This commit is contained in:
Ingy döt Net 2013-04-10 21:29:02 -07:00
parent 764da6cbbb
commit db842d013d
19005 changed files with 197040 additions and 7 deletions

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NB.*getBresenhamCircle v Returns points for a circle given center and radius
NB. y is: y0 x0 radius
getBresenhamCircle=: monad define
'y0 x0 radius'=. y
x=. 0
y=. radius
f=. -. radius
pts=. 0 2$0
while. x <: y do.
pts=. pts , y , x
if. f >: 0 do.
y=. <:y
f=. f + _2 * y
end.
x=. >:x
f =. f + >: 2 * x
end.
offsets=. (,|."1) (1 _1 {~ #: i.4) *"1"1 _ pts
~.,/ (y0,x0) +"1 offsets
)
NB.*drawCircles v Draws circle(s) (x) on image (y)
NB. x is: 2-item list of boxed (y0 x0 radius) ; (color)
drawCircles=: (1&{:: ;~ [: ; [: <@getBresenhamCircle"1 (0&{::))@[ setPixels ]

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myimg=: 0 255 0 makeRGB 25 25 NB. 25 by 25 green image
myimg=: (12 12 12 ; 255 0 0) drawCircles myimg NB. draw red circle with radius 12
viewRGB ((12 12 9 ,: 12 12 6) ; 0 0 255) drawCircles myimg NB. draw two more concentric circles

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import java.awt.Color;
public class MidPointCircle {
private BasicBitmapStorage image;
public MidPointCircle(final int imageWidth, final int imageHeight) {
this.image = new BasicBitmapStorage(imageWidth, imageHeight);
}
private void drawCircle(final int centerX, final int centerY, final int radius) {
int d = (5 - r * 4)/4;
int x = 0;
int y = radius;
Color circleColor = Color.white;
do {
image.setPixel(centerX + x, centerY + y, circleColor);
image.setPixel(centerX + x, centerY - y, circleColor);
image.setPixel(centerX - x, centerY + y, circleColor);
image.setPixel(centerX - x, centerY - y, circleColor);
image.setPixel(centerX + y, centerY + x, circleColor);
image.setPixel(centerX + y, centerY - x, circleColor);
image.setPixel(centerX - y, centerY + x, circleColor);
image.setPixel(centerX - y, centerY - x, circleColor);
if (d < 0) {
d += 2 * x + 1;
} else {
d += 2 * (x - y) + 1;
y--;
}
x++;
} while (x <= y);
}
}