NinePatch.java

/*******************************************************************************
 * Copyright 2011 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.badlogic.gdx.graphics.g2d;

import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.utils.GdxRuntimeException;

/**
 * A 3x3 grid of texture regions. Any of the regions may be omitted. Padding may be set as a hint on how to inset
 * content on top of the ninepatch.
 */
public class NinePatch {
	public static final int TOP_LEFT = 0;
	public static final int TOP_CENTER = 1;
	public static final int TOP_RIGHT = 2;
	public static final int MIDDLE_LEFT = 3;
	public static final int MIDDLE_CENTER = 4;
	public static final int MIDDLE_RIGHT = 5;
	public static final int BOTTOM_LEFT = 6;
	public static final int BOTTOM_CENTER = 7;
	public static final int BOTTOM_RIGHT = 8;

	static private final Color tempColor = new Color();

	private Texture texture;
	private int bottomLeft = -1, bottomCenter = -1, bottomRight = -1;
	private int middleLeft = -1, middleCenter = -1, middleRight = -1;
	private int topLeft = -1, topCenter = -1, topRight = -1;
	private float leftWidth, rightWidth, middleWidth, middleHeight, topHeight, bottomHeight;
	private float[] vertices = new float[9 * 4 * 5];
	private int idx;
	private final Color color = new Color(Color.WHITE);
	private int padLeft = -1, padRight = -1, padTop = -1, padBottom = -1;

	/**
	 * @param left
	 *            Pixels from left edge.
	 * @param right
	 *            Pixels from right edge.
	 * @param top
	 *            Pixels from top edge.
	 * @param bottom
	 *            Pixels from bottom edge.
	 */
	public NinePatch(Texture texture, int left, int right, int top, int bottom) {
		this(new TextureRegion(texture), left, right, top, bottom);
	}

	/**
	 * @param left
	 *            Pixels from left edge.
	 * @param right
	 *            Pixels from right edge.
	 * @param top
	 *            Pixels from top edge.
	 * @param bottom
	 *            Pixels from bottom edge.
	 */
	public NinePatch(TextureRegion region, int left, int right, int top, int bottom) {
		if (region == null)
			throw new IllegalArgumentException("region cannot be null.");
		int middleWidth = region.getRegionWidth() - left - right;
		int middleHeight = region.getRegionHeight() - top - bottom;

		TextureRegion[] patches = new TextureRegion[9];
		if (top > 0) {
			if (left > 0)
				patches[0] = new TextureRegion(region, 0, 0, left, top);
			if (middleWidth > 0)
				patches[1] = new TextureRegion(region, left, 0, middleWidth, top);
			if (right > 0)
				patches[2] = new TextureRegion(region, left + middleWidth, 0, right, top);
		}
		if (middleHeight > 0) {
			if (left > 0)
				patches[3] = new TextureRegion(region, 0, top, left, middleHeight);
			if (middleWidth > 0)
				patches[4] = new TextureRegion(region, left, top, middleWidth, middleHeight);
			if (right > 0)
				patches[5] = new TextureRegion(region, left + middleWidth, top, right, middleHeight);
		}
		if (bottom > 0) {
			if (left > 0)
				patches[6] = new TextureRegion(region, 0, top + middleHeight, left, bottom);
			if (middleWidth > 0)
				patches[7] = new TextureRegion(region, left, top + middleHeight, middleWidth, bottom);
			if (right > 0)
				patches[8] = new TextureRegion(region, left + middleWidth, top + middleHeight, right, bottom);
		}

		// If split only vertical, move splits from right to center.
		if (left == 0 && middleWidth == 0) {
			patches[TOP_CENTER] = patches[TOP_RIGHT];
			patches[MIDDLE_CENTER] = patches[MIDDLE_RIGHT];
			patches[BOTTOM_CENTER] = patches[BOTTOM_RIGHT];
			patches[TOP_RIGHT] = null;
			patches[MIDDLE_RIGHT] = null;
			patches[BOTTOM_RIGHT] = null;
		}
		// If split only horizontal, move splits from bottom to center.
		if (top == 0 && middleHeight == 0) {
			patches[MIDDLE_LEFT] = patches[BOTTOM_LEFT];
			patches[MIDDLE_CENTER] = patches[BOTTOM_CENTER];
			patches[MIDDLE_RIGHT] = patches[BOTTOM_RIGHT];
			patches[BOTTOM_LEFT] = null;
			patches[BOTTOM_CENTER] = null;
			patches[BOTTOM_RIGHT] = null;
		}

		load(patches);
	}

	public NinePatch(Texture texture, Color color) {
		this(texture);
		setColor(color);
	}

	public NinePatch(Texture texture) {
		this(new TextureRegion(texture));
	}

	public NinePatch(TextureRegion region, Color color) {
		this(region);
		setColor(color);
	}

	public NinePatch(TextureRegion region) {
		load(new TextureRegion[] {
				//
				null, null, null, //
				null, region, null, //
				null, null, null //
		});
	}

	public NinePatch(TextureRegion... patches) {
		if (patches == null || patches.length != 9)
			throw new IllegalArgumentException("NinePatch needs nine TextureRegions");

		load(patches);

		float leftWidth = getLeftWidth();
		if ((patches[TOP_LEFT] != null && patches[TOP_LEFT].getRegionWidth() != leftWidth)
				|| (patches[MIDDLE_LEFT] != null && patches[MIDDLE_LEFT].getRegionWidth() != leftWidth)
				|| (patches[BOTTOM_LEFT] != null && patches[BOTTOM_LEFT].getRegionWidth() != leftWidth)) {
			throw new GdxRuntimeException("Left side patches must have the same width");
		}

		float rightWidth = getRightWidth();
		if ((patches[TOP_RIGHT] != null && patches[TOP_RIGHT].getRegionWidth() != rightWidth)
				|| (patches[MIDDLE_RIGHT] != null && patches[MIDDLE_RIGHT].getRegionWidth() != rightWidth)
				|| (patches[BOTTOM_RIGHT] != null && patches[BOTTOM_RIGHT].getRegionWidth() != rightWidth)) {
			throw new GdxRuntimeException("Right side patches must have the same width");
		}

		float bottomHeight = getBottomHeight();
		if ((patches[BOTTOM_LEFT] != null && patches[BOTTOM_LEFT].getRegionHeight() != bottomHeight)
				|| (patches[BOTTOM_CENTER] != null && patches[BOTTOM_CENTER].getRegionHeight() != bottomHeight)
				|| (patches[BOTTOM_RIGHT] != null && patches[BOTTOM_RIGHT].getRegionHeight() != bottomHeight)) {
			throw new GdxRuntimeException("Bottom side patches must have the same height");
		}

		float topHeight = getTopHeight();
		if ((patches[TOP_LEFT] != null && patches[TOP_LEFT].getRegionHeight() != topHeight)
				|| (patches[TOP_CENTER] != null && patches[TOP_CENTER].getRegionHeight() != topHeight)
				|| (patches[TOP_RIGHT] != null && patches[TOP_RIGHT].getRegionHeight() != topHeight)) {
			throw new GdxRuntimeException("Top side patches must have the same height");
		}
	}

	public NinePatch(NinePatch ninePatch) {
		this(ninePatch, new Color(ninePatch.color));
	}

	public NinePatch(NinePatch ninePatch, Color color) {
		texture = ninePatch.texture;

		bottomLeft = ninePatch.bottomLeft;
		bottomCenter = ninePatch.bottomCenter;
		bottomRight = ninePatch.bottomRight;
		middleLeft = ninePatch.middleLeft;
		middleCenter = ninePatch.middleCenter;
		middleRight = ninePatch.middleRight;
		topLeft = ninePatch.topLeft;
		topCenter = ninePatch.topCenter;
		topRight = ninePatch.topRight;

		leftWidth = ninePatch.leftWidth;
		rightWidth = ninePatch.rightWidth;
		middleWidth = ninePatch.middleWidth;
		middleHeight = ninePatch.middleHeight;
		topHeight = ninePatch.topHeight;
		bottomHeight = ninePatch.bottomHeight;

		vertices = new float[ninePatch.vertices.length];
		System.arraycopy(ninePatch.vertices, 0, vertices, 0, ninePatch.vertices.length);
		idx = ninePatch.idx;
		this.color.set(color);
	}

	private void load(TextureRegion[] patches) {
		float color = Color.WHITE.toFloatBits();

		if (patches[BOTTOM_LEFT] != null) {
			bottomLeft = add(patches[BOTTOM_LEFT], color);
			leftWidth = patches[BOTTOM_LEFT].getRegionWidth();
			bottomHeight = patches[BOTTOM_LEFT].getRegionHeight();
		}
		if (patches[BOTTOM_CENTER] != null) {
			bottomCenter = add(patches[BOTTOM_CENTER], color);
			middleWidth = Math.max(middleWidth, patches[BOTTOM_CENTER].getRegionWidth());
			bottomHeight = Math.max(bottomHeight, patches[BOTTOM_CENTER].getRegionHeight());
		}
		if (patches[BOTTOM_RIGHT] != null) {
			bottomRight = add(patches[BOTTOM_RIGHT], color);
			rightWidth = Math.max(rightWidth, patches[BOTTOM_RIGHT].getRegionWidth());
			bottomHeight = Math.max(bottomHeight, patches[BOTTOM_RIGHT].getRegionHeight());
		}
		if (patches[MIDDLE_LEFT] != null) {
			middleLeft = add(patches[MIDDLE_LEFT], color);
			leftWidth = Math.max(leftWidth, patches[MIDDLE_LEFT].getRegionWidth());
			middleHeight = Math.max(middleHeight, patches[MIDDLE_LEFT].getRegionHeight());
		}
		if (patches[MIDDLE_CENTER] != null) {
			middleCenter = add(patches[MIDDLE_CENTER], color);
			middleWidth = Math.max(middleWidth, patches[MIDDLE_CENTER].getRegionWidth());
			middleHeight = Math.max(middleHeight, patches[MIDDLE_CENTER].getRegionHeight());
		}
		if (patches[MIDDLE_RIGHT] != null) {
			middleRight = add(patches[MIDDLE_RIGHT], color);
			rightWidth = Math.max(rightWidth, patches[MIDDLE_RIGHT].getRegionWidth());
			middleHeight = Math.max(middleHeight, patches[MIDDLE_RIGHT].getRegionHeight());
		}
		if (patches[TOP_LEFT] != null) {
			topLeft = add(patches[TOP_LEFT], color);
			leftWidth = Math.max(leftWidth, patches[TOP_LEFT].getRegionWidth());
			topHeight = Math.max(topHeight, patches[TOP_LEFT].getRegionHeight());
		}
		if (patches[TOP_CENTER] != null) {
			topCenter = add(patches[TOP_CENTER], color);
			middleWidth = Math.max(middleWidth, patches[TOP_CENTER].getRegionWidth());
			topHeight = Math.max(topHeight, patches[TOP_CENTER].getRegionHeight());
		}
		if (patches[TOP_RIGHT] != null) {
			topRight = add(patches[TOP_RIGHT], color);
			rightWidth = Math.max(rightWidth, patches[TOP_RIGHT].getRegionWidth());
			topHeight = Math.max(topHeight, patches[TOP_RIGHT].getRegionHeight());
		}
		if (idx < vertices.length) {
			float[] newVertices = new float[idx];
			System.arraycopy(vertices, 0, newVertices, 0, idx);
			vertices = newVertices;
		}
	}

	private int add(TextureRegion region, float color) {
		if (texture == null)
			texture = region.getTexture();
		else if (texture != region.getTexture()) //
			throw new IllegalArgumentException("All regions must be from the same texture.");

		final float u = region.u;
		final float v = region.v2;
		final float u2 = region.u2;
		final float v2 = region.v;
		final float[] vertices = this.vertices;

		idx += 2;
		vertices[idx++] = color;
		vertices[idx++] = u;
		vertices[idx] = v;
		idx += 3;
		vertices[idx++] = color;
		vertices[idx++] = u;
		vertices[idx] = v2;
		idx += 3;
		vertices[idx++] = color;
		vertices[idx++] = u2;
		vertices[idx] = v2;
		idx += 3;
		vertices[idx++] = color;
		vertices[idx++] = u2;
		vertices[idx++] = v;

		return idx - 4 * 5;
	}

	private void set(int idx, float x, float y, float width, float height, float color) {
		final float fx2 = x + width;
		final float fy2 = y + height;
		final float[] vertices = this.vertices;
		vertices[idx++] = x;
		vertices[idx++] = y;
		vertices[idx] = color;
		idx += 3;
		vertices[idx++] = x;
		vertices[idx++] = fy2;
		vertices[idx] = color;
		idx += 3;
		vertices[idx++] = fx2;
		vertices[idx++] = fy2;
		vertices[idx] = color;
		idx += 3;
		vertices[idx++] = fx2;
		vertices[idx++] = y;
		vertices[idx] = color;
	}

	public void draw(SpriteBatch batch, float x, float y, float width, float height) {
		float centerColumnX = x + leftWidth;
		float rightColumnX = x + width - rightWidth;
		float middleRowY = y + bottomHeight;
		float topRowY = y + height - topHeight;
		float c = tempColor.set(color).mul(batch.getColor()).toFloatBits();

		if (bottomLeft != -1)
			set(bottomLeft, x, y, centerColumnX - x, middleRowY - y, c);
		if (bottomCenter != -1)
			set(bottomCenter, centerColumnX, y, rightColumnX - centerColumnX, middleRowY - y, c);
		if (bottomRight != -1)
			set(bottomRight, rightColumnX, y, x + width - rightColumnX, middleRowY - y, c);
		if (middleLeft != -1)
			set(middleLeft, x, middleRowY, centerColumnX - x, topRowY - middleRowY, c);
		if (middleCenter != -1)
			set(middleCenter, centerColumnX, middleRowY, rightColumnX - centerColumnX, topRowY - middleRowY, c);
		if (middleRight != -1)
			set(middleRight, rightColumnX, middleRowY, x + width - rightColumnX, topRowY - middleRowY, c);
		if (topLeft != -1)
			set(topLeft, x, topRowY, centerColumnX - x, y + height - topRowY, c);
		if (topCenter != -1)
			set(topCenter, centerColumnX, topRowY, rightColumnX - centerColumnX, y + height - topRowY, c);
		if (topRight != -1)
			set(topRight, rightColumnX, topRowY, x + width - rightColumnX, y + height - topRowY, c);

		batch.draw(texture, vertices, 0, idx);
	}

	public void setColor(Color color) {
		this.color.set(color);
	}

	public Color getColor() {
		return color;
	}

	public float getLeftWidth() {
		return leftWidth;
	}

	public void setLeftWidth(float leftWidth) {
		this.leftWidth = leftWidth;
	}

	public float getRightWidth() {
		return rightWidth;
	}

	public void setRightWidth(float rightWidth) {
		this.rightWidth = rightWidth;
	}

	public float getTopHeight() {
		return topHeight;
	}

	public void setTopHeight(float topHeight) {
		this.topHeight = topHeight;
	}

	public float getBottomHeight() {
		return bottomHeight;
	}

	public void setBottomHeight(float bottomHeight) {
		this.bottomHeight = bottomHeight;
	}

	public float getMiddleWidth() {
		return middleWidth;
	}

	public void setMiddleWidth(float middleWidth) {
		this.middleWidth = middleWidth;
	}

	public float getMiddleHeight() {
		return middleHeight;
	}

	public void setMiddleHeight(float middleHeight) {
		this.middleHeight = middleHeight;
	}

	public float getTotalWidth() {
		return leftWidth + middleWidth + rightWidth;
	}

	public float getTotalHeight() {
		return topHeight + middleHeight + bottomHeight;
	}

	public void setPadding(int left, int right, int top, int bottom) {
		this.padLeft = left;
		this.padRight = right;
		this.padTop = top;
		this.padBottom = bottom;
	}

	/** Returns the left padding if set, else returns {@link #getLeftWidth()}. */
	public float getPadLeft() {
		if (padLeft == -1)
			return getLeftWidth();
		return padLeft;
	}

	public void setPadLeft(int left) {
		this.padLeft = left;
	}

	/** Returns the right padding if set, else returns {@link #getRightWidth()}. */
	public float getPadRight() {
		if (padRight == -1)
			return getRightWidth();
		return padRight;
	}

	public void setPadRight(int right) {
		this.padRight = right;
	}

	/** Returns the top padding if set, else returns {@link #getTopHeight()}. */
	public float getPadTop() {
		if (padTop == -1)
			return getTopHeight();
		return padTop;
	}

	public void setPadTop(int top) {
		this.padTop = top;
	}

	/** Returns the bottom padding if set, else returns {@link #getBottomHeight()}. */
	public float getPadBottom() {
		if (padBottom == -1)
			return getBottomHeight();
		return padBottom;
	}

	public void setPadBottom(int bottom) {
		this.padBottom = bottom;
	}

	public Texture getTexture() {
		return texture;
	}
}