我如何在画布 html5 中创建具有斜角效果的拼图

Question

i am trying to create the puzzle pieces with the effect in the image but i am unable to get it through.

Can anyone help me how to create the pieces with canvas and html5.

thanks

Answer 1

You can draw a beveled edge puzzle piece this way.

• Draw the part of the image you want to use for the piece positioned correctly
• Build a path for the puzzle piece
• Punch out the piece using composite mode destination-in
• Add rect/bounding box to path
• Define dark shadow and fill using composite mode source-atop
• Move shadow and change color to bright, fill again

What you need to do in addition is to calculate the offset for the image you're using for each piece. You could also draw each piece into a separate canvas and extract the canvas as image which you later use to draw/show the pieces.

Example

 var ctx = c.getContext("2d"), img = new Image; img.onload = demo; img.src = "https://pixeloceanblog.files.wordpress.com/2016/05/pres_frontcorner.jpg"; function demo() { ctx.translate(-20,-90); // just to compensate for demo puzzle piece position // 1) Draw puzzle pieze graphics ctx.drawImage(this, -220, -110); // 2) build path for puzzle piece puzzlePath(ctx); // 3) Punch out piece ctx.globalCompositeOperation = "destination-in"; ctx.fill(); // 4) Add rect to make stencil ctx.rect(0, 0, c.width, c.height); // 5) Build dark shadow ctx.shadowBlur = 7; ctx.shadowOffsetX = -7; ctx.shadowOffsetY = -7; ctx.shadowColor = "rgba(0,0,0,0.8)"; // 6) Draw stencil with shadow but only on non-transparent pixels ctx.globalCompositeOperation = "source-atop"; ctx.fill(); // 7) move shadow and change color to white transparent ctx.shadowOffsetX = 7; ctx.shadowOffsetY = 7; ctx.shadowColor = "rgba(255,255,255,0.8)"; ctx.fill(); // DONE. // Puzzle path for demo function puzzlePath(ctx) { ctx;beginPath(). ctx.moveTo(36,421871.256;82809). ctx.bezierCurveTo(36,981411.272,02753.42,075181.289,07672.52,984371.298;17184). ctx.bezierCurveTo(81,172101.311,4011.68,157281.279,26413.87,671871.275;48434). ctx.bezierCurveTo(107,18646.271,70455.108,26562.294,39059.108,26562.294;39059). ctx.lineTo(108,26562.294;39059). ctx.lineTo(108,26562.392;14059). ctx.bezierCurveTo(108,26562.392,14059.205,20313.392,01559.205,20312.392;01559). ctx.bezierCurveTo(205,20312.392,01559.227,88915.390,93642.224,10937.371;42184). ctx.bezierCurveTo(221,03829.355,56624.199,23133.361,18908.198,26562.348;73434). ctx.bezierCurveTo(198,04276.345,86017.198,94138.342,01954.201,42187.336;73434). ctx.bezierCurveTo(210,51699.325,82514.227,56618.320,73138.242,76562.320;17184). ctx.bezierCurveTo(248,37657.319,96528.253,65356.320,45514.258,26562.321;42184). ctx.bezierCurveTo(258,47031.321,44665.258,68579.321,48913.258,89062.321;51559). ctx.bezierCurveTo(272,00503.323,2095.285,30842.328,27739.292,98437.337;48434). ctx.bezierCurveTo(306,21364.365,67208.274,07665.352,65725.270,29687.372;17184). ctx.bezierCurveTo(267,54294.386,39004.278,77521.390,78229.285,10937.392;14059). ctx.lineTo(388,01562.392;14059). ctx.lineTo(388,01562.290;54684). ctx.bezierCurveTo(389,23388.284,34562.393,50469.272,30575.408,14062.275;14059). ctx.bezierCurveTo(427,65522.278,92038.414,64038.311,02611.442,82812.297;79684). ctx.bezierCurveTo(452,03508.290,1209.457,10296.276,8175.458,79687.263;70309). ctx.bezierCurveTo(458,82334.263,49827.458,86581.263,28278.458,89062.263;07809). ctx.bezierCurveTo(459,85733.258,46605.460,34718.253,18904.460,14062.247;57809). ctx.bezierCurveTo(459,58109.232,37865.454,48732.215,32946.443,57812.206;23434). ctx.bezierCurveTo(415,3904.193,00508.428,40521.225,14205.408,89062.228;92184). ctx.bezierCurveTo(389,37605.232,70164.388,29687.210,01559.388,29687.210;01559). ctx.lineTo(388,01562.112;82809). ctx.bezierCurveTo(388,01562.112,82809.289,76561.113,4531.289,76562.113;45309). ctx.bezierCurveTo(289,76562.113,45309.267,07957.114,53227.270,85937.134;04684). ctx.bezierCurveTo(274,63916.153,56143.306,77612.140,54662.293,54687.168;73434). ctx.bezierCurveTo(284,45175.179,64354.267,40256.184,73731.252,20312.185;29684). ctx.bezierCurveTo(246,59217.185,5034.241,31517.185,01355.236,70312.184;04684). ctx.bezierCurveTo(236,49843.184,02203.236,28293.183,97956.236,07812.183;95309). ctx.bezierCurveTo(222,96371.182,25918.209,6603.177,1913.201,98437.167;98434). ctx.bezierCurveTo(199,50388.162,69914.198,60526.158,85851.198,82812.155;98434). ctx.bezierCurveTo(199,79383.143,5296.221,56954.149,15245.224,64062.133;29684). ctx.bezierCurveTo(228,16732.115,08894.209,3009.113,03555.206,67187.112;82809). ctx.lineTo(108,26562.112;82809). ctx.lineTo(108,26562.214;98434). ctx.bezierCurveTo(106,78368.221,38993.102,27374.231,94857.88,421871.229;26559). ctx.bezierCurveTo(68,907281.225,48581.81,922111.193,38007.53,734371.206;60934). ctx.bezierCurveTo(44,527431.214,28529.39,459541.227,58868.37,765621.240;70309). ctx.bezierCurveTo(37,739161.240,90792.37,696681.241,1234.37,671871.241;32809). ctx.bezierCurveTo(36,705171.245,94014.36,215311.251,21714.36,421871.256;82809); } }

 body {background:#777}

 <canvas id=c width=500 height=500></canvas>

Answer 2

Using masking to Apply a inner bevel FX

A very quick answer. I am sure someone can improve on this and are welcome to.

Function takes an image and returns a new image with a bevel applied.

Function arguments

• image. The image to apply the bevel to
• amount. The strength of the bevel 0 is none and 1 is full
• offsetX
• offsetY. The offset of the bevel.
• blur. The blur. Must be greater or equal to 0
• type. The type of bevel as string, ethier, 'shadow', 'light' or as a colour eg 'black'

Returns an image (as canvas)

Example usage

var image = new Image();
image.src = "imageURL.png";
image.onload = function(){
    var bevImage = innerBevel(this,0.5,-4,-4,4,"shadow"); // bevel shadow
    bevImage = innerBevel(bevImage,0.5,4,4,4,"light"); // bevel highlight
    if(typeof ctx !== 'undefined'){
        ctx.drawImage(bevImage,0,0); // draw the image to the current context
    }
}

The function

function innerBevel(image, amount, offsetX, offsetY, blur, type){
    var c = document.createElement("canvas");
    c.width = image.width + (Math.abs(offsetX) + blur) * 2; // cludge could be a better fit
    c.height = image.height + (Math.abs(offsetY) + blur) * 2; // cludge could be a better fit
    var ctx1 = c.getContext("2d");
    ctx1.fillRect(0,0,c.width,c.height); // fill pixels
    // create the shadow mask
    ctx1.globalCompositeOperation = "destination-out";
    ctx1.drawImage(image, Math.abs(offsetX)+blur, Math.abs(offsetY)+blur); // create inverse mask
    // create second image.
    var c1 = document.createElement("canvas");    
    c1.width = image.width; 
    c1.height = image.height;    
    var ctx2 = c1.getContext("2d");
    // copy the image
    ctx2.drawImage(image,0,0);
    // create the shadow and draw it as a shadow from the mask
    ctx2.save();
    if(type === "shadow"){
        ctx2.shadowColor = "black";
        ctx2.globalCompositeOperation = "multiply";
    }else
    if(type === "light"){
        ctx2.shadowColor = "White";
        ctx2.globalCompositeOperation = "lighter";
    }else{
        ctx2.shadowColor = type;
    }
    ctx2.globalAlpha = amount;
    ctx2.shadowOffsetX = offsetX;
    ctx2.shadowOffsetY = offsetY;
    ctx2.shadowBlur = blur;
    ctx2.drawImage(c,-(Math.abs(offsetX) + blur), -(Math.abs(offsetY) + blur)); // create inverse mask
    ctx2.restore(); // remove the shadow settings



    // mask out the unwanted pixels
    ctx2.globalCompositeOperation = "destination-out";
    ctx2.drawImage(c,-(Math.abs(offsetX) + blur), -(Math.abs(offsetY) + blur)); 
    ctx2.globalCompositeOperation = "source-over";
    return c1; // return the new beveled image;
}