📜  JOGL-3D基础知识(1)

📅  最后修改于: 2023-12-03 14:43:07.159000             🧑  作者: Mango

JOGL-3D基础知识

JOGL(Java OpenGL)是一个Java编程语言的代码库,它允许Java应用程序使用OpenGL API。JOGL提供了许多OpenGL特性,例如着色器和顶点缓冲对象。

环境搭建

要开始使用JOGL进行3D编程,您需要安装JOGL库并配置您的开发环境。以下是一些简单的步骤,让您开始进入3D编程的世界。

  1. 下载JOGL库。您可以从其官方网站下载JOGL库:https://jogamp.org/deployment/jogamp-current/archive/

  2. 导入库。在您的Java项目中安装JOGL库。您可以通过使用以下操作导入库:

    file > project structure > libraries > add external jars
    
  3. 配置类路径。在您的Java项目中配置类路径,以便您的代码可以访问JOGL库。您可以通过使用以下操作配置类路径:

    run > edit configurations > VM options > -Djava.library.path=path/to/jogl/library/
    
渲染三角形

创建一个简单的3D场景,让我们首先从渲染三角形开始。以下是一个例子:

import com.jogamp.opengl.GL2;
import com.jogamp.opengl.GLAutoDrawable;
import com.jogamp.opengl.GLCapabilities;
import com.jogamp.opengl.GLEventListener;
import com.jogamp.opengl.awt.GLCanvas;

import javax.swing.*;

public class TriangleRenderer extends JFrame implements GLEventListener {
    private GLCanvas glCanvas;

    public TriangleRenderer() {
        setTitle("Triangle Renderer");
        setSize(800, 600);
        setLocationRelativeTo(null);

        GLCapabilities glCapabilities = new GLCapabilities(null);
        glCanvas = new GLCanvas(glCapabilities);
        glCanvas.addGLEventListener(this);
        getContentPane().add(glCanvas);

        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }

    public static void main(String[] args) {
        new TriangleRenderer();
    }

    @Override
    public void init(GLAutoDrawable drawable) {
        GL2 gl = drawable.getGL().getGL2();
        gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    }

    @Override
    public void display(GLAutoDrawable drawable) {
        GL2 gl = drawable.getGL().getGL2();
        gl.glClear(GL2.GL_COLOR_BUFFER_BIT);

        gl.glBegin(GL2.GL_TRIANGLES);
        gl.glColor3f(1.0f, 0.0f, 0.0f);
        gl.glVertex3f(0.0f, 1.0f, 0.0f);
        gl.glColor3f(0.0f, 1.0f, 0.0f);
        gl.glVertex3f(-1.0f, -1.0f, 0.0f);
        gl.glColor3f(0.0f, 0.0f, 1.0f);
        gl.glVertex3f(1.0f, -1.0f, 0.0f);
        gl.glEnd();
    }

    // Additional GLEventListener methods...
}

该示例创建了一个名为TriangleRenderer的Java JFrame类。该类实现了JOGL的GLEventListener接口,这意味着该类监听JOGL事件。该类渲染了一个三角形,使用了红色、绿色和蓝色的颜色。

旋转三角形

您还可以旋转三角形。以下是一个例子:

import com.jogamp.opengl.*;
import com.jogamp.opengl.awt.*;
import javax.swing.*;

public class RotatingTriangle extends JFrame implements GLEventListener {
    private GLCanvas canvas;
    private float angle = 0.0f;

    public RotatingTriangle() {
        setTitle("Rotating Triangle");
        setSize(800, 600);
        setLocationRelativeTo(null);

        GLCapabilities capabilities = new GLCapabilities(null);
        canvas = new GLCanvas(capabilities);
        getContentPane().add(canvas);

        canvas.addGLEventListener(this);

        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }

    public static void main(String[] args) {
        new RotatingTriangle();
    }

    public void display(GLAutoDrawable drawable) {
        GL2 gl = drawable.getGL().getGL2();

        gl.glClear(GL.GL_COLOR_BUFFER_BIT);

        gl.glMatrixMode(GL2.GL_MODELVIEW);
        gl.glLoadIdentity();
        gl.glRotatef(angle, 0.0f, 0.0f, 1.0f);

        gl.glBegin(GL2.GL_TRIANGLES);
        gl.glColor3f(1.0f, 0.0f, 0.0f);
        gl.glVertex3f(0.0f, 1.0f, 0.0f);
        gl.glColor3f(0.0f, 1.0f, 0.0f);
        gl.glVertex3f(-1.0f, -1.0f, 0.0f);
        gl.glColor3f(0.0f, 0.0f, 1.0f);
        gl.glVertex3f(1.0f, -1.0f, 0.0f);
        gl.glEnd();

        angle += 0.5f;
    }

    public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
        GL2 gl = drawable.getGL().getGL2();
        gl.glMatrixMode(GL2.GL_PROJECTION);
        gl.glLoadIdentity();

        float aspect = (float) width / (float) height;
        float fov = 45.0f;
        float near = 0.1f;
        float far = 100.0f;

        float top = near * (float) Math.tan(Math.toRadians(fov / 2.0));
        float bottom = -top;
        float right = top * aspect;
        float left = -right;

        gl.glFrustum(left, right, bottom, top, near, far);

        gl.glMatrixMode(GL2.GL_MODELVIEW);
    }

    public void dispose(GLAutoDrawable drawable) {

    }

    public void init(GLAutoDrawable drawable) {
        GL2 gl = drawable.getGL().getGL2();
        gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
    }
}

该示例创建了一个名为RotatingTriangle的JFrame Java类。该类实现了JOGL的GLEventListener接口,并渲染了一个三角形。在GOpenGL的渲染循环中,三角形将沿着z轴旋转。

结论

上述代码示例向您介绍了JOGL-3D基础知识。渲染一个简单的三角形,并将其旋转。您可以结合这些基础知识开发更加复杂的3D应用程序。