Computer_Graphics/lab_02_2.html at master · capsidimit/Computer_Graphics · GitHub

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
<html>
    <body>
        <canvas width="500" , height="500" , id="layer_1"> </canvas>
        <canvas width="500" , height="500" , id="layer_2"> </canvas>

        <script>
            var canvas = document.getElementById("layer_1");
            var ctx = canvas.getContext("2d");

            var canvas2 = document.getElementById("layer_2");
            var ctx2 = canvas2.getContext("2d");

            let img_data = new ImageData(canvas.width,canvas.height)

            let _average = 0;

            function randomInteger(min, max) {
            // получить случайное число от (min-0.5) до (max+0.5)
            let rand = min - 0.5 + Math.random() * (max - min + 1);
            return Math.round(rand);
            }

            for (var index = 0; index < img_data.data.length; index += 4)
                {
                    _average = img_data.data[index] + img_data.data[index+1] + img_data.data[index+2];

                    img_data.data[index] = randomInteger(0, 255);
                    img_data.data[index + 1] = randomInteger(0, 255);
                    img_data.data[index + 2] = randomInteger(0, 255);
                    img_data.data[index + 3] = 255;
                }
            ctx.putImageData(img_data, 0, 0, 0, 0, canvas.width, canvas.height);
            for (var index = 0; index < img_data.data.length; index += 4)
                {
                    _average = (img_data.data[index] + img_data.data[index+1] + img_data.data[index+2])/3;

                    img_data.data[index] = _average;
                    img_data.data[index + 1] = _average;
                    img_data.data[index + 2] = _average;
                    img_data.data[index + 3] = 255;
                }
            ctx2.putImageData(img_data, 0, 0, 0, 0, canvas2.width, canvas2.height);
        </script>
    </body>
</html>