/******************************************************************************
 * Spine Runtimes Software License
 * Version 2
 * 
 * Copyright (c) 2013, Esoteric Software
 * All rights reserved.
 * 
 * You are granted a perpetual, non-exclusive, non-sublicensable and
 * non-transferable license to install, execute and perform the Spine Runtimes
 * Software (the "Software") solely for internal use. Without the written
 * permission of Esoteric Software, you may not (a) modify, translate, adapt or
 * otherwise create derivative works, improvements of the Software or develop
 * new applications using the Software or (b) remove, delete, alter or obscure
 * any trademarks or any copyright, trademark, patent or other intellectual
 * property or proprietary rights notices on or in the Software, including
 * any copy thereof. Redistributions in binary or source form must include
 * this license and terms. THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTARE BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

package com.esotericsoftware.spine;

import com.esotericsoftware.spine.attachments.Attachment;
import com.esotericsoftware.spine.attachments.MeshAttachment;
import com.esotericsoftware.spine.attachments.RegionAttachment;
import com.esotericsoftware.spine.attachments.SkeletonAttachment;

import com.badlogic.gdx.graphics.GL11;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.graphics.g2d.PolygonSpriteBatch;
import com.badlogic.gdx.utils.Array;

public class SkeletonRenderer {
	static private final short[] quadTriangle = {0, 1, 2, 2, 3, 0};

	private boolean premultipliedAlpha;

	public void draw (PolygonSpriteBatch batch, Skeleton skeleton) {
		boolean premultipliedAlpha = this.premultipliedAlpha;
		int srcFunc = premultipliedAlpha ? GL11.GL_ONE : GL11.GL_SRC_ALPHA;
		batch.setBlendFunction(srcFunc, GL11.GL_ONE_MINUS_SRC_ALPHA);

		boolean additive = false;

		float[] vertices;
		short[] triangles;
		Texture texture;
		Array<Slot> drawOrder = skeleton.drawOrder;
		for (int i = 0, n = drawOrder.size; i < n; i++) {
			Slot slot = drawOrder.get(i);
			Attachment attachment = slot.attachment;
			if (attachment instanceof RegionAttachment) {
				RegionAttachment region = (RegionAttachment)attachment;
				region.updateWorldVertices(slot, premultipliedAlpha);
				vertices = region.getWorldVertices();
				triangles = quadTriangle;
				texture = region.getRegion().getTexture();

				if (slot.data.getAdditiveBlending() != additive) {
					additive = !additive;
					if (additive)
						batch.setBlendFunction(srcFunc, GL11.GL_ONE);
					else
						batch.setBlendFunction(srcFunc, GL11.GL_ONE_MINUS_SRC_ALPHA);
				}

				batch.draw(texture, vertices, 0, vertices.length, triangles, 0, triangles.length);

			} else if (attachment instanceof MeshAttachment) {
				MeshAttachment mesh = (MeshAttachment)attachment;
				mesh.updateWorldVertices(slot, true);
				vertices = mesh.getWorldVertices();
				triangles = mesh.getTriangles();
				texture = mesh.getRegion().getTexture();
				batch.draw(texture, vertices, 0, vertices.length, triangles, 0, triangles.length);

			} else if (attachment instanceof SkeletonAttachment) {
				Skeleton attachmentSkeleton = ((SkeletonAttachment)attachment).getSkeleton();
				if (attachmentSkeleton == null) continue;
				Bone bone = slot.getBone();
				Bone rootBone = attachmentSkeleton.getRootBone();
				float oldScaleX = rootBone.getScaleX();
				float oldScaleY = rootBone.getScaleY();
				float oldRotation = rootBone.getRotation();
				attachmentSkeleton.setX(bone.getWorldX());
				attachmentSkeleton.setY(bone.getWorldY());
				rootBone.setScaleX(1 + bone.getWorldScaleX() - oldScaleX);
				rootBone.setScaleY(1 + bone.getWorldScaleY() - oldScaleY);
				rootBone.setRotation(oldRotation + bone.getWorldRotation());
				attachmentSkeleton.updateWorldTransform();

				draw(batch, attachmentSkeleton);

				attachmentSkeleton.setX(0);
				attachmentSkeleton.setY(0);
				rootBone.setScaleX(oldScaleX);
				rootBone.setScaleY(oldScaleY);
				rootBone.setRotation(oldRotation);
			}
		}
	}

	public void draw (Batch batch, Skeleton skeleton) {
		boolean premultipliedAlpha = this.premultipliedAlpha;
		int srcFunc = premultipliedAlpha ? GL11.GL_ONE : GL11.GL_SRC_ALPHA;
		batch.setBlendFunction(srcFunc, GL11.GL_ONE_MINUS_SRC_ALPHA);

		boolean additive = false;

		Array<Slot> drawOrder = skeleton.drawOrder;
		for (int i = 0, n = drawOrder.size; i < n; i++) {
			Slot slot = drawOrder.get(i);
			Attachment attachment = slot.attachment;
			if (attachment instanceof RegionAttachment) {
				RegionAttachment regionAttachment = (RegionAttachment)attachment;
				regionAttachment.updateWorldVertices(slot, premultipliedAlpha);
				float[] vertices = regionAttachment.getWorldVertices();
				if (slot.data.getAdditiveBlending() != additive) {
					additive = !additive;
					if (additive)
						batch.setBlendFunction(srcFunc, GL11.GL_ONE);
					else
						batch.setBlendFunction(srcFunc, GL11.GL_ONE_MINUS_SRC_ALPHA);
				}
				batch.draw(regionAttachment.getRegion().getTexture(), vertices, 0, 20);
			} else if (attachment instanceof SkeletonAttachment) {
				Skeleton attachmentSkeleton = ((SkeletonAttachment)attachment).getSkeleton();
				if (attachmentSkeleton == null) continue;
				Bone bone = slot.getBone();
				Bone rootBone = attachmentSkeleton.getRootBone();
				float oldScaleX = rootBone.getScaleX();
				float oldScaleY = rootBone.getScaleY();
				float oldRotation = rootBone.getRotation();
				attachmentSkeleton.setX(bone.getWorldX());
				attachmentSkeleton.setY(bone.getWorldY());
				rootBone.setScaleX(1 + bone.getWorldScaleX() - oldScaleX);
				rootBone.setScaleY(1 + bone.getWorldScaleY() - oldScaleY);
				rootBone.setRotation(oldRotation + bone.getWorldRotation());
				attachmentSkeleton.updateWorldTransform();

				draw(batch, attachmentSkeleton);

				attachmentSkeleton.setX(0);
				attachmentSkeleton.setY(0);
				rootBone.setScaleX(oldScaleX);
				rootBone.setScaleY(oldScaleY);
				rootBone.setRotation(oldRotation);
			}
		}
	}

	public void setPremultipliedAlpha (boolean premultipliedAlpha) {
		this.premultipliedAlpha = premultipliedAlpha;
	}
}