de.grogra.imp3d.shading
Class RGBAShader

java.lang.Object
  javax.vecmath.Tuple4f
      javax.vecmath.Color4f
          de.grogra.imp3d.shading.RGBAShader

All Implemented Interfaces:

Icon, IconSource, Manageable, Shareable, Scattering, Shader, java.io.Serializable, java.lang.Cloneable

public final class RGBAShader
extends Color4f
implements Shader, Shareable, Manageable, IconSource, Icon

A RGBAShader implements a simple lambertian material with a single color and an alpha-value for the transparency. Some methods which are related to the color palette of the EGA graphics card are declared, they are used in the context of the emulation of the GROGRA software.

Author:

Ole Kniemeyer

See Also:

Serialized Form

Field Summary

static ManageableType	$TYPE
static RGBAShader	BLACK RGBAShader whose color is Color.BLACK.
static RGBAShader	BLUE RGBAShader whose color is Color.BLUE.
static RGBAShader	CYAN RGBAShader whose color is Color.CYAN.
static RGBAShader	DARK_GRAY RGBAShader whose color is Color.DARK_GRAY.
static RGBAShader	EGA_0 RGBAShader whose color is EGA color number 0.
static RGBAShader	EGA_1 RGBAShader whose color is EGA color number 1.
static RGBAShader	EGA_10 RGBAShader whose color is EGA color number 10.
static RGBAShader	EGA_11 RGBAShader whose color is EGA color number 11.
static RGBAShader	EGA_12 RGBAShader whose color is EGA color number 12.
static RGBAShader	EGA_13 RGBAShader whose color is EGA color number 13.
static RGBAShader	EGA_14 RGBAShader whose color is EGA color number 14.
static RGBAShader	EGA_15 RGBAShader whose color is EGA color number 15.
static RGBAShader	EGA_2 RGBAShader whose color is EGA color number 2.
static RGBAShader	EGA_3 RGBAShader whose color is EGA color number 3.
static RGBAShader	EGA_4 RGBAShader whose color is EGA color number 4.
static RGBAShader	EGA_5 RGBAShader whose color is EGA color number 5.
static RGBAShader	EGA_6 RGBAShader whose color is EGA color number 6.
static RGBAShader	EGA_7 RGBAShader whose color is EGA color number 7.
static RGBAShader	EGA_8 RGBAShader whose color is EGA color number 8.
static RGBAShader	EGA_9 RGBAShader whose color is EGA color number 9.
static RGBAShader	GRAY RGBAShader whose color is Color.GRAY.
static RGBAShader	GREEN RGBAShader whose color is Color.GREEN.
static RGBAShader	LIGHT_GRAY RGBAShader whose color is Color.LIGHT_GRAY.
static RGBAShader	MAGENTA RGBAShader whose color is Color.MAGENTA.
static RGBAShader	ORANGE RGBAShader whose color is Color.ORANGE.
static RGBAShader	PINK RGBAShader whose color is Color.PINK.
static RGBAShader	RED RGBAShader whose color is Color.RED.
static RGBAShader	WHITE RGBAShader whose color is Color.WHITE.
static RGBAShader	YELLOW RGBAShader whose color is Color.YELLOW.

Fields inherited from class javax.vecmath.Tuple4f

w, x, y, z

Fields inherited from interface de.grogra.ray.physics.Shader

LAMBERTIAN_VARIANCE

Fields inherited from interface de.grogra.ray.physics.Scattering

DELTA_FACTOR, IS_NON_OPAQUE, MIN_UNUSED_FLAG, NEEDS_NORMAL, NEEDS_POINT, NEEDS_TANGENTS, NEEDS_TRANSFORMATION, NEEDS_UV, RANDOM_RAYS_GENERATE_ORIGINS

Fields inherited from interface de.grogra.icon.Icon

DEFAULT, DISABLED

Constructor Summary

RGBAShader()

RGBAShader(Color4f color)

RGBAShader(float red, float green, float blue)

RGBAShader(float red, float green, float blue, float alpha)

RGBAShader(int rgba)
Specify colors as ARGB integer.

RGBAShader(Shader a)

Method Summary

void	accept(ShaderVisitor visitor)
void	addReference(SharedObjectReference ref)
void	appendReferencesTo(java.util.List out)
java.lang.Object	clone()
float	computeBSDF(Environment env, Vector3f in, Spectrum specIn, Vector3f out, boolean adjoint, Spectrum bsdf) Evaluates bidirectional scattering distribution function for given input.
void	computeMaxRays(Environment env, Vector3f in, Spectrum specIn, Ray reflected, Tuple3f refVariance, Ray transmitted, Tuple3f transVariance) Computes, for the given input, the reflected and transmitted importance rays for which the reflection/transmission probability densities (integrated over the spectrum) attain a maximum.
void	fieldModified(PersistenceField field, int[] indices, Transaction t)
static RGBAShader	forEGAColor(int index) Returns the RGBAShader whose color has the specified index in the palette of the EGA graphics card.
void	generateRandomRays(Environment env, Vector3f out, Spectrum specOut, RayList rays, boolean adjoint, java.util.Random rnd) Pseudorandomly generates, for the given input, a set of scattered rays.
int	getAverageColor() Returns an average color for the scattering entity.
static int	getEGAColorIndex(Color3f c) Returns the index of the color in the palette of the EGA graphics card which is closest to the specified color.
static int	getEGAColorIndex(Color4f c) Returns the index of the color in the palette of the EGA graphics card which is closest to the specified color.
static int	getEGAColorIndex(float r, float g, float b) Returns the index of the color in the palette of the EGA graphics card which is closest to the specified color.
int	getFlags()
Icon	getIcon(java.awt.Dimension size, int state)
java.awt.Rectangle	getIconBounds()
IconSource	getIconSource()
java.awt.Image	getImage()
java.awt.Image	getImage(int w, int h)
java.net.URL	getImageSource()
ManageableType	getManageableType()
java.awt.Dimension	getPreferredIconSize(boolean small)
SharedObjectProvider	getProvider()
int	getStamp() Returns a stamp for this object.
void	initProvider(SharedObjectProvider provider)
boolean	isMutable()
boolean	isPredefined()
boolean	isTransparent()
Manageable	manageableReadResolve()
java.lang.Object	manageableWriteReplace()
void	paintIcon(java.awt.Component c, java.awt.Graphics2D g, int x, int y, int w, int h, int state)
void	prepareIcon()
void	removeReference(SharedObjectReference ref)
void	scale(double r, Tuple3d color)
void	shade(Environment env, RayList in, Vector3f out, Spectrum specOut, Tuple3d color) Computes color of outgoing light ray for given input.

Methods inherited from class javax.vecmath.Color4f

get, set

Methods inherited from class javax.vecmath.Tuple4f

absolute, absolute, add, add, clamp, clamp, clampMax, clampMax, clampMin, clampMin, epsilonEquals, equals, equals, get, get, hashCode, interpolate, interpolate, negate, negate, scale, scale, scaleAdd, scaleAdd, set, set, set, set, sub, sub, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

$TYPE

public static final ManageableType $TYPE

BLACK

public static final RGBAShader BLACK

RGBAShader whose color is Color.BLACK.

BLUE

public static final RGBAShader BLUE

RGBAShader whose color is Color.BLUE.

CYAN

public static final RGBAShader CYAN

RGBAShader whose color is Color.CYAN.

DARK_GRAY

public static final RGBAShader DARK_GRAY

RGBAShader whose color is Color.DARK_GRAY.

EGA_0

public static final RGBAShader EGA_0

RGBAShader whose color is EGA color number 0.

EGA_1

public static final RGBAShader EGA_1

RGBAShader whose color is EGA color number 1.

EGA_10

public static final RGBAShader EGA_10

RGBAShader whose color is EGA color number 10.

EGA_11

public static final RGBAShader EGA_11

RGBAShader whose color is EGA color number 11.

EGA_12

public static final RGBAShader EGA_12

RGBAShader whose color is EGA color number 12.

EGA_13

public static final RGBAShader EGA_13

RGBAShader whose color is EGA color number 13.

EGA_14

public static final RGBAShader EGA_14

RGBAShader whose color is EGA color number 14.

EGA_15

public static final RGBAShader EGA_15

RGBAShader whose color is EGA color number 15.

EGA_2

public static final RGBAShader EGA_2

RGBAShader whose color is EGA color number 2.

EGA_3

public static final RGBAShader EGA_3

RGBAShader whose color is EGA color number 3.

EGA_4

public static final RGBAShader EGA_4

RGBAShader whose color is EGA color number 4.

EGA_5

public static final RGBAShader EGA_5

RGBAShader whose color is EGA color number 5.

EGA_6

public static final RGBAShader EGA_6

RGBAShader whose color is EGA color number 6.

EGA_7

public static final RGBAShader EGA_7

RGBAShader whose color is EGA color number 7.

EGA_8

public static final RGBAShader EGA_8

RGBAShader whose color is EGA color number 8.

EGA_9

public static final RGBAShader EGA_9

RGBAShader whose color is EGA color number 9.

GRAY

public static final RGBAShader GRAY

RGBAShader whose color is Color.GRAY.

GREEN

public static final RGBAShader GREEN

RGBAShader whose color is Color.GREEN.

LIGHT_GRAY

public static final RGBAShader LIGHT_GRAY

RGBAShader whose color is Color.LIGHT_GRAY.

MAGENTA

public static final RGBAShader MAGENTA

RGBAShader whose color is Color.MAGENTA.

ORANGE

public static final RGBAShader ORANGE

RGBAShader whose color is Color.ORANGE.

PINK

public static final RGBAShader PINK

RGBAShader whose color is Color.PINK.

RED

public static final RGBAShader RED

RGBAShader whose color is Color.RED.

WHITE

public static final RGBAShader WHITE

RGBAShader whose color is Color.WHITE.

YELLOW

public static final RGBAShader YELLOW

RGBAShader whose color is Color.YELLOW.

Constructor Detail

RGBAShader

public RGBAShader()

RGBAShader

public RGBAShader(Color4f color)

RGBAShader

public RGBAShader(float red,
                  float green,
                  float blue)

RGBAShader

public RGBAShader(float red,
                  float green,
                  float blue,
                  float alpha)

RGBAShader

public RGBAShader(int rgba)

Specify colors as ARGB integer. This means the bits 31-24 are alpha, 23-16 are red, 15-8 are green and 7-0 are blue.

Parameters:

rgba - color as 0xAARRGGBB

RGBAShader

public RGBAShader(Shader a)

Method Detail

accept

public void accept(ShaderVisitor visitor)

addReference

public void addReference(SharedObjectReference ref)

Specified by:

addReference in interface Shareable

appendReferencesTo

public void appendReferencesTo(java.util.List out)

Specified by:

appendReferencesTo in interface Shareable

clone

public java.lang.Object clone()

Overrides:

clone in class Color4f

computeBSDF

public float computeBSDF(Environment env,
                         Vector3f in,
                         Spectrum specIn,
                         Vector3f out,
                         boolean adjoint,
                         Spectrum bsdf)

Description copied from interface: Scattering

Evaluates bidirectional scattering distribution function for given input.

The computed spectrum is an integral over the spectrum of the following product:

|cos θ| BSDF(ω_i, ν_i; ω_o, ν_o) where BSDF is the bidirectional scattering distribution function (= BRDF + BTDF) at the point env.point, ω_i the (negated) direction of the incoming light ray, ν_i the frequency where the incoming ray is sampled, ω_o the direction of the outgoing light ray, ν_o the frequency where the outgoing ray is sampled, and θ the angle between the surface normal and out.

If adjoint is false, in and out describe true light rays from light sources to sensors. In this case, ω_i = in, ω_o = out, and the integral is

bsdf(ν) = |cos θ| ∫ BSDF(in, ν_i; out, ν) specIn(ν_i) dν_i Otherwise, adjoint is true. in and out then describe importance rays (inverse light rays from sensors to light sources). In this case, ω_i = out, ω_o = in, and the integral is bsdf(ν) = |cos θ| ∫ BSDF(out, ν; in, ν_o) specIn(ν_o) dν_o

If this Scattering instance is in fact a Light source, adjoint is false, and the BSDF is defined as BSDF(in, μ; ω, ν) = L¹(ω, ν) δ(μ - ν), i.e., the directional distribution of the emitted radiance at env.point, see Emitter. In this case, in is not used.

If this Scattering instance is in fact a Sensor, adjoint is true, and the BSDF is defined as BSDF(ω, ν; in, μ) = W¹(ω, ν) δ(μ - ν), i.e., the directional distribution of the emitted importance at env.point, see Emitter. In this case, in is not used.

The computation should be physically valid. This excludes, e.g., ambient or emissive light contributions.

The returned value is the value of the probability density p_ω that would be calculated by Scattering.generateRandomRays(de.grogra.ray.physics.Environment, javax.vecmath.Vector3f, de.grogra.ray.physics.Spectrum, de.grogra.ray.util.RayList, boolean, java.util.Random) if the ray happened to be one of the randomly generated rays.

Specified by:

computeBSDF in interface Scattering

Parameters:

env - the environment for scattering

in - the (negated) direction unit vector of the incoming ray (i.e., pointing away from the surface)

specIn - the spectrum of the incoming ray

out - the direction unit vector of the outgoing ray (i.e., pointing away from the surface)

adjoint - light ray or importance ray?

bsdf - the computed spectrum of the outgoing ray will be placed in here

Returns:

the value of the probability density for the ray direction

computeMaxRays

public void computeMaxRays(Environment env,
                           Vector3f in,
                           Spectrum specIn,
                           Ray reflected,
                           Tuple3f refVariance,
                           Ray transmitted,
                           Tuple3f transVariance)

Description copied from interface: Shader

Computes, for the given input, the reflected and transmitted importance rays for which the reflection/transmission probability densities (integrated over the spectrum) attain a maximum. The reflection probability density (measured with respect to solid angle) for the outgoing importance direction (i.e., incoming light direction) ω, given a fixed incident direction in, is p_r(ω) = cos θ BRDF(ω, in) / R where BRDF is the bidirectional reflectivity distribution function, θ the angle between the surface normal and ω, and R the total reflectivity for the incident direction, i.e., the integral over cos θ BRDF(ω, in). The transmission probability density is defined correspondingly.

The color-fields are set to the total reflectivity/transparency for the incident direction for each color component R, G, B. Thus, for physically plausible BRDF/BTDF, the component-wise sum of reflected.color and transmitted.color lies in the interval [0, 1], and the difference to 1 is the amount absorbed.

The color may be zero if there is no reflected or transmitted ray, respectively, i.e., if the surface is fully transparent, opaque, or absorbing. The origin-fields of the rays will never be set.

The computed variances are defined to be, for each color component, (approximations for) the angular mean quadratic deviations of the densities from the returned maximal ray directions. E.g., for perfect reflection/transmission, these variances are zero, whereas for a perfect lambertian reflector, the variance of reflection is ∫ cos θ (1 / π) θ² dω = (π² - 4) / 8. This is the value of Shader.LAMBERTIAN_VARIANCE.

The ray properties which are not mentioned are neither used nor modified. These are the origin and its density, and the direction density.

Specified by:

computeMaxRays in interface Shader

Parameters:

env - the environment for scattering

in - the (negated) direction unit vector of the incoming ray (i.e., pointing away from the surface)

specIn - spectrum of incoming ray

reflected - the reflected ray with maximal probability

refVariance - the angular mean quadratic deviation from reflected

transmitted - the transmitted ray with maximal probability

transVariance - the angular mean quadratic deviation from transmitted

fieldModified

public void fieldModified(PersistenceField field,
                          int[] indices,
                          Transaction t)

Specified by:

fieldModified in interface Manageable

forEGAColor

public static final RGBAShader forEGAColor(int index)

Returns the RGBAShader whose color has the specified index in the palette of the EGA graphics card.

Parameters:

index - palette index (only the lowest 4 bits are used)

Returns:

corresponding shader

generateRandomRays

public void generateRandomRays(Environment env,
                               Vector3f out,
                               Spectrum specOut,
                               RayList rays,
                               boolean adjoint,
                               java.util.Random rnd)

Description copied from interface: Scattering

Pseudorandomly generates, for the given input, a set of scattered rays. The scattered rays are generated such that they can be used for a Monte Carlo integration of a function f(ω;ν) over cos θ BSDF(ω_i, ν_i; ω_o, ν_o) in the following way:

• If adjoint is false, out = ω_o describes the direction of an outgoing light ray. In this case, the integration is with respect to ω_i. Let g(ω, ν; out, μ) = BSDF(ω, ν; out, μ)
• Otherwise, adjoint is true. In this case, out = ω_i describes the direction of an outgoing importance ray (an inverse light ray). Now the integration is with respect to ω_o. Let g(ω, ν; out, μ) = BSDF(out, μ; ω, ν)

Let d_i and s_i denote the directions and spectra of the N generated rays (N = rays.size). Then, for every frequency ν the sum 1 / N ∑_i s_i(ν) f(d_i; ν) is an unbiased estimate for the integral ∫ cos θ f(ω; ν) g(ω, ν; out, μ) specOut(μ) dμ dω θ is the angle between the surface normal and ω. The domain of integration is the whole sphere, since the bidirectional scattering distribution includes both reflection and transmission (BSDF = BRDF + BTDF).

If this Scattering instance is in fact a Light source, adjoint is true, and the BSDF is defined as BSDF(out, μ; ω, ν) = L¹(ω, ν) δ(μ - ν), i.e., the directional distribution of the emitted radiance at env.point, see Emitter. In this case, out is not used.

If this Scattering instance is in fact a Sensor, adjoint is false, and the BSDF is defined as BSDF(ω, ν; out, μ) = W¹(ω, ν) δ(μ - ν), i.e., the directional distribution of the emitted importance at env.point, see Emitter. In this case, out is not used.

Let p_ω be the probability density used for the ray direction (measured with respect to solid angle ω), then the field directionDensity of the ray i is set to p_ω(d_i). For ideal specular reflection or transmission, or for directional lights or sensors, p_ω is not a regular function, the value directionDensity will be set to a multiple of Scattering.DELTA_FACTOR.

The ray properties which are not mentioned in the given formulas are neither used nor modified. These are the origin and its density.

Specified by:

generateRandomRays in interface Scattering

Parameters:

env - the environment for scattering

out - the direction unit vector of the outgoing ray (i.e., pointing away from the surface)

specOut - the spectrum of the outgoing ray

rays - the rays to be generated

adjoint - represents out a light ray or an importance ray?

rnd - pseudorandom generator

See Also:

Scattering.computeBSDF(de.grogra.ray.physics.Environment, javax.vecmath.Vector3f, de.grogra.ray.physics.Spectrum, javax.vecmath.Vector3f, boolean, de.grogra.ray.physics.Spectrum)

getAverageColor

public int getAverageColor()

Description copied from interface: Scattering

Returns an average color for the scattering entity. This color is used for simplified graphical representations of the corresponding objects.

Specified by:

getAverageColor in interface Scattering

Returns:

an average color in Java's default sRGB color space, encoded as an int (0xAARRGGBB).

getEGAColorIndex

public static final int getEGAColorIndex(Color3f c)

Returns the index of the color in the palette of the EGA graphics card which is closest to the specified color.

Parameters:

c - a color

Returns:

index of closest EGA color

getEGAColorIndex

public static final int getEGAColorIndex(Color4f c)

Returns the index of the color in the palette of the EGA graphics card which is closest to the specified color.

Parameters:

c - a color

Returns:

index of closest EGA color

getEGAColorIndex

public static final int getEGAColorIndex(float r,
                                         float g,
                                         float b)

Returns the index of the color in the palette of the EGA graphics card which is closest to the specified color.

Parameters:

r - red value of color (between 0 and 1)

g - green value of color (between 0 and 1)

b - blue value of color (between 0 and 1)

Returns:

index of closest EGA color

getFlags

public int getFlags()

Specified by:

getFlags in interface Scattering

getIcon

public Icon getIcon(java.awt.Dimension size,
                    int state)

Specified by:

getIcon in interface IconSource

getIconBounds

public java.awt.Rectangle getIconBounds()

Specified by:

getIconBounds in interface Icon

getIconSource

public IconSource getIconSource()

Specified by:

getIconSource in interface Icon

getImage

public java.awt.Image getImage()

Specified by:

getImage in interface Icon

getImage

public java.awt.Image getImage(int w,
                               int h)

Specified by:

getImage in interface Icon

getImageSource

public java.net.URL getImageSource()

Specified by:

getImageSource in interface Icon

getManageableType

public ManageableType getManageableType()

Specified by:

getManageableType in interface Manageable

getPreferredIconSize

public java.awt.Dimension getPreferredIconSize(boolean small)

Specified by:

getPreferredIconSize in interface IconSource

getProvider

public SharedObjectProvider getProvider()

Specified by:

getProvider in interface Shareable

getStamp

public int getStamp()

Description copied from interface: Manageable

Returns a stamp for this object. Each modification to this object increments the stamp. The initial stamp is non-negative.

Specified by:

getStamp in interface Manageable

Returns:

a stamp

initProvider

public void initProvider(SharedObjectProvider provider)

Specified by:

initProvider in interface Shareable

isMutable

public boolean isMutable()

Specified by:

isMutable in interface Icon

isPredefined

public boolean isPredefined()

isTransparent

public boolean isTransparent()

Specified by:

isTransparent in interface Shader

manageableReadResolve

public Manageable manageableReadResolve()

Specified by:

manageableReadResolve in interface Manageable

manageableWriteReplace

public java.lang.Object manageableWriteReplace()

Specified by:

manageableWriteReplace in interface Manageable

paintIcon

public void paintIcon(java.awt.Component c,
                      java.awt.Graphics2D g,
                      int x,
                      int y,
                      int w,
                      int h,
                      int state)

Specified by:

paintIcon in interface Icon

prepareIcon

public void prepareIcon()

Specified by:

prepareIcon in interface Icon

removeReference

public void removeReference(SharedObjectReference ref)

Specified by:

removeReference in interface Shareable

scale

public void scale(double r,
                  Tuple3d color)

shade

public void shade(Environment env,
                  RayList in,
                  Vector3f out,
                  Spectrum specOut,
                  Tuple3d color)

Description copied from interface: Shader

Computes color of outgoing light ray for given input. The computed value is, for each color component j = R, G, B, the following sum over all incident rays k: ∑_k |cos θ_k| BSDF_j(ω_k, out) c_k,j where BSDF_j is the bidirectional scattering distribution function (= BRDF + BTDF) at the point env.point, ω_k and c_k the direction and color of ray k, and θ_k the angle between the surface normal and ω_k.

The computation may include physically invalid contributions, which may not fit into the formula above, e.g., ambient or emissive light contributions.

Specified by:

shade in interface Shader

Parameters:

env - the environment for scattering

in - the incoming rays

out - the direction unit vector of the outgoing ray (i.e., pointing away from the surface)

specOut - spectrum of outgoing ray

color - the output color will be placed in here