Gob() Graphics Object documentation

Gob = (G)raphics (Ob)ject

Public Class Gob extends Linkable

implements HyperConstants,TextConstants

Inheritance Heirarchy.

Linkable.class
        |
+--Gob.class

implements HyperConstants,TextConstants

A Gob.class is a "Lightweight Component" and is derived image file.
ie: a .gif or a .jpg file, and this means a Gob can easily be edited with standard paint program.

Gob.Means " Graphics Object "

A Gob Is easily created from an Image file

A Gob can be set to receive Mouse Events.

A Gob can be made to move in a given a series X/Y/Z directions by creating a Spline.class and attaching it to the Gob via a call to Gob.addSpline( Spline )

Gob(HyperView tView,String tName,int tFlags)

Gob(Gob tGob,String tName,int tX,int tY,int pX,int pY,Spline tSpline,int tFlags)

Gob(HyperView tView,String tName,int tX,int tY,int pX,int pY)

Gob(Gob tGob,String tName,int tX,int tY,int pX,int pY,int tFlags)

Gob(Gob tGob,String tName,int tX,int tY,int tFlags)
Gob(HyperView tView,String tName,int sx,int sy,int pX,int pY,int tFlags)
Gob(HyperView tView,String tName,int sx,int sy,Spline tSpline,int tFlags)

void printGobAttr(HyperView)
This method is for debugging your display. Use it to
print some if the Gob's current values.



                            void addSpline(Spline)

Add a movement Spline to this Gob (before adding to display)

public

                                void onClick()



                              Generic
                              Mouse IO method. 

                              Note: This is called from the
                              HyperView.blitterLock Thread monitor
                              context and is the default

                              Mouse Event Handler for Gob.class Objects
                              that do not have a Dispatch.class
                              attached.

If enabled, the lightweight onClick() method is called when the Gob.class is clicked on by the mouse.
To implement this method you must

"overwrite" the onClick() method.
Set the Gob.gobFlags GOB_DO_ONCLICK bit.

Gob how to get mouse clicks example

<CODE>

// Note: Gob.class super() constructor called in this example.
// ie Gob(HyperView, String, int, int, int)
// View "ImageName" width, height,flags.

public class MyGob extends Gob
{
MyGob(HyperView tView)
{    // Call relevant super() constructor.
     super(tView,"myImage.gif",100,100,100,100,)
   gobFlags |= GOB_DO_ONCLICK; // Enable Gob onclick bit
}

public void onClick()
{
int x = mouseX;
int y = mouseY;
     System.out.println("Click x="+x+" y="+y);
}
}

</CODE>

overwriting onClick() is the simplest mouse even method in the HyperView.
However it does not erase/change the current display. The onClick() method
is called between video rendering frames. It does not have the full licence to
change the entire display that a Dispatch.class does. But because it is between
render frames, it can change its own graphics with no display interference
(jaggies/screen tears basically contention between display/render hardware.)

The other method of trapping Mouse IO is to make a Gadget and attach a fully qualified Dispatch.class Object to it.

HyperView.class has 2 different mouse event handling techniques.

Dispatch.class

Advantage:
-Backs up/restores
entire display.
-Full access to entire display variables during VBLANK,
- Uses the Display stack to restore the previous view.
- Fastest event response time.

Disadvantage:
- Extra setup time

- Must use a Gob
Gadget.class

- Saving/restoring
display takes
overhead.
- Gadgets can take more video RAM than a Gob-
class because they
have am extra display Image for a selected Image.

Gob.onClick()

Advantage:
-Simple overwrite
of onClick() method

- Faster to process with no
display backup or restore.

Disadvantage:
Because onClick()
is called by the
View between render frames, too many of such calls can slow down video rendering.

Another example. Creating a Gob from a gif
Here is a 46 pixel width X 47 pixel height image called "ea2.gif"

Note that the area around the globe is transparent. Thus you can create/modify
images for Gobs in your favorite paint program.
Note: This is done from "ViewMain.main();

<CODE>

Gob.class example code

</CODE>

 public

                                void zENA();

Enable ZBuffer emulation (Z plane Depth scaling)

public void zOff()
Disable ZBuffer emulation

void gobZInit()
initialize Gob zbuffer

public void initScanline(int tInt)
Convert this Gob into a series of scanlines. This was initially for collision detection via a 32 bit OR with a 1
bit bitmask, but instead collision detection will be implemented with a point in poly polygon compare which
is computationally much more efficient.

public void printScanLines()
print the scanlines to stdout

public void collisionOn()
enable collision detection.

public void collisionOff()

disable collision detection.

public void remove()
remove this gob from the HyperView and flag it for destruction.

public void move(int,int)
Move the Gob to this X/Y location.

public void enable()

Enable the GOB_ON_DISPLAY bit.

public void disable()

Disable the GOB_ON_DISPLAY bit.

public boolean inView()
Returns true if the Gob.x and Gob.y are within the HyperView width/Height
Otherwise false

public boolean onDisplay()
Returns true if the Gob.x and Gob.y are within the HyperView width/Height
and sets/unsets the Gob.gobFlags -> GOB_ON_DISPLAY bit.
Note: See HyperConstants.class for all Gob.gobFlags bit definitions.

public Graphics getGraphics()
Returns a awt.Graphics reference for this gob.

public boolean onClick()

Called when this Gob is clicked on
and if implemented and "overwritten". ie: You must overwrite this method to implement it.
See above for implementation of onClick()

public void onRelease()

Called when the mouse button is released. If enabled in flag bits. To properly use this you must overwrite
this method and enable the mouse released bit. See HyperConstants.class for all bit definitions.

public void addGob(Gob)

Add/Attach a Gob on to this Gob. This is how you make more complicated displays by adding Gobs to
other Gobs. The "attached" Gobs are always thereafter rendered on top of the Gob they are
attached to.
Note: The HyperView CLI command "dumpgobs" dumps most Gob.class info including all attachments.

public void center()

Center this Gob either in the View or in the parent Gob if attached to another Gob.

public Image getImageFromJar(String)

Gets an Image from the jar file the parent HyperView.class is running from.
Note:This will only work when called from a Browser that is running the HyperView from a jar.
The View does this inherently so there is no real user implementation of this method.

public int[] getPixels()
Return an array of (width * height) integers that represents the RGB/Alpha values for the Gob.gobImage

public void cleanUp()
Dispose of all Graphics memory for this Gob.