ae53754392371fb4f12ce622b5ccaf79321d0556 kate Mon Mar 12 15:29:40 2018 -0700 Curve function returns max y drawn (helps max box placement). refs #17512 diff --git src/hg/lib/hvGfx.c src/hg/lib/hvGfx.c index cef8423..6ec4c60 100644 --- src/hg/lib/hvGfx.c +++ src/hg/lib/hvGfx.c @@ -314,115 +314,138 @@ while (--dots >= 0) { if (dots % dotFreq) hvGfxDot(hvg,x1,y1,color); duty_cycle += delta_x; y1+=incy; if (duty_cycle > 0) { duty_cycle -= delta_y; /* update duty cycle */ x1 += 1; } } } } -void hvGfxCurveSegAA(struct hvGfx *hvg, int x0, int y0, int x1, int y1, int x2, int y2, +int hvGfxCurveSegAA(struct hvGfx *hvg, int x0, int y0, int x1, int y1, int x2, int y2, Color color, boolean isDashed) /* Draw a segment of an anti-aliased curve within 3 points (quadratic Bezier) - * Optionally alternate dots. + * Return max y value. Optionally alternate dots. * Adapted trivially from code posted on github and at http://members.chello.at/~easyfilter/bresenham.html */ /* Thanks to author * @author Zingl Alois * @date 22.08.2016 */ { + int yMax = 0; int sx = x2-x1, sy = y2-y1; long xx = x0-x1, yy = y0-y1, xy; /* relative values for checks */ double dx, dy, err, ed, cur = xx*sy-yy*sx; /* curvature */ assert(xx*sx <= 0 && yy*sy <= 0); /* sign of gradient must not change */ if (sx*(long)sx+sy*(long)sy > xx*xx+yy*yy) { /* begin with longer part */ x2 = x0; x0 = sx+x1; y2 = y0; y0 = sy+y1; cur = -cur; /* swap P0 P2 */ } if (cur != 0) { /* no straight line */ xx += sx; xx *= sx = x0 < x2 ? 1 : -1; /* x step direction */ yy += sy; yy *= sy = y0 < y2 ? 1 : -1; /* y step direction */ xy = 2*xx*yy; xx *= xx; yy *= yy; /* differences 2nd degree */ if (cur*sx*sy < 0) { /* negated curvature? */ xx = -xx; yy = -yy; xy = -xy; cur = -cur; } dx = 4.0*sy*(x1-x0)*cur+xx-xy; /* differences 1st degree */ dy = 4.0*sx*(y0-y1)*cur+yy-xy; xx += xx; yy += yy; err = dx+dy+xy; /* error 1st step */ int dots = 0; do { cur = fmin(dx+xy,-xy-dy); ed = fmax(dx+xy,-xy-dy); /* approximate error distance */ ed += 2*ed*cur*cur/(4*ed*ed+cur*cur); if (!isDashed || (++dots % 3)) + { mixDot(hvg, x0,y0, 1-fabs(err-dx-dy-xy)/ed, color); /* plot curve */ + if (y0 > yMax) + yMax = y0; + } if (x0 == x2 || y0 == y2) break; /* last pixel -> curve finished */ x1 = x0; cur = dx-err; y1 = 2*err+dy < 0; if (2*err+dx > 0) { /* x step */ if (err-dy < ed) + { mixDot(hvg, x0,y0+sy, 1-fabs(err-dy)/ed, color); + if (y0 > yMax) + yMax = y0; + } x0 += sx; dx -= xy; err += dy += yy; } if (y1) { /* y step */ - if (cur < ed) mixDot(hvg, x1+sx,y0, 1-fabs(cur)/ed, color); + if (cur < ed) + { + mixDot(hvg, x1+sx,y0, 1-fabs(cur)/ed, color); + if (y0 > yMax) + yMax = y0; + } y0 += sy; dy -= xy; err += dx += xx; } } while (dy < dx); /* gradient negates -> close curves */ } hvGfxLine(hvg, x0,y0, x2,y2, color); /* plot remaining needle to end */ + if (y0 > yMax) + yMax = y0; + return yMax; } -void hvGfxCurve(struct hvGfx *hvg, int x0, int y0, int x1, int y1, int x2, int y2, +int hvGfxCurve(struct hvGfx *hvg, int x0, int y0, int x1, int y1, int x2, int y2, Color color, boolean isDashed) /* Draw a segment of an anti-aliased curve within 3 points (quadratic Bezier) - * Optionally alternate dots. - * Adapted trivially from code posted at http://members.chello.at/~easyfilter/bresenham.html */ + * Return max y value. Optionally alternate dots. + * Adapted trivially from code posted at http://members.chello.at/~easyfilter/bresenham.html + */ { int x = x0-x1, y = y0-y1; double t = x0-2*x1+x2, r; - + int yMax = 0, yMaxRet = 0; if ((long)x*(x2-x1) > 0) { /* horizontal cut at P4? */ if ((long)y*(y2-y1) > 0) /* vertical cut at P6 too? */ if (fabs((y0-2*y1+y2)/t*x) > abs(y)) { /* which first? */ x0 = x2; x2 = x+x1; y0 = y2; y2 = y+y1; /* swap points */ } /* now horizontal cut at P4 comes first */ t = (x0-x1)/t; r = (1-t)*((1-t)*y0+2.0*t*y1)+t*t*y2; /* By(t=P4) */ t = (x0*x2-x1*x1)*t/(x0-x1); /* gradient dP4/dx=0 */ x = floor(t+0.5); y = floor(r+0.5); r = (y1-y0)*(t-x0)/(x1-x0)+y0; /* intersect P3 | P0 P1 */ - hvGfxCurveSegAA(hvg,x0,y0, x,floor(r+0.5), x,y, color, isDashed); + yMax = hvGfxCurveSegAA(hvg,x0,y0, x,floor(r+0.5), x,y, color, isDashed); r = (y1-y2)*(t-x2)/(x1-x2)+y2; /* intersect P4 | P1 P2 */ x0 = x1 = x; y0 = y; y1 = floor(r+0.5); /* P0 = P4, P1 = P8 */ } if ((long)(y0-y1)*(y2-y1) > 0) { /* vertical cut at P6? */ t = y0-2*y1+y2; t = (y0-y1)/t; r = (1-t)*((1-t)*x0+2.0*t*x1)+t*t*x2; /* Bx(t=P6) */ t = (y0*y2-y1*y1)*t/(y0-y1); /* gradient dP6/dy=0 */ x = floor(r+0.5); y = floor(t+0.5); r = (x1-x0)*(t-y0)/(y1-y0)+x0; /* intersect P6 | P0 P1 */ - hvGfxCurveSegAA(hvg,x0,y0, floor(r+0.5),y, x,y, color, isDashed); + yMaxRet = hvGfxCurveSegAA(hvg,x0,y0, floor(r+0.5),y, x,y, color, isDashed); + if (yMaxRet > yMax) + yMax = yMaxRet; r = (x1-x2)*(t-y2)/(y1-y2)+x2; /* intersect P7 | P1 P2 */ x0 = x; x1 = floor(r+0.5); y0 = y1 = y; /* P0 = P6, P1 = P7 */ } - hvGfxCurveSegAA(hvg,x0,y0, x1,y1, x2,y2, color, isDashed); /* remaining part */ + yMaxRet = hvGfxCurveSegAA(hvg,x0,y0, x1,y1, x2,y2, color, isDashed); /* remaining part */ + if (yMaxRet > yMax) + yMax = yMaxRet; + return yMax; } void hvGfxEllipseDraw(struct hvGfx *hvg, int x0, int y0, int x1, int y1, Color color, int mode, boolean isDashed) /* Draw an ellipse (or limit to top or bottom) specified by rectangle, using Bresenham algorithm. * Optionally, alternate dots. * Point 0 is left, point 1 is top of rectangle * Adapted trivially from code posted at http://members.chello.at/~easyfilter/bresenham.html */ { int a = abs(x1-x0), b = abs(y1-y0), b1 = b&1; /* values of diameter */ long dx = 4*(1-a)*b*b, dy = 4*(b1+1)*a*a; /* error increment */ long err = dx+dy+b1*a*a, e2; /* error of 1.step */ if (x0 > x1) { x0 = x1; x1 += a; } /* if called with swapped points */