练习63 手电筒效果.doc

练习63 手电筒效果本例知识点一句话讲解新学知识使用ColorModel类制作颜色模板使用PixelGrabber类处理像素效果已学知识使用Color类处理颜色使用Graphics类处理图像一、练习具体要求本练习制作手电筒效果的实例。如图63-1所示，程序执行后，创建一个能够加载图片的面板，随后将会出现一束绿色的光束在图片上方扫描，形成手电筒效果。手电筒的光束颜色和光束大小都可以通过stn_bump.html文件的参数进行设置。当鼠标移动到图片上方时，窗口左下方的状态栏将会出现响应的动作提示。二、程序及注释（1）编程思路：首先，本练习因为要制作手电筒效果的实例，所以首先要生成程序界面：在函数public void init()中，首先通过函数int getParameter(String s1, int s2)和函数String getParameter(String s1, String s2)得到stn_bump.html文件中的参数，然后通过语句m_dimWindow = new Dimension(getSize().width, getSize().height)得到屏幕尺寸，resize(m_dimWindow)语句设置屏幕尺寸。最后通过m_colormodel = new DirectColorModel(24, 0xff0000, 65280, 255)制作颜色模板。然后，为了实现手电筒效果，所以要进行颜色设置，在函数public void run()中，首先通过语句mediatracker.addImage(m_imgColor, 0)和ediatracker.addImage(m_imgBump, 0)设置颜色，然后通过实例化PixelGrabber类来进行像素的颜色设置，实现手电筒的光照效果。（2）程序实现及注释：/stn_bump.javaimport java.applet.Applet;import java.applet.AppletContext;import java.awt.*;import java.awt.image.*;import .MalformedURLException;import .URL;public class stn_bump extends Applet implements Runnable /变量定义 private String m_bmColor = null; private String m_bmBump = null; private String m_link = null; private String m_descr = null; private int m_garbage = 0; private int m_sleep = 0; private int m_hred = 0; private int m_hgreen = 0; private int m_hblue = 0; private int m_hexp = 0; private final String PARAM_bmColor = color; private final String PARAM_bmBump = bump; private final String PARAM_link = link; private final String PARAM_descr = descr; private final String PARAM_garbage = garbage; private final String PARAM_sleep = sleep; private final String PARAM_hred = hred; private final String PARAM_hgreen = hgreen; private final String PARAM_hblue = hblue; private final String PARAM_hexp = hexp; Dimension m_dimWindow = null; boolean m_bImgLoaded = false; Image m_imgColor = null; Image m_imgBump = null; Thread m_animator = null; ColorModel m_colormodel = null; Dimension m_dimBitmap = null; int m_rawColor = null; int m_rawBump = null; int m_rawPhong = null; int m_offsetBump = null; int m_bitmap = null; boolean m_bMouseMove = false; int m_iCenterX = 0; int m_iCenterY = 0; /启动小程序 public void start() if(m_animator = null) m_animator = new Thread(this); m_animator.setPriority(10); m_animator.start(); /停止小程序 public void stop() m_animator = null; /响应鼠标进入 public boolean mouseEnter(Event event, int i, int j) if(m_animator != null) showStatus(m_descr); m_bMouseMove = true; return true; /响应鼠标退出 public boolean mouseExit(Event event, int i, int j) if(m_animator != null) showStatus(); m_bMouseMove = false; return true; /响应鼠标按下 public boolean mouseDown(Event event, int i, int j) if(m_animator != null & m_link != null) URL url; try url = new URL(m_link); catch(MalformedURLException _ex) showStatus(URL + m_link + is invalid!); return true; getAppletContext().showDocument(url); return true; /画屏函数 public void paint(Graphics g) if(m_animator != null) MemoryImageSource memoryimagesource = new MemoryImageSource(m_dimBitmap.width, m_dimBitmap.height, m_colormodel, m_bitmap, 0, m_dimBitmap.width); Image image = createImage(memoryimagesource); g.drawImage(image, 0, 0, m_dimWindow.width, m_dimWindow.height, this); /刷新图片 public boolean imageUpdate(Image image, int i, int j, int k, int l, int m) return true; /运行小程序 public void run() float f3 = 0.0F; float f4 = 0.0F; if(!m_bImgLoaded) repaint(); MediaTracker mediatracker = new MediaTracker(this); m_imgColor = getImage(getDocumentBase(), m_bmColor); m_imgBump = getImage(getDocumentBase(), m_bmBump); mediatracker.addImage(m_imgColor, 0); mediatracker.addImage(m_imgBump, 0); try mediatracker.waitForAll(); m_bImgLoaded = !mediatracker.isErrorAny(); catch(InterruptedException _ex) if(!m_bImgLoaded) stop(); getGraphics().drawString(Error loading images!, 10, 40); return; if(m_imgColor.getHeight(this)!=m_imgBump.getHeight(this) | m_imgColor.getWidth(this) != m_imgBump.getWidth(this) stop(); getGraphics().drawString( Images must have same extends!, 10, 40); return; m_dimBitmap = new Dimension(m_imgColor.getWidth(this), m_imgColor.getHeight(this); m_bitmap=new intm_dimBitmap.width * m_dimBitmap.height; m_rawColor=new intm_dimBitmap.width * m_dimBitmap.height; PixelGrabber pixelgrabber = new PixelGrabber(m_imgColor, 0, 0, m_dimBitmap.width, m_dimBitmap.height, m_rawColor, 0, m_dimBitmap.width); try pixelgrabber.grabPixels(); catch(InterruptedException _ex) stop(); getGraphics().drawString( Error retrieving image data of + m_bmColor + !, 10, 40); return; m_rawBump = new intm_dimBitmap.width * m_dimBitmap.height; PixelGrabber pixelgrabber1 = new PixelGrabber(m_imgBump, 0, 0, m_dimBitmap.width, m_dimBitmap.height, m_rawBump, 0, m_dimBitmap.width); try pixelgrabber1.grabPixels(); catch(InterruptedException _ex) stop(); getGraphics().drawString( Error retrieving image data of + m_bmBump + !, 10, 40); return; m_offsetBump = new intm_dimBitmap.width * m_dimBitmap.height; for(int p_row = 1; p_row m_dimBitmap.height - 1; p_row+) int p_col = p_row * m_dimBitmap.width + 1; for(int i = 1; i 1) - (m_rawBumpp_col + 1 & 0xff) 1); int pBump2 = (m_rawBumpp_col - m_dimBitmap.width & 0xff) 1) - (m_rawBumpp_col + m_dimBitmap.width & 0xff) 1); m_offsetBumpp_col = (pBump1 & 0xff) + (pBump2 & 0xff) 1.0F) light_color = 0.0F; else light_color = (float)Math.pow(Math.cos(Math.sqrt(edge1 + edge2) * Math.PI) / 2D), m_hexp); int setRed = (int)(light_color * (float)m_hred); int setGreen = (int)(light_color * (float)m_hgreen); int setBlue = (int)(light_color * (float)m_hblue); if(setRed 8 & setGreen 8 & setBlue 8) setRed = 0; setGreen = 0; setBlue = 0; m_rawPhongbase2 = setBlue + (setGreen 8) + (setRed 16); base2+; while(+j 256); while(+base1 256); repaint(); int i5 = m_garbage; do do if(!m_bMouseMove) m_iCenterX = (int)(128D - (double) (float)m_dimBitmap.width / 2.0F) + (Math.sin(f3) * (double)(float)m_dimBitmap.width) / 2D) / 2D); m_iCenterY = (int)(128D - (double) (float)m_dimBitmap.height / 2.0F) + (Math.sin(f4) * (double)(float)m_dimBitmap.height) / 2D) / 2D); f3 += 0.04846F; f4 += 0.06145F; for(int p_row=0;p_rowm_dimBitmap.height;p_row+) int light_x = p_row * m_dimBitmap.width; int light_y = (p_row / 2 + m_iCenterY) * 256 + m_iCenterX; for(int p_col=0; p_col 0xff0000) cRed = 0xff0000; if(cGreen 65280) cGreen = 65280; if(cBlue 255) cBlue = 255; m_bitmaplight_x=cRed|cGreen|cBlue; else m_bitmaplight_x = pColor; light_x+; paint(getGraphics(); if(-i5 0) System.gc(); i5 = m_garbage; while(m_sleep = 0 | m_animator = null); try Thread.sleep(m_sleep); catch(InterruptedException _ex) stop(); return; while(true); /得到一个字符串和一个整数型的参数 int getParameter(String s1, int s2) String s = getParameter(s1) ; return (s != null) ? Integer.parseInt(s) : s2 ; /得到两个字符串的参数 String getParameter(String s1, String s2) String s = getParameter(s1) ; return (s != null) ? s : s2 ; /初始化小程序 public void init() m_bmColor = getParameter(color,color.gif); m_bmBump = getParameter(bump,bump.gif); m_link = getParameter(link,localhost); m_descr = getParameter(descr,Hello World); m_garbage = getParameter(garbage,16); m_sleep = getParameter(sleep,20); m_hred = getParameter(hred,32); m_hgreen = getParameter(hgreen,192); m_hblue = getParameter(hblue,192); m_hexp = getParameter(hexp,8); m_dimWindow = new Dimension(getSi