时间戳

首页 > 解决方案 > 如何在java中使用 glrotate 只旋转一个对象

java - 如何在java中使用 glrotate 只旋转一个对象

问题描述

我试图只旋转一个正方形，但它不起作用它旋转了所有正方形

在此代码中，当我单击 N 时，它会创建一个新正方形并将其推送到我想要的数组中，当我单击 R 时

旋转特定的正方形而不是全部

当我在谷歌上搜索时，我发现 glrotate 移动了调用后创建的所有对象，我做到了

知道是否是正确的包分配；

import static org.lwjgl.opengl.GL11.*;

import java.util.ArrayList;
import java.util.Random;

import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.LWJGLException;
import org.lwjgl.input.Keyboard;
import org.lwjgl.input.Mouse;


public class input {

private static final ArrayList<Square> shapes = new ArrayList<Square>();
private static boolean thingselected=false;
private static boolean flag=true;
public static void main(String[] args) {
    // TODO Auto-generated method stub

    try {
        Display.setDisplayMode(new DisplayMode(640, 480));
        Display.setTitle("Input Demo");
        Display.create();
    } catch (LWJGLException e) {
        e.printStackTrace();
        Display.destroy();
        System.exit(1);
    }
   
    
    
    glMatrixMode(GL_PROJECTION);
    glOrtho(0, 640, 480, 0, 1, -1);
    glMatrixMode(GL_MODELVIEW);
    
    shapes.add(new Square(20,20));
    
    while (!Display.isCloseRequested()) {

        glClear(GL_COLOR_BUFFER_BIT);
        if (Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)) {
            Display.destroy();
            System.exit(0);
        }
        


 while(Keyboard.next()) {
            if(Keyboard.getEventKey()==Keyboard.KEY_N && Keyboard.getEventKeyState()) {
                shapes.add(new Square(15,15));
            }
   }
    
            for (final Square square:shapes) {
                System.out.println(square.rotated);
                if(Mouse.isButtonDown(0) && square.ismoved(Mouse.getX(),480-`Mouse.getY())&&!thingselected) {`
                    square.selected=true;
                thingselected=true;
            }
            
            if(square.selected) {
                square.update(Mouse.getDX(), -Mouse.getDY());
            }
            
            if(Mouse.isButtonDown(1) ) {
                square.selected=false;
                thingselected=false;
            }
            

            if(Keyboard.isKeyDown(Keyboard.KEY_C)&&square.ismoved(Mouse.getX(),480-Mouse.getY())&&!thingselected ) {
                square.changeColor();
            }
            
              if(Keyboard.getEventKey() == Keyboard.KEY_R && square.ismoved(Mouse.getX(),480-Mouse.getY())){
                        if(flag)
                            square.rotated=true;
                        if(square.rotated)
                        {
                            square.rotate();
                            
                        }
                        flag = false;
              }
              if(Keyboard.getEventKey() == Keyboard.KEY_T) {
                    square.transelate();
                }
            square.draw();
            
        }
        
        
        Display.update();
        Display.sync(60);
    }

    Display.destroy();
    }

    
private static class Square{
    
    public int x,y;
    private float red,green,blue;
    public boolean selected=false;
    public boolean rotated=false;
    
    Square(int x, int y){
        this.x=x;
        this.y=y;
        
        Random random=new Random();
        red=random.nextFloat();
        green=random.nextFloat();
        blue=random.nextFloat();

    }
    
    
    void draw() {
        glColor3f(red, green, blue);
        glBegin(GL_QUADS);
        glVertex2f(x, y);
        glVertex2f(x+50, y);
        glVertex2f(x+50, y+50);
        glVertex2f(x, y+50);

        glEnd();
    }
    
    boolean ismoved(int mousex,int mousey) {
        return mousex > x && mousex < x+50 && mousey > y && mousey < y+50;
    }
    
    void update(double dx,double dy) {
        x+=dx;
        y+=dy;
    }
    
    void changeColor() {
        Random random=new Random();
        red=random.nextFloat();
        green=random.nextFloat();
        blue=random.nextFloat();
    }
    
    
    void transelate() {
        glTranslated(0.1, 0, 0);
    }
    
    void rotate() {
            
            glRotated(0.1, 0, 0, 1);
            
            
    }
}

标签： javaopenglgraphicslwjglglrotate

解决方案

glRotate并glTranslate操纵当前矩阵。您必须在绘制对象之前进行旋转和平移。使用 glPushMatrix和glPopMatrix（参见glPushMatrix/glPopMatrix）在更改它之前将当前矩阵保存在矩阵堆栈上，并在绘制对象后恢复它。
为旋转和平移添加变量并translate在roatate. 使用中的变量draw：

private static class Square {

    private double translateX, angleZ;

    // [...]

    void draw() {
       
        glPushMatrix(); 
       
        glTranslated(translateX, 0, 0);
        glRotated(angleZ, 0, 0, 1);  

        glColor3f(red, green, blue);
        glBegin(GL_QUADS);
        glVertex2f(x, y);
        glVertex2f(x+50, y);
        glVertex2f(x+50, y+50);
        glVertex2f(x, y+50);
        glEnd();

        glPopMatrix();
    }

    void transelate() {
        translateX += 0.1;
    }
    
    void rotate() {       
        angleZ += 0.1;        
    }
}

推荐阅读