1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
| <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=<device-width>, initial-scale=1.0">
<title>Document</title>
<style>
body {
margin: 0;
padding: 0;
}
#container {
margin: 20px auto;
display: flex;
border: 2px solid rgb(255, 4, 4);
}
#zoneimg {
width: 200px;
height: 200px;
border: 1px solid #fdfdfd;
position: absolute;
display: flex;
align-items: center;
justify-content: center;
}
</style>
</head>
<body>
<div id="container">
<canvas id="principal-Img"></canvas>
<canvas id="zoneimg"></canvas>
</div>
<script>
var container = document.getElementById('container'),
canvasImg = document.getElementById('principal-Img'), zoom = [1, 1], convasPrincipal;
//Chargement et redimensionnement de l'image
var img = new Image();
img.src = 'https://unsplash.it/800?random';
var maxWidth = 1000;
var maxHeight = 800;
if (img.width > img.height) {
if (img.width > maxWidth) {
img.height *= maxWidth / img.width;
img.width = maxWidth;
}
} else {
if (img.height > maxHeight) {
img.width *= maxHeight / img.height;
img.height = maxHeight;
}
}
img.onload = function () {
imagePrincipale(img);
};
function zoneselction() {
let ttop, lleft, c;
c = {
top: event.clientY + (zoneimg.clientHeight / 2),
left: event.clientX + (zoneimg.clientWidth / 2),
minLeft: canvasImg.offsetLeft + (zoneimg.offsetWidth),
minTop: canvasImg.offsetTop + (zoneimg.offsetHeight),
maxLeft: canvasImg.offsetWidth + canvasImg.offsetLeft,
maxTop: canvasImg.offsetHeight + canvasImg.offsetTop,
}
c.left = c.left < c.minLeft ? c.minLeft : c.left > c.maxLeft ? c.maxLeft : c.left;
c.top = c.top < c.minTop ? c.minTop : c.top > c.maxTop ? c.maxTop : c.top;
zoneimg.style.top = `${c.top - (zoneimg.offsetHeight)}px`;
zoneimg.style.left = `${c.left - (zoneimg.offsetWidth)}px`;
lleft = (c.left - (zoneimg.offsetWidth)) - (convasPrincipal.offsetLeft) + 1;
ttop = (c.top - (zoneimg.offsetHeight)) - (convasPrincipal.offsetTop) + 1;
cloneCanvas(convasPrincipal, lleft, ttop, 200, 200, zoom[0], zoom[1])
}
container.onmousemove = function (event) { zoneselction() }
container.onwheel = function (event) {
event.preventDefault();
if ((zoom[0] + Math.sign(event.deltaY)) >= 1) {
if (zoom[0] < 15) {
zoom[0] += Math.sign(event.deltaY);
} else {
zoom[0] -= 1;
}
zoom[1] = zoom[0];
zoneselction()
}
}
function imagePrincipale(image) {
convasPrincipal = document.getElementById('principal-Img');
let width = image.width, height = image.height, ctx;
convasPrincipal.width = width;
convasPrincipal.height = height;
convasPrincipal.style.position = "absolute";
container.style.width = width + "px";
container.style.height = height + "px";
container.style.maxHeight = height + "px";
ctx = convasPrincipal.getContext('2d');
ctx.drawImage(image, 0, 0, width, height);
cloneCanvas(convasPrincipal, 1, 1, 200, 200, 1, 1);
}
function cloneCanvas(oldCanvas, x, y, widtH, heighT, a, b) {
let newCanvas = document.getElementById('zoneimg'), context, xOffset = x, yOffset = y, wp, hp;
newCanvas.width = widtH;
newCanvas.height = heighT;
context = newCanvas.getContext('2d');
context.scale(a, b); //zoom
wp = Math.pow(widtH, 2)
hp = Math.pow(heighT, 2)
if (zoom[0] > 1) {
xOffset = (x + (wp / 1000)), yOffset = (y + (hp / 1000));
}
context.drawImage(oldCanvas, xOffset, yOffset, newCanvas.width, newCanvas.height, 0, 0, newCanvas.width, newCanvas.height);
zoneimg = document.getElementById('zoneimg')
}
</script>
</body>
</html> |
