mirror of https://github.com/vitalif/phantomjs
46 lines
1.4 KiB
CoffeeScript
46 lines
1.4 KiB
CoffeeScript
if phantom.state.length is 0
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phantom.state = 1
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phantom.viewportSize = { width: 400, height : 400 }
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phantom.content = '<html><body><canvas id="surface">' +
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'</canvas></body></html>'
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else
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el = document.getElementById 'surface'
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context = el.getContext '2d'
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width = window.innerWidth
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height = window.innerHeight
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cx = width / 2
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cy = height / 2
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radius = width / 2.3
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i = 0
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el.width = width
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el.height = height
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imageData = context.createImageData(width, height)
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pixels = imageData.data
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for y in [0...height]
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for x in [0...width]
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i = i + 4
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rx = x - cx
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ry = y - cy
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d = rx * rx + ry * ry
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if d < radius * radius
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hue = 6 * (Math.atan2(ry, rx) + Math.PI) / (2 * Math.PI)
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sat = Math.sqrt(d) / radius
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g = Math.floor(hue)
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f = hue - g
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u = 255 * (1 - sat)
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v = 255 * (1 - sat * f)
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w = 255 * (1 - sat * (1 - f))
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pixels[i] = [255, v, u, u, w, 255, 255][g]
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pixels[i + 1] = [w, 255, 255, v, u, u, w][g]
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pixels[i + 2] = [u, u, w, 255, 255, v, u][g]
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pixels[i + 3] = 255
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context.putImageData imageData, 0, 0
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document.body.style.backgroundColor = 'white'
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document.body.style.margin = '0px'
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phantom.render 'colorwheel.png'
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phantom.exit()
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