Inherits from CC3TextureUnit : NSObject
Declared in CC3TextureUnit.h

Overview

A texture unit that provides complete flexibility in defining the way the texture will be combined with the output of previous texture units.

Tasks

Properties

alphaOperand0

Defines the operand to be applied to the alpha component of alphaSource0 prior to it being used by the combiner.

@property (nonatomic, assign) GLenum alphaOperand0

Discussion

This property may be set to any of the following values: – GL_SRC_ALPHA – the source alpha. – GL_ONE_MINUS_SRC_ALPHA – the inverse of the source alpha.

The initial value of this property is GL_SRC_ALPHA, indicating that the alpha component of alphaSource0 will be used as-is by the combiner.

Declared In

CC3TextureUnit.h

alphaOperand1

Defines the operand to be applied to the alpha component of alphaSource1 prior to it being used by the combiner.

@property (nonatomic, assign) GLenum alphaOperand1

Discussion

See the notes for the alphaOperand0 property for the list of permitted values.

The initial value of this property is GL_SRC_ALPHA, indicating that the alpha component of alphaSource1 will be used as-is by the combiner.

Declared In

CC3TextureUnit.h

alphaOperand2

Defines the operand to be applied to the alpha component of alphaSource2 prior to it being used by the combiner.

@property (nonatomic, assign) GLenum alphaOperand2

Discussion

See the notes for the alphaOperand0 property for the list of permitted values.

The initial value of this property is GL_SRC_ALPHA, indicating that the alpha component of alphaSource2 will be used as-is by the combiner.

Declared In

CC3TextureUnit.h

alphaSource0

Identifies the source texture for the alpha component used as argument zero in the texture function defined by the combineAlphaFunction property.

@property (nonatomic, assign) GLenum alphaSource0

Discussion

This property may be set to any of the following values: – GL_TEXTURE – use this texture – GL_CONSTANT – use the alpha component in the constantColor property of this texture unit. – GL_PRIMARY_COLOR – use the color of the material. – GL_PREVIOUS – use the output of the previous texture unit in the chain, or the color of the material when processing texture unit zero.

The intial value of this property is GL_TEXTURE, indicating that the texture combiner will use this texture as argument zero in the texture combiner function.

Declared In

CC3TextureUnit.h

alphaSource1

Identifies the source texture for the alpha components used as argument one in the texture function defined by the combineAlphaFunction property.

@property (nonatomic, assign) GLenum alphaSource1

Discussion

See the notes for the alphaSource0 property for the list of permitted values.

The intial value of this property is GL_PREVIOUS, indicating that the texture combiner will use the output of the previous texture unit in the chain, or the color of the material if processing texture unit zero.

Declared In

CC3TextureUnit.h

alphaSource2

Identifies the source texture for the alpha components used as argument two in the texture function defined by the combineAlphaFunction property.

@property (nonatomic, assign) GLenum alphaSource2

Discussion

See the notes for the alphaSource0 property for the list of permitted values.

The intial value of this property is GL_CONSTANT, indicating that the texture combiner will use the alpha value in the constantColor property of this texture unit.

Declared In

CC3TextureUnit.h

combineAlphaFunction

If the textureEnvironmentMode property is set to GL_COMBINE, this property defines the form of combining function used to combine the alpha component of the texture associated with this texture unit with the output of the previous texture unit.

@property (nonatomic, assign) GLenum combineAlphaFunction

Discussion

This property may be set to any of the following values: – GL_REPLACE – simply use the texture identified by the rgbSource0 property. – GL_MODULATE – multiply together the alpha components of the textures identified by the rgbSource0 and rgbSource1 properties. – GL_ADD – add together the alpha components of the textures identified by the rgbSource0 and rgbSource1 properties. – GL_ADD_SIGNED – add together the alpha components of the textures identified by the rgbSource0 and rgbSource1 properties and then subtract 0.5. – GL_SUBTRACT – subtract the alpha component of the texture identified by rgbSource1 from that of the texture identified by rgbSource0. – GL_INTERPOLATE – interpolate the alpha components between the textures identified by the rgbSource0, rgbSource1 and rgbSource1 properties

The initial value of this property is set to GL_MODULATE, which replicates the behaviour of the CC3Texture class

Declared In

CC3TextureUnit.h

combineRGBFunction

If the textureEnvironmentMode property is set to GL_COMBINE, this property defines the form of combining function used to combine the RGB components of the texture associated with this texture unit with the output of the previous texture unit.

@property (nonatomic, assign) GLenum combineRGBFunction

Discussion

This property may be set to any of the following values: – GL_REPLACE – simply use the texture identified by the rgbSource0 property. – GL_MODULATE – multiply together the RGB components of the textures identified by the rgbSource0 and rgbSource1 properties. – GL_ADD – add together the RGB components of the textures identified by the rgbSource0 and rgbSource1 properties. – GL_ADD_SIGNED – add together the RGB components of the textures identified by the rgbSource0 and rgbSource1 properties and then subtract 0.5. – GL_SUBTRACT – subtract the RGB components of the texture identified by rgbSource1 from those of the texture identified by rgbSource0. – GL_INTERPOLATE – interpolate the RGB components between the textures identified by the rgbSource0, rgbSource1 and rgbSource1 properties – GL_DOT3_RGB or GL_DOT3_RGBA – treat the RGB components of the textures identified by the rgbSource0 and rgbSource1 properties as the three coordinates of a normal vector, take the dot product of the two vectors, and put the resulting scalar value into each of the 3 (RGB) or 4 (RGBA) components on output. This has the effect of modulating the underlying light colors in such a way that the surface appears to be three-dimensional.

The initial value of this property is set to GL_MODULATE, which replicates the behaviour of the CC3Texture class

Declared In

CC3TextureUnit.h

isBumpMap

Returns whether this texture unit is configured as a bump-map.

@property (nonatomic, readonly) BOOL isBumpMap

Discussion

This implementation always returns YES if the textureEnvironmentMode property is set to GL_COMBINE and the combineRGBFunction property is set to either GL_DOT3_RGB or GL_DOT3_RGBA.

Declared In

CC3TextureUnit.h

rgbOperand0

Defines the operand to be applied to the RGB components of rgbSource0 prior to them being used by the combiner.

@property (nonatomic, assign) GLenum rgbOperand0

Discussion

This property may be set to any of the following values: – GL_SRC_COLOR – the source color. – GL_ONE_MINUS_SRC_COLOR – the inverse of the source color. – GL_SRC_ALPHA – the source alpha. – GL_ONE_MINUS_SRC_ALPHA – the inverse of the source alpha.

The initial value of this property is GL_SRC_COLOR, indicating that the RGB color of rgbSource0 will be used as-is by the combiner.

Declared In

CC3TextureUnit.h

rgbOperand1

Defines the operand to be applied to the RGB components of rgbSource1 prior to them being used by the combiner.

@property (nonatomic, assign) GLenum rgbOperand1

Discussion

See the notes for the rgbOperand0 property for the list of permitted values.

The initial value of this property is GL_SRC_COLOR, indicating that the RGB color of rgbSource1 will be used as-is by the combiner.

Declared In

CC3TextureUnit.h

rgbOperand2

Defines the operand to be applied to the RGB components of rgbSource2 prior to them being used by the combiner.

@property (nonatomic, assign) GLenum rgbOperand2

Discussion

See the notes for the rgbOperand2 property for the list of permitted values.

The initial value of this property is GL_SRC_ALPHA, indicating that the alpha component of rgbSource2 will be used by the combiner.

Declared In

CC3TextureUnit.h

rgbSource0

Identifies the source texture for the RGB components used as argument zero in the texture function defined by the combineRGBFunction property.

@property (nonatomic, assign) GLenum rgbSource0

Discussion

This property may be set to any of the following values: – GL_TEXTURE – use this texture – GL_CONSTANT – use the color in the constantColor property of this texture unit. – GL_PRIMARY_COLOR – use the color of the material. – GL_PREVIOUS – use the output of the previous texture unit in the chain, or the color of the material when processing texture unit zero.

The intial value of this property is GL_TEXTURE, indicating that the texture combiner will use this texture as argument zero in the texture combiner function.

Declared In

CC3TextureUnit.h

rgbSource1

Identifies the source texture for the RGB components used as argument one in the texture function defined by the combineRGBFunction property.

@property (nonatomic, assign) GLenum rgbSource1

Discussion

See the notes for the rgbSource0 property for the list of permitted values.

The intial value of this property is GL_PREVIOUS, indicating that the texture combiner will use the output of the previous texture unit in the chain, or the color of the material if processing texture unit zero.

Declared In

CC3TextureUnit.h

rgbSource2

Identifies the source texture for the RGB components used as argument two in the texture function defined by the combineRGBFunction property.

@property (nonatomic, assign) GLenum rgbSource2

Discussion

See the notes for the rgbSource0 property for the list of permitted values.

The intial value of this property is GL_CONSTANT, indicating that the texture combiner will use the value in the constantColor property of this texture unit.

Declared In

CC3TextureUnit.h

textureEnvironmentMode

Defines the texture function to be used when combining this texture unit with the output of the previous texture unit. This can be set to one of several fixed texture functions (GL_ADD, GL_MODULATE, GL_DECAL, GL_BLEND, GL_REPLACE), in which case the remaining configuration properties of this class are ignored. Setting this property to GL_MODULATE replicates the default behaviour of the CC3Texture class.

@property (nonatomic, assign) GLenum textureEnvironmentMode

Discussion

Setting this property to GL_COMBINE activates the other configuration properties of this class, opening up significant additional configuration flexibility.

The initial value of this property is GL_COMBINE, indicating that all configuration properties are active.

Declared In

CC3TextureUnit.h