93fe466f71fc1e40c33e27f311f846d26028cb26 kate Thu Jan 11 18:18:16 2018 -0800 Abandon unaliased bezier curve after Braney fixed aliased version. Checked timing on aliased and it was speedy, so ono reason to keep ugly drawer. refs #17512 diff --git src/hg/lib/hvGfx.c src/hg/lib/hvGfx.c index e710428..392e1d2 100644 --- src/hg/lib/hvGfx.c +++ src/hg/lib/hvGfx.c @@ -253,33 +253,30 @@ struct memPng *png = (struct memPng *)hvg->vg->data; struct memGfx *img = (struct memGfx *)png; if ((x < img->clipMinX) || (x > img->clipMaxX) || (y < img->clipMinY) || (y > img->clipMaxY)) return; Color *pt = _mgPixAdr(img,x,y); float invFrac = 1 - frac; int r = COLOR_32_RED(*pt) * invFrac + COLOR_32_RED(col) * frac; int g = COLOR_32_GREEN(*pt) * invFrac + COLOR_32_GREEN(col) * frac; int b = COLOR_32_BLUE(*pt) * invFrac + COLOR_32_BLUE(col) * frac; hvGfxDot(hvg, x, y, MAKECOLOR_32(r,g,b)); hvGfxDot(hvg, x, y, MAKECOLOR_32(r,g,b)); } -#define fraction(X) (((double)(X))-(double)(int)(X)) -#define invFraction(X) (1.0-fraction(X)) - void hvGfxCurveSeg(struct hvGfx *hvg, int x0, int y0, int x1, int y1, int x2, int y2, Color color) /* Draw a segment of a curve within 3 points (quadratic Bezier) * 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 sx = x2-x1, sy = y2-y1; long xx = x0-x1, yy = y0-y1, xy; /* relative values for checks */ double dx, dy, err, 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 */ } @@ -338,31 +335,31 @@ 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); x0 += sx; dx -= xy; err += dy += yy; } if (y1) { /* y step */ if (cur < ed) mixDot(hvg, x1+sx,y0, 1-fabs(cur)/ed, color); 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 */ } -void hvGfxCurveAA(struct hvGfx *hvg, int x0, int y0, int x1, int y1, int x2, int y2, Color color) +void hvGfxCurve(struct hvGfx *hvg, int x0, int y0, int x1, int y1, int x2, int y2, Color color) /* Draw a segment of an anti-aliased curve within 3 points (quadratic Bezier) * 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; 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); @@ -372,92 +369,61 @@ 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 hvGfxCurve(struct hvGfx *hvg, int x0, int y0, int x1, int y1, int x2, int y2, Color color) -/* Draw a segment of an anti-aliased curve within 3 points (quadratic Bezier) - * 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; - - 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 */ - hvGfxCurveSeg(hvg,x0,y0, x,floor(r+0.5), x,y, color); - 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 */ - hvGfxCurveSeg(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 */ - } - hvGfxCurveSeg(hvg,x0,y0, x1,y1, x2,y2, color); /* remaining part */ -} - -#ifdef INFINITE +#ifdef PROBLEM +// TODO: Tame anti-aliasing with Braney help, or drop void hvGfxEllipseAA(struct hvGfx *hvg, int x0, int y0, int x1, int y1, Color color) /* Draw an anti-aliased ellipse 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 */ { 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; int q = 0; for (q=0; q<1000; q++) { /* approximate ed=sqrt(dx*dx+dy*dy) */ //for (;;) { /* 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 */ mixDot(hvg, x0,y0, i, color); mixDot(hvg, x0,y1, i, color); mixDot(hvg, x1,y0, 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) { mixDot(hvg, x0,y0+1, i, color); mixDot(hvg, x0,y1-1, i, color); mixDot(hvg, x1,y0+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) { mixDot(hvg, x0+1,y0, i, color); mixDot(hvg, x1-1,y0, i, color); mixDot(hvg, x0+1,y1, i, color); mixDot(hvg, x1-1,y1, i, color); } y0++; y1--; err += dy += a;