Class: StarFieldProgram

StarFieldProgram(gl)

StarFieldProgram is a GLSL program that draws points representing stars.

Constructor

new StarFieldProgram(gl)

Constructs a new program. Initializes, compiles and links this GLSL program with the source code for its vertex and fragment shaders.

This method creates WebGL shaders for the program's shader sources and attaches them to a new GLSL program. This method then compiles the shaders and then links the program if compilation is successful. Use the bind method to make the program current during rendering.

Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
Source:
Throws:
If the shaders cannot be compiled, or linking of the compiled shaders into a program fails.
Type
ArgumentError

Extends

Members

(static, readonly) key :string

A string that uniquely identifies this program.
Type:
  • string
Source:

(readonly) magnitudeRangeLocation :WebGLUniformLocation

The WebGL location for this program's 'magnitudeRangeLocation' uniform.
Type:
  • WebGLUniformLocation
Source:

(readonly) mvpMatrixLocation :WebGLUniformLocation

The WebGL location for this program's 'mvpMatrix' uniform.
Type:
  • WebGLUniformLocation
Source:

(readonly) numDaysLocation :WebGLUniformLocation

The WebGL location for this program's 'numDays' uniform.
Type:
  • WebGLUniformLocation
Source:

(readonly) programId :WebGLProgram

Indicates the WebGL program object associated with this GPU program.
Type:
  • WebGLProgram
Inherited From:
Source:

(readonly) textureEnabledLocation :WebGLUniformLocation

The WebGL location for this program's 'textureEnabled' uniform.
Type:
  • WebGLUniformLocation
Source:

(readonly) textureUnitLocation :WebGLUniformLocation

The WebGL location for this program's 'textureSampler' uniform.
Type:
  • WebGLUniformLocation
Source:

(readonly) vertexPointLocation :Number

The WebGL location for this program's 'vertexPoint' attribute.
Type:
  • Number
Source:

Methods

attributeLocation(gl, attributeName) → {Number}

Returns the GLSL attribute location of a specified attribute name.
Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
attributeName String The name of the attribute whose location is determined.
Inherited From:
Source:
Throws:
If the specified attribute name is null, empty or undefined.
Type
ArgumentError
Returns:
The WebGL attribute location of the specified attribute, or -1 if the attribute is not found.
Type
Number

dispose(gl)

Releases this GPU program's WebGL program and associated shaders. Upon return this GPU program's WebGL program ID is 0 as is that of the associated shaders.
Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
Inherited From:
Source:
Links a specified GLSL program. This method is not meant to be called by applications. It is called internally as needed.
Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
program WebGLProgram The WebGL program.
Inherited From:
Source:
Returns:
true if linking was successful, otherwise false.
Type
Boolean

loadMagnitudeRange(gl, minMag, maxMag)

Loads the specified numbers as the value of this program's 'magnitudeRange' uniform variable.
Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
minMag Number
maxMag Number
Source:
Throws:
If the specified numbers are null or undefined.
Type
ArgumentError

loadModelviewProjection(gl, matrix)

Loads the specified matrix as the value of this program's 'mvpMatrix' uniform variable.
Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
matrix Matrix The matrix to load.
Source:
Throws:
If the specified matrix is null or undefined.
Type
ArgumentError

loadNumDays(gl, numDays)

Loads the specified number as the value of this program's 'numDays' uniform variable.
Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
numDays Number The number of days (positive or negative) since Greenwich noon, Terrestrial Time, on 1 January 2000 (J2000.0)
Source:
Throws:
If the specified number is null or undefined.
Type
ArgumentError

loadTextureEnabled(gl, value)

Loads the specified boolean as the value of this program's 'textureEnabledLocation' uniform variable.
Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
value Boolean
Source:

loadTextureUnit(gl, unit)

Loads the specified number as the value of this program's 'textureSampler' uniform variable.
Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
unit Number The texture unit.
Source:

loadUniformColor(gl, color, location)

Loads a specified color as the value of a GLSL vec4 uniform variable with the specified location.

This function multiplies the red, green and blue components by the alpha component prior to loading the color in the GLSL uniform variable, but does not modify the specified color.

Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
color Color The color to load.
location WebGLUniformLocation The location of the uniform variable in the currently bound GLSL program.
Inherited From:
Source:
Throws:
If the specified color is null or undefined.
Type
ArgumentError

loadUniformColorComponents(gl, red, green, blue, alpha, location)

Loads the specified RGBA color components as the value of a GLSL vec4 uniform variable with the specified location.

This function multiplies the red, green and blue components by the alpha component prior to loading the color in the GLSL uniform variable.

Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
red Number The red component, a number between 0 and 1.
green Number The green component, a number between 0 and 1.
blue Number The blue component, a number between 0 and 1.
alpha Number The alpha component, a number between 0 and 1.
location WebGLUniformLocation The location of the uniform variable in the currently bound GLSL program.
Inherited From:
Source:

loadUniformMatrix(gl, matrix, location)

Loads a specified matrix as the value of a GLSL 4x4 matrix uniform variable with the specified location.

This functions converts the matrix into column-major order prior to loading its components into the GLSL uniform variable, but does not modify the specified matrix.

Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
matrix Matrix The matrix to load.
location WebGLUniformLocation The location of the uniform variable in the currently bound GLSL program.
Inherited From:
Source:
Throws:
If the specified matrix is null or undefined.
Type
ArgumentError

uniformLocation(gl, uniformName) → {WebGLUniformLocation}

Returns the GLSL uniform location of a specified uniform name.
Parameters:
Name Type Description
gl WebGLRenderingContext The current WebGL context.
uniformName String The name of the uniform variable whose location is determined.
Inherited From:
Source:
Throws:
If the specified uniform name is null, empty or undefined.
Type
ArgumentError
Returns:
The WebGL uniform location of the specified uniform variable, or -1 if the uniform is not found.
Type
WebGLUniformLocation