VariableRuggednessEffect.java

package rtg.world.gen.terrain;

import rtg.api.world.RTGWorld;

/**
 * This provides a standard "ruggedness switch" between a rugged terrain and a smooth one
 * it has its wavelength standardized to provide cooperation between adjacent terrains
 *
 * @author Zeno410
 */
public class VariableRuggednessEffect extends HeightEffect {

    public static float STANDARD_RUGGEDNESS_WAVELENGTH = 200f;
    public static int STANDARD_RUGGEDNESS_OCTAVE = 1;
    // not going to bother to set up a creator shell to make sure everything is set
    // set defaults to absurd values to crash if they're not set
    public HeightEffect smoothTerrain;
    public HeightEffect ruggedTerrain;
    public float startTransition = Integer.MAX_VALUE;
    public float transitionWidth = 0;
    public int octave = 1;// this is the standard "ruggedness octave"
    public float wavelength;// standard ruggedness wavelength

    public VariableRuggednessEffect() {

    }

    public VariableRuggednessEffect(HeightEffect smoothTerrain, HeightEffect ruggedTerrain,
                                    float startTransition, float transitionWidth, float wavelength) {

        this.smoothTerrain = smoothTerrain;
        this.ruggedTerrain = ruggedTerrain;
        this.startTransition = startTransition;
        this.transitionWidth = transitionWidth;
        this.wavelength = wavelength;
    }

    public VariableRuggednessEffect(HeightEffect smoothTerrain, HeightEffect ruggedTerrain,
                                    float startTransition, float transitionWidth) {

        this(smoothTerrain, ruggedTerrain, startTransition, transitionWidth, STANDARD_RUGGEDNESS_WAVELENGTH);

    }

    @Override
    public final float added(RTGWorld rtgWorld, float x, float y) {

        float choice = rtgWorld.simplex.octave(octave).noise2((float) x / wavelength, (float) y / wavelength);
        if (choice <= startTransition) {
            return smoothTerrain.added(rtgWorld, x, y);
        }
        if (choice >= startTransition + transitionWidth) {
            return ruggedTerrain.added(rtgWorld, x, y);
        }
        // otherwise in the transition zone;
        float smooth = smoothTerrain.added(rtgWorld, x, y);
        float rugged = ruggedTerrain.added(rtgWorld, x, y);
        return ((choice - startTransition) * rugged + (startTransition + transitionWidth - choice) * smooth) /
            transitionWidth;
    }

}