Function zoomMove

src/plots/ternary/ternary.js:627–671

(dx0, dy0)

    function getCFrac(x, y) { return ((x - (_this.h - y) / Math.sqrt(3)) / _this.w); }

    function zoomMove(dx0, dy0) {
        var x1 = x0 + dx0 * scaleX;
        var y1 = y0 + dy0 * scaleY;
        var afrac = Math.max(0, Math.min(1, getAFrac(x0, y0), getAFrac(x1, y1)));
        var bfrac = Math.max(0, Math.min(1, getBFrac(x0, y0), getBFrac(x1, y1)));
        var cfrac = Math.max(0, Math.min(1, getCFrac(x0, y0), getCFrac(x1, y1)));
        var xLeft = ((afrac / 2) + cfrac) * _this.w;
        var xRight = (1 - (afrac / 2) - bfrac) * _this.w;
        var xCenter = (xLeft + xRight) / 2;
        var xSpan = xRight - xLeft;
        var yBottom = (1 - afrac) * _this.h;
        var yTop = yBottom - xSpan / whRatio;

        if(xSpan < constants.MINZOOM) {
            mins = mins0;
            zb.attr('d', path0);
            corners.attr('d', 'M0,0Z');
        } else {
            mins = {
                a: mins0.a + afrac * span0,
                b: mins0.b + bfrac * span0,
                c: mins0.c + cfrac * span0
            };
            zb.attr('d', path0 + 'M' + xLeft + ',' + yBottom +
                'H' + xRight + 'L' + xCenter + ',' + yTop +
                'L' + xLeft + ',' + yBottom + 'Z');
            corners.attr('d', 'M' + x0 + ',' + y0 + STARTMARKER +
                'M' + xLeft + ',' + yBottom + BLPATH +
                'M' + xRight + ',' + yBottom + BRPATH +
                'M' + xCenter + ',' + yTop + TOPPATH);
        }

        if(!dimmed) {
            zb.transition()
                .style('fill', lum > 0.2 ? 'rgba(0,0,0,0.4)' :
                    'rgba(255,255,255,0.3)')
                .duration(200);
            corners.transition()
                .style('opacity', 1)
                .duration(200);
            dimmed = true;
        }

        gd.emit('plotly_relayouting', makeUpdate(mins));
    }

    function zoomDone() {
        removeZoombox(gd);