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Added JavaScript support for drawing directly to <canvas> tags. #9

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Added JavaScript support for drawing directly to <canvas> tags. #9

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42 changes: 42 additions & 0 deletions js/qrcode.js
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Original file line number Diff line number Diff line change
Expand Up @@ -464,9 +464,30 @@ var qrcode = function() {
} );
};

_this.drawOnCanvas = function(canvas, cellSize, margin) {

cellSize = cellSize || 2;
margin = (typeof margin == 'undefined')? cellSize * 4 : margin;

var size = _this.getModuleCount() * cellSize + margin * 2;
var min = margin;
var max = size - margin;

drawOnCanvas(canvas, size, size, function(x, y) {
if (min <= x && x < max && min <= y && y < max) {
var c = Math.floor( (x - min) / cellSize);
var r = Math.floor( (y - min) / cellSize);
return _this.isDark(r, c)? 0 : 1;
} else {
return 1;
}
} );
};

return _this;
};


//---------------------------------------------------------------------
// qrcode.stringToBytes
//---------------------------------------------------------------------
Expand Down Expand Up @@ -1627,6 +1648,27 @@ var qrcode = function() {
return img;
};

var drawOnCanvas = function(canvas, width, height, getPixel) {
// Set the canvas size
canvas.width = width;
canvas.height = height;
// Get a drawing context
var ctx = canvas.getContext("2d");
// Fill the background with black
ctx.fillStyle = "#000";
ctx.fillRect(0,0,width,height);
// Draw the white pixels
ctx.fillStyle = "#fff";
for(var x = 0; x < width; x++)
{
for(var y = 0; y < height; y++)
{
if(getPixel(x,y))
ctx.fillRect(x,y,1,1);
}
}
};

//---------------------------------------------------------------------
// returns qrcode function.

Expand Down