/*
 * Pixel Dungeon
 * Copyright (C) 2012-2015  Oleg Dolya
 *
 * Shattered Pixel Dungeon
 * Copyright (C) 2014-2016 Evan Debenham
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 */

package com.watabou.glwrap;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.IntBuffer;

import android.graphics.Bitmap;
import android.opengl.GLES20;
import android.opengl.GLUtils;

public class Texture {

	public static final int NEAREST	= GLES20.GL_NEAREST;
	public static final int LINEAR	= GLES20.GL_LINEAR;
	
	public static final int REPEAT	= GLES20.GL_REPEAT;
	public static final int MIRROR	= GLES20.GL_MIRRORED_REPEAT;
	public static final int CLAMP	= GLES20.GL_CLAMP_TO_EDGE;
	
	public int id = -1;
	private static int bound_id = 0; //id of the currently bound texture
	
	public boolean premultiplied = false;

	protected void generate(){
		int[] ids = new int[1];
		GLES20.glGenTextures( 1, ids, 0 );
		id = ids[0];
	}
	
	public static void activ1ate( int index ) {
		GLES20.glActiveTexture( GLES20.GL_TEXTURE0 + index );
	}
	
	public void bind() {
		if (id == -1){
			generate();
		}
		if (id != bound_id) {
			GLES20.glBindTexture( GLES20.GL_TEXTURE_2D, id );
			bound_id = id;
		}
	}
	
	public void filter( int minMode, int maxMode ) {
		bind();
		GLES20.glTexParameterf( GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, minMode );
		GLES20.glTexParameterf( GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, maxMode );
	}
	
	public void wrap( int s, int t ) {
		bind();
		GLES20.glTexParameterf( GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, s );
		GLES20.glTexParameterf( GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, t );
	}
	
	public void delete() {
		if (bound_id == id) bound_id = 0;
		int[] ids = {id};
		GLES20.glDeleteTextures( 1, ids, 0 );
	}
	
	public void bitmap( Bitmap bitmap ) {
		bind();
		GLUtils.texImage2D( GLES20.GL_TEXTURE_2D, 0, bitmap, 0 );
		
		premultiplied = true;
	}
	
	public void pixels( int w, int h, int[] pixels ) {
	
		bind();
		
		IntBuffer imageBuffer = ByteBuffer.
			allocateDirect( w * h * 4 ).
			order( ByteOrder.nativeOrder() ).
			asIntBuffer();
		imageBuffer.put( pixels );
		imageBuffer.position( 0 );
		
		GLES20.glTexImage2D(
			GLES20.GL_TEXTURE_2D,
			0,
			GLES20.GL_RGBA,
			w,
			h,
			0,
			GLES20.GL_RGBA,
			GLES20.GL_UNSIGNED_BYTE,
			imageBuffer );
	}
	
	public void pixels( int w, int h, byte[] pixels ) {
		
		bind();
		
		ByteBuffer imageBuffer = ByteBuffer.
			allocateDirect( w * h ).
			order( ByteOrder.nativeOrder() );
		imageBuffer.put( pixels );
		imageBuffer.position( 0 );
		
		GLES20.glPixelStorei( GLES20.GL_UNPACK_ALIGNMENT, 1 );

		GLES20.glTexImage2D(
			GLES20.GL_TEXTURE_2D,
			0,
			GLES20.GL_ALPHA,
			w,
			h,
			0,
			GLES20.GL_ALPHA,
			GLES20.GL_UNSIGNED_BYTE,
			imageBuffer );
	}
	
	// If getConfig returns null (unsupported format?), GLUtils.texImage2D works
	// incorrectly. In this case we need to load pixels manually
	public void handMade( Bitmap bitmap, boolean recode ) {

		int w = bitmap.getWidth();
		int h = bitmap.getHeight();
		
		int[] pixels = new int[w * h];
		bitmap.getPixels( pixels, 0, w, 0, 0, w, h );

		// recode - components reordering is needed
		if (recode) {
			for (int i=0; i < pixels.length; i++) {
				int color = pixels[i];
				int ag = color & 0xFF00FF00;
				int r = (color >> 16) & 0xFF;
				int b = color & 0xFF;
				pixels[i] = ag | (b << 16) | r;
			}
		}
		
		pixels( w, h, pixels );
		
		premultiplied = false;
	}
	
	public static Texture create( Bitmap bmp ) {
		Texture tex = new Texture();
		tex.bitmap( bmp );
		
		return tex;
	}
	
	public static Texture create( int width, int height, int[] pixels ) {
		Texture tex = new Texture();
		tex.pixels( width, height, pixels );
		
		return tex;
	}
	
	public static Texture create( int width, int height, byte[] pixels ) {
		Texture tex = new Texture();
		tex.pixels( width, height, pixels );
		
		return tex;
	}
}