GridView.java

/*
 * ******************************************************************************
 *  * Copyright 2015 See AUTHORS file.
 *  *
 *  * Licensed under the Apache License, Version 2.0 (the "License");
 *  * you may not use this file except in compliance with the License.
 *  * You may obtain a copy of the License at
 *  *
 *  *   http://www.apache.org/licenses/LICENSE-2.0
 *  *
 *  * Unless required by applicable law or agreed to in writing, software
 *  * distributed under the License is distributed on an "AS IS" BASIS,
 *  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  * See the License for the specific language governing permissions and
 *  * limitations under the License.
 *  *****************************************************************************
 */

package com.uwsoft.editor.view.ui.widget.actors;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.ui.Label;
import com.badlogic.gdx.utils.Array;
import com.kotcrab.vis.ui.widget.VisLabel;
import com.uwsoft.editor.view.stage.Sandbox;

public class GridView extends Actor {

	private Array<Segment> lines = new Array<>();
	private ShapeRenderer shapeRenderer;

	private Label zeroLabel;

	private int pixelsPerWU = 1;

	private int gridSize;
	int gridLinesCount;

	public GridView() {
		gridSize = 50;
		gridLinesCount = 40;

		pixelsPerWU = Sandbox.getInstance().getPixelPerWU();
		shapeRenderer = new ShapeRenderer();

		for(int i = 0; i <gridLinesCount; i++) {
			Segment tmp = new Segment(i*gridSize-(gridLinesCount/2-1)*gridSize, -(gridLinesCount/2-1)*gridSize, i*gridSize-(gridLinesCount/2-1)*gridSize, gridSize*gridLinesCount-(gridLinesCount/2-1)*gridSize);
			lines.add(tmp);
		}
		
		for(int i = 0; i <gridLinesCount; i++) {
			Segment tmp = new Segment(-(gridLinesCount/2-1)*gridSize, i*gridSize-(gridLinesCount/2-1)*gridSize, gridSize*gridLinesCount-(gridLinesCount/2-1)*gridSize, i*gridSize-(gridLinesCount/2-1)*gridSize);
			 lines.add(tmp);
		}
		
		this.setWidth(gridSize * gridLinesCount);
		this.setHeight(gridSize * gridLinesCount);

		zeroLabel = new VisLabel("0.0");
		zeroLabel.setColor(new Color(1, 1, 1, 0.4f));
	}

	@Override
	public void draw(Batch batch, float parentAlpha) {
		batch.end();

		OrthographicCamera uiCamera = (OrthographicCamera) Sandbox.getInstance().getUIStage().getCamera();

		Gdx.gl.glLineWidth(1.0f);
		Gdx.gl.glEnable(GL20.GL_BLEND);
		Gdx.gl.glBlendFunc(GL20.GL_SRC_ALPHA, GL20.GL_ONE_MINUS_SRC_ALPHA);

		shapeRenderer.setProjectionMatrix(uiCamera.projection);

		drawLines();

		Gdx.gl.glDisable(GL20.GL_BLEND);
		batch.begin();
		batch.setColor(Color.WHITE);


		OrthographicCamera runtimeCamera = Sandbox.getInstance().getCamera();
		batch.setProjectionMatrix(uiCamera.projection);
		zeroLabel.draw(batch, parentAlpha);
		zeroLabel.setX(-(runtimeCamera.position.x*pixelsPerWU)/runtimeCamera.zoom - 5 - zeroLabel.getWidth());
		zeroLabel.setY(-(runtimeCamera.position.y*pixelsPerWU)/runtimeCamera.zoom - zeroLabel.getHeight());
	}

	private void drawLines() {
		shapeRenderer.begin(ShapeRenderer.ShapeType.Line);

		OrthographicCamera runtimeCamera = Sandbox.getInstance().getCamera();
		float offsetX = (runtimeCamera.position.x*pixelsPerWU)/runtimeCamera.zoom % gridSize;
		float offsetY = (runtimeCamera.position.y*pixelsPerWU)/runtimeCamera.zoom % gridSize;

		for(int i = 0; i < lines.size; i++) {
			shapeRenderer.setColor(getLineColor(i));
			shapeRenderer.line(lines.get(i).start.x - offsetX, lines.get(i).start.y-offsetY, lines.get(i).end.x-offsetX, lines.get(i).end.y-offsetY);
		}

		shapeRenderer.end();
	}
	
	private Color getLineColor(int i) {
		OrthographicCamera runtimeCamera = Sandbox.getInstance().getCamera();

		float offsetTmp = ((runtimeCamera.position.x*pixelsPerWU)/runtimeCamera.zoom) / gridSize;
		if(i >= gridLinesCount) {
			i-= gridLinesCount;
			offsetTmp = ((runtimeCamera.position.y*pixelsPerWU)/runtimeCamera.zoom) / gridSize;
		}

		// offset
		int offset = 0;
		if(offsetTmp > 0) offset = (int) Math.floor(offsetTmp);
		if(offsetTmp < 0) offset = (int) -Math.floor(-offsetTmp);
		i += offset;

		Color color = new Color(Color.WHITE);

		if((gridLinesCount/2 - i - 1) % 4 == 0) {
			color.a = 0.1f;
		} else if((gridLinesCount/2 - i - 1) % 2 == 0) {
			color.a = 0.05f;
		} else {
			color.a = 0.02f;
		}

		return color;
	}

	public class Segment {
		public Vector2 start;
		public Vector2 end;

		public Segment(float startX, float startY, float endX, float endY) {
			start = new Vector2(startX, startY);
			end = new Vector2(endX, endY);
		}

		public Segment(Vector2 start, Vector2 end) {
			this.start = start;
			this.end = end;
		}
	}
}