Java使用Maven工程操作OpenGL ES绘制三角形和圆形;绘制完成后操作键盘控制然图形移动

OpenGL ES 绘制三角形,操作键盘移动位置

PS:想快速看到效果的小伙伴,可以在引入依赖后,先跳到完整代码部分

第一步:依赖引入

	<properties>
        <lwjgl.version>3.2.3</lwjgl.version>
        <joml.version>1.9.25</joml.version>
        <steamworks4j.version>1.8.0</steamworks4j.version>
        <steamworks4j-server.version>1.8.0</steamworks4j-server.version>
    </properties>

    <profiles>
        <profile>
            <id>lwjgl-natives-macos-amd64</id>
            <activation>
                <os>
                    <family>mac</family>
                    <arch>amd64</arch>
                </os>
            </activation>
            <properties>
                <lwjgl.natives>natives-macos</lwjgl.natives>
            </properties>
            <dependencies>
                <dependency>
                    <groupId>org.lwjgl</groupId>
                    <artifactId>lwjgl-vulkan</artifactId>
                    <classifier>natives-macos</classifier>
                </dependency>
            </dependencies>
        </profile>
        <profile>
            <id>lwjgl-natives-windows-amd64</id>
            <activation>
                <os>
                    <family>windows</family>
                    <arch>amd64</arch>
                </os>
            </activation>
            <properties>
                <lwjgl.natives>natives-windows</lwjgl.natives>
            </properties>
        </profile>
        <profile>
            <id>lwjgl-natives-windows-x86</id>
            <activation>
                <os>
                    <family>windows</family>
                    <arch>x86</arch>
                </os>
            </activation>
            <properties>
                <lwjgl.natives>natives-windows-x86</lwjgl.natives>
            </properties>
        </profile>
    </profiles>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.lwjgl</groupId>
                <artifactId>lwjgl-bom</artifactId>
                <version>${lwjgl.version}</version>
                <scope>import</scope>
                <type>pom</type>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-assimp</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-bgfx</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-cuda</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-egl</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-glfw</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-jawt</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-jemalloc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-libdivide</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-llvm</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-lmdb</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-lz4</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-meow</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-nanovg</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-nfd</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-nuklear</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-odbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-openal</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-opencl</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-opengl</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-opengles</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-openvr</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-opus</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-ovr</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-par</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-remotery</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-rpmalloc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-shaderc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-sse</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-stb</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-tinyexr</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-tinyfd</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-tootle</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-vma</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-vulkan</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-xxhash</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-yoga</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-zstd</artifactId>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-assimp</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-bgfx</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-glfw</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-jemalloc</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-libdivide</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-llvm</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-lmdb</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-lz4</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-meow</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-nanovg</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-nfd</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-nuklear</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-openal</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-opengl</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-opengles</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-openvr</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-opus</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-ovr</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-par</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-remotery</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-rpmalloc</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-shaderc</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-sse</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-stb</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-tinyexr</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-tinyfd</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-tootle</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-vma</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-xxhash</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-yoga</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.lwjgl</groupId>
            <artifactId>lwjgl-zstd</artifactId>
            <classifier>${lwjgl.natives}</classifier>
        </dependency>
        <dependency>
            <groupId>org.joml</groupId>
            <artifactId>joml</artifactId>
            <version>${joml.version}</version>
        </dependency>
        <dependency>
            <groupId>com.code-disaster.steamworks4j</groupId>
            <artifactId>steamworks4j</artifactId>
            <version>${steamworks4j.version}</version>
        </dependency>
        <dependency>
            <groupId>com.code-disaster.steamworks4j</groupId>
            <artifactId>steamworks4j-server</artifactId>
            <version>${steamworks4j-server.version}</version>
        </dependency>
    </dependencies>

第二步:创建类,引入需要的包,设置全局参数

1.创建类
public class TriangleExample {
......
}
2. 包引入
import org.lwjgl.glfw.*;
import org.lwjgl.opengl.*;
import org.lwjgl.system.MemoryStack;
import static org.lwjgl.glfw.GLFW.*;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.system.MemoryUtil.*;

import java.nio.IntBuffer;
import java.util.Objects;
import java.util.Random;
3. 全局参数
    // 窗口句柄
    private long window;
    // x坐标
    private float triangleX = 0.0f;
    // y坐标
    private float triangleY = 0.0f;
    // 步长
    private final float triangleSpeed = 0.05f;

第三步:定义一个初始化方法 init()

1. GLFW 错误信息的回调函数

这样做,在发生 GLFW 错误时,错误信息将被打印到标准错误流(System.err)

	GLFWErrorCallback.createPrint(System.err).set();
2. 初始化 GLFW 库
	if (!glfwInit()) {
           throw new IllegalStateException("Unable to initialize GLFW");
 	}
3. 窗口设置
    //设置默认的窗口提示参数
    glfwDefaultWindowHints();
    //设置窗口不可见
    glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
    //设置窗口可调整大小
    glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);
    //指定窗口宽度
    int width = 500;
    //指定窗口高度
    int height = 500;
    //创建一个指定大小和标题的窗口。
    window = glfwCreateWindow(width, height, "OpenGL Triangle Example", NULL, NULL);
    //如果创建失败,抛出一个运行时异常
    if (window == NULL) {
        throw new RuntimeException("Failed to create the GLFW window");
    }
4. 设置键盘回调函数
  • 参数说明:
    • window: 表示触发键盘事件的窗口句柄。它指定了事件发生的窗口。
    • key:表示被按下或释放的键的键码。每个按键都有一个对应的唯一键码,用于标识不同的按键。
    • scancode:表示键的扫描码。扫描码是键盘硬件生成的唯一标识符,它与特定的键码相对应。
    • action: 表示键盘事件的动作类型。它可以有以下几种取值
      • GLFW_PRESS:按下了键。
      • GLFW_RELEASE:释放了键。
      • GLFW_REPEAT:重复按下了键,通常在按键持续按下时触发。
    • mods: 表示与键盘事件同时按下的修饰键(如 Shift、Ctrl、Alt 等),它是一个位字段,通过对特定位进行设置来表示修饰键的状态。

我们这里监听上下左右键,aswd键和一个esc退出键

	glfwSetKeyCallback(window, (window, key, scancode, action, mods) -> {
        if (key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE) {
            glfwSetWindowShouldClose(window, true);
        }
        if (key == GLFW_KEY_LEFT || key == GLFW_KEY_A) {
            triangleX -= triangleSpeed;
        } else if (key == GLFW_KEY_RIGHT || key == GLFW_KEY_D) {
            triangleX += triangleSpeed;
        } else if (key == GLFW_KEY_UP || key == GLFW_KEY_W) {
            triangleY += triangleSpeed;
        } else if (key == GLFW_KEY_DOWN || key == GLFW_KEY_S) {
            triangleY -= triangleSpeed;
        }
    });
5. 创建一个内存栈,窗口定位
	try (MemoryStack stack = MemoryStack.stackPush()) {
        //使用内存栈分配两个整型缓冲区,用于存储窗口的宽度和高度
        IntBuffer pWidth = stack.mallocInt(1);
        IntBuffer pHeight = stack.mallocInt(1);
        //获取窗口的实际大小,并将宽度和高度存储到缓冲区中
        glfwGetWindowSize(window, pWidth, pHeight);
        //获取当前主显示器的视频模式
        GLFWVidMode vidMode = glfwGetVideoMode(glfwGetPrimaryMonitor());
        //将窗口定位到屏幕中心,根据窗口和屏幕尺寸计算得到位置。
        glfwSetWindowPos(window, (Objects.requireNonNull(vidMode).width() - pWidth.get(0)) / 2, (vidMode.height() - pHeight.get(0)) / 2);
    }
6. 将指定的窗口设置为当前上下文

在进行 OpenGL 渲染之前,需要将窗口的 OpenGL 上下文设置为当前上下文
以确保 OpenGL 命令在正确的上下文中执行。

	glfwMakeContextCurrent(window);
7. 设置垂直同步(Vertical Sync)的刷新率

垂直同步是一种同步机制,它将渲染的帧率与显示器的刷新率进行同步
以避免出现画面撕裂(Tearing)的现象。
通过设置刷新率为1,表示与显示器的刷新率保持同步
即每次渲染完一帧后等待显示器垂直同步信号再进行下一帧的渲染。

	glfwSwapInterval(1);
8. 显示指定的窗口

在创建窗口后,默认是不可见的,通过调用该函数可以将窗口显示出来

	glfwShowWindow(window);
9. init()代码
    private void init() {
        GLFWErrorCallback.createPrint(System.err).set();
        if (!glfwInit()) {
            throw new IllegalStateException("Unable to initialize GLFW");
        }
        glfwDefaultWindowHints();
        glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
        glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);
        int width = 500;
        int height = 500;
        window = glfwCreateWindow(width, height, "OpenGL Triangle Example", NULL, NULL);
        if (window == NULL) {
            throw new RuntimeException("Failed to create the GLFW window");
        }
        glfwSetKeyCallback(window, (window, key, scancode, action, mods) -> {
            if (key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE) {
                glfwSetWindowShouldClose(window, true);
            }
            if (key == GLFW_KEY_LEFT || key == GLFW_KEY_A) {
                triangleX -= triangleSpeed;
            } else if (key == GLFW_KEY_RIGHT || key == GLFW_KEY_D) {
                triangleX += triangleSpeed;
            } else if (key == GLFW_KEY_UP || key == GLFW_KEY_W) {
                triangleY += triangleSpeed;
            } else if (key == GLFW_KEY_DOWN || key == GLFW_KEY_S) {
                triangleY -= triangleSpeed;
            }
        });
        try (MemoryStack stack = MemoryStack.stackPush()) {
            IntBuffer pWidth = stack.mallocInt(1);
            IntBuffer pHeight = stack.mallocInt(1);
            glfwGetWindowSize(window, pWidth, pHeight);
            GLFWVidMode vidMode = glfwGetVideoMode(glfwGetPrimaryMonitor());
            glfwSetWindowPos(window, (Objects.requireNonNull(vidMode).width() - pWidth.get(0)) / 2, (vidMode.height() - pHeight.get(0)) / 2);
        }
        glfwMakeContextCurrent(window);
        glfwSwapInterval(1);
        glfwShowWindow(window);
    }

第四步:定义主循环体loop()

1. 创建并激活 OpenGL 上下文的功能
	GL.createCapabilities();
2. 设置清空颜色缓冲区的颜色

该行代码将清空颜色设置为黑色

	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
3. 主循环

用于不断渲染场景,直到窗口被关闭

	while (!glfwWindowShouldClose(window)){
		......
	}

----------------------------------以下属于循环体中的内容----------------------------------

4. 清空颜色缓冲区和深度缓冲区

将之前设置的清空颜色应用到缓冲区,并清除之前渲染的内容

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
5. 设置坐标系的原点
	glLoadIdentity();
6. 根据给定的偏移量将当前矩阵进行移动

triangleX和triangleY是控制三角形位置的变量,通过平移变换可以改变三角形的位置

 	glTranslatef(triangleX, triangleY, 0.0f);
7. 创建三角形

这个步骤可以简单理解为:着色–>画画–>着色–>画画–>…

	// 定义一个三角形的顶点序列
	glBegin(GL_TRIANGLES);
	//设置当前绘制的图元的颜色为红色
	glColor3f(1.0f, 0.0f, 0.0f);
	//定义三角形的一个顶点坐标
	glVertex2f(-0.6f, -0.4f);
	//设置当前绘制的图元的颜色为绿色
	glColor3f(0.0f, 1.0f, 0.0f);
	//定义三角形的第二个顶点坐标
	glVertex2f(0.6f, -0.4f);
	//设置当前绘制的图元的颜色为蓝色
	glColor3f(0.0f, 0.0f, 1.0f);
	//定义三角形的第三个顶点坐标
	glVertex2f(0.0f, 0.6f);
	//结束定义图元的顶点序列
	glEnd();
8. 交换前后缓冲区的内容,用于显示渲染结果
	glfwSwapBuffers(window);
9. 处理窗口事件,使窗口保持响应状态

例如处理键盘输入、鼠标事件等

	glfwPollEvents();
10. loop()代码
    private void loop() {
        GL.createCapabilities();
        glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
        while (!glfwWindowShouldClose(window)) {
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
            glLoadIdentity();
            glTranslatef(triangleX, triangleY, 0.0f);
            glBegin(GL_TRIANGLES);
            glColor3f(1.0f, 0.0f, 0.0f);
            glVertex2f(-0.6f, -0.4f);
            glColor3f(0.0f, 1.0f, 0.0f);
            glVertex2f(0.6f, -0.4f);
            glColor3f(0.0f, 0.0f, 1.0f);
            glVertex2f(0.0f, 0.6f);
            glEnd();
            glfwSwapBuffers(window);
            glfwPollEvents();
        }
    }

第五步:定义执行方法run()

1. 执行init()loop()
	init();
	loop();
2. 销毁窗口,关闭程序

用于销毁指定的 GLFW 窗口。它接受一个窗口句柄作为参数,通过调用该函数,可以释放窗口所占用的资源并关闭窗口

	glfwDestroyWindow(window);

用于终止 GLFW 库。它用于释放 GLFW 所使用的资源,并进行清理操作。在你的程序即将退出时,调用glfwTerminate()是一个好的实践,以确保资源被正确释放。

	glfwTerminate();
4. run()代码
   public void run() {
		init();
		loop();
        glfwDestroyWindow(window);
        glfwTerminate();
    }

完整代码

import org.lwjgl.glfw.*;
import org.lwjgl.opengl.*;
import org.lwjgl.system.MemoryStack;
import static org.lwjgl.glfw.GLFW.*;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.system.MemoryUtil.*;

import java.nio.IntBuffer;
import java.util.Objects;
import java.util.Random;

public class TriangleExample {
    private long window;
    private float triangleX = 0.0f;
    private float triangleY = 0.0f;
    private final float triangleSpeed = 0.05f;

    public void run() {
        init();
        loop();
        glfwDestroyWindow(window);
        glfwTerminate();
    }

    private void init() {
        GLFWErrorCallback.createPrint(System.err).set();
        if (!glfwInit()) {
            throw new IllegalStateException("Unable to initialize GLFW");
        }
        glfwDefaultWindowHints();
        glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);
        glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);
        int width = 500;
        int height = 500;
        window = glfwCreateWindow(width, height, "OpenGL Triangle Example", NULL, NULL);
        if (window == NULL) {
            throw new RuntimeException("Failed to create the GLFW window");
        }
        glfwSetKeyCallback(window, (window, key, scancode, action, mods) -> {
            if (key == GLFW_KEY_ESCAPE && action == GLFW_RELEASE) {
                glfwSetWindowShouldClose(window, true);
            }
            if (key == GLFW_KEY_LEFT || key == GLFW_KEY_A) {
                triangleX -= triangleSpeed;
            } else if (key == GLFW_KEY_RIGHT || key == GLFW_KEY_D) {
                triangleX += triangleSpeed;
            } else if (key == GLFW_KEY_UP || key == GLFW_KEY_W) {
                triangleY += triangleSpeed;
            } else if (key == GLFW_KEY_DOWN || key == GLFW_KEY_S) {
                triangleY -= triangleSpeed;
            }
        });
        try (MemoryStack stack = MemoryStack.stackPush()) {
            IntBuffer pWidth = stack.mallocInt(1);
            IntBuffer pHeight = stack.mallocInt(1);
            glfwGetWindowSize(window, pWidth, pHeight);
            GLFWVidMode vidMode = glfwGetVideoMode(glfwGetPrimaryMonitor());
            glfwSetWindowPos(window, (Objects.requireNonNull(vidMode).width() - pWidth.get(0)) / 2, (vidMode.height() - pHeight.get(0)) / 2);
        }
        glfwMakeContextCurrent(window);
        glfwSwapInterval(1);
        glfwShowWindow(window);
    }

    private void loop() {
        GL.createCapabilities();
        glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
        while (!glfwWindowShouldClose(window)) {
            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
            glLoadIdentity();
            glTranslatef(triangleX, triangleY, 0.0f);
            glBegin(GL_TRIANGLES);
            glColor3f(1.0f, 0.0f, 0.0f);
            glVertex2f(-0.6f, -0.4f);
            glColor3f(0.0f, 1.0f, 0.0f);
            glVertex2f(0.6f, -0.4f);
            glColor3f(0.0f, 0.0f, 1.0f);
            glVertex2f(0.0f, 0.6f);
            glEnd();
            glfwSwapBuffers(window);
            glfwPollEvents();
        }
    }
    
    public static void main(String[] args) {
        new TriangleExample().run();
    }
}

效果图
在这里插入图片描述

画圆

	glBegin(GL_TRIANGLE_FAN);
	
	float centerX = 0.0f;    // 圆心的X坐标
	float centerY = 0.0f;    // 圆心的Y坐标
	float radius = 0.5f;     // 圆的半径
	int numSegments = 99;    // 圆的细分段数
	
	glColor3f(0.0f, 2.4f, 5.5f);
	// 添加圆心顶点0
	glVertex2f(centerX, centerY);
	
	Random random = new Random();
	// 添加圆上的顶点
	for (int i = 0; i <= numSegments; i++) {
	
	    float v = random.nextFloat();
	    float v1 = random.nextFloat();
	    float v2 = random.nextFloat();
	    glColor3f(v, v1, v2);
	
	    float angle = (float) (2.0 * Math.PI * i / numSegments);
	    float x = centerX + radius * (float) Math.cos(angle);
	    float y = centerY + radius * (float) Math.sin(angle);
	    glVertex2f(x, y);
	}

效果图
在这里插入图片描述

记得把三角形的代码注释了,不然可能会出现下面的效果

在这里插入图片描述

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