具有着色器的顶点缓冲区对象/顶点阵列对象

时间:2017-02-27 03:19:54

标签: java opengl lwjgl vbo vao

我无法将任何内容渲染到屏幕上。

private void initVBO() {
    vao = GL30.glGenVertexArrays();
    GL30.glBindVertexArray(vao);

    float[] vertices = {
            -0.5f, 0.5f, 0f,
            0.5f, 0.5f, 0f,
            0.5f, -0.5f, 0f,
            -0.5f, -0.5f, 0f
    };
    FloatBuffer vertBuffer = BufferUtils.createFloatBuffer(vertices.length);
    vertBuffer.put(vertices);
    vertBuffer.flip();

    this.vboID = GL15.glGenBuffers();
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, this.vboID);
    GL15.glBufferData(GL15.GL_ARRAY_BUFFER, vertBuffer, GL15.GL_STATIC_DRAW);
    positionAttribute = GL20.glGetAttribLocation(getMaterial().getShader()
            .getProgram(), "position");
    GL20.glEnableVertexAttribArray(positionAttribute);
    GL20.glVertexAttribPointer(positionAttribute, 3, GL11.GL_FLOAT, false, 0,
            0);

    Color c = getMaterial().getColor();
    float[] colors = {
        c.red, c.green, c.blue, c.alpha,
        c.red, c.green, c.blue, c.alpha,
        c.red, c.green, c.blue, c.alpha,
    };
    FloatBuffer colorBuffer = BufferUtils.createFloatBuffer(colors.length);
    colorBuffer.put(colors);
    colorBuffer.flip();

    this.vbocID = GL15.glGenBuffers();
    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, this.vbocID);
    GL15.glBufferData(GL15.GL_ARRAY_BUFFER, colorBuffer, GL15.GL_STATIC_DRAW);
    colorAttribute = GL20.glGetAttribLocation(getMaterial().getShader().getProgram
            (), "color");
    GL20.glEnableVertexAttribArray(colorAttribute);
    GL20.glVertexAttribPointer(colorAttribute, 4, GL11.GL_FLOAT, false, 0, 0);

    byte[] indices = {
            0, 1, 2,
            2, 3, 0
    };
    ByteBuffer indicesBuffer = BufferUtils.createByteBuffer(indices.length);
    indicesBuffer.put(indices);
    indicesBuffer.flip();

    this.vboiID = GL15.glGenBuffers();
    GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, this.vboiID);
    GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, indicesBuffer,
            GL15.GL_STATIC_DRAW);

    GL30.glBindVertexArray(0);

    GL20.glDisableVertexAttribArray(positionAttribute);
    GL20.glDisableVertexAttribArray(colorAttribute);

    GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
    GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);
}

public void render() {
    GL20.glUseProgram(getMaterial().getShader().getProgram());

    GL30.glBindVertexArray(this.vao);
    GL20.glEnableVertexAttribArray(positionAttribute);
    GL20.glEnableVertexAttribArray(colorAttribute);

    GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, this.vboiID);

    GL11.glDrawElements(GL11.GL_TRIANGLES, 6, GL11.GL_BYTE, 0);

    GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0);
    GL20.glDisableVertexAttribArray(colorAttribute);
    GL20.glDisableVertexAttribArray(positionAttribute);
    GL30.glBindVertexArray(0);
    GL20.glUseProgram(0);
}

着色器正在正确编译,我正在绑定位置和颜色的属性。我只是使用glOrtho,它设置正确,因为通过立即模式绘图工作正常。我不确定问题是否可能来自创建索引或者它是否存在于glVertexAttribPointer中的问题。我只是试图得到一个彩色绘制到屏幕的矩形。

更新: 顶点着色器:

#version 150

in vec3 position;
in vec4 color;

out vec4 passColor;

void main(void) {
  gl_Position = vec4(position, 1.0);
  passColor = color;
}

Fragment Shader:

#version 150

in vec4 passColor;

out vec4 outColor;

void main(void) {
  outColor = vec4(1.0, 1.0, 1.0, 1.0);
}

我还更新了上面的init和渲染代码。这里还有着色器的加载代码:

private void load(File vertex, File fragment) {
        this.vertexID = FileUtility.loadShader(vertex, GL20.GL_VERTEX_SHADER);
        this.fragmentID = FileUtility.loadShader(fragment, GL20.GL_FRAGMENT_SHADER);

        programID = GL20.glCreateProgram();
        GL20.glAttachShader(programID, vertexID);
        GL20.glAttachShader(programID, fragmentID);

        GL20.glBindAttribLocation(programID, 0, "position");
        GL20.glBindAttribLocation(programID, 1, "color");

        GL30.glBindFragDataLocation(programID, 0, "outColor");

        GL20.glLinkProgram(programID);
        GL20.glValidateProgram(programID);

        int status = GL20.glGetProgrami(programID, GL20.GL_LINK_STATUS);
        if (status != GL11.GL_TRUE) {
            Log.print(LogLevel.Error, GL20.glGetProgramInfoLog(programID));
        }
    }

1 个答案:

答案 0 :(得分:0)

这里有很多问题,主要是你的VBO实际上没有问题。

您创建,绑定,然后立即取消绑定您的VAO。因此,请移除对glBindVertexArray(0)的通话,或将其向下推至initVBO的底部。在取消绑定VAO之前,也不要取消绑定你的VBO,否则你的VAO不会被绑定到VBO。

您没有发布着色器,但您正在使用VAO,这意味着您至少可以访问GLSL 1.30。带有着色器的glOrtho仅受到短暂支持,使用GLSL 1.20进行折旧并在核心配置文件中删除。我强烈建议尽快远离固定功能矩阵堆栈。 LWJGL有自己的矩阵类,开关应该非常简单。

除了着色器中的任何其他问题,首先应该在屏幕上显示某些内容