How to render Processing.org images on Java servlet?
My scala code is:
class Image extends PApplet {
override def setup {
size(200,200)
background(0)
}
override def draw {
stroke(255)
line(10,10,50,50)
}
def renderImage = g.getImage
}
class ImageServlet extends HttpServlet {
override def doGet(request: HttpServletRequest, response: HttpServletResponse) {
response.setContentType("image/gif")
val os: OutputStream = response.getOutputStream
val image = new Image
javax.imageio.ImageIO.write(image.renderImage.asInstanceOf[RenderedImage],"GIF86", os);
}
}
I've just posted some example code here, which sounds like it would solve your problem too, take a look. It's Java, not Scala, but the conversion should be trivial.
Applets are usually executed client-side (i.e. inside a browser). If you simply call new Image the plumbing around it, for example calling setup() won't be executed.
Perhaps try some of the lower level Processing.org API classes. I don't know the API but PGraphics or one of its subclasses look promising.
You can get processing to render from a servlet but unless you have a monitor plugged into your server you will get "headless" exceptions. Checkout ServletUtils from Fluid Forms Libs.
If your server doesn't have a screen plugged in you can still instantiate any of Processings PGraphics classes. PApplet, the base class for processing applets, basically passes all drawing API, calls such as rect(), onto a PGraphics class.
