Java OpenGL

Design

The base OpenGL C API, as well as its associated Windowing API,{{cite web |access-date=2011-02-06

JOGL differs from some other Java OpenGL wrapper libraries in that it merely exposes the procedural OpenGL API via methods on a few classes, rather than trying to map OpenGL functionality onto the object-oriented programming paradigm. Indeed, most of the JOGL code is autogenerated from the OpenGL C header files via a conversion tool named GlueGen, which was programmed specifically to facilitate the creation of JOGL.

Status and standardization

, JOGL provides full access to the OpenGL 4.6 and OpenGL ES 3.2 specification as well as almost all vendor extensions (and OpenCL, OpenMAX and OpenAL). The 2.5.0 version is the reference implementation for JSR-231 (Java Bindings for OpenGL).{{cite web |access-date=2011-02-06

Wayland and Vulkan support is planned.

Java2D-OpenGL interoperability

Since the Java SE 6 version of the Java language, Java2D (the API for drawing two dimensional graphics in Java) and JOGL have become interoperable, allowing it to :

• Overlay Swing components (lightweight menus, tooltips, and other widgets) on top of OpenGL rendering.
• Draw 3D OpenGL graphics on top of Java2D rendering (see here for a button with an OpenGL icon).
• Use 3D graphics anywhere where ordinarily a Swing widget would be used. (Inside a JTable, JTree, ...)
• Draw Java2D graphics on top of 3D OpenGL rendering.

Tutorials

• OpenGL ES 2 sample
• Hello Triangle, gl3 and gl4 Hello Triangle and Texture. The samples are offered in Java and Kotlin
• Java OpenGL Sample Pack, porting of g-truc OpenGL Sample Pack. The over 230 samples illustrate almost all OpenGL features ranging from ES 2.0 up to the last GL extensions, same of them usually also called AZDO (Almost Zero Driver Overhead).
• modern jogl examples, Porting of Learning Modern 3D Graphics Programming, Jason L. McKesson . Java and Kotlin side by side.
• Immediate mode sample (simplest example, using the Fixed-function graphics pipeline)

Code example

    @Override
    public void display(GLAutoDrawable drawable) {

        GL4 gl4 = drawable.getGL().getGL4();

        gl4.glClearBufferfv(GL2ES3.GL_COLOR, 0, clearColor);
        gl4.glClearBufferfv(GL2ES3.GL_DEPTH, 0, clearDepth);

        {
            FloatUtil.makeLookAt(view, 0, eye, 0, at, 0, up, 0, tmp);
            FloatUtil.makePerspective(projection, 0, reset, 45f, aspect, near, far);

            FloatUtil.multMatrix(projection, view); // projection *= view

            transformPointer.asFloatBuffer().put(projection);
        }

        gl4.glUseProgram(programName);
        gl4.glBindVertexArray(vertexArrayName.get(0));
        gl4.glBindBufferBase(GL2ES3.GL_UNIFORM_BUFFER /*target*/, 1 /*TRANSFORM0, index*/, bufferName.get(2) /*TRANSFORM, buffer*/);

        gl4.glBindTextureUnit(0 /*diffuse*/, textureName.get(0));
        gl4.glBindSampler(0 /*diffuse*/, samplerName.get(0));

        gl4.glDrawElements(GL.GL_TRIANGLES, elementCount, GL.GL_UNSIGNED_SHORT, 0);
    }

References

References

1. "JOGL - Java Binding for the OpenGL API".
2. (2013-08-05). "Bug 794 - Add Wayland Windowing/Surface Interoperability".
3. "JOGL Userguide".