Rescaling a range which max value includes a margin

[scooterlord]

Hello there, I've been struggling for some time to resolve an issue that seems to be a bug.

Using the following sample code:

var margin = {top: 20, right: 10, bottom: 20, left: 10};
var width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;
var x = d3.scale.linear()
    .range([0, width]);
var zoom = d3.zoom()
    .scaleExtent([1, 5])
    .translateExtent([[0, 0], [width, height]])
    .on("zoom", zoomed)
function zoomed() {
    (...)
    var xz = d3.event.transform.rescaleX(x);
    (...)
}

In the example above the rescaleX of the x scale also forces the margin included in the width variable to be proportionally scaled. As a result, when zooming in the margin is multiplied *k times (while it should stay the same) and as a result the far right side of the generated shape, eg line is not aligned to the right margin.

[mbostock]

You probably want to define a zoom.extent (related discussion #86) rather than relying on the default:

var zoom = d3.zoom()
    .scaleExtent([1, 5])
    .translateExtent([[0, 0], [width, height]])
    .extent([[0, 0], [width, height]])
    .on("zoom", zoomed);

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