src/org/math/plot/render/Projection3D.java

package org.math.plot.render;

public class Projection3D extends Projection {

        protected double theta;

        protected double phi;

        // protected boolean useRoundTrigonometry = false;

        public Projection3D(AWTDrawer _draw) {
                super(_draw);
                theta = Math.PI / 4;
                phi = Math.PI / 4;
                initBaseCoordsProjection();
        }

        protected double[] baseCoordsScreenProjectionRatio(double[] xyz) {
                double factor = 1.7;
                double[] sC = new double[2];
                sC[0] = 0.5
                                + (cos(theta)
                                                * ((xyz[1] - (draw.canvas.base.roundXmax[1] + draw.canvas.base.roundXmin[1]) / 2) / (draw.canvas.base.roundXmax[1] - draw.canvas.base.roundXmin[1])) - sin(theta)
                                                * ((xyz[0] - (draw.canvas.base.roundXmax[0] + draw.canvas.base.roundXmin[0]) / 2) / (draw.canvas.base.roundXmax[0] - draw.canvas.base.roundXmin[0])))
                                / factor;
                sC[1] = 0.5
                                + (cos(phi)
                                                * ((xyz[2] - (draw.canvas.base.roundXmax[2] + draw.canvas.base.roundXmin[2]) / 2) / (draw.canvas.base.roundXmax[2] - draw.canvas.base.roundXmin[2]))
                                                - sin(phi)
                                                * cos(theta)
                                                * ((xyz[0] - (draw.canvas.base.roundXmax[0] + draw.canvas.base.roundXmin[0]) / 2) / (draw.canvas.base.roundXmax[0] - draw.canvas.base.roundXmin[0])) - sin(phi)
                                                * sin(theta)
                                                * ((xyz[1] - (draw.canvas.base.roundXmax[1] + draw.canvas.base.roundXmin[1]) / 2) / (draw.canvas.base.roundXmax[1] - draw.canvas.base.roundXmin[1])))
                                / factor;
                // System.out.println("Theta = " + theta + " Phi = " + phi);
                // System.out.println("(" + xyz[0] +"," + xyz[1] +"," + xyz[2] + ") ->
                // (" + sC[0] + "," + sC[1] + ")");
                return sC;
        }

        // TODO test efficiceny of an approximation of cos and sin fuctions.
        
        /*
         * private final static double _2PI = 2 * Math.PI;
         * 
         * private final static int N = 100;
         * 
         * private final static double[] COS =
         * DoubleArray.f(DoubleArray.increment(N, 0, 2 * Math.PI / (N - 1)), new
         * Function() { public double f(double x) { return Math.cos(x); } });
         * 
         * private final static double[] SIN =
         * DoubleArray.f(DoubleArray.increment(N, 0, 2 * Math.PI / (N - 1)), new
         * Function() { public double f(double x) { return Math.sin(x); } });
         */
        private double cos(double x) {
                return Math.cos(x);
        }

        private double sin(double x) {
                return Math.sin(x);
        }

        public void setView(double _theta, double _phi) {
                theta = _theta;
                phi = _phi;
                initBaseCoordsProjection();
        }

        public void rotate(int[] screenTranslation, int[] dimension) {
                theta = theta - ((double) screenTranslation[0]) / 100;
                phi = phi + ((double) screenTranslation[1]) / 100;
                initBaseCoordsProjection();
        }

}

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