION_FORWARD,
_cairo_path_bounder_move_to,
_cairo_path_bounder_line_to,
_cairo_path_bounder_curve_to,
_cairo_path_bounder_close_path,
&bounder);
assert (status == CAIRO_STATUS_SUCCESS);
/* include trailing move-to for degenerate segments */
if (path->has_last_move_point) {
const cairo_point_t *point = &path->last_move_point;

if (point->x < bounder.extents.p1.x)
bounder.extents.p1.x = point->x;
if (point->y < bounder.extents.p1.y)
bounder.extents.p1.y = point->y;

if (point->x > bounder.extents.p2.x)
bounder.extents.p2.x = point->x;
if (point->y > bounder.extents.p2.y)
bounder.extents.p2.y = point->y;
}

bounder.has_point = bounder.extents.p1.x <= bounder.extents.p2.x;
bounder.has_initial_point = FALSE;
} else {
_cairo_path_bounder_init (&bounder);

status = _cairo_path_fixed_interpret (path, CAIRO_DIRECTION_FORWARD,
_cairo_path_bounder_move_to,
_cairo_path_bounder_line_to,
_cairo_path_bounder_curve_to,
_cairo_path_bounder_close_path,
&bounder);
assert (status == CAIRO_STATUS_SUCCESS);
}

if (bounder.has_point) {
double dx, dy;
Expand Down Expand Up @@ -294,12 +294,12 @@ _cairo_path_fixed_approximate_stroke_extents (const cairo_path_fixed_t *path,
}

cairo_status_t
_cairo_path_fixed_stroke_extents (const cairo_path_fixed_t *path,
const cairo_stroke_style_t *stroke_style,
const cairo_matrix_t *ctm,
const cairo_matrix_t *ctm_inverse,
double tolerance,
cairo_rectangle_int_t *extents)
_cairo_path_fixed_stroke_extents (const cairo_path_fixed_t *path,
const cairo_stroke_style_t *stroke_style,
const cairo_matrix_t *ctm,
const cairo_matrix_t *ctm_inverse,
double tolerance,
cairo_rectangle_int_t *extents)
{
cairo_traps_t traps;
cairo_box_t bbox;
Expand All @@ -322,14 +322,18 @@ _cairo_path_fixed_stroke_extents (const cairo_path_fixed_t *path,
return status;
}

void
_cairo_path_fixed_bounds (const cairo_path_fixed_t *path,
double *x1, double *y1,
double *x2, double *y2)
cairo_bool_t
_cairo_path_fixed_extents (const cairo_path_fixed_t *path,
cairo_box_t *box)
{
cairo_path_bounder_t bounder;
cairo_status_t status;

if (! path->has_curve_to) {
*box = path->extents;
return path->extents.p1.x < path->extents.p2.x;
}

_cairo_path_bounder_init (&bounder);

status = _cairo_path_fixed_interpret (path, CAIRO_DIRECTION_FORWARD,
Expand All @@ -340,15 +344,6 @@ _cairo_path_fixed_bounds (const cairo_path_fixed_t *path,
&bounder);
assert (status == CAIRO_STATUS_SUCCESS);

if (bounder.has_point) {
*x1 = _cairo_fixed_to_double (bounder.extents.p1.x);
*y1 = _cairo_fixed_to_double (bounder.extents.p1.y);
*x2 = _cairo_fixed_to_double (bounder.extents.p2.x);
*y2 = _cairo_fixed_to_double (bounder.extents.p2.y);
} else {
*x1 = 0.0;
*y1 = 0.0;
*x2 = 0.0;
*y2 = 0.0;
}
*box = bounder.extents;
return bounder.has_point;
}
4 changes: 3 additions & 1 deletion src/cairo-path-fixed-private.h
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Original file line number Diff line number Diff line change
Expand Up @@ -80,15 +80,17 @@ struct _cairo_path_fixed {
cairo_point_t last_move_point;
cairo_point_t current_point;
unsigned int has_current_point : 1;
unsigned int has_last_move_point : 1;
unsigned int has_curve_to : 1;
unsigned int is_rectilinear : 1;
unsigned int maybe_fill_region : 1;
unsigned int is_empty_fill : 1;

cairo_box_t extents;

cairo_path_buf_fixed_t buf;
};


cairo_private void
_cairo_path_fixed_translate (cairo_path_fixed_t *path,
cairo_fixed_t offx,
Expand Down
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