mf_vp

A view port manager

This project has regressed into a very primitive version of a view port manager. I now have a more advanced project called mf_vp_zoom that is a more involved alternative of this.

Where a view port manager starts

As of this writing the code of the view port manager is just simply this:

var vp = {

    w : 320, // current width and height
    h : 240,

    x : -160, // upper left corner of the view port
    y : -120,

    // just make a map relative object view port relative
    mkVPRel : function (obj) {

        return {

            x : obj.x - this.x,
            y : obj.y - this.y,
            w : obj.w,
            h : obj.h

        };

    }

};

At a minimum a view port manager should just simply contain the current state of the view port. The means of converting a map relative position to a view port relative position is simple enough, but for starters I just have one method that helps with that.

props

vp.x, vp.y

The position of the upper left corner of the view port in the game world map.

vp.w,vp.h

The present width and height of the view port, because this project does not support zooming this will typically be set to the native canvas size of the project.

vp.mkVPRel(obj)

returns a new box object that has a view port relative position that is ready to be rendered.