java - LWJGL 无法使用 VBO 创建立方体

Question

在尝试使用 Java 中的 VBO 创建立方体时，我发现只渲染了立方体的一个面(而且也是错误的)。代码如下，有人可以告诉我为什么它不会渲染超过单面吗？

渲染类

package engine;

import static org.lwjgl.opengl.GL11.GL_COLOR_BUFFER_BIT;
import static org.lwjgl.opengl.GL11.GL_DEPTH_BUFFER_BIT;
import static org.lwjgl.opengl.GL11.GL_DEPTH_TEST;
import static org.lwjgl.opengl.GL11.glClear;
import static org.lwjgl.opengl.GL11.glEnable;
import static org.lwjgl.opengl.GL15.GL_ARRAY_BUFFER;
import static org.lwjgl.opengl.GL15.GL_STATIC_DRAW;
import static org.lwjgl.opengl.GL15.glBindBuffer;
import static org.lwjgl.opengl.GL15.glBufferData;
import static org.lwjgl.opengl.GL15.glGenBuffers;

import java.nio.FloatBuffer;
import java.util.ArrayList;

import org.lwjgl.BufferUtils;
import org.lwjgl.opengl.GL11;
import org.lwjgl.util.vector.Vector3f;

public class Render{

    private int amountOfVerts;
    private int vertexSize = 3;
    private int colorSize = 3;
    private FloatBuffer vertData, colorData;
    private int handle, colorHandle;
    private ArrayList<Cube> cubes = new ArrayList<Cube>();

    public Render() {
        addCube(new Cube(new Vector3f(0,0,0)));
        amountOfVerts = cubes.size() * 72;
        vertData = BufferUtils.createFloatBuffer(amountOfVerts * vertexSize);
        createCubeArray();

        colorData = BufferUtils.createFloatBuffer(amountOfVerts * colorSize);
        colorData.put(new float[]{1f,1f,1f, 1f,1f,1f, 1f,1f,1f, 1f,1f,1f});
        colorData.flip();

        handle = glGenBuffers();
        glBindBuffer(GL_ARRAY_BUFFER, handle); //sets the current buffer to this
        glBufferData(GL_ARRAY_BUFFER, vertData, GL_STATIC_DRAW); // fills the new buffer / stores data
        glBindBuffer(GL_ARRAY_BUFFER, 0); // unbinds

        colorHandle = glGenBuffers();
        glBindBuffer(GL_ARRAY_BUFFER, colorHandle); //sets the current buffer to this
        glBufferData(GL_ARRAY_BUFFER, colorData, GL_STATIC_DRAW); // fills the new buffer / stores data
        glBindBuffer(GL_ARRAY_BUFFER, 0); // unbinds
    }

    public void createCubeArray(){
        for (int i = 0; i < cubes.size(); i++){
            Cube c = cubes.get(i);
            storeVertexData(c.getData());
        }
    }

    public void storeVertexData(float[] data){
        vertData.put(data);
        vertData.flip();
    }

    public void addCube(Cube c){
        this.cubes.add(c);
    }

    public void removeCube(Cube c){
        this.cubes.remove(c);
    }

    public void render(){
        glEnable(GL_DEPTH_TEST);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glBindBuffer(GL_ARRAY_BUFFER, handle);
        GL11.glVertexPointer(vertexSize, GL11.GL_FLOAT, 0, 0L);

        glBindBuffer(GL_ARRAY_BUFFER, colorHandle);
        GL11.glColorPointer(colorSize, GL11.GL_FLOAT, 0, 0L);

        GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);
        GL11.glEnableClientState(GL11.GL_COLOR_ARRAY);
        GL11.glDrawArrays(GL11.GL_QUADS, 0, amountOfVerts);
        GL11.glDisableClientState(GL11.GL_COLOR_ARRAY);
        GL11.glDisableClientState(GL11.GL_VERTEX_ARRAY);

    }


}

立方体类

package engine;

import org.lwjgl.util.vector.Vector3f;

public class Cube {

    private Vector3f pos = null;
    private float cubeSize = 100f;

    public Cube(Vector3f pos) {
        this.pos = pos;
    }

    public float[] getData(){
        return new float[] {    pos.x,pos.y,pos.z,
                    pos.x + cubeSize,pos.y,pos.z,
                    pos.x + cubeSize,pos.y + cubeSize,pos.z,
                    pos.x,pos.y + cubeSize,pos.z,

                    pos.x,pos.y,pos.z + cubeSize,
                    pos.x + cubeSize,pos.y,pos.z + cubeSize,
                    pos.x + cubeSize,pos.y + cubeSize,pos.z + cubeSize,
                    pos.x,pos.y + cubeSize,pos.z + cubeSize,

                    pos.x,pos.y,pos.z,
                    pos.x,pos.y,pos.z + cubeSize,
                    pos.x,pos.y + cubeSize,pos.z + cubeSize,
                    pos.x,pos.y + cubeSize,pos.z,

                    pos.x + cubeSize,pos.y,pos.z,
                    pos.x + cubeSize,pos.y,pos.z + cubeSize,
                    pos.x + cubeSize,pos.y + cubeSize,pos.z + cubeSize,
                    pos.x + cubeSize,pos.y + cubeSize,pos.z,

                    pos.x,pos.y,pos.z,
                    pos.x,pos.y,pos.z + cubeSize,
                    pos.x + cubeSize,pos.y,pos.z + cubeSize,
                    pos.x + cubeSize,pos.y,pos.z,

                    pos.x,pos.y + cubeSize,pos.z,
                    pos.x,pos.y + cubeSize,pos.z + cubeSize,
                    pos.x + cubeSize,pos.y + cubeSize,pos.z + cubeSize,
                    pos.x + cubeSize,pos.y + cubeSize,pos.z,
                };
    }

}

编辑

public Render() {
    addCube(new Cube(new Vector3f(0,0,0)));
    amountOfVerts = cubes.size() * 24;
    vertData = BufferUtils.createFloatBuffer(amountOfVerts * vertexSize);
    createCubeArray();
    vertData.flip();
    colorData = BufferUtils.createFloatBuffer(amountOfVerts * colorSize);
    float[] color = new float[amountOfVerts * colorSize];
    Arrays.fill(color, 1f);
    colorData.put(color);
    handle = glGenBuffers();
    glBindBuffer(GL_ARRAY_BUFFER, handle); //sets the current buffer to this
    glBufferData(GL_ARRAY_BUFFER, vertData, GL_STATIC_DRAW); // fills the new buffer / stores data
    glBindBuffer(GL_ARRAY_BUFFER, 0); // unbinds

    colorHandle = glGenBuffers();
    glBindBuffer(GL_ARRAY_BUFFER, colorHandle); //sets the current buffer to this
    glBufferData(GL_ARRAY_BUFFER, colorData, GL_STATIC_DRAW); // fills the new buffer / stores data
    glBindBuffer(GL_ARRAY_BUFFER, 0); // unbinds
}

Answer 1

按照你当前渲染的方式，你的颜色缓冲区中需要有与位置缓冲区中一样多的 float (如果你的 float 较少，它只使用 0 作为我的其余值，尽管我不是确定这是否会发生在您身上)。

float[] color = new float[amountOfVerts * colorSize];
Arrays.fill(color, 1f);
colorData.put(color);

此外，您在添加每个 float[] 后都会翻转位置缓冲区，这意味着您将覆盖以前的数据。添加完成后才应翻转它。

您的 amountOfVerts 也应该是 cubes.size() * 24 而不是 cubes.size() * 72。