内容表

• 关于
• FieldLayerData
• 注册
• 范例
• 延伸阅读

关于

FieldLayerData is the base class for custom field layers ( FieldLayer )

A new FieldLayerData based class is registered with RegisterFieldLayerPlugin() .

FieldLayerData

In a FieldLayerData based class the following functions can be implemented:

• FieldLayerData::InitSampling() : Prepares data for sampling.
• FieldLayerData::Sample() : Samples the layer.
• FieldLayerData::Aggregate() : Called after each thread/block if FIELDLAYER_AGGREGATE is set.
• FieldLayerData::FreeSampling() : Frees data after sampling.
• FieldLayerData::IsEqual() : Returns true if the layer is equal to the given layer.
• FieldLayerData::GetLinkedObject() : Returns a referenced object.
• FieldLayerData::SetLinkedObject() : Sets a referenced object.
• FieldLayerData::CheckDirty() : Updates the dirtiness.

注册

A FieldLayerData based class has to be registered with RegisterFieldLayerPlugin() . The flags are:

• FIELDLAYER_DIRECT : The FieldLayer will have access to directly manipulate the 'result' data in ModifyValues rather than purely overwrite it.
• FIELDLAYER_CHILDREN : The FieldLayer accepts child layers (which it then must evaluate itself in it's Sample function).
• FIELDLAYER_NOVALUEOUT : The FieldLayer doesn't calculate values.
• FIELDLAYER_NOCOLOROUT : The FieldLayer doesn't calculate colors.
• FIELDLAYER_NODIRECTIONOUT : The FieldLayer doesn't calculate slopes.
• FIELDLAYER_AGGREGATE : FieldLayerData::Aggregate() should be called after each block.

注意

Modifier layers are registered with FIELDLAYER_DIRECT .

范例

// ------------------------------------------------------------------------------ // This example field layer shifts the hue of the sample color. // ------------------------------------------------------------------------------ class HueShiftFieldLayer : public FieldLayerData { INSTANCEOF (HueShiftFieldLayer, FieldLayerData )