JSparrow Overview

The usage of JSparrow is very similar to the OpenGL in C/C++. Probably, you don't need to read many extra documents for JSparrow itself. If you are an OpenGL programer in C/C++, only required some knowledge of Java. If you are a Java programer, you may need a book "OpenGL programing guide" for C/C++. You can make OpenGL programs in Java, in the style of C/C++.

GLUT support

JSparrow supports following libraries:

GL
GLU
GLUT: Some functions are not supported, e.g. window management functions like glutInitWindowPosition()

JSparrow supports not only GL and GLU, but GLUT. GLUT is very popular especially for small to medium sized programs. If you can not use GLUT, you have to change sturucture of programs to adapt Java programing style. JSparrow enables to port the C/C++ OpenGL programs to Java without any structural changes.

See sample program 2 and 3

Callbacks

Generally, it's hard to support callback in java, because Java doesn't support the pointer to function in common meaning. In JSparrow, pinter to function is specified by the "name" and the "object" that has the method. The style is very similar to C.

C:	gluNurbsCallback(theNurb, GLU_ERROR, nurbsError);
JSparrow:	gluNurbsCallback(theNurb, GLU_ERROR, "nurbsError", this);

See sample program 5.

Display Surface

JSparrow supports normal AWT components like Canvas, Frame, Panel, Applet etc. For example, if you use Panel for rendering, you can put other components, such as Buttons, on top of the Panel.

JSparrow also provides special Components for convenience such as OGLCanvas, OGLPanel. If you extends these classes, the source code of the program is much similar to C.

See sample program 1 and 3.

Data Types

Data type matching is very simple and reasonable.

OpenGL Type C Type Java Type GLbyte singned char byte GLshort short short GLint int int GLfloat float float GLdouble double double GLboolean unsigned char boolean GLenum unsigned int int GLbitfield unsigned int int

OpenGL Type C Type Java Type GLsizei int int GLclampf float float GLclampd double double GLubyte unsigned char byte GLushort unsigned short short GLuint unsigned int int GLvoid void Object or array * * See package document in detail.

jsparrow.gl Package

OGL class

Core of Java binding for OpenGL. This object has all native methods and manages OpenGL contexts.

OGLContext class

OpenGL rendering context.

OGLCanvas, OGLPanel class

For convinience writing GUI-base program.
In JSparrow, you can use java.awt.Component objects for rendering, e.g. Canvas, Panel, Frame etc. But sometimes, you have to override some methods, paint() etc.

OGLConstants interface

This interface defines constants in OpenGL, GL_PROJECTION etc. If you implements this interface, you can write simply 'GL_PROJECTION' instead of something like 'ogl.GL_PROJECTION'.

GLUquadric, GLUquadricObj class

You can use this type for quadric functions, gluNewQuadric(), gluQuadricNormals() etc.

GLUnurbs, GLUnurbsObj class

You can use this type for nurbs functions, gluNewNurbsRenderer(), gluNurbsProperty() etc.

GLUtesselator, GLUtesselatorObj class

You can use this type for tesselation functions, gluNewTess(), gluTessVertex() etc.