I decided to use this plugin , but it uses image transformation on 4 points, and I need on 6.
This is how the transformation should go:
and so it happens now:
I changed the code in drag_points.html from the \PerspectiveTransform.js-master\examples folder (what I changed, marked it with a comment). fiddle (but for some reason it doesn't work on fidle )
<div id="container"><img class="backofthis" alt="qq" height="300"> <div class="img"></div> <div class="pt tl"></div> <div class="pt tr"></div> <div class="pt bl"></div> <div class="pt br"></div> <div class="pt bc"></div><!--i add this --> <div class="pt tc"></div><!--i add this --> </div> <script> var container = $("#container"); var img = $(".img"); var pts = $(".pt"); var IMG_WIDTH = 512; var IMG_HEIGHT = 512; var transform = new PerspectiveTransform(img[0], IMG_WIDTH, IMG_HEIGHT, true); var tl = pts.filter(".tl").css({ left : transform.topLeft.x, top : transform.topLeft.y }); var tr = pts.filter(".tr").css({ left : transform.topRight.x, top : transform.topRight.y }); var bl = pts.filter(".bl").css({ left : transform.bottomLeft.x, top : transform.bottomLeft.y }); var br = pts.filter(".br").css({ left : transform.bottomRight.x, top : transform.bottomRight.y }); var tc = pts.filter(".tc").css({ /*i add this*/ left : transform.topCenter.x, top : transform.topCenter.y }); var bc = pts.filter(".bc").css({ /*i add this*/ left : transform.bottomCenter.x, top : transform.bottomCenter.y }); var target; var targetPoint; function onMouseMove(e) { targetPoint.x = e.pageX - container.offset().left - 20; targetPoint.y = e.pageY - container.offset().top - 20; target.css({ left : targetPoint.x, top : targetPoint.y }); // check the polygon error, if it's 0, which mean there is no error if(transform.checkError()==0){ transform.update(); img.show(); }else{ img.hide(); } } pts.mousedown(function(e) { target = $(this); /*i change this*/ targetPoint = target.hasClass("tl") ? transform.topLeft : target.hasClass("tr") ? transform.topRight : target.hasClass("bl") ? transform.bottomLeft : target.hasClass("br") ? transform.bottomRight : target.hasClass("tc") ? transform.topCenter : transform.bottomCenter ;/*i change this*/ onMouseMove.apply(this, Array.prototype.slice.call(arguments)); $(window).mousemove(onMouseMove); $(window).mouseup(function() { $(window).unbind('mousemove', onMouseMove); }) }); </script> Modifying PerspectiveTransform.js
(function (define) { define(function(){ function PerspectiveTransform(element, width, height, useBackFacing){ this.element = element; this.style = element.style; this.computedStyle = window.getComputedStyle(element); this.width = width; this.height = height; this.useBackFacing = !!useBackFacing; this.topLeft = {x: 0, y: 0}; this.topRight = {x: width, y: 0}; this.bottomLeft = {x: 0, y: height}; this.bottomRight = {x: width, y: height}; this.topCenter = { x:width/2, y: 0};/*i add this*/ this.bottomCenter = { x: width/2, y: height };/*i add this*/ } PerspectiveTransform.useDPRFix = false; PerspectiveTransform.dpr = 1; PerspectiveTransform.prototype = (function(){ var app = { stylePrefix: '' }; var _transformStyleName; var _transformDomStyleName; var _transformOriginDomStyleName; var aM = [[0, 0, 1, 0, 0, 0, 0, 0], [0, 0, 1, 0, 0, 0, 0, 0], [0, 0, 1, 0, 0, 0, 0, 0], [0, 0, 1, 0, 0, 0, 0, 0], [0, 0, 0, 0, 0, 1, 0, 0], [0, 0, 0, 0, 0, 1, 0, 0], [0, 0, 0, 0, 0, 1, 0, 0], [0, 0, 0, 0, 0, 1, 0, 0]]; var bM = [0, 0, 0, 0, 0, 0, 0, 0]; function _setTransformStyleName(){ var testStyle = document.createElement('div').style; app.stylePrefix = 'webkitTransform' in testStyle ? 'webkit' : 'MozTransform' in testStyle ? 'Moz' : 'msTransform' in testStyle ? 'ms' : ''; _transformStyleName = app.stylePrefix + (app.stylePrefix.length>0?'Transform':'transform'); _transformOriginDomStyleName = '-'+app.stylePrefix.toLowerCase()+'-transform-origin'; } // Check the distances between each points and if there is some points with the distance lequal to or less than 1 pixel, then return true. Otherwise return false; function _hasDistancesError(){ var lenX = this.topLeft.x - this.topRight.x; var lenY = this.topLeft.y - this.topRight.y; if(Math.sqrt(lenX * lenX + lenY * lenY)<=1) return true; lenX = this.bottomLeft.x - this.bottomRight.x; lenY = this.bottomLeft.y - this.bottomRight.y; if(Math.sqrt(lenX * lenX + lenY * lenY)<=1) return true; lenX = this.topLeft.x - this.bottomLeft.x; lenY = this.topLeft.y - this.bottomLeft.y; if(Math.sqrt(lenX * lenX + lenY * lenY)<=1) return true; lenX = this.topRight.x - this.bottomRight.x; lenY = this.topRight.y - this.bottomRight.y; if( Math.sqrt(lenX * lenX + lenY * lenY)<=1) return true; lenX = this.topLeft.x - this.bottomRight.x; lenY = this.topLeft.y - this.bottomRight.y; if( Math.sqrt(lenX * lenX + lenY * lenY)<=1) return true; lenX = this.topRight.x - this.bottomLeft.x; lenY = this.topRight.y - this.bottomLeft.y; if( Math.sqrt(lenX * lenX + lenY * lenY)<=1) return true; return false; } // Get the determinant of given 3 points function _getDeterminant(p0, p1, p2){ return p0.x * p1.y + p1.x * p2.y + p2.x * p0.y - p0.y * p1.x - p1.y * p2.x - p2.y * p0.x; } // Return true if it is a concave polygon or if it is backfacing when the useBackFacing property is false. Otehrwise return true; function _hasPolyonError(){ var det1 = _getDeterminant(this.topLeft, this.topRight, this.bottomRight); var det2 = _getDeterminant(this.bottomRight, this.bottomLeft, this.topLeft); if(this.useBackFacing){ if(det1*det2<=0) return true; }else{ if(det1<=0||det2<=0) return true; } var det1 = _getDeterminant(this.topRight, this.bottomRight, this.bottomLeft); var det2 = _getDeterminant(this.bottomLeft, this.topLeft, this.topRight); if(this.useBackFacing){ if(det1*det2<=0) return true; }else{ if(det1<=0||det2<=0) return true; } return false; } function checkError(){ if(_hasDistancesError.apply(this)) return 1; // Points are too close to each other. if(_hasPolyonError.apply(this)) return 2; // Concave or backfacing if the useBackFacing property is false return 0; // no error } function update() { var width = this.width; var height = this.height; // get the offset from the transfrom origin of the element var offsetX = 0; var offsetY = 0; var offset = this.computedStyle.getPropertyValue(_transformOriginDomStyleName); if(offset.indexOf('px')>-1){ offset = offset.split('px'); offsetX = -parseFloat(offset[0]); offsetY = -parseFloat(offset[1]); }else if(offset.indexOf('%')>-1){ offset = offset.split('%'); offsetX = -parseFloat(offset[0]) * width / 100; offsetY = -parseFloat(offset[1]) * height / 100; } // magic here: var dst = [this.topLeft, this.topRight, this.bottomLeft, this.bottomRight, this.topCenter, this.bottomCenter];/*i add this*/ var arr = [0, 1, 2, 3, 4, 5, 6, 7]; for(var i = 0; i < 4; i++) { aM[i][0] = aM[i+4][3] = i & 1 ? width + offsetX : offsetX; aM[i][1] = aM[i+4][4] = (i > 1 ? height + offsetY : offsetY); aM[i][6] = (i & 1 ? -offsetX-width : -offsetX) * (dst[i].x + offsetX); aM[i][7] = (i > 1 ? -offsetY-height : -offsetY) * (dst[i].x + offsetX); aM[i+4][6] = (i & 1 ? -offsetX-width : -offsetX) * (dst[i].y + offsetY); aM[i+4][7] = (i > 1 ? -offsetY-height : -offsetY) * (dst[i].y + offsetY); bM[i] = (dst[i].x + offsetX); bM[i + 4] = (dst[i].y + offsetY); aM[i][2] = aM[i+4][5] = 1; aM[i][3] = aM[i][4] = aM[i][5] = aM[i+4][0] = aM[i+4][1] = aM[i+4][2] = 0; } var kmax, sum; var row; var col = []; var i, j, k, tmp; for(var j = 0; j < 8; j++) { for(var i = 0; i < 8; i++) col[i] = aM[i][j]; for(i = 0; i < 8; i++) { row = aM[i]; kmax = i<j?i:j; sum = 0.0; for(var k = 0; k < kmax; k++) sum += row[k] * col[k]; row[j] = col[i] -= sum; } var p = j; for(i = j + 1; i < 8; i++) { if(Math.abs(col[i]) > Math.abs(col[p])) p = i; } if(p != j) { for(k = 0; k < 8; k++) { tmp = aM[p][k]; aM[p][k] = aM[j][k]; aM[j][k] = tmp; } tmp = arr[p]; arr[p] = arr[j]; arr[j] = tmp; } if(aM[j][j] != 0.0) for(i = j + 1; i < 8; i++) aM[i][j] /= aM[j][j]; } for(i = 0; i < 8; i++) arr[i] = bM[arr[i]]; for(k = 0; k < 8; k++) { for(i = k + 1; i < 8; i++) arr[i] -= arr[k] * aM[i][k]; } for(k = 7; k > -1; k--) { arr[k] /= aM[k][k]; for(i = 0; i < k; i++) arr[i] -= arr[k] * aM[i][k]; } var style = 'matrix3d(' + arr[0].toFixed(9) + ',' + arr[3].toFixed(9) + ', 0,' + arr[6].toFixed(9) + ',' + arr[1].toFixed(9) + ',' + arr[4].toFixed(9) + ', 0,' + arr[7].toFixed(9) + ',0, 0, 1, 0,' + arr[2].toFixed(9) + ',' + arr[5].toFixed(9) + ', 0, 1)'; //A fix for firefox on retina display, require setting PerspectiveTransform.useDPRFix to true and update the PerspectiveTransform.dpr with the window.devicePixelRatio if(PerspectiveTransform.useDPRFix) { var dpr = PerspectiveTransform.dpr; style = 'scale(' + dpr + ',' + dpr + ')perspective(1000px)' + style + 'translateZ('+ ((1 - dpr) * 1000) + 'px)'; } // use toFixed() just in case the Number became something like 3.10000001234e-9 return this.style[_transformStyleName] = style; } _setTransformStyleName(); app.update = update; app.checkError = checkError; return app; })(); return PerspectiveTransform; }); }(typeof define === "function" && define.amd ? define : function (app) { window["PerspectiveTransform"] = app(); })); What do I need to change in this function? After all, as I understood that I did all the work in vain, if I did not change this function, but I do not understand what I need to change here?
var dst = [this.topLeft, this.topRight, this.bottomLeft, this.bottomRight, this.topCenter, this.bottomCenter];/*i add this*/ var arr = [0, 1, 2, 3, 4, 5, 6, 7]; for(var i = 0; i < 4; i++) { aM[i][0] = aM[i+4][3] = i & 1 ? width + offsetX : offsetX; aM[i][1] = aM[i+4][4] = (i > 1 ? height + offsetY : offsetY); aM[i][6] = (i & 1 ? -offsetX-width : -offsetX) * (dst[i].x + offsetX); aM[i][7] = (i > 1 ? -offsetY-height : -offsetY) * (dst[i].x + offsetX); aM[i+4][6] = (i & 1 ? -offsetX-width : -offsetX) * (dst[i].y + offsetY); aM[i+4][7] = (i > 1 ? -offsetY-height : -offsetY) * (dst[i].y + offsetY); bM[i] = (dst[i].x + offsetX); bM[i + 4] = (dst[i].y + offsetY); aM[i][2] = aM[i+4][5] = 1; aM[i][3] = aM[i][4] = aM[i][5] = aM[i+4][0] = aM[i+4][1] = aM[i+4][2] = 0; } UPDATE 
