Swizzling (Vertex Shader)

Source swizzle allows individual component of a source register to take on the value of any of the four components of the same source register before the register is read for computation.

Source Swizzling

For example, the .zxxy swizzle means:

.x component will take on the value of .z component
.y component will take on the value of .x component
.z component will take on the value of .x component
.w component will take on the value of .y component

The components can appear in any order. If fewer than four components are specified, the last component is repeated. For example:

.xy  = .xyyy
.wzx = .wzxx
.z   = .zzzz

If no component is specified, no swizzling is applied.

Some instructions have restrictions for source swizzle. They are listed in the respected instruction reference pages.

Vertex shader versions	1_1	2_0	2_x	2_sw	3_0	3_sw
swizzling	x	x	x	x	x	x

Arbitrary Swizzle

Swizzles can be applied to source registers in an arbitrary order; that is, any source register can take any component mask, in any order.

Vertex shader versions	1_1	2_0	2_x	2_sw	3_0	3_sw
arbitrary swizzling	x	x	x	x	x	x

Replicate Swizzle

Replicate swizzle, is used to replicate or copy one component to another. This is, exactly one of the .x, .y, .z, .w swizzle components (or the .r, .g, .b, .a equivalents) must be specified.