LWJGL教程05 - 改进渲染

让Mesh类创建VBO和VAO对象

[imports ...]

public class Mesh {
    private float[] vertices;
    private int verticesCount;
    private int vaoId;
    private int vboId;

    public Mesh(float[] vertices) {
        this.vertices = vertices;
        this.verticesCount = vertices.length / 3;

        FloatBuffer verticesBuffer = MemoryUtil.memAllocFloat(this.vertices.length);
        verticesBuffer.put(this.vertices).flip();

        // 顶点
        vaoId = glGenVertexArrays();
        glBindVertexArray(vaoId);
        vboId = glGenBuffers();
        glBindBuffer(GL_ARRAY_BUFFER, vboId);
        glBufferData(GL_ARRAY_BUFFER, verticesBuffer, GL_STATIC_DRAW);
        glEnableVertexAttribArray(0);
        glVertexAttribPointer(0, 3, GL_FLOAT, false, 0, 0);
        // 解绑VBO
        glBindBuffer(GL_ARRAY_BUFFER, 0);
        // 解绑VAO
        glBindVertexArray(0);

        MemoryUtil.memFree(verticesBuffer);
    }

    [G etter ...]

    public void cleanup() {
        glDisableVertexAttribArray(0);

        // 删除VBO
        glBindBuffer(GL_ARRAY_BUFFER, 0);
        glDeleteBuffers(vboId);

        // 删除VAO
        glBindVertexArray(0);
        glDeleteVertexArrays(vaoId);
    }
}

一个程序不会只有一个Mesh，所以创建Scene来存储多个Mesh。

[imports ...]

public class Scene {
    private List<Mesh> meshes = new ArrayList<>();

    public List<Mesh> getMeshes() {
        return meshes;
    }

    public void addMesh(Mesh mesh) {
        meshes.add(mesh);
    }

    public void cleanup() {
        meshes.forEach(Mesh::cleanup);
    }
}

然后在Engine中实例化它。

修改Render.render()。

public static void render(Scene scene) {
    [...]

    Render.shaderProgram.bind();

    scene.getMeshes().forEach((mesh) -> {
        // 绑定VAO
        glBindVertexArray(mesh.getVaoId());

        // 绘制顶点
        glDrawArrays(GL_TRIANGLES, 0, mesh.getVerticesCount());

        // 还原状态
        glBindVertexArray(0);
    });

    Render.shaderProgram.unbind();
}

然后在Engine.cleanup()中记得调用Scene.cleanup()。

private void cleanup() {
    logic.cleanup();
    Render.cleanup();
    scene.cleanup();
    Window.cleanup();
}

最后测试一下。

[imports ...]

public class TestLogic implements ILogic {

    @Override
    public void init() {
        float[] vertices1 = new float[]{
                0.0f,  0.5f, 0.0f,
                -0.5f, -0.5f, 0.0f,
                0.5f, -0.5f, 0.0f
        };

        float[] vertices2 = new float[]{
                -1.0f, 1.0f, 0.0f,
                -1.0f, 0.0f, 0.0f,
                0.0f, 1.0f, 0.0f
        };

        Mesh mesh1 = new Mesh(vertices1);
        Mesh mesh2 = new Mesh(vertices2);

        Engine.scene.addMesh(mesh1);
        Engine.scene.addMesh(mesh2);
    }
    
    [...]
}

运行结果

在测试一个。

[imports ...]

public class TestLogic implements ILogic {

    @Override
    public void init() {
        float[] vertices1 = new float[]{
                -0.5f,  0.5f, 0.0f,
                -0.5f, -0.5f, 0.0f,
                0.5f,  0.5f, 0.0f,
                0.5f,  0.5f, 0.0f,
                -0.5f, -0.5f, 0.0f,
                0.5f, -0.5f, 0.0f,
        };

        Mesh mesh1 = new Mesh(vertices1);

        Engine.scene.addMesh(mesh1);
    }
    
    [...]
}