org.j3d.aviatrix3d.pipeline.graphics
Class StateSortComparator

java.lang.Object
  org.j3d.aviatrix3d.pipeline.graphics.StateSortComparator

All Implemented Interfaces:

java.util.Comparator<GraphicsCullOutputDetails>

public class StateSortComparator
extends java.lang.Object
implements java.util.Comparator<GraphicsCullOutputDetails>

A comparator that provides the mechanics for state sorting, given configurable priority listing.

Since this is a comparator, the basic sorting algorithm will be capped at O(n log n) as given by the lower bounds for any comparison-based sort.

Comparison Rules

The following rules are used for comparing objects of the same type:

Bias towards objects with state first over objects with no state. Thus given two objects a and b. If b is null, a is greater than b and return +1. If a is null and b is non null, return -1.

Where no explicit test is defined, use a per-object test with it's appropriate compareTo() method. If the method returns 0 then continue on with the next in the priority order, otherwise exit with the appropriate state set.

Lights

1. Number of lights are zero, ignore the test
2. Number of lights is not equal, -1 to the lower number
3. Use per-light comparison

Textures

1. Number of texture units are zero, ignore the test
2. Number of texture units is not equal, -1 to the lower number
3. Use per-texture unit comparison

Version:

$Revision: 3.5 $

Author:

Justin Couch

Field Summary

static int	BLEND_ATTRIBS Priority state is checking blend attributes.
static int	CLIP_PLANES Priority state is checking clip planes
static int	DEPTH_ATTRIBS Priority state is checking depth buffer attributes
static int	FRAGMENT_SHADERS Priority state is fragment shaders
static int	LIGHTS Priority state is lights
static int	LINE_ATTRIBS Priority state is checking line attributes
static int	LOCAL_FOG Priority state is checking local fog
static int	MATERIALS Priority state is material values
static int	POINT_ATTRIBS Priority state is checking point attributes
static int	POLYGON_ATTRIBS Priority state is checking polygon attributes
static int	SHADER_OBJECTS Priority state is shader objects (ie GL 1.5/2.0)
static int	STENCIL_ATTRIBS Priority state is checking stencil buffer attributes
static int	TEXTURE_UNIT_0 Priority state is texture unit 0
static int	TEXTURE_UNIT_1 Priority state is texture unit 1
static int	TEXTURE_UNIT_2 Priority state is texture unit 2
static int	TEXTURE_UNIT_3 Priority state is texture unit 3
static int	VERTEX_SHADERS Priority state is vertex shaders

Constructor Summary

StateSortComparator()
Construct an instance of this comparator using the default priority settings.

StateSortComparator(int[] priList)
Construct an instance of this comparator given the listed set of priorities.

Method Summary

int	compare(GraphicsCullOutputDetails cd1, GraphicsCullOutputDetails cd2) Compares its two arguments for order.
boolean	equals(java.lang.Object obj) Indicates whether some other object is "equal to" this Comparator by checking to see if it is the same class instance, and then if the priority listing between the two is the same.

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LIGHTS

public static final int LIGHTS

Priority state is lights

See Also:

Constant Field Values

MATERIALS

public static final int MATERIALS

Priority state is material values

See Also:

Constant Field Values

FRAGMENT_SHADERS

public static final int FRAGMENT_SHADERS

Priority state is fragment shaders

See Also:

Constant Field Values

VERTEX_SHADERS

public static final int VERTEX_SHADERS

Priority state is vertex shaders

See Also:

Constant Field Values

SHADER_OBJECTS

public static final int SHADER_OBJECTS

Priority state is shader objects (ie GL 1.5/2.0)

See Also:

Constant Field Values

POLYGON_ATTRIBS

public static final int POLYGON_ATTRIBS

Priority state is checking polygon attributes

See Also:

Constant Field Values

LINE_ATTRIBS

public static final int LINE_ATTRIBS

Priority state is checking line attributes

See Also:

Constant Field Values

POINT_ATTRIBS

public static final int POINT_ATTRIBS

Priority state is checking point attributes

See Also:

Constant Field Values

BLEND_ATTRIBS

public static final int BLEND_ATTRIBS

Priority state is checking blend attributes. Theoretically we should Never see this here as the blending attributes should be pre-sorted out of the listing first. But, if we're going to do that, we may have to deal with a separate set of state sorting for the blended geometry from the main geometry.

See Also:

Constant Field Values

CLIP_PLANES

public static final int CLIP_PLANES

Priority state is checking clip planes

See Also:

Constant Field Values

LOCAL_FOG

public static final int LOCAL_FOG

Priority state is checking local fog

See Also:

Constant Field Values

DEPTH_ATTRIBS

public static final int DEPTH_ATTRIBS

Priority state is checking depth buffer attributes

See Also:

Constant Field Values

STENCIL_ATTRIBS

public static final int STENCIL_ATTRIBS

Priority state is checking stencil buffer attributes

See Also:

Constant Field Values

TEXTURE_UNIT_0

public static final int TEXTURE_UNIT_0

Priority state is texture unit 0

See Also:

Constant Field Values

TEXTURE_UNIT_1

public static final int TEXTURE_UNIT_1

Priority state is texture unit 1

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Constant Field Values

TEXTURE_UNIT_2

public static final int TEXTURE_UNIT_2

Priority state is texture unit 2

See Also:

Constant Field Values

TEXTURE_UNIT_3

public static final int TEXTURE_UNIT_3

Priority state is texture unit 3

See Also:

Constant Field Values

Constructor Detail

StateSortComparator

public StateSortComparator()

Construct an instance of this comparator using the default priority settings.

StateSortComparator

public StateSortComparator(int[] priList)

Construct an instance of this comparator given the listed set of priorities. If any priority is repeated, the second (or more) instance is ignored. If the list instance is null or zero length, the default order is assumed.

Parameters:

priList - The listing of priorities to use

Method Detail

compare

public int compare(GraphicsCullOutputDetails cd1,
                   GraphicsCullOutputDetails cd2)

Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

Specified by:

compare in interface java.util.Comparator<GraphicsCullOutputDetails>

Parameters:

cd1 - The first object to be compared

cd2 - The second object to be compared

Returns:

-1, 0, or 1 depending on equality

Throws:

java.lang.ClassCastException - Can't be compared as the types are wrong

equals

public boolean equals(java.lang.Object obj)

Indicates whether some other object is "equal to" this Comparator by checking to see if it is the same class instance, and then if the priority listing between the two is the same.

Specified by:

equals in interface java.util.Comparator<GraphicsCullOutputDetails>

Overrides:

equals in class java.lang.Object