Macro pasture_core::attributes_as

macro_rules! attributes_as {
    ($attr1:expr => $t1:ty, $attr2:expr => $t2:ty, $buffer:expr) => { ... };
    ($attr1:expr => $t1:ty, $attr2:expr => $t2:ty, $attr3:expr => $t3:ty, $buffer:expr) => { ... };
    ($attr1:expr => $t1:ty, $attr2:expr => $t2:ty, $attr3:expr => $t3:ty, $attr4:expr => $t4:ty, $buffer:expr) => { ... };
}

Create an iterator over multiple attributes within a PointBuffer, supporting type converisons. This macro uses some special syntax to determine the attributes and their types:

attributes_as!{ ATTRIBUTE_1_EXPR => ATTRIBUTE_1_TYPE, ATTRIBUTE_2_EXPR => ATTRIBUTE_2_TYPE, ..., buffer }

ATTRIBUTE_X_EXPR must be an expression that evaluates to a &PointAttributeDefinition and ATTRIBUTE_X_TYPE must be the Pasture PrimitiveType that the attribute will be returned as. This type must be convertible from the actual type that the attribute is stored with inside buffer. The iterator will then return tuples of the form:

(ATTRIBUTE_1_TYPE, ATTRIBUTE_2_TYPE, ...)

Note: Currently, a maximum of 4 attributes at the same time are supported.

Panics

Panics if any of the attributes are not contained within the buffer. Panics if, for any attribute, no conversion exists between this attributes PointAttributeDataType and the desired type for this attribute.