Logical Operations and Transparency Interactions

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Logical Operations and Transparency
Interactions

As described above, transparency modes operate in addition to
logical operations. The logical operations in Table 2-5, Logical
Operations (ROP3), on the following pages, are true only if source
and pattern transparency (for white pixels) are explicitly set to opaque
(

?

*v1N and

?

*v1O). If source and/or pattern transparency modes

are transparent (defaulted), the additional operations shown on the
following page must be performed to achieve the final result.

The four basic interactions are:

Case 1: Source and Pattern are opaque.

Return ROP3 (Dest, Src, Texture).

Case 2: Source is opaque, Pattern is transparent.

Temporary_ROP3 = ROP3 (Dest, Src, Texture).
Image_A = Temporary_ROP3, & Not Src.
Image_B = Temporary_ROP3 & Pattern.
Image_C = Not Pattern & Src & Dest.
Return Image_A | Image_B | Image_C

Case 3: Source is transparent, Pattern is opaque.

Temporary_ROP3 = ROP3 (Dest, Src, Texture).
Image_A = Temporary_ROP3 & Src.
Image_B = Dest & Not Src.
Return Image_A | Image_B

Case 4: Source and Pattern are transparent

Temporary_ROP3 = ROP3 (Dest, Src, Texture).
Image_A = Temporary_ROP3 & Src & Pattern.
Image_B = Dest & Not Src.
Image_C = Dest & Not Pattern.
Return Image_A | Image_B | Image_C.

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2-16 Printer-Specific Differences

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