Java Bindings for OpenGL
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Java Binding for the OpenGL API is a JSR API specification (JSR 231) for the Java SE platform which allows to use OpenGL [1] on the Java Platform. There is also Java Binding for the OpenGL ES API (JSR 239) for the Java ME platform.
Programming concepts
Core OpenGL API and GLU library calls are available from Java through a thin wrapper looking very much as the original OpenGL C API [2].
All platform specific libraries (available from the CGL API for Mac OS X, GLX for X Window System, and WGL for Microsoft Windows) are also abstracted out to create a platform independent way of selecting Framebuffer attributes and performing platform specific Framebuffer operations[3].
Example
This examples shows how to draw a polygon (without initialization or repaint code) [4]. Here is the reference C implementation:
int DrawGLScene(GLvoid) {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(-1.5f, 0.0f, -6.0f); // Move Left 1.5 Units
glBegin(GL_TRIANGLES); //Drawing Using Triangles
glVertex3f( 0.0f, 1.0f, 0.0f); // Top
glVertex3f(-1.0f,-1.0f, 0.0f); // Bottom Left
glVertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right
glEnd();
glTranslatef(3.0f, 0.0f, 0.0f);
glBegin(GL_QUADS); // Draw A Quad
glVertex3f(-1.0f, 1.0f, 0.0f); // Top Left
glVertex3f( 1.0f, 1.0f, 0.0f); // Top Right
glVertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right
glVertex3f(-1.0f,-1.0f, 0.0f); // Bottom Left
glEnd();
glFlush();
return TRUE;
}
Which translates to the following Java implementation:
public void display(GLAutoDrawable gLDrawable) {
final GL gl = gLDrawable.getGL();
gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
gl.glLoadIdentity();
gl.glTranslatef(-1.5f, 0.0f, -6.0f); // Move Left 1.5 Units
gl.glBegin(GL.GL_TRIANGLES); // Drawing Using Triangles
gl.glVertex3f( 0.0f, 1.0f, 0.0f); // Top
gl.glVertex3f(-1.0f,-1.0f, 0.0f); // Bottom Left
gl.glVertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right
gl.glEnd();
gl.glTranslatef(3.0f, 0.0f, 0.0f);
gl.glBegin(GL.GL_QUADS); // Draw A Quad
gl.glVertex3f(-1.0f, 1.0f, 0.0f); // Top Left
gl.glVertex3f( 1.0f, 1.0f, 0.0f); // Top Right
gl.glVertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right
gl.glVertex3f(-1.0f,-1.0f, 0.0f); // Bottom Left
gl.glEnd();
gl.glFlush();
}
Implementations
- Java OpenGL : The reference implementation, available on Microsoft Windows, Linux, Mac OS X, and Solaris platforms.
References
- ^ All functions in core OpenGL 2.0 have been included.
- ^ Except GLU NURBS routines which are not exposed through the public API.
- ^ Platform-specific extensions are not included in the public API. Each implementation can choose to export some of these APIs via the GL.getPlatformGLExtensions() and GL.getExtension(String) method calls which return Objects whose data types are specific to the given implementation.
- ^ Borrowed from the Nehe tutorial, whose code is free to use elsewhere.