SparkleLibrary/Sprites/ImageSprite.cs

/*
 * ImageSprite - A sprite that draws an Image
 * 
 * Author: Phillip Piper
 * Date: 08/02/2010 6:18 PM
 *
 * Change log:
 * 2010-02-08   JPP  - Initial version
 *
 * To do:
 *
 * Copyright (C) 2010 Phillip Piper
 *
 * 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/>.
 *
 * If you wish to use this code in a closed source application, please contact phillip_piper@bigfoot.com.
 */

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Windows.Forms;

namespace BrightIdeasSoftware
{
    /// <summary>
    /// An ImageSprite draws an image onto the animation, to which animations can be applied
    /// </summary>
    /// <remarks>The image can even be an animated GIF!</remarks>
    public class ImageSprite : Sprite
    {
        #region Life and death

        public ImageSprite(Image image) {
            this.Image = image;
        }

        #endregion

        #region Implementation properties

        protected Image Image ;

        #endregion

        #region Sprite properties

        /// <summary>
        /// Gets or sets how big the image is
        /// </summary>
        /// <remarks>The image size cannot be set, since it is natural size multiplied by 
        /// the Scale property.</remarks>
        public override Size Size {
            get {
                if (this.Image == null)
                    return Size.Empty;

                // Internal the Image class cannot handle being accessed by multiple threads
                // at the same time. So make sure the access is serialized.
                lock (this.locker) {
                    if (this.Scale == 1.0f)
                        return this.Image.Size;
                    else
                        return new Size((int)(this.Image.Size.Width * this.Scale),
                            (int)(this.Image.Size.Height * this.Scale));
                }
            }
            set {
            }
        }

        #endregion

        #region Sprite methods

        public override void Start() {
            if (this.Image != null && ImageAnimator.CanAnimate(this.Image)) {
                isAnimatedImage = true;
                ImageAnimator.Animate(this.Image, this.OnFrameChanged);
            }
        }
        bool isAnimatedImage;

        public override void Stop() {
            if (this.isAnimatedImage)
                ImageAnimator.StopAnimate(this.Image, this.OnFrameChanged);
        }

        public override void Draw(Graphics g) {
            this.ApplyState(g);
            lock (this.locker) {
                if (this.Image != null) {
                    if (this.isAnimatedImage)
                        ImageAnimator.UpdateFrames(this.Image);

                    this.DrawTransparentBitmap(g, this.Bounds, this.Image, this.Opacity);
                }
                this.UnapplyState(g);
            }
        }

        private Object locker = new object();

        #endregion

        #region Implementation methods

        /// <summary>
        /// The frame on an animated GIF has changed. Normally we would redraw, but
        /// we leave that to the animation controller.
        /// </summary>
        /// <param name="o"></param>
        /// <param name="e"></param>
        private void OnFrameChanged(object o, EventArgs e) {
        }

        /// <summary>
        /// Draw an image in a (possibilty) transluscent fashion
        /// </summary>
        /// <param name="g"></param>
        /// <param name="r"></param>
        /// <param name="image"></param>
        /// <param name="transparency"></param>
        protected void DrawTransparentBitmap(Graphics g, Rectangle r, Image image, float transparency) {
            if (transparency <= 0.0f)
                return;

            ImageAttributes imageAttributes = null;
            if (transparency < 1.0f) {
                imageAttributes = new ImageAttributes();
                float[][] colorMatrixElements = {
                    new float[] {1,  0,  0,  0, 0},
                    new float[] {0,  1,  0,  0, 0},
                    new float[] {0,  0,  1,  0, 0},
                    new float[] {0,  0,  0,  transparency, 0},
                    new float[] {0,  0,  0,  0, 1}};

                imageAttributes.SetColorMatrix(new ColorMatrix(colorMatrixElements));
            }

            Rectangle dest = new Rectangle(Point.Empty, this.Size);
            g.DrawImage(image,
               dest,                                          // destination rectangle
               0, 0, image.Size.Width, image.Size.Height,  // source rectangle
               GraphicsUnit.Pixel,
               imageAttributes);
        }

        #endregion
    }
}