package sparseviewer.interp;

public class Grid2D {

    private final int width;
    private final int height;

    private final double xmin;
    private final double xmax;
    private final double ymin;
    private final double ymax;

    public Grid2D(int width, int height,
                  double xmin, double xmax,
                  double ymin, double ymax) {
        this.width = width;
        this.height = height;
        this.xmin = xmin;
        this.xmax = xmax;
        this.ymin = ymin;
        this.ymax = ymax;
    }

    public int getWidth() {
        return width;
    }

    public int getHeight() {
        return height;
    }

    public double getXMin() {
        return xmin;
    }

    public double getXMax() {
        return xmax;
    }

    public double getYMin() {
        return ymin;
    }

    public double getYMax() {
        return ymax;
    }

    public double xAt(int ix) {
        if (width <= 1) {
            return xmin;
        }

        return xmin + ix * (xmax - xmin) / (double) (width - 1);
    }

    public double yAt(int iy) {
        if (height <= 1) {
            return ymin;
        }

        return ymin + iy * (ymax - ymin) / (double) (height - 1);
    }

    public int xToIndex(double x) {
        if (xmax == xmin) {
            return 0;
        }

        double t = (x - xmin) / (xmax - xmin);
        int ix = (int) Math.round(t * (width - 1));

        if (ix < 0) {
            ix = 0;
        }

        if (ix >= width) {
            ix = width - 1;
        }

        return ix;
    }

    public int yToIndex(double y) {
        if (ymax == ymin) {
            return 0;
        }

        double t = (y - ymin) / (ymax - ymin);
        int iy = (int) Math.round(t * (height - 1));

        if (iy < 0) {
            iy = 0;
        }

        if (iy >= height) {
            iy = height - 1;
        }

        return iy;
    }
}