矩阵缩放/从点平移

一种简单的方法是创建一个屏幕外对象并将其变换原点居中。将缩放应用于该对象。

然后将矩阵变换从屏幕外元素复制到屏幕上元素，您应该有正确的比例。

以下是一些复制矩阵的图像原型：

HTMLImageElement.prototype.getMatrix = function() {
    var st = window.getComputedStyle(this, null);
    return st.getPropertyValue("-webkit-transform") ||
        st.getPropertyValue("-moz-transform") ||
        st.getPropertyValue("-ms-transform") ||
        st.getPropertyValue("-o-transform") ||
        st.getPropertyValue("transform") ||
        'none';
};
HTMLImageElement.prototype.setMatrix = function(matrix) {
    this.style.webkitTransform = 
    this.style.msTransform = 
    this.style.MozTransform = 
    this.style.OTransform = 
    this.style.transform = 
         matrix;
  return this;
};

getMatrix返回一个矩阵字符串。setMatrix取一个矩阵字符串。

targetImage.setMatrix(sourceImage.getMatrix())

was targetImage是显示的图像sourceImage是屏幕外图像

我得到了一个部分解。我认为它可以随心所欲，放大和缩小鼠标指定的点。不幸的是，如果你缩放，然后将鼠标移动到另一个点，然后再次缩放，它会跳来跳去。

var image_center = $("#image");
var base_image = $(".outer");
var dim = {};
var original_offset = image_center.offset();
function resetDim() {
  // Initialize image.dim with values
  dim.cont_width = base_image.width(); // Container width
  dim.cont_height = base_image.height(); // Container height
  dim.width = image_center.width(); // Element width
  dim.height = image_center.height(); // Element height
  dim.new_x = 0; // Initial/new x position
  dim.new_y = 0; // Initial/new y position
  dim.new_scale = 1; // Initial/new scale
  dim.max_scale = 3; // Max image scale
};
function transform() {
  var matrix = [dim.new_scale, 0, 0, dim.new_scale, dim.new_x, dim.new_y].join(",");
  image_center.css({
    "transform": "matrix(" + matrix + ") translate3d(0, 0, 0)",
    "-webkit-transform": "matrix(" + matrix + ") translate3d(0, 0, 0)",
    "-moz-transform": "matrix(" + matrix + ") translate3d(0, 0, 0)",
  });
}
$(document).ready(function() {
  resetDim();
  $('.outer').bind('mousewheel', function(ev) {
    // onScroll start
    // Determine pointer origin in relation to picture
    var originX = ev.originalEvent.pageX - original_offset.left;
    var originY = ev.originalEvent.pageY - original_offset.top;
    // onScroll ev
    dim.new_scale += (ev.originalEvent.deltaY > 0) ? -0.1 : 0.1;
    if (dim.new_scale > dim.max_scale) dim.new_scale = dim.max_scale;
    else if (dim.new_scale < 1) dim.new_scale = 1;
    // Translate based on origin
    dim.new_x = -(originX * (dim.new_scale-1) );
    dim.new_y = -(originY * (dim.new_scale-1) );
    transform();
  });
});

试试这个：https://jsfiddle.net/6c585qom/2/

当然，如果滚动过快，过渡不会跟上，但如果滚动缓慢，图像会锁定在鼠标上。

var image_center = $("#image");
var base_image = $(".outer");
var dim = {};
function resetDim() {
  // Initialize image.dim with values
  dim.cont_width = base_image.width(); // Container width
  dim.cont_height = base_image.height(); // Container height
  dim.width = image_center.width(); // Element width
  dim.height = image_center.height(); // Element height
  dim.left_edge = 0;
  dim.top_edge = 0; // Edge translation
  dim.init_x = 0;
  dim.new_x = 0; // Initial/new x position
  dim.init_y = 0;
  dim.new_y = 0; // Initial/new y position
  dim.init_scale = 1;
  dim.new_scale = 1; // Initial/new scale
  dim.max_scale = 3; // Max image scale
};
function transform() {
  var matrix = [dim.new_scale, 0, 0, dim.new_scale, dim.new_x, dim.new_y].join(",");
  image_center.css({
    "transform": "matrix(" + matrix + ") translate3d(0, 0, 0)",
    "-webkit-transform": "matrix(" + matrix + ") translate3d(0, 0, 0)",
    "-moz-transform": "matrix(" + matrix + ") translate3d(0, 0, 0)",
  });
}
$(document).ready(function() {
  resetDim();
  transform();
  $('.outer').bind('mousewheel', function(ev) {
    // onScroll start
    // Determine pointer origin in relation to picture
    var offset = image_center.offset();
    var originX = ev.originalEvent.pageX - offset.left;
    var originY = ev.originalEvent.pageY - offset.top;
    // Calculate current size of the image.
    var width = dim.width * dim.new_scale;
    var height = dim.height * dim.new_scale;
        // Calculate the relative position of the mouse independent of current scale.
    var mx = originX / width;
    var my = originY / height;
    // onScroll ev
    dim.new_scale += (ev.originalEvent.deltaY > 0) ? -0.1 : 0.1;
    if (dim.new_scale > dim.max_scale) dim.new_scale = dim.max_scale;
    else if (dim.new_scale < 1) dim.new_scale = 1;
    // Update new image position based upon new scale.
    var new_width = dim.width * dim.new_scale;
    var new_height = dim.height * dim.new_scale;
    var new_mouse_x = new_width * mx;
    var new_mouse_y = new_height * my;
    dim.new_x += originX - new_mouse_x;
    dim.new_y += originY - new_mouse_y;
    transform();
  });
});