java - 测试了一些 LWJGL OpenGL，不会生成盒子。我应该怎么办？

Question

可以在 OpenGL ES 1.0 和 2.0 上运行。

目标:制作一个盒子，然后显示它

在 Win 7 上无法与 LWJGL 一起使用。加载一个绿色框(应该如此)，然后开始显示一堆非常粗的白线，这些线不会保留为框。有很多闪烁。这是一张图片。

这是 Windows 的代码。

Main.java

package play.box;

import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;

public class Main {

    public static final boolean VSYNC = true;

    public static final int WIDTH = 800;
    public static final int HEIGHT = 600;

    public static final boolean FULLSCREEN = false;

    protected boolean running = false;

    public static void main(String[] args) {
        try {
            start();
        } catch (LWJGLException e) {
            e.printStackTrace();
        }
    }

    public static void start() throws LWJGLException {
        Display.setTitle("Display example");
        Display.setResizable(false);
        Display.setDisplayMode(new DisplayMode(WIDTH, HEIGHT));
        Display.setVSyncEnabled(VSYNC);
        Display.setFullscreen(FULLSCREEN);

        Display.create();

        // Setup OpenGL
        GL11.glMatrixMode(GL11.GL_PROJECTION);
        GL11.glLoadIdentity();
        GL11.glOrtho(-3, 3, -2, 2, -1, 1);
        GL11.glMatrixMode(GL11.GL_MODELVIEW);

        new Renderer().run();
    }

}

渲染器.java

package play.box;

import org.lwjgl.input.Keyboard;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.GL11;

public class Renderer implements Runnable {

    public Renderer() {

    }

    @Override
    public void run() {
        while(!Display.isCloseRequested() && !Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)) {
            GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT | GL11.GL_STENCIL_BUFFER_BIT);
            GL11.glClearColor(0.0f, 0.5f, 0.0f, 1.0f);

            // Rendering //
            /*GL11.glBegin(GL11.GL_TRIANGLES);

            GL11.glColor3f(1.0f, 0.0f, 0.0f);
            GL11.glVertex2f(0.0f, 1.0f);

            GL11.glColor3f(1.0f, 0.0f, 0.0f);
            GL11.glVertex2f(1.0f, 1.0f);

            GL11.glColor3f(1.0f, 0.0f, 0.0f);
            GL11.glVertex2f(1.0f, -1.0f);

            GL11.glEnd();*/

            Box box = new Box();
            box.draw();
            // End of Rendering //

            Display.update();

            try {
                Thread.sleep(1000);
            } catch(Exception e) {
                e.printStackTrace();
            }
        }
    }

}

Box.java

package play.box;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.ShortBuffer;

import org.lwjgl.opengl.GL11;

public class Box {

    private float verticies[] = {
            -1.0f,  1.0f, // Left Top (0)
            -1.0f, -1.0f, // Left Bottom (1)
             1.0f, -1.0f, // Right Bottom (2)
             1.0f,  1.0f  // Right Top (4)
    };
    private short indicies[] = {
            0, 1, 2,
            2, 3, 0
    };

    private FloatBuffer vertBuff;
    private ShortBuffer indexBuff;

    public Box() {
        this.setupBuffers();
    }

    private void setupBuffers() {
        ByteBuffer bBuff = ByteBuffer.allocateDirect(this.verticies.length * 4);
        bBuff.order(ByteOrder.nativeOrder());
        this.vertBuff = bBuff.asFloatBuffer();
        this.vertBuff.put(this.verticies);
        this.vertBuff.position(0);

        ByteBuffer pbBuff = ByteBuffer.allocateDirect(this.indicies.length * 2);
        pbBuff.order(ByteOrder.nativeOrder());
        this.indexBuff = pbBuff.asShortBuffer();
        this.indexBuff.put(this.indicies);
        this.indexBuff.position(0);
    }

    public void draw() {
        GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);

        GL11.glVertexPointer(2, GL11.GL_FLOAT, this.vertBuff);
        GL11.glDrawElements(GL11.GL_TRIANGLES, this.indexBuff);

        GL11.glDisableClientState(GL11.GL_VERTEX_ARRAY);
    }

}

更新的代码:

package play.box;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.ShortBuffer;

import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GL15;
import org.lwjgl.opengl.GL20;
import org.lwjgl.opengl.GL30;

public class Box {

    private float verticies[] = {
            -1.0f,  1.0f, // Left Top (0)
            -1.0f, -1.0f, // Left Bottom (1)
             1.0f, -1.0f, // Right Bottom (2)
             1.0f,  1.0f  // Right Top (4)
    };
    private short indicies[] = {
            0, 1, 2,
            2, 3, 0
    };

    private FloatBuffer vertBuff;
    private ShortBuffer indexBuff;

    private int vbo_handle;
    private int ibo_handle;
    private int vao_handle;

    private String vShaderStr =
              "attribute vec4 vPosition; \n"
            + "void main() {             \n"
            + "  gl_Position = vPosition;\n"
            + "}                         \n";

    private String fShaderStr =
              "precision mediump float;                   \n"
            + "void main() {                              \n"
            + "  gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0); \n"
            + "}                                          \n";

    private int vertexShader;
    private int fragmentShader;
    private int programObject;

    public Box() {
    }

    public void create() {
        ByteBuffer bBuff = ByteBuffer.allocateDirect(this.verticies.length * 4);
        bBuff.order(ByteOrder.nativeOrder());
        this.vertBuff = bBuff.asFloatBuffer();
        this.vertBuff.put(this.verticies);
        //this.vertBuff.flip();
        this.vertBuff.position(0);

        ByteBuffer pbBuff = ByteBuffer.allocateDirect(this.indicies.length * 2);
        pbBuff.order(ByteOrder.nativeOrder());
        this.indexBuff = pbBuff.asShortBuffer();
        this.indexBuff.put(this.indicies);
        //this.indexBuff.flip();
        this.indexBuff.position(0);

        // Create VBO
        this.vbo_handle = GL15.glGenBuffers();

        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, this.vbo_handle);
        GL15.glBufferData(GL15.GL_ARRAY_BUFFER, this.vertBuff, GL15.GL_DYNAMIC_DRAW);
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);

        // Create IBO
        this.ibo_handle = GL15.glGenBuffers();

        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, this.ibo_handle);
        GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, this.indexBuff, GL15.GL_DYNAMIC_DRAW);
        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);

        // Create VAO
        this.vao_handle = GL30.glGenVertexArrays();

        GL30.glBindVertexArray(vao_handle);
        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo_handle);
        GL20.glEnableVertexAttribArray(0);
        GL20.glVertexAttribPointer(0, 2, GL11.GL_FLOAT, false, 0, 0);

        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, ibo_handle);
        GL30.glBindVertexArray(0);

        // Setup Shaders
        this.vertexShader = this.loadShader(GL20.GL_VERTEX_SHADER, this.vShaderStr);
        this.fragmentShader = this.loadShader(GL20.GL_FRAGMENT_SHADER, this.fShaderStr);

        // Setup Program
        int program = GL20.glCreateProgram();

        if(program == 0) {
            return;
        }

        GL20.glAttachShader(program, this.vertexShader);
        GL20.glAttachShader(program, this.fragmentShader);

        GL20.glBindAttribLocation(program, 0, "vPosition");

        GL20.glLinkProgram(program);

        if(GL20.glGetProgrami(program, GL20.GL_LINK_STATUS) == 0) {
            System.out.println("Error Creating Program: " + GL20.glGetProgramInfoLog(program, Integer.MAX_VALUE));
            GL20.glDeleteProgram(program);
            return;
        }

        this.programObject = program;
    }

    public void draw() {
        this.create();
        GL20.glUseProgram(this.programObject);
        GL30.glBindVertexArray(vao_handle);
        GL11.glDrawElements(GL11.GL_TRIANGLES, 2, GL11.GL_FLOAT, 0);
        GL30.glBindVertexArray(0);
        this.dispose();
    }

    public void draw(boolean useVAO) {
        if(useVAO) {
            this.draw();
        } else {
            this.create();
            GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, this.vbo_handle);
            GL11.glVertexPointer(2, GL11.GL_FLOAT, 0, 0L);
            GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, this.ibo_handle);
            GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);
            GL11.glDrawElements(GL11.GL_TRIANGLES, this.indicies.length, GL11.GL_UNSIGNED_SHORT, 0L);
            GL11.glDisableClientState(GL11.GL_VERTEX_ARRAY);
            this.dispose();
        }
    }

    public void dispose() {
        GL30.glDeleteVertexArrays(vao_handle);
        GL30.glDeleteVertexArrays(vbo_handle);
        GL30.glDeleteVertexArrays(ibo_handle);

        this.vao_handle = -1;
        this.vbo_handle = -1;
        this.ibo_handle = -1;
    }

    private int loadShader(int type, String shaderSrc) {
        int shader;

        shader = GL20.glCreateShader(type);

        if(shader == 0) {
            return 0;
        }

        GL20.glShaderSource(shader, shaderSrc);
        GL20.glCompileShader(shader);

        if(GL20.glGetShaderi(shader, GL20.GL_COMPILE_STATUS) == 0) {
            System.out.println("Error Loading Shader: " + GL20.glGetShaderInfoLog(shader, Integer.MAX_VALUE));
            GL20.glDeleteShader(shader);
            return 0;
        }

        return shader;
    }

}

Answer 1

我将演示如何使用 VBO 和 IBO 创建、渲染和处置 VAO，而不只是向您展示您在评论中要求的内容。

• VAO <=> 顶点数组对象
• VBO <=> 顶点缓冲区对象
• IBO <=>索引缓冲区对象

创建 VAO、VBO 和 IBO

vao_handle、vbo_handle和ibo_handle是3个包含id/handle的整数，这3个变量在下面的整个代码中使用。

• vbo_data <=> 包含顶点的FloatBuffer
• ibo_data <=> 包含索引的 IntBuffer

下面的代码中使用了上述两个变量。

// Creating the VBO
vbo_handle = glGenBuffers();

glBindBuffer(GL_ARRAY_BUFFER, vbo_handle);
glBufferData(GL_ARRAY_BUFFER, vbo_data, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);

// Creating the IBO
ibo_handle = glGenBuffers();

glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_handle );
glBufferData(GL_ELEMENT_ARRAY_BUFFER, ibo_data, GL_DYNAMIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);

// Creating the VAO
vao_handle = glGenVertexArrays();

glBindVertexArray(vao_handle);

glBindBuffer(GL_ARRAY_BUFFER, vbo_handle);

glEnableVertexAttribArray(INDEX); // Place your own INDEX value in the parenthesis
glVertexAttribPointer(INDEX, SIZE, TYPE, NORMALIZED, STRIDE, OFFSET); // Replace all the VARIABLES with the values which fit to your VAO, VBO and IBO

glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_handle);

glBindVertexArray(0);

/*
 * Remember that the INDEX given in the
 * glEnableVertexAttribArray() and in
 * glVertexAttribPointer() is the same
 * INDEX used in Shaders (GLSL)
 *
 * If the INDEX is 0 then in GLSL it
 * should look like this
 * GLSL: layout(location = 0) in vec3 position;
 *
 * ^ we can ignore this if you aren't
 * using Shaders, though keep it in mind
 * since we might need it in the future
 */

渲染 VAO

glBindVertexArray(vao_handle);
glDrawElements(MODE, SIZE, TYPE, OFFSET); // Again replace the variables, so it fits to your VAO, VBO and IBO
glBindVertexArray(0);

处置 VAO、VBO 和 IBO

这就是删除不同缓冲区的方法，当您关闭程序或在某个时候不再需要它们时，这是一件好事。

glDeleteVertexArrays(vao_handle); // Deletes the VAO
glDeleteBuffers(vbo_handle); // Deletes the VBO
glDeleteBuffers(ibo_handle); // Deletes the IBO

vao_handle = -1;
vbo_handle = -1;
ibo_handle = -1;