mirror of
https://github.com/gnustep/libs-gui.git
synced 2025-05-30 22:00:38 +00:00
Fixes to appending an arc
git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/gui/trunk@9252 72102866-910b-0410-8b05-ffd578937521
This commit is contained in:
nico
parent
333bb896ae
commit
d3b32aaf20
1 changed files with 100 additions and 70 deletions
|
|
@ -828,103 +828,132 @@ static Class NSBezierPath_concrete_class = nil;
|
|||
[self lineToPoint: points[i]];
|
||||
}
|
||||
|
||||
- (void)appendBezierPathWithOvalInRect:(NSRect)aRect
|
||||
- (void) appendBezierPathWithOvalInRect: (NSRect)aRect
|
||||
{
|
||||
[self appendBezierPath: [isa bezierPathWithOvalInRect: aRect]];
|
||||
}
|
||||
|
||||
- (void)appendBezierPathWithArcWithCenter:(NSPoint)center
|
||||
radius:(float)radius
|
||||
startAngle:(float)startAngle
|
||||
endAngle:(float)endAngle
|
||||
clockwise:(BOOL)clockwise
|
||||
/* startAngle and endAngle are in degrees, counterclockwise, from the
|
||||
x axis */
|
||||
- (void) appendBezierPathWithArcWithCenter: (NSPoint)center
|
||||
radius: (float)radius
|
||||
startAngle: (float)startAngle
|
||||
endAngle: (float)endAngle
|
||||
clockwise: (BOOL)clockwise
|
||||
{
|
||||
NSBezierPath *path = [isa bezierPath];
|
||||
float strtangrd, endangrd, diff;
|
||||
float startAngle_rad, endAngle_rad, diff;
|
||||
NSPoint p0, p1, p2, p3;
|
||||
|
||||
while(startAngle < 0)
|
||||
while (startAngle < 0)
|
||||
startAngle = startAngle + 360;
|
||||
while(startAngle > 360)
|
||||
while (startAngle > 360)
|
||||
startAngle = startAngle - 360;
|
||||
|
||||
while(endAngle < 0)
|
||||
while (endAngle < 0)
|
||||
endAngle = endAngle + 360;
|
||||
while(endAngle > 360)
|
||||
while (endAngle > 360)
|
||||
endAngle = endAngle - 360;
|
||||
|
||||
strtangrd = PI * startAngle / 180;
|
||||
endangrd = PI * endAngle / 180;
|
||||
/* Convert the angles to radians */
|
||||
startAngle_rad = PI * startAngle / 180;
|
||||
endAngle_rad = PI * endAngle / 180;
|
||||
|
||||
p0 = NSMakePoint(center.x + radius * cos(strtangrd), center.y + radius * sin(strtangrd));
|
||||
[path moveToPoint: p0];
|
||||
/* Start point */
|
||||
p0 = NSMakePoint (center.x + radius * cos (startAngle_rad),
|
||||
center.y + radius * sin (startAngle_rad));
|
||||
[self moveToPoint: p0];
|
||||
|
||||
if (clockwise)
|
||||
{
|
||||
diff = -PI / 2;
|
||||
if (strtangrd < endangrd)
|
||||
strtangrd += 2 * PI;
|
||||
if (startAngle_rad < endAngle_rad)
|
||||
{
|
||||
startAngle_rad += 2 * PI;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
diff = PI / 2;
|
||||
if (strtangrd > endangrd)
|
||||
strtangrd -= 2 * PI;
|
||||
if (startAngle_rad > endAngle_rad)
|
||||
{
|
||||
startAngle_rad -= 2 * PI;
|
||||
}
|
||||
}
|
||||
|
||||
while (strtangrd > endangrd)
|
||||
{
|
||||
if (strtangrd + diff >= endangrd)
|
||||
{
|
||||
float sin_sta = sin(strtangrd);
|
||||
float cos_sta = cos(strtangrd);
|
||||
|
||||
// FIXME: Add a quarter circle, for clockwise the signs are not correct!
|
||||
p1 = NSMakePoint(center.x + radius * (cos_sta - KAPPA * sin_sta),
|
||||
center.y + radius * (sin_sta + KAPPA * cos_sta));
|
||||
p2 = NSMakePoint(center.x + radius * (KAPPA * cos_sta -sin_sta),
|
||||
center.y + radius * (cos_sta + KAPPA * sin_sta));
|
||||
p3 = NSMakePoint(center.x + radius * (-sin_sta),
|
||||
center.y + radius * cos_sta);
|
||||
[path curveToPoint: p3 controlPoint1: p1 controlPoint2: p2];
|
||||
strtangrd += diff;
|
||||
}
|
||||
else
|
||||
{
|
||||
float diff_ang = (endangrd - strtangrd) / 2;
|
||||
float cos_da = cos(diff_ang);
|
||||
float sin_da = sin(diff_ang);
|
||||
double x, y;
|
||||
float sin_sta = sin(strtangrd + diff_ang);
|
||||
float cos_sta = cos(strtangrd + diff_ang);
|
||||
|
||||
x = (4 - cos_da) / 3;
|
||||
y = ((1- cos_da) * (cos_da - 3)) / (3 * sin_da);
|
||||
// FIXME: Add just the missing bit, for clockwise the signs are not correct!
|
||||
p1 = NSMakePoint(center.x + radius * (cos_sta * x - sin_sta * y),
|
||||
center.y + radius * (sin_sta * y + cos_sta * x));
|
||||
p2 = NSMakePoint(center.x + radius * (cos_sta * x + sin_sta * y),
|
||||
center.y + radius * (sin_sta * (-y) + cos_sta * x));
|
||||
p3 = NSMakePoint(center.x + radius * cos(endangrd),
|
||||
center.y + radius * sin(endangrd));
|
||||
[path curveToPoint: p3 controlPoint1: p1 controlPoint2: p2];
|
||||
break;
|
||||
}
|
||||
while ((clockwise) ? (startAngle_rad > endAngle_rad)
|
||||
: (startAngle_rad < endAngle_rad))
|
||||
{
|
||||
/* Add a quarter circle */
|
||||
if ((clockwise) ? (startAngle_rad + diff >= endAngle_rad)
|
||||
: (startAngle_rad + diff <= endAngle_rad))
|
||||
{
|
||||
float sin_start = sin (startAngle_rad);
|
||||
float cos_start = cos (startAngle_rad);
|
||||
float sign = (clockwise) ? -1.0 : 1.0;
|
||||
|
||||
p1 = NSMakePoint (center.x
|
||||
+ radius * (cos_start - KAPPA * sin_start * sign),
|
||||
center.y
|
||||
+ radius * (sin_start + KAPPA * cos_start * sign));
|
||||
p2 = NSMakePoint (center.x
|
||||
+ radius * (-sin_start * sign + KAPPA * cos_start),
|
||||
center.y
|
||||
+ radius * (cos_start * sign + KAPPA * sin_start));
|
||||
p3 = NSMakePoint (center.x + radius * (-sin_start * sign),
|
||||
center.y + radius * cos_start * sign);
|
||||
|
||||
[self curveToPoint: p3 controlPoint1: p1 controlPoint2: p2];
|
||||
startAngle_rad += diff;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* Add the missing bit
|
||||
* We require that the arc be less than a semicircle.
|
||||
* The arc may go either clockwise or counterclockwise.
|
||||
* The approximation is a very simple one: a single curve
|
||||
* whose middle two control points are a fraction F of the way
|
||||
* to the intersection of the tangents, where
|
||||
* F = (4/3) / (1 + sqrt (1 + (d / r)^2))
|
||||
* where r is the radius and d is the distance from either tangent
|
||||
* point to the intersection of the tangents. This produces
|
||||
* a curve whose center point, as well as its ends, lies on
|
||||
* the desired arc.
|
||||
*/
|
||||
NSPoint ps = [self currentPoint];
|
||||
/* tangent is the tangent of half the angle */
|
||||
float tangent = tan ((endAngle_rad - startAngle_rad) / 2);
|
||||
/* trad is the distance from either tangent point to the
|
||||
intersection of the tangents */
|
||||
float trad = radius * tangent;
|
||||
/* pt is the intersection of the tangents */
|
||||
NSPoint pt = NSMakePoint (ps.x - trad * sin (startAngle_rad),
|
||||
ps.y + trad * cos (startAngle_rad));
|
||||
/* This is F - in this expression we need to compute
|
||||
(trad/radius)^2, which is simply tangent^2 */
|
||||
float f = (4.0 / 3.0) / (1.0 + sqrt (1.0 + (tangent * tangent)));
|
||||
|
||||
p1 = NSMakePoint (ps.x + (pt.x - ps.x) * f, ps.y + (pt.y - ps.y) * f);
|
||||
p3 = NSMakePoint(center.x + radius * cos (endAngle_rad),
|
||||
center.y + radius * sin (endAngle_rad));
|
||||
p2 = NSMakePoint (p3.x + (pt.x - p3.x) * f, p3.y + (pt.y - p3.y) * f);
|
||||
[self curveToPoint: p3 controlPoint1: p1 controlPoint2: p2];
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
- (void)appendBezierPathWithArcWithCenter:(NSPoint)center
|
||||
radius:(float)radius
|
||||
startAngle:(float)startAngle
|
||||
endAngle:(float)endAngle
|
||||
- (void) appendBezierPathWithArcWithCenter: (NSPoint)center
|
||||
radius: (float)radius
|
||||
startAngle: (float)startAngle
|
||||
endAngle: (float)endAngle
|
||||
{
|
||||
[self appendBezierPathWithArcWithCenter: center radius: radius
|
||||
startAngle: startAngle endAngle: endAngle clockwise: NO];
|
||||
[self appendBezierPathWithArcWithCenter: center radius: radius
|
||||
startAngle: startAngle endAngle: endAngle clockwise: NO];
|
||||
}
|
||||
|
||||
- (void)appendBezierPathWithArcFromPoint:(NSPoint)point1
|
||||
toPoint:(NSPoint)point2
|
||||
radius:(float)radius
|
||||
- (void) appendBezierPathWithArcFromPoint: (NSPoint)point1
|
||||
toPoint: (NSPoint)point2
|
||||
radius: (float)radius
|
||||
{
|
||||
// TODO
|
||||
}
|
||||
|
|
@ -1326,9 +1355,9 @@ typedef struct _PathElement
|
|||
INVALIDATE_CACHE();
|
||||
}
|
||||
|
||||
- (void)curveToPoint:(NSPoint)aPoint
|
||||
controlPoint1:(NSPoint)controlPoint1
|
||||
controlPoint2:(NSPoint)controlPoint2
|
||||
- (void) curveToPoint: (NSPoint)aPoint
|
||||
controlPoint1: (NSPoint)controlPoint1
|
||||
controlPoint2: (NSPoint)controlPoint2
|
||||
{
|
||||
PathElement elem;
|
||||
|
||||
|
|
@ -1666,3 +1695,4 @@ static void flatten(NSPoint coeff[], float flatness, NSBezierPath *path)
|
|||
[path lineToPoint: coeff[3]];
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue