请教，怎样在全屏相机画布上绘制其它东西

2009-10-20 09:59:31 224 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

URP相机系统深度解析：从基础配置到高级渲染策略实战在实时渲染管线中，相机（Camera）是定义视锥体、控制画面呈现的核心组件。其工作原理涉及几何变换、裁剪与投影，将3D场景转换为2D图像。通用渲染管线（URP）通过模块化设计提升了渲染策略的灵活性与性能。相机堆栈（Camera Stack）和渲染器资源（Renderer Asset）等技术，允许开发者对渲染流程进行精细控制，实现UI与场景分离、多重视角等复杂需求，从而优化渲染效率并提升视觉表现。本文聚焦于URP相机系统，深入探讨如何通过配置Base与Overlay相机、设计Renderer Features 阅读详情

import java.io.IOException;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;
import javax.microedition.media.Manager;
import javax.microedition.media.MediaException;
import javax.microedition.media.Player;
import javax.microedition.media.control.VideoControl;
import javax.microedition.midlet.MIDlet;

public class VideoControlExample extends MIDlet {
private Display display;
private Form form;
private Player player;
private VideoControl videoControl;
private Video video;

public VideoControlExample() {
display = Display.getDisplay(this);
showCamera();
}

public void startApp() {
display.setCurrent(form);
}

public void pauseApp() {}

public void destroyApp(boolean unconditional){
notifyDestroyed();
}

public void showCamera(){
try{
player = Manager.createPlayer("capture://video");
player.realize();
videoControl = (VideoControl)player.getControl("VideoControl");
Canvas canvas = new VideoCanvas(this, videoControl);
videoControl.setDisplayFullScreen(true);//当去掉这句话时，照相机的屏幕占据了整个画布，在上面绘制的东西就没了
videoControl.setVisible(true);
player.start();
display.setCurrent(canvas);
player.start();
} catch (IOException ioe) {} catch (MediaException me) {}
}

class Video extends Thread {
VideoControlExample midlet;
public Video(VideoControlExample midlet) {
this.midlet = midlet;
}

public void run() {
captureVideo();
}

public void captureVideo() {
try {
byte[] photo = videoControl.getSnapshot(null);
Image image = Image.createImage(photo, 0, photo.length);
form.append(image);
display.setCurrent(form);
player.close();
player = null;
videoControl = null;
} catch (MediaException me) { }
}
};
}

class VideoCanvas extends Canvas {

public VideoCanvas(VideoControlExample midlet, VideoControl videoControl) {
this.setFullScreenMode(true);
int width = getWidth();
int height = getHeight();

videoControl.initDisplayMode(VideoControl.USE_DIRECT_VIDEO, this);
try {
videoControl.setDisplayLocation(2, 2);
videoControl.setDisplaySize(width - 4, height - 4);
} catch (MediaException me) {}
videoControl.setVisible(true);
}

public void paint(Graphics g) {
int width = getWidth();
int height = getHeight();

g.setColor(255, 0, 0);
g.drawRect(0, 0, width - 1, height - 1);
g.drawRect(1, 1, width - 3, height - 3);
g.setColor(0x000000);
g.drawString("拍照", 0, 0, 0);
}
}

当去掉videoControl.setDisplayFullScreen(true)，后面paint方法中绘制的字符串（或者小图片）就会没了，怎样解决啊？

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