package com.hw.photomovie.opengl;

import com.hw.photomovie.opengl.animations.AnimationTime;
import com.hw.photomovie.util.Utils;

// FadeTexture is a texture which fades the given texture along the time.
public abstract class FadeTexture implements Texture {
    // The duration of the fading animation in milliseconds
    public static final int DURATION = 180;
    protected final BasicTexture mTexture;
    private final long mStartTime;
    private final int mWidth;
    private final int mHeight;
    private final boolean mIsOpaque;
    private boolean mIsAnimating;

    public FadeTexture(BasicTexture texture) {
        mTexture = texture;
        mWidth = mTexture.getWidth();
        mHeight = mTexture.getHeight();
        mIsOpaque = mTexture.isOpaque();
        mStartTime = now();
        mIsAnimating = true;
    }

    @Override
    public void draw(GLESCanvas canvas, int x, int y) {
        draw(canvas, x, y, mWidth, mHeight);
    }

    @Override
    public boolean isOpaque() {
        return mIsOpaque;
    }

    @Override
    public int getWidth() {
        return mWidth;
    }

    @Override
    public int getHeight() {
        return mHeight;
    }

    public boolean isAnimating() {
        if (mIsAnimating) {
            if (now() - mStartTime >= DURATION) {
                mIsAnimating = false;
            }
        }
        return mIsAnimating;
    }

    protected float getRatio() {
        float r = (float) (now() - mStartTime) / DURATION;
        return Utils.clamp(1.0f - r, 0.0f, 1.0f);
    }

    private long now() {
        return AnimationTime.get();
    }
}