(PECL cairo >= 0.1.0)
CairoContext::arcNegative -- cairo_arc_negative — Adds a negative arc
Object oriented style (method):
Procedural style:
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.
A valid CairoContext object
double x position
double y position
The radius of the desired negative arc
Start angle of the arc
End angle of the arc
No value is returned.
Example #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');
?>
Example #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');
?>