c22e9170ef4e25c0eb5cd75c8988537d1a27aabe
kate
  Wed Jan 17 16:22:42 2018 -0800
Removing antialiased ellipse code -- too buggy. refs #17512

diff --git src/hg/lib/hvGfx.c src/hg/lib/hvGfx.c
index 1ac59e9..a52ab67 100644
--- src/hg/lib/hvGfx.c
+++ src/hg/lib/hvGfx.c
@@ -333,115 +333,30 @@
       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);
       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);                  /* remaining part */
 }
 
-void hvGfxEllipseDrawAA(struct hvGfx *hvg, int x0, int y0, int x1, int y1, Color color, int mode)
-// TODO: Tame anti-aliasing with Braney help, or drop
-/* Draw an anti-aliased ellipse or half (top or bottom) using Bresenham algorithm.
- * Point 0 is left, point 1 is top of rectangle
- * Adapted trivially from code posted at http://members.chello.at/~easyfilter/bresenham.html
- */
-{
-   long a = abs(x1-x0), b = abs(y1-y0), b1 = b&1;                 /* diameter */
-   float dx = 4*(a-1.0)*b*b, dy = 4*(b1+1)*a*a;            /* error increment */
-   float ed, i, err = b1*a*a-dx+dy;                        /* error of 1.step */
-   bool f;
-
-   if (a == 0 || b == 0) return hvGfxLine(hvg, x0, y0, x1, y1, color);
-   if (x0 > x1) { x0 = x1; x1 += a; }        /* if called with swapped points */
-   if (y0 > y1) y0 = y1;                                  /* .. exchange them */
-   y0 += (b+1)/2; y1 = y0-b1;                               /* starting pixel */
-   a = 8*a*a; b1 = 8*b*b;
-
-   // FIXME: end condition not triggered on this loop
-   //for (;;) {                             /* approximate ed=sqrt(dx*dx+dy*dy) */
-   int q = 0;
-   for (q=0; q<10000; q++) {                             /* approximate ed=sqrt(dx*dx+dy*dy) */
-   //
-      i = min(dx,dy); ed = max(dx,dy);
-      if (y0 == y1+1 && err > dy && a > b1) ed = 255*4./a;           /* x-tip */
-      else ed = 255/(ed+2*ed*i*i/(4*ed*ed+i*i));             /* approximation */
-      i = ed*fabs(err+dx-dy);           /* get intensity value by pixel error */
-      if (mode == ELLIPSE_BOTTOM || mode == ELLIPSE_FULL) {
-          mixDot(hvg, x0,y0, i, color); 
-          mixDot(hvg, x1,y0, i, color); 
-      }
-      if (mode == ELLIPSE_TOP || mode == ELLIPSE_FULL) {
-          mixDot(hvg, x0,y1, i, color);
-          mixDot(hvg, x1,y1, i, color);
-      }
-
-      //mixDot(hvg, x0,y0, 1-fabs(err-dx-dy-xy)/ed, color);          /* plot curve */
-
-      if ((f = 2*err+dy) >= 0) {                  /* x step, remember condition */
-         if (x0 >= x1) break;
-         i = ed*(err+dx);
-         if (i < 255) {
-             if (mode == ELLIPSE_BOTTOM || mode == ELLIPSE_FULL) {
-                 mixDot(hvg, x0,y0+1, i, color); 
-                 mixDot(hvg, x1,y0+1, i, color); 
-             }
-             if (mode == ELLIPSE_TOP || mode == ELLIPSE_FULL) {
-                 mixDot(hvg, x0,y1-1, i, color);
-                 mixDot(hvg, x1,y1-1, i, color);
-             }
-         }          /* do error increment later since values are still needed */
-      }
-      if ((2*err) <= dx) {                                            /* y step */
-         i = ed*(dy-err);
-         if (i < 255) {
-             if (mode == ELLIPSE_BOTTOM || mode == ELLIPSE_FULL) {
-                 mixDot(hvg, x0+1,y0, i, color); 
-                 mixDot(hvg, x1-1,y0, i, color); 
-             }
-             if (mode == ELLIPSE_TOP || mode == ELLIPSE_FULL) {
-                 mixDot(hvg, x0+1,y1, i, color);
-                 mixDot(hvg, x1-1,y1, i, color);
-             }
-         }
-         y0++; y1--; err += dy += a;
-      }
-      if (f) { x0++; x1--; err -= dx -= b1; }            /* x error increment */
-   }
-   if (--x0 == x1++)                       /* too early stop of flat ellipses */
-      while (y0-y1 < b) {
-         i = 255*4*fabs(err+dx)/b1;               /* -> finish tip of ellipse */
-         if (mode == ELLIPSE_BOTTOM || mode == ELLIPSE_FULL) {
-             mixDot(hvg, x0,y0+1, i, color); 
-             mixDot(hvg, x1,y0+1, i, color); 
-         }
-         if (mode == ELLIPSE_TOP || mode == ELLIPSE_FULL) {
-             mixDot(hvg, x0,y1-1, i, color);
-             mixDot(hvg, x1,y1-1, i, color);
-         }
-         y0++; y1--;
-         err += dy += a;
-      }
-}
-
-
 void hvGfxEllipseDraw(struct hvGfx *hvg, int x0, int y0, int x1, int y1, Color color, int mode)
 /* Draw an ellipse (or limit to top or bottom) specified by rectangle, using Bresenham algorithm.
  * 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 */
    if (y0 > y1) y0 = y1; /* .. exchange them */
    y0 += (b+1)/2; y1 = y0-b1;   /* starting pixel */
    a *= 8*a; b1 = 8*b*b;