ps_1_4 source register modifiers for texld, texcrd
Two pixel shader version 1_4 texture address instructions, texld - ps_1_4 and texcrd - ps, have custom syntax. These instructions support their own set of source register modifiers, source register selectors, and destination-register write masks, as shown here.
Source Register Modifiers for texld and texcrd
These modifiers provide projective divide functionality by dividing the x and y values by either the z or w values.
| Source register modifiers | Description | Syntax |
|---|---|---|
| _dz | Divide x,y components by z | register_dz |
| _db | Divide x,y components by z | register_db |
| _dw | Divide x,y components by w | register_dw |
| _da | Divide x,y components by w | register_da |
Remarks
The _dz or _db modifier does the following:
x' = x/z ( x' = 1.0 if z == 0)
y' = y/z ( y' = 1.0 if z == 0)
z' is undefined
w' is undefined
The _dw or _da modifier does the following:
x' = x/w ( x' = 1.0 if w == 0)
y' = y/w ( y' = 1.0 if w == 0)
z' is undefined
w' is undefined
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