Tạo hiệu ứng chuyển hình ảnh - Thumb Rotator

Bài viết hôm nay mình thay đổi không khí 1 xíu, mình sẽ giới thiệu để các bạn bài về tạo hiệu ứng chuyển ảnh xoay tròn giống JavaScript cho web. Các bạn xem demo bên dưới để hiểu rõ thêm nha

Sau đây là code của chương trình

    public partial class Form1 : Form
    {
        float m_Alfa = 0;
        ThumbElement m_Selected = null;
        float m_AlfaAccel = 1;
        float m_Perspective= 4;
        double PI_FACT = Math.PI / 180.0f;
        List m_arImages = new List();
        List m_arFO=new List();

        public Form1()
        {
            InitializeComponent();

            this.SetStyle(
                ControlStyles.UserPaint |
                ControlStyles.AllPaintingInWmPaint |
                ControlStyles.DoubleBuffer, true);

            LoadThumbs();

            m_Timer.Interval = 30;
            m_Timer.Tick += new EventHandler(m_Timer_Tick);
            m_Timer.Enabled = true;
        }

        void m_Timer_Tick(object sender, EventArgs e)
        {
            m_Alfa += m_AlfaAccel;
            if (m_Alfa > 360)
                m_Alfa = m_Alfa - 360;
            if (m_Alfa < 0)
                m_Alfa = m_Alfa + 360;
            //
            int maxDX = Bounds.Width/2;
            int maxDY = Bounds.Height/2;
            for (int i = 0; i < m_arFO.Count; i++)
            {
                FlyingObject f = m_arFO[i];
                Rectangle rc;
                int newWidth = 0;
                int newHeight = 0;
                if (newWidth*f.m_bmpFLyingBitmap.Height/f.m_bmpFLyingBitmap.Width> maxDY)
                {
                    newWidth = maxDX;
                    newHeight = newWidth * f.m_bmpFLyingBitmap.Height / f.m_bmpFLyingBitmap.Width;
                }
                else
                {
                    newHeight= maxDY;
                    newWidth = newHeight * f.m_bmpFLyingBitmap.Width/ f.m_bmpFLyingBitmap.Height;
                }
                rc = new Rectangle(Bounds.Width / 2 - newWidth / 2,
                    Bounds.Height / 2 - newHeight / 2,
                    newWidth,
                    newHeight);
                switch (f.m_nFBState)
                {
                    case 0:
                        {
                            f.m_rcFB = new Rectangle(
                                f.m_rcFBStart.X + (rc.X - f.m_rcFBStart.X) * f.m_nFBPerc / 100,
                                f.m_rcFBStart.Y + (rc.Y - f.m_rcFBStart.Y) * f.m_nFBPerc / 100,
                                f.m_rcFBStart.Width + (rc.Width - f.m_rcFBStart.Width) * f.m_nFBPerc / 100,
                                f.m_rcFBStart.Height + (rc.Height - f.m_rcFBStart.Height) * f.m_nFBPerc / 100
                                );

                            f.m_nFBPerc += 5;

                            if (f.m_nFBPerc > 100)
                            {
                                f.m_nFBPerc = 100;
                                f.m_nFBState = 0;
                            }
                        }
                        break;
                    case 1:
                        break;
                    case 2:
                        {
                            f.m_rcFB = new Rectangle(
                                f.m_rcFB.X + (f.m_tRef.m_Rect.X - f.m_rcFB.X) * (100 - f.m_nFBPerc) / 100,
                                f.m_rcFB.Y + (f.m_tRef.m_Rect.Y - f.m_rcFB.Y) * (100 - f.m_nFBPerc) / 100,
                                f.m_rcFB.Width + (f.m_tRef.m_Rect.Width - f.m_rcFB.Width) * (100 - f.m_nFBPerc) / 100,
                                f.m_rcFB.Height + (f.m_tRef.m_Rect.Height - f.m_rcFB.Height) * (100 - f.m_nFBPerc) / 100
                                );

                            f.m_nFBPerc -= 5;

                            if (f.m_nFBPerc < 0)
                            {
                                m_arFO.RemoveAt(i);
                                i--;
                            }
                        }
                        break;
                }
            }

            Refresh();
        }

        Timer m_Timer = new Timer();

        void LoadThumbs()
        {
            String[] arStrings=Directory.GetFiles(Application.StartupPath+"Image");
            FormProgress pb = new FormProgress();
            pb.Show();
            for (int i = 0; i < arStrings.Length; i++)
            {
                pb.progressBar1.Value= (i+1) * 100 / arStrings.Length;
                pb.Refresh();
                m_arImages.Add(new ThumbElement(arStrings[i]));
            }
            pb.Visible=false;
            pb.Dispose();
            pb = null;
            for (int i = 0; i < m_arImages.Count; i++)
                m_arImages[i].m_dAngleOriginal = (float)i * (360.0f) / (float)m_arImages.Count;
        }

        protected override void OnPaintBackground(PaintEventArgs e)
        {
            //base.OnPaintBackground(e);
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            Color c=Color.FromArgb(255,0,0,0);
            e.Graphics.FillRectangle(new SolidBrush(c),0,0,Width,Height);

            int x0 = Width / 2;
            int y0 = Height / 2;

            int nRadX = (Width / 2) * 7 / 10;
            int nRadY = (int)(nRadX / m_Perspective);

            for (int i = 0; i < m_arImages.Count; i++)
            {
                ThumbElement t = m_arImages[i];

                m_arImages[i].m_dAngleActual = (m_arImages[i].m_dAngleOriginal + m_Alfa)*PI_FACT;

                m_arImages[i].m_dDistanceFromScreen = 10 + 10 * Math.Cos(m_arImages[i].m_dAngleActual);

                int x = x0 + (int)(nRadX * Math.Sin(t.m_dAngleActual));
                int y = y0 - (int)(nRadY * Math.Cos(t.m_dAngleActual));

                float dSize = (float)(80 - 20 * Math.Cos(t.m_dAngleActual));

                dSize = dSize / 100;

                t.m_Rect.X = (int)(x - (t.m_bmpMain.Width * dSize) / 2);
                t.m_Rect.Y = (int)(y - (t.m_bmpMain.Height * dSize));
                t.m_Rect.Width = (int)(t.m_bmpMain.Width * dSize);
                t.m_Rect.Height = (int)(t.m_bmpMain.Height * dSize);

                t.m_RectShadow.X = (int)(x - (t.m_bmpMain.Width * dSize) / 2);
                t.m_RectShadow.Y = (int)y;
                t.m_RectShadow.Width = (int)(t.m_bmpMain.Width * dSize);
                t.m_RectShadow.Height = (int)(t.m_bmpMain.Height * dSize);
            }

            m_arImages.Sort(delegate(ThumbElement p1, ThumbElement p2) { return p2.m_dDistanceFromScreen.CompareTo(p1.m_dDistanceFromScreen); });

            int nIndex = -1;
            Point ptClient = PointToClient(MousePosition);

            for (int i = m_arImages.Count - 1; i >= 0 && nIndex==-1; i--)
            {
                ThumbElement t = m_arImages[i];

                if (t.m_Rect.Contains(ptClient))
                    nIndex=i;
            }
            m_Selected = null;

            if (nIndex!=-1)
                m_Selected = m_arImages[nIndex];

            for (int i = 0; i < m_arImages.Count; i++)
            {
                ThumbElement t=m_arImages[i];

                float dTrasp = (float)(100 + 100 * Math.Cos(t.m_dAngleActual));

                e.Graphics.DrawImage(t.m_bmpMain, t.m_Rect);
                e.Graphics.DrawImage(t.m_bmpShadow, t.m_RectShadow);

                if (nIndex != i)
                {
                    SolidBrush sb = new SolidBrush(Color.FromArgb((int)dTrasp, c.R, c.G, c.B));
                    e.Graphics.FillRectangle(sb, t.m_Rect);
                    e.Graphics.FillRectangle(sb, t.m_RectShadow);
                }

                if (nIndex == i)
                    e.Graphics.DrawRectangle(Pens.White, t.m_Rect);
            }

            for (int i=0;i

Tiếp theo là khai báo các đối tượng

    class ThumbElement
    {
        static public int m_ThumbSize=200;

        public Bitmap m_bmpOriginal = null;

        public Bitmap m_bmpMain= null;
        public Bitmap m_bmpShadow = null;

        public double m_dAngleOriginal = 0;
        public double m_dAngleActual = 0;

        public double m_dDistanceFromScreen = 0;

        public Rectangle m_Rect = new Rectangle();
        public Rectangle m_RectShadow = new Rectangle();

        public ThumbElement(String strFileName)
        {
            m_bmpOriginal = new Bitmap(strFileName);

            int nWidth=m_ThumbSize;
            int nHeight=m_bmpOriginal.Height*m_ThumbSize/m_bmpOriginal.Width;

            if (nHeight>m_ThumbSize)
            {
                nHeight=m_ThumbSize;
                nWidth=m_bmpOriginal.Width*m_ThumbSize/m_bmpOriginal.Height;
            }

            m_bmpMain=new Bitmap(nWidth,nHeight);
            
            Graphics g=Graphics.FromImage(m_bmpMain);

            g.DrawImage(m_bmpOriginal, 0, 0, nWidth, nHeight);

            m_bmpShadow = new Bitmap(m_bmpMain);

            unsafe
            {
                m_bmpShadow.RotateFlip(RotateFlipType.RotateNoneFlipY);

                System.Drawing.Imaging.BitmapData bmd = m_bmpShadow.LockBits(new Rectangle(0, 0, m_bmpShadow.Width, m_bmpShadow.Height),
                    System.Drawing.Imaging.ImageLockMode.ReadWrite,
                    m_bmpShadow.PixelFormat);

                int PixelSize = 4;

                byte* row = (byte*)bmd.Scan0;

                for (int y = 0; y < bmd.Height; y++)
                {
                    byte trasp = (byte)(100 * ((m_bmpMain.Height - y)) / m_bmpMain.Height);

                    int xx = 3;

                    for (int x = 0; x < bmd.Width; x++)
                    {
                        row[xx] = trasp;

                        xx += PixelSize;
                    }

                    row += bmd.Stride;
                }
                m_bmpShadow.UnlockBits(bmd);
            }
        }
    }

    class FlyingObject
    {
        public Bitmap m_bmpFLyingBitmap = null;
        public Rectangle m_rcFBStart = new Rectangle();
        public Rectangle m_rcFB = new Rectangle();
        public int m_nFBPerc = 0;
        public int m_nFBState = 0;
        public ThumbElement m_tRef = null;
    }

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