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MyGraphics.prejava
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MyGraphics.prejava
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//
// ARGH evidently this has totally diverged from the one in donhatchsw.com
//
// Wrapper class for Graphics
// that does a subset of the Graphics2D API
// (But with saner API.)
//
#include "macros.h"
import com.donhatchsw.util.MyMath;
import com.donhatchsw.util.VecMath;
public class MyGraphics
{
public MyGraphics(java.awt.Graphics g,
java.awt.Dimension gsize,
double x0, double x1, double y0, double y1)
{
this.g = g;
this.gsize = gsize;
fitToWindow(x0, x1, y0, y1);
}
public MyGraphics(java.awt.Graphics g,
java.awt.Dimension gsize)
{
this.g = g;
this.gsize = gsize;
fitToWindow(-1., 1., -1., 1.);
}
//
// Set translate and scale
// so that x0,x1,y0,y0
// map to left,right,bottom,top.
//
public void fit(double x0, double x1, double y0, double y1,
double left, double right, double bottom, double top)
{
scaleX = (right-left) / (x1-x0);
scaleY = (top-bottom) / (y1-y0);
translateX = left - scaleX*x0;
translateY = bottom - scaleY*y0;
}
public void fitToWindow(double x0, double x1, double y0, double y1)
{
fit(x0, x1, y0, y1,
.5, gsize.width-.5, gsize.height-.5, .5);
}
public void fitToPixel(double centerX, double centerY,
double pixelSizeX, double pixelSizeY)
{
fit(centerX, centerX+pixelSizeX, centerY, centerY+pixelSizeY,
gsize.width*.5, gsize.width*.5 + 1., gsize.height*.5, gsize.height*.5 + 1);
}
public void translate(double x, double y)
{
translateX += x*scaleX;
translateY += y*scaleY;
}
public void scale(double x, double y)
{
scaleX *= x;
scaleY *= y;
}
// window coords to input coords
public void pick(double x, double y, double result[/*2*/])
{
result[0] = (x-translateX)/scaleX;
result[1] = (y-translateY)/scaleY;
}
// input coords to window coords
// XXX name is dorky
public void unpick(double x, double y, double result[/*2*/])
{
result[0] = x*scaleX + translateX;
result[1] = y*scaleY + translateY;
}
public void fillWindow()
{
g.fillRect(0,0, gsize.width,gsize.height);
}
public void drawLineNonClipped(double x0, double y0, double x1, double y1,
boolean antiAlias)
{
if (antiAlias)
{
if (x0 == x1 && y0 == y1)
{
drawPoint(x0, y0, 1);
return;
}
// Transform to window coords...
// "the pen hangs down and to the right of the coordinate",
// so adjust the coordinate by half a pixel up and to the left...
x0 = (x0 * scaleX + translateX - .5);
y0 = (y0 * scaleY + translateY - .5);
x1 = (x1 * scaleX + translateX - .5);
y1 = (y1 * scaleY + translateY - .5);
java.awt.Color savedColor = getColor();
java.awt.Color[/*256*/] transparentColorCache = getTransparentColorCache(savedColor);
if (Math.abs(y1-y0) >= Math.abs(x1-x0))
{
int Y0 = (int)Math.round(y0);
int Y1 = (int)Math.round(y1);
int dirY = (Y0 <= Y1 ? 1 : -1);
double slope = (x1-x0)/(y1-y0);
for (int Y = Y0; Y != Y1; Y += dirY)
{
// XXX should use Wu's algorithm,
// XXX although I doubt this is the bottleneck
double x = x0 + (Y-y0) * slope;
int X = (int)Math.floor(x);
double frac = x-X;
int alpha = (int)(frac * 256.);
setColor(transparentColorCache[255-alpha]);
g.fillRect(X, Y, 1, 1);
setColor(transparentColorCache[alpha]);
g.fillRect(X+1, Y, 1, 1);
}
}
else
{
int X0 = (int)Math.round(x0);
int X1 = (int)Math.round(x1);
int dirX = (X0 <= X1 ? 1 : -1);
double slope = (y1-y0)/(x1-x0);
for (int X = X0; X != X1; X += dirX)
{
// XXX should use Wu's algorithm,
// XXX although I doubt this is the bottleneck
double y = y0 + (X-x0) * slope;
int Y = (int)Math.floor(y);
double frac = y-Y;
int alpha = (int)(frac * 256.);
setColor(transparentColorCache[255-alpha]);
g.fillRect(X, Y, 1, 1);
setColor(transparentColorCache[alpha]);
g.fillRect(X, Y+1, 1, 1);
}
}
setColor(savedColor);
}
else
{
// window coordinates are all >= 0, so it should be okay
// to truncate rather than round.
// "the pen hangs down and to the right of the coordinate",
// so adjust the coordinate by half a pixel up and to the left...
// XXX except currently the curved arcs don't do this properly,
// XXX so we end up not matching. need to fix both!
if (false)
g.drawLine((int)(x0 * scaleX + translateX - .5),
(int)(y0 * scaleY + translateY - .5),
(int)(x1 * scaleX + translateX - .5),
(int)(y1 * scaleY + translateY - .5));
else
g.drawLine((int)(x0 * scaleX + translateX),
(int)(y0 * scaleY + translateY),
(int)(x1 * scaleX + translateX),
(int)(y1 * scaleY + translateY));
}
} // drawLineNonClipped
public void drawLineClipped(double x0, double y0, double x1, double y1,
boolean antiAlias,
double clipX0, double clipX1, double clipY0, double clipY1,
double slack)
{
{
double temp;
// make the line left to right
if (x0 > x1)
{
SWAP(x0, x1, temp);
SWAP(y0, y1, temp);
}
else if (x0 == x1 && y0 == y1)
return;
if (clipX0 > clipX1)
SWAP(clipX0, clipX1, temp);
if (clipY0 > clipY1)
SWAP(clipY0, clipY1, temp);
}
if (false) // this works, but can be optimized better
{
double t0, t1;
if (y0 <= y1)
{
// Positive slope
//if (true) {drawLineNonClipped(x0, y0, x1, y1, antiAlias); return;}
//if (true) return;
//t0 = MAX((clipX0-x0)/(x1-x0), (clipY0-y0)/(y1-y0));
// t0 = (clipX0-x0)/(x1-x0) >= (clipY0-y0)/(y1-y0) ? (clipX0-x0)/(x1-x0) : (clipY0-y0)/(y1-y0);
t0 = (clipX0-x0)*(y1-y0) >= (clipY0-y0)*(x1-x0) ? (clipX0-x0)/(x1-x0) : (clipY0-y0)/(y1-y0);
//t1 = MIN((clipX1-x0)/(x1-x0), (clipY1-y0)/(y1-y0));
t1 = (clipX1-x0)*(y1-y0) <= (clipY1-y0)*(x1-x0) ? (clipX1-x0)/(x1-x0) : (clipY1-y0)/(y1-y0);
}
else
{
// Negative slope
//if (true) {drawLineNonClipped(x0, y0, x1, y1, antiAlias); return;}
//if (true) return;
//t0 = MAX((clipX0-x0)/(x1-x0), (clipY1-y0)/(y1-y0));
//t0 = MAX((clipX0-x0)/(x1-x0), (y0-clipY1)/(y0-y1));
t0 = (clipX0-x0)*(y0-y1) >= (y0-clipY1)*(x1-x0) ? (clipX0-x0)/(x1-x0) : (y0-clipY1)/(y0-y1);
//t1 = MIN((clipX1-x0)/(x1-x0), (clipY0-y0)/(y1-y0));
//t1 = MIN((clipX1-x0)/(x1-x0), (y0-clipY0)/(y0-y1));
t1 = (clipX1-x0)*(y0-y1) <= (y0-clipY0)*(x1-x0) ? (clipX1-x0)/(x1-x0) : (y0-clipY0)/(y0-y1);
}
t0 = MAX(t0, 0);
t1 = MIN(t1, 1);
if (t1 > t0)
drawLineNonClipped(LERP(x0, x1, t0),
LERP(y0, y1, t0),
LERP(x0, x1, t1),
LERP(y0, y1, t1),
antiAlias);
}
else
{
// super optimized
// XXX in progress
double clippedx0, clippedy0, clippedx1, clippedy1;
if (y1 >= y0)
{
// Non-negative slope
if (x1 <= clipX0
|| x0 >= clipX1
|| y1 <= clipY0
|| y0 >= clipY1)
return;
if (x0 < clipX0 - slack)
{
if (y0 < clipY0 - slack)
{
if ((clipX0-x0)*(y1-y0) >= (clipY0-y0)*(x1-x0))
{
// Clip to clipX0
clippedy0 = LERP(y0, y1, (clipX0-x0)/(x1-x0));
clippedx0 = clipX0;
}
else
{
// Clip to clipY0
clippedx0 = LERP(x0, x1, (clipY0-y0)/(y1-y0));
clippedy0 = clipY0;
}
}
else
{
// Clip to clipX0
clippedy0 = LERP(y0, y1, (clipX0-x0)/(x1-x0));
clippedx0 = clipX0;
}
}
else if (y0 < clipY0 - slack)
{
// Clip to clipY0
clippedx0 = LERP(x0, x1, (clipY0-y0)/(y1-y0));
clippedy0 = clipY0;
}
else
{
clippedx0 = x0;
clippedy0 = y0;
}
if (x1 > clipX1 + slack)
{
if (y1 > clipY1 + slack)
{
if ((clipX1-x0)*(y1-y0) <= (clipY1-y0)/(x1-x0))
{
// Clip to clipX1
clippedy1 = LERP(y0, y1, (clipX1-x0)/(x1-x0));
clippedx1 = clipX1;
}
else
{
// Clip to clipY1
clippedx1 = LERP(x0, x1, (clipY1-y0)/(y1-y0));
clippedy1 = clipY1;
}
}
else
{
// Clip to clipX1
clippedy1 = LERP(y0, y1, (clipX1-x0)/(x1-x0));
clippedx1 = clipX1;
}
}
else if (y1 > clipY1 + slack)
{
// Clip to clipY1
clippedx1 = LERP(x0, x1, (clipY1-y0)/(y1-y0));
clippedy1 = clipY1;
}
else
{
clippedx1 = x1;
clippedy1 = y1;
}
if (clippedx0 > clippedx1
&& clippedy0 > clippedy1)
return;
}
else // y1 < y0
{
//if (true) return;
// Negative slope
if (x1 <= clipX0
|| x0 >= clipX1
|| y0 <= clipY0 // since y0 == max(y0,y1)
|| y1 >= clipY1) // since y1 == min(y0,y1)
return;
if (x0 < clipX0 - slack)
{
if (y0 > clipY1 + slack)
{
if ((clipX0-x0)*(y0-y1) >= (y0-clipY1)*(x1-x0))
{
// Clip to clipX0
clippedy0 = LERP(y0, y1, (clipX0-x0)/(x1-x0));
clippedx0 = clipX0;
}
else
{
// Clip to clipY1
clippedx0 = LERP(x0, x1, (clipY1-y0)/(y1-y0));
clippedy0 = clipY1;
}
}
else
{
// Clip to clipX0
clippedy0 = LERP(y0, y1, (clipX0-x0)/(x1-x0));
clippedx0 = clipX0;
}
}
else if (y0 > clipY1 + slack)
{
// Clip to clipY1
clippedx0 = LERP(x0, x1, (clipY1-y0)/(y1-y0));
clippedy0 = clipY1;
}
else
{
clippedx0 = x0;
clippedy0 = y0;
}
if (x1 > clipX1 + slack)
{
if (y1 < clipY0 - slack)
{
// if (clipX1-x0)/(x1-x0) <= (clipY0-y0)/(y1-y0) but y1-y0 < 0
if ((clipX1-x0)*(y0-y1) <= (y0-clipY0)*(x1-x0))
{
// Clip to clipX1
clippedy1 = LERP(y0, y1, (clipX1-x0)/(x1-x0));
clippedx1 = clipX1;
}
else
{
// hits this case when should hit other casse!
// Clip to clipY0
clippedx1 = LERP(x0, x1, (clipY0-y0)/(y1-y0));
clippedy1 = clipY0;
}
}
else
{
// Clip to clipX1
clippedy1 = LERP(y0, y1, (clipX1-x0)/(x1-x0));
clippedx1 = clipX1;
}
}
else if (y1 < clipY0 - slack)
{
// Clip to clipY0
clippedx1 = LERP(x0, x1, (clipY0-y0)/(y1-y0));
clippedy1 = clipY0;
}
else
{
clippedx1 = x1;
clippedy1 = y1;
}
if (false)
{
clippedx0 = x0;
clippedx1 = x1;
clippedy0 = y0;
clippedy1 = y1;
}
if (clippedx0 > clippedx1
&& clippedy0 < clippedy1)
return;
}
drawLineNonClipped(clippedx0, clippedy0, clippedx1, clippedy1,
antiAlias);
}
} // drawLineClipped
public void drawLine(double x0, double y0, double x1, double y1,
boolean antiAlias)
{
boolean jitterFlag = false; // hardcode to true to debug
if (jitterFlag)
{
double jitterRadius = .02; // hardcode as desired
x0 += (Math.random() * 2*jitterRadius) - jitterRadius;
x1 += (Math.random() * 2*jitterRadius) - jitterRadius;
y0 += (Math.random() * 2*jitterRadius) - jitterRadius;
y1 += (Math.random() * 2*jitterRadius) - jitterRadius;
}
// clip; it sucks without clipping
double clipX0 = (0-translateX)/scaleX;
double clipX1 = (gsize.width-translateX)/scaleX;
double clipY0 = (0-translateY)/scaleY;
double clipY1 = (gsize.height-translateY)/scaleY;
if (debugClip)
{
// debug by setting clip to half what it was
clipX0 *= .95;
clipX1 *= .95;
clipY0 *= .95;
clipY1 *= .95;
}
drawLineClipped(x0, y0, x1, y1,
antiAlias,
clipX0, clipX1, clipY0, clipY1,
2./((Math.abs(scaleX)+Math.abs(scaleY))*.5)); // 2 pixels
} // drawLine
public void drawPoint(double x, double y, int nPixelsX, int nPixelsY)
{
int x0 = (int)Math.round(x * scaleX + translateX - .5*nPixelsX);
int y0 = (int)Math.round(y * scaleY + translateY - .5*nPixelsY);
if (verbose >= 2) System.out.println("in drawPoint("+x+","+y+","+nPixelsX+","+nPixelsY+") -> "+x0+","+y0);
// have to check, otherwise java fillRect does weird wraparound stuff
// XXX should check in floating-point
if (x0 < -nPixelsX
|| x0 > gsize.width+nPixelsX
|| y0 < -nPixelsY
|| y0 > gsize.height+nPixelsY)
return;
g.fillRect(x0, y0, nPixelsX, nPixelsY);
}
public void drawPoint(double x, double y, int nPixels)
{
drawPoint(x, y, nPixels, nPixels);
}
public void drawString(String s, double x, double y)
{
g.drawString(s, (int)(x * scaleX + translateX),
(int)(y * scaleY + translateY));
}
public void drawStringRotated(String s,
double x, double y,
double xJustify, // -1,0,1 -> L,C,R
double yJustify, // -1,0,1 -> T,C,B
java.awt.Color backgroundColor,
double theta)
{
// rotate about xformed x,y
java.awt.Graphics2D g2d = (java.awt.Graphics2D)g;
CHECK_NE(g2d, null);
java.awt.geom.AffineTransform origXform = g2d.getTransform();
java.awt.geom.AffineTransform rotated = (java.awt.geom.AffineTransform)origXform.clone();
rotated.rotate(
theta * (scaleX*scaleY < 0. ? -1 : 1),
(int)(x*scaleX + translateX),
(int)(y*scaleY + translateY));
g2d.setTransform(rotated);
drawString(s, x, y, xJustify, yJustify, backgroundColor);
g2d.setTransform(origXform);
}
public void drawString(String s, double x, double y,
double xJustify, // -1,0,1 -> L,C,R
double yJustify, // -1,0,1 -> T,C,B
java.awt.Color backgroundColor)
{
java.awt.FontMetrics fm = g.getFontMetrics();
/*
x:
-1 -> 0
0 -> -.5
1 -> -1
y:
-1 -> 1
0 -> .5
1 -> 0
*/
int xFinal = (int)(x * scaleX + translateX - fm.stringWidth(s)*(xJustify+1.)*.5);
int yFinal = (int)(y * scaleY + translateY + fm.getAscent()*(1.-yJustify)*.5); // XXX centered height seems to come out a bit low-- maybe fiddle with leading?
if (backgroundColor != null)
{
java.awt.Color savedColor = g.getColor();
g.setColor(backgroundColor);
g.fillRect(xFinal-1,yFinal-fm.getAscent(), // the -1 is fudge
fm.stringWidth(s)+2, fm.getAscent()+fm.getDescent()); // the +2 is fudge
g.setColor(savedColor);
}
g.drawString(s, xFinal, yFinal);
}
public void drawString(String s, double x, double y,
double xJustify, // -1,0,1 -> L,C,R
double yJustify) // -1,0,1 -> T,C,B
{
drawString(s, x, y, xJustify, yJustify, null);
}
public void drawStringCentered(String s, double x, double y)
{
drawString(s, x, y, 0, 0);
}
public void drawStringRightJustified(String s, double x, double y)
{
drawString(s, x, y, 1, 0);
}
// XXX should be more of these, maybe...
public double getFontHeight()
{
java.awt.FontMetrics fm = g.getFontMetrics();
return Math.abs(fm.getHeight() / scaleY);
}
//private static int recursionLevel = 0;
public void smartDrawArcNonClipped(
double focusX, double focusY, // a point on the arc
double focusAngleRadians, // from center to focus
double c, // curvature, i.e. 1/radius
double start, double end, // arc goes from focusAngle+start to focusAngle+end in arc length
boolean antiAlias)
{
//System.out.println(spaces(4*recursionLevel++)+" in smartDrawArcNonClipped(focusX="+focusX+",focusY="+focusY+",focusAngleDegrees="+focusAngleRadians*180/Math.PI+",c="+c+"=1/"+1./c+",start="+start+",end="+end+"");
final boolean useSegments = antiAlias; // implement antialiasing by drawing the circle as a sequence of antialiased segments with floating point coords
if (useSegments)
{
int nSegs = MAX(10, (int)(ABS((end-start)*c) / (1*(Math.PI/180)))); // 1 degree-- delicate tradeoff, if we make it too fine, it looks all warbly because the endpoints are snapped to unit pixel coords XXX but this comment is no longer true since we are using our own antialiased line procedure
//PRINT(nSegs);
double cosFocusAngle = Math.cos(focusAngleRadians);
double sinFocusAngle = Math.sin(focusAngleRadians);
double normalAndTangent[][] = {
{ cosFocusAngle, sinFocusAngle}, // unit normal vector
{-sinFocusAngle, cosFocusAngle}, // unit tangent vector
};
double prevPoint[] = new double[2];
double point[] = new double[2];
double scratch[] = new double[2];
for (int i = 0; i < nSegs+1; ++i)
{
double t = LERP(start, end, (double)i/nSegs);
findPointOnArc(t, focusX, focusY, c, normalAndTangent, scratch, point);
if (i > 0)
this.drawLineNonClipped(prevPoint[0], prevPoint[1],
point[0], point[1],
antiAlias);
//VecMath.setvec(prevPoint, point);
System.arraycopy(point, 0, prevPoint, 0, 2);
}
return;
}
// our end condition can only handle angles < 180 degrees,
// so split in half if that is not the case
// (a full circle will be recursively split again).
if (c*Math.abs(start-end) > .75*Math.PI)
{
smartDrawArcNonClipped(focusX, focusY, focusAngleRadians, c,
start, (start+end)*.5,
antiAlias);
smartDrawArcNonClipped(focusX, focusY, focusAngleRadians, c,
(start+end)*.5, end,
antiAlias);
//System.out.println(spaces(4*--recursionLevel)+" out smartDrawArcNonClipped");
return;
}
//
// Need to work in pixel space
// so that we can be aware of the integer grid...
//
{
focusX = focusX * scaleX + translateX;
focusY = focusY * scaleY + translateY;
if (scaleY < 0.)
{
focusAngleRadians *= -1.;
start *= -1.;
end *= -1.;
}
double scale = .5 * (Math.abs(scaleX) + Math.abs(scaleY)); // XXX not really right unless scaleX == scaleY, but that's usually the case
c /= scale;
start *= scale;
end *= scale;
}
//
// Reverse/swap parameters if necessary so that we are
// going CCW around an arc of positive radius...
// XXX figure out how much of this is necessary
//
{
if (c < 0.)
{
c *= -1.;
focusAngleRadians += Math.PI;
start *= -1.;
end *= -1.;
}
if (start > end)
{
double temp = start;
start = end;
end = temp;
}
}
//System.out.println("in smartDrawArcNonClipped(focusX="+focusX+",focusY="+focusY+",focusAngleDegrees="+focusAngleRadians*180/Math.PI+",c="+c+"=1/"+1./c+",start="+start+",end="+end+"");
double normalX = Math.cos(focusAngleRadians);
double normalY = Math.sin(focusAngleRadians);
double normalAndTangent[][] = {
{ normalX, normalY}, // unit normal vector
{-normalY, normalX}, // unit tangent vector
};
//
// Find start point...
//
double startX, startY;
double endX, endY;
{
double point[] = new double[2];
double scratch[] = new double[2];
findPointOnArc(start, focusX, focusY, c, normalAndTangent, scratch, point);
startX = point[0];
startY = point[1];
findPointOnArc(end, focusX, focusY, c, normalAndTangent, scratch, point);
endX = point[0];
endY = point[1];
}
// At most one point drawn for every pixel width of arc length
int maxPointsToDraw = (int)Math.ceil(Math.abs(end-start)) + 1;
int nPointsDrawn = 0;
int x = (int)Math.round(startX), y = (int)Math.round(startY);
double X = x - focusX; // XXX clean this up
double Y = y - focusY; // XXX clean this up
//System.out.println("point at "+x+","+y);
this.g.fillRect(x, y, 1, 1);
nPointsDrawn++;
if (c < 1) // i.e. radius > 1
{
while (true)
{
final int quantizedDirVectors[][] = {
{1,0}, {1,1}, {0,1}, {-1,1}, {-1,0}, {-1,-1}, {0,-1}, {1,-1}
};
// What direction are we most likely to be going in?
int dir; // index into quantizedDirVectors
{
// Figure out current normal and tangent (dir),
// not necessarily normalized to unit length
double thisNormalX = c*X + normalX;
double thisNormalY = c*Y + normalY;
double thisTangentX = -thisNormalY;
double thisTangentY = thisNormalX;
int quantizedDirX = (thisTangentX < 0. ? -1 : thisTangentX > 0. ? 1 : 0);
int quantizedDirY = (thisTangentY < 0. ? -1 : thisTangentY > 0. ? 1 : 0);
double absThisTangentX = Math.abs(thisTangentX);
double absThisTangentY = Math.abs(thisTangentY);
if (absThisTangentX > 2*absThisTangentY)
quantizedDirY = 0;
else if (absThisTangentY > 2*absThisTangentX)
quantizedDirX = 0;
// XXX figure out more efficient way!
for (dir = 0; dir < 8; ++dir)
{
if (quantizedDirVectors[dir][0] == quantizedDirX
&& quantizedDirVectors[dir][1] == quantizedDirY)
break; // found it
}
if (dir == 8)
{
System.out.println("huh?????"); // XXX
break; // only happens when radius is very small
}
}
x += quantizedDirVectors[dir][0];
y += quantizedDirVectors[dir][1];
X = x - focusX;
Y = y - focusY;
// the following was worked out on paper...
// XXX should show derivation for posterity
double signedDistanceOutsideCircle =
(c * (X*X + Y*Y) + 2 * (X*normalX + Y*normalY))
/ (MyMath.hypot(c*X + normalX, c*Y + normalY) + 1.);
//
// Make it "manhattan distance" from circle,
// by inflating distance when normal is in diagonal direction.
//
double inflation;
{
double thisNormalX = c*X + normalX;
double thisNormalY = c*Y + normalY;
inflation = MyMath.hypot(thisNormalX, thisNormalY)
/ Math.max(Math.abs(thisNormalX), Math.abs(thisNormalY));
}
//System.out.println(" signedDistanceOutsideCircle = "+signedDistanceOutsideCircle);
signedDistanceOutsideCircle *= inflation;
//System.out.println(" inflated signedDistanceOutsideCircle = "+signedDistanceOutsideCircle);
if (signedDistanceOutsideCircle > .5001) // too far outside circle XXX use GT?
{
x -= quantizedDirVectors[dir][0];
y -= quantizedDirVectors[dir][1];
// pull inward, i.e. turn direction of travel CCW
dir = (dir + 1) % 8;
x += quantizedDirVectors[dir][0];
y += quantizedDirVectors[dir][1];
X = x - focusX;
Y = y - focusY;
}
else if (signedDistanceOutsideCircle < -.5001) // too far inside circle XXX use LT?
{
x -= quantizedDirVectors[dir][0];
y -= quantizedDirVectors[dir][1];
// pull outward, i.e. turn direction of travel CW
dir = (dir - 1 + 8) % 8;
x += quantizedDirVectors[dir][0];
y += quantizedDirVectors[dir][1];
X = x - focusX;
Y = y - focusY;
}
//System.out.println("maybe point at "+x+","+y);
// XXX if radius <= 2 or so,
// XXX may need to do the above multiple times!
// XXX Ignoring this issue for now, so tiny arcs
// XXX might draw some garbage (tiny garbage though)
//
// Determine whether we've past the end...
// XXX this test is wrong for arcs > 180 degrees,
// XXX and also when end < start!
// XXX That is why we subdivided any arc > .75 * 180 degrees
// XXX above, and we reversed start and end
// XXX so that end <= start.
//
{
double thisNormalX = c*X + normalX;
double thisNormalY = c*Y + normalY;
signedDistanceOutsideCircle =
(c * (X*X + Y*Y) + 2 * (X*normalX + Y*normalY))
/ (MyMath.hypot(c*X + normalX, c*Y + normalY) + 1.);
double arcPointX = focusX + X - signedDistanceOutsideCircle * thisNormalX;
double arcPointY = focusY + Y - signedDistanceOutsideCircle * thisNormalY;
double startToArcPoint = MyMath.hypot(arcPointX-startX,
arcPointY-startY);
double arcDistance = startToArcPoint * MyMath.asin_over_x(c*startToArcPoint*.5);
if (false)
{
System.out.println(" nPointsDrawn = "+nPointsDrawn);
System.out.println(" signedDistanceOutsideCircle = "+signedDistanceOutsideCircle);
System.out.println(" startX = "+startX);
System.out.println(" startY = "+startY);
System.out.println(" arcPointX = "+arcPointX);
System.out.println(" arcPointY = "+arcPointY);
System.out.println(" startToArcPoint = "+startToArcPoint);
System.out.println(" arcDistance = "+arcDistance);
System.out.println(" start = "+start);
System.out.println(" end = "+end);
System.out.println(" c = "+c);
}
if (arcDistance >= end-start) // XXX use GEQ I think
break;
}
this.g.fillRect(x, y, 1, 1);
nPointsDrawn++;
// XXX For some small circles, the above will never be satisfied
// XXX so put a limit on number of points to draw.
// XXX Shouldn't need this if we get the above condition right
if (nPointsDrawn >= maxPointsToDraw-1)
break;
}
this.g.fillRect((int)Math.round(endX), (int)Math.round(endY), 1, 1);
nPointsDrawn++;
}
//System.out.println(spaces(4*--recursionLevel)+" out smartDrawArcNonClipped");
} // smartDrawArcNonClipped
public void smartDrawArcClipped(
double focusX, double focusY, // a point on the arc
double focusAngleRadians, // from center to focus
double c, // curvature, i.e. 1/radius
double start, double end, // arc goes from focusAngle+start to focusAngle+end in arc length
boolean antiAlias,
double clipX0, double clipX1, double clipY0, double clipY1,
double slack)
{
if (verbose >= 2) System.out.println(" in smartDrawArcClipped");
// I don't know how to clip analytically yet,
// so do the following instead:
// while an endpoint is outside the clip area,
// cut off that length of the arc.
// This will exponentially approach the clip rectangle
// (or exponentially recede from it).
// Stop when our distance from the clip rectangle
// is <= slack (typically 2 pixels).
double clipMinX = Math.min(clipX0, clipX1);
double clipMaxX = Math.max(clipX0, clipX1);
double clipMinY = Math.min(clipY0, clipY1);
double clipMaxY = Math.max(clipY0, clipY1);
if (c * Math.abs(end-start) > 2*Math.PI)
{
start = 0.;
end = 2*Math.PI / c;
}
int dir = (start <= end ? 1 : -1);
double normalX = Math.cos(focusAngleRadians);
double normalY = Math.sin(focusAngleRadians);
double normalAndTangent[][] = {
{ normalX, normalY}, // unit normal vector
{-normalY, normalX}, // unit tangent vector
};
double point[] = new double[2];
double scratch[] = new double[2];
//System.out.println("clipMinX = "+clipMinX);
//System.out.println("clipMaxX = "+clipMaxX);
//System.out.println("clipMinY = "+clipMinY);
//System.out.println("clipMaxY = "+clipMaxY);
//System.out.println("slack = "+slack);
while (true)
{
//System.out.println("start="+start);
//System.out.println("end="+end);
findPointOnArc(start, focusX, focusY, c, normalAndTangent, scratch, point);
double startX = point[0];
double startY = point[1];
//System.out.println("startX = "+startX);
//System.out.println("startY = "+startY);
double dist = MAX4(startX-clipMaxX,
clipMinX-startX,
startY-clipMaxY,
clipMinY-startY);
//System.out.println("dist = "+dist);
if (dist <= slack)
break;
start += dir * dist;
//System.out.println("new start="+start);
if (dir * (end-start) < 0)
{
//System.out.println(" out smartDrawArcClipped (without drawing)");
return;
}
}
while (true)
{
//System.out.println("start="+start);
//System.out.println("end="+end);
findPointOnArc(end, focusX, focusY, c, normalAndTangent, scratch, point);
double endX = point[0];
double endY = point[1];
//System.out.println("endX = "+endX);
//System.out.println("endY = "+endY);
double dist = MAX4(endX-clipMaxX,
clipMinX-endX,
endY-clipMaxY,
clipMinY-endY);
if (dist <= slack)
break;
end -= dir * dist;
//System.out.println("new end="+end);
if (dir * (end-start) < 0)
{
//System.out.println(" out smartDrawArcClipped (without drawing.");
return;
}
}
// Prevent huge circles that start and end in the clip rectangle.
// Note this doesn't clip away all arc segments
// that leave the clip rectangle, but it does
// guarantee that any it misses won't be much larger
// than the clip rectangle (and usually much smaller).
{
double mid = (start+end)*.5;
findPointOnArc(mid, focusX, focusY, c, normalAndTangent, scratch, point);
double midX = point[0];
double midY = point[1];
double dist = MAX4(midX-clipMaxX,
clipMinX-midX,
midY-clipMaxY,
clipMinY-midY);
if (dist > slack)
{
smartDrawArcClipped(focusX, focusY, focusAngleRadians, c,
start, mid,
antiAlias,
clipX0, clipX1, clipY0, clipY1, slack);
smartDrawArcClipped(focusX, focusY, focusAngleRadians, c,
mid, end,
antiAlias,
clipX0, clipX1, clipY0, clipY1, slack);
if (verbose >= 2) System.out.println(" out smartDrawArcClipped (split in two)");
return;
}
}
smartDrawArcNonClipped(focusX,focusY, focusAngleRadians, c, start,end,
antiAlias);
if (verbose >= 2) System.out.println(" out smartDrawArcClipped (bottom)");
} // smartDrawArcClipped
public void smartDrawArc_(
double focusX, double focusY, // a point on the arc
double focusAngleRadians, // from center to focus
double c, // curvature, i.e. 1/radius
double start, double end, // arc goes from focusAngle+start to focusAngle+end in arc length
boolean antiAlias)
{
if (verbose >= 2) System.out.println(" in smartDrawArc_");
//System.out.println("scaleX="+scaleX);
//System.out.println("scaleY="+scaleY);
//System.out.println(" in smartDrawArc");
double clipX0 = (0-translateX)/scaleX;
double clipX1 = (gsize.width-translateX)/scaleX;
double clipY0 = (0-translateY)/scaleY;
double clipY1 = (gsize.height-translateY)/scaleY;
if (debugClip)
{
// debug by setting clip to half what it was
clipX0 *= .95;
clipX1 *= .95;
clipY0 *= .95;
clipY1 *= .95;
}
smartDrawArcClipped(focusX, focusY, focusAngleRadians, c, start, end,
antiAlias,
clipX0, clipX1, clipY0, clipY1,
2./((Math.abs(scaleX)+Math.abs(scaleY))*.5)); // 2 pixels
if (verbose >= 2) System.out.println(" out smartDrawArc_");
} // smartDrawArc_
//
// Thickness is in pixels. This will probably do something not-right
// if scaleX != scaleY.