CairoContext::arcNegative
cairo_arc_negative
(PECL cairo >= 0.1.0)
CairoContext::arcNegative -- cairo_arc_negative — Adds a negative arc
Beskrivelse
Object oriented style (method):
$x
, float $y
, float $radius
, float $angle1
, float $angle2
)Procedural style:
$context
, float $x
, float $y
, float $radius
, float $angle1
, float $angle2
)
Adds a circular arc of the given radius to the current path.
The arc is centered at (x, y), begins at
angle1 and proceeds in the direction of decreasing angles to end at
angle2. If angle2 is greater than
angle1 it will be progressively decreased by 2*M_PI until it is less than
angle1.
See CairoContext::arc() or cairo_arc() for more details.
This function differs only in the direction of the arc between the two angles.
Parametre
-
context -
A valid CairoContext object
-
x -
double x position
-
y -
double y position
-
radius -
The radius of the desired negative arc
-
angle1 -
Start angle of the arc
-
angle2 -
End angle of the arc
Returnerings Værdier
No value is returned.
Eksempler
Eksempel #1 Object oriented style
<?php
$s = new CairoImageSurface(CairoFormat::ARGB32, 100, 100);
$c = new CairoContext($s);
$c->setSourceRgb(0, 0, 0);
$c->paint();
$c->setLineWidth(1);
$c->setSourceRgb(1, 1, 1);
for ($r = 50; $r > 0; $r -= 10) {
$c->arcNegative(50, 50, $r, 2 * M_PI, 0);
$c->stroke();
$c->fill();
}
$s->writeToPng(dirname(__FILE__) . '/CairoContext__arcNegative.png');
?>
Eksempel #2 Procedural style
<?php
$s = cairo_image_surface_create(CAIRO_SURFACE_TYPE_IMAGE, 100, 100);
$c = cairo_create($s);
cairo_set_source_rgb($c, 0, 0, 0);
cairo_paint($c);
cairo_set_source_rgb($c, 1, 1, 1);
cairo_set_line_width($c, 1);
for ($r = 50; $r > 0; $r -= 10) {
cairo_arc_negative($c, 50, 50, $r, 2 * M_PI, 0);
cairo_stroke($c);
cairo_fill($c);
}
cairo_surface_write_to_png($s, dirname(__FILE__) . '/cairo_arc_negative.png');
?>
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