No errors inside shader Java OpenGL code, but nothing is rendered inside window

Question

I am trying to find what am I doing wrong in my code. I am using JOGL.

I'd like to make two VBOs, one for vertices, other for indices, inside a given object.

There is no error inside init(GLAutoDrawable glAutoDrawable) function, but display(GLAutoDrawable glAutoDrawable) does not show my object when running the program.

Where am I making a mistake? Thank you for help.

My code:

public class Test1 implements GLEventListener {

    private int program;

    IntBuffer vao = IntBuffer.allocate(1);
    private IntBuffer buffers = IntBuffer.allocate(2);
    private float[] vertices = {
            -0.853250f, -0.136293f, -0.188932f,
             -0.129650f, 0.416492f, 0.336788f,
             -1.129635f, 0.416492f, 0.661708f,
             -1.747674f, 0.416492f, -0.188932f,
             -1.129635f, 0.416492f, -1.039572f,
             -0.129650f, 0.416492f, -0.714652f,
             -0.576865f, 1.310922f, 0.661708f,
             -1.576849f, 1.310922f, 0.336788f,
             -1.576849f, 1.310922f, -0.714652f,
             -0.576865f, 1.310922f, -1.039572f,
             0.041175f, 1.310922f, -0.188932f,
             -0.853250f, 1.863707f, -0.188932f
    };

Xirema · Accepted Answer · 2017-11-17 19:43:40Z

1

There are a considerable number of things wrong.

Your Vertex Shader is very clearly the code for a Fragment Shader. I don't know where you copied it from, but you need to fix that.
gluPerspective is intended for use with the Fixed-Function-Pipeline. It has no effect when you're using programmable shaders. You need to put a uniform for a projection matrix in your vertex shader and manually pass that matrix to the GL.
Most Java Wrappers for OpenGL require that their Buffers be "Directly Allocated", which means the backing memory is natively allocated, as opposed to being Java-Allocated. The easiest way to do that is with ByteBuffer.allocateDirect(sizeInBytes);, which returns a ByteBuffer that can then be converted to an IntBuffer or FloatBuffer using asFloatBuffer and asIntBuffer.

answered Nov 17, 2017 at 19:43

Xirema

19.9k4 gold badges37 silver badges70 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

gouessej Over a year ago

You can use com.jogamp.common.nio.Buffers.newDirectIntBuffer(int) to create direct NIO buffers for JOGL and "new GLU()" should be replaced by "GLU.createGLU(gl)". Excellent reply by the way, it deserves an upvote :)

Collectives™ on Stack Overflow

No errors inside shader Java OpenGL code, but nothing is rendered inside window

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related