C#水波纹能量传递特效实现

【实例简介】

    通过模拟水波能量传递的，界面上溅起涟漪，程序中，用一个页面装载原始的图象，用另外一个页面来进行渲染。先用 Lock 函数锁定两个页面，取得指向页面内存区的指针，然后用根据偏移量将原始图象上的每一个象素复制到渲染页
面上

【实例截图】

【核心代码】

       //绘制水波
        private void timerDraw_Tick(object sender, EventArgs e) {
            int nNewX = 0;
            int nNewY = 0;
            BitmapData bmpData = m_bmp.LockBits(new Rectangle(0, 0, m_bmp.Width, m_bmp.Height), ImageLockMode.ReadWrite, m_bmp.PixelFormat);
            Marshal.Copy(bmpData.Scan0, m_byArrClrBuff, 0, m_byArrClrBuff.Length);
            for (int y = 1; y < m_nBmpHeight - 1; y  ) {
                for (int x = 1; x < m_nBmpWidth - 1; x  ) {
                    m_nArrWaveNext[x, y] = ((               //能量传递
                        m_nArrWaveCurrent[x - 1, y]         //注意 能量传递是通过当前波形计算新的波形
                        m_nArrWaveCurrent[x   1, y]         //m_nArrWaveCurrent m_nArrWaveNext 不要弄翻
                        m_nArrWaveCurrent[x, y - 1]  
                        m_nArrWaveCurrent[x, y   1])
                        >> 1) - m_nArrWaveNext[x, y];
                    m_nArrWaveNext[x, y] -= m_nArrWaveNext[x, y] >> 5;  //产生阻尼
                    //像素偏移 (模拟折射)
                    nNewX = ((m_nArrWaveNext[x   1, y] - m_nArrWaveNext[x - 1, y]) >> 0)   x;   //右移越大 折射变大
                    nNewY = ((m_nArrWaveNext[x, y   1] - m_nArrWaveNext[x, y - 1]) >> 0)   y;   //左移也可 折射变小

                    if (nNewX == x && nNewY == y) continue;     //没有产生像素偏移 直接跳过
                    if (nNewX < 0) nNewX = -nNewX;              //也可将其赋值为 0
                    if (nNewX >= m_nBmpWidth) nNewX = m_nBmpWidth - 1;
                    if (nNewY < 0) nNewY = -nNewY;
                    if (nNewY >= m_nBmpHeight) nNewY = m_nBmpHeight - 1;
                    //模拟光的反射 也可以跳过 不过波纹明暗度不明显
                    //m_byArrClrBuff[y * m_nBmpWidthBySize   x * 3] = m_byArrClrInfo[nNewY * m_nBmpWidthBySize   nNewX * 3];
                    //m_byArrClrBuff[y * m_nBmpWidthBySize   x * 3   1] = m_byArrClrInfo[nNewY * m_nBmpWidthBySize   nNewX * 3   1];
                    //m_byArrClrBuff[y * m_nBmpWidthBySize   x * 3   2] = m_byArrClrInfo[nNewY * m_nBmpWidthBySize   nNewX * 3   2];
                    //continue;
                    int nIncrement = m_nArrWaveNext[x, y];      //用当前像素点的能量作为光线明暗度变化标志
                    nIncrement >>= nIncrement < 0 ? 5 : 3;      //如果负数变暗 正数变量 (适当的位移一下不然差距太大)
                    //重置RGB值
                    int r = m_byArrClrInfo[nNewY * m_nBmpWidthBySize   nNewX * 3]   nIncrement;
                    int g = m_byArrClrInfo[nNewY * m_nBmpWidthBySize   nNewX * 3   1]   nIncrement;
                    int b = m_byArrClrInfo[nNewY * m_nBmpWidthBySize   nNewX * 3   2]   nIncrement;
                    if (nIncrement < 0) {       //如果是负数便是变暗 则不能让其越界 0 - 255 
                        r = r < 0 ? 0 : r;
                        g = g < 0 ? 0 : g;
                        b = b < 0 ? 0 : b;
                    } else {
                        r = r > 255 ? 255 : r;
                        g = g > 255 ? 255 : g;
                        b = b > 255 ? 255 : b;
                    }
                    m_byArrClrBuff[y * m_nBmpWidthBySize   x * 3] = (byte)r;
                    m_byArrClrBuff[y * m_nBmpWidthBySize   x * 3   1] = (byte)g;
                    m_byArrClrBuff[y * m_nBmpWidthBySize   x * 3   2] = (byte)b;
                }
            }
            Marshal.Copy(m_byArrClrBuff, 0, bmpData.Scan0, m_byArrClrBuff.Length);
            m_bmp.UnlockBits(bmpData);
            pictureBox1.Refresh();
            //交换能量缓存 将新产生的波形 赋值给当前波形的缓存 计算下一帧的波形
            int[,] temp = m_nArrWaveCurrent;
            m_nArrWaveCurrent = m_nArrWaveNext;
            m_nArrWaveNext = temp;
        }