com.threed.jpct
Interface IRenderHook

All Known Implementing Classes:

GLSLShader

public interface IRenderHook

Provides a hook into the rendering pipeline of compiled Object3Ds. For any other object, the methods of this interface will never be called even if an implementation of it is attached to that object. This is meant to be used for executing your own OpenGL (or whatever...) code directly in the render pipeline. Can be useful to set up your own vertex and/or fragment shaders for an Object3D for example.
A render hook is attached to an Object3D. However, this doesn't mean that it's only called once per object. In fact, an object can be compiled into hundreds of display lists/vertex arrays. These methods will be called for each of them, if they are going to be rendered in this frame.

Method Summary

void	afterRendering(int polyID) Will be called immediately after the actual rendering takes place.
void	beforeRendering(int polyID) Will be called immediately before the actual rendering takes place.
void	clear() Will be called if this IRenderHook implemention has been used to render the current object-(part) but won't be used for the next one.
void	onDispose() Will be called, if the underlying compiled structures get disposed.
boolean	repeatRendering() If this returns true, the same geometry that was rendered will be rendered again using the exact same settings. beforeRendering() won't be called again. afterRendering() won't be called yet.
void	setCurrentObject3D(Object3D obj) Sets the currently rendered object.
void	setCurrentShader(GLSLShader shader) Sets the currently active shader.
void	setTransparency(float transparency) Set which transparency value is used for this object.

Method Detail

beforeRendering

public void beforeRendering(int polyID)

Will be called immediately before the actual rendering takes place. It is guaranteed that this happens within the thread that is bound to the OpenGL context, i.e. you can execute OpenGL commands within here. Texture stages, blending modes, lighting and all is already set up as the object's configuration demands it.

Parameters:

polyID - the ID of the polygon that is first in the current list that is about to render.

afterRendering

public void afterRendering(int polyID)

Will be called immediately after the actual rendering takes place. It is guaranteed that this happens within the thread that is bound to the OpenGL context, i.e. you can execute OpenGL commands within here.

Parameters:

polyID - the ID of the polygon that is first in the current list that is about to render.

setCurrentObject3D

public void setCurrentObject3D(Object3D obj)

Sets the currently rendered object. This will be called before calling beforeRendering()

Parameters:

obj - the current Object3D

setCurrentShader

public void setCurrentShader(GLSLShader shader)

Sets the currently active shader. This will be called after beforeRendering().
Because in jPCT (unlike in jPCT-AE), shaders ARE IRenderHooks, this method doesn't serve much purpose. It's mainly here to stay compatible with jPCT-AE.

Parameters:

shader - the shader or null if none is used

setTransparency

public void setTransparency(float transparency)

Set which transparency value is used for this object. This is the value OpenGL uses, not the one assigned to the object, i.e. it has already been processed. This will be called before setCurrentObject3D().

onDispose

public void onDispose()

Will be called, if the underlying compiled structures get disposed. It's not guaranteed that this will happen in an application and depending on the object's compiled structure, it may happen several times.

repeatRendering

public boolean repeatRendering()

If this returns true, the same geometry that was rendered will be rendered again using the exact same settings. beforeRendering() won't be called again. afterRendering() won't be called yet.
The rendering will be redone as often as this method returns true. If this method always returns true, you've created an infinite loop.

Returns:

true, if the rendering should be redone, false otherwise.

clear

public void clear()

Will be called if this IRenderHook implemention has been used to render the current object-(part) but won't be used for the next one. This can be used to optimize some things. The idea is optimize setup/teardown work that would otherwise have to take place in every call to before- and afterRendering(). If you are not sure how to deal with this, just implement an empty method.