Example: The Logical Operation default value is 252 (TSo), corresponding to a logical function of:
(texture source)
The result is computed below for both case 1 (source and pattern opaque) and case 4 (source and pattern transparent) on the previous page. Note that the ROP3 value of 252 results only with case 1, when both source and pattern transparency modes are set to opaque.
Table 2-5. Logical Operation (ROP3)
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| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Texture | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 0 |
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Source | 1 | 1 | 0 | 0 | 1 | 1 | 0 | 0 |
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Destination | 1 | 0 | 1 | 0 | 1 | 0 | 1 | 0 |
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ROP3 (source & pattern are opaque) | 1 | 1 | 1 | 1 | 1 | 1 | 0 | 0 |
| (decimal 252) |
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ROP3 +Transparencies | 1 | 1 | 1 | 0 | 1 | 0 | 1 | 0 |
(source & pattern are transparent) |
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Each column of destination, source, and texture values are the input to the logical function. The result, 252, is the value that would be sent to identify the logical operation (source and pattern transparency modes are opaque). The last row, “ROP3 + Transparencies (source & pattern are transparent)” shows the result if source and pattern transparency modes are transparent (the default transparency mode).
