The SWIs Font_Paint and Font_ScanString now accept strings in 8, 16 or 32-bit forms (all other SWIs only accept 8-bit strings). This is invoked by bits in the flags word in R2.
A 16-bit string must be half-word aligned, and consists of a number of 16-bit halfwords. A 32-bit string must be word aligned, and consists of a number of 32-bit words.
For example, the string "Hello" might be represented as follows:
8-bit : 48 65 6C 6C 6F 00
16-bit : 0048 0065 006C 006C 006F 0000
32-bit : 00000048 00000065 0000006C 0000006C 0000006F 00000000
This allows access to characters outside the first 256. Control codes work as before, but have to be introduced by a character of the appropriate width. The parameters of control sequences are handled differently in 16 and 32-bit modes. See also the notes on the font's encoding.
Regardless of the setting of the 16/32-bit bits, string lengths continue to be in bytes (such as R7 on entry to Font_Paint).
Control code parameters
16-bit parameter forms:
9,11 : dx/dy comprised of 2 16-bit words.
17 : 1 16-bit word
18 : 3 16-bit words
19 : 2 x (RR00, BBGG word pairs) + 1 16-bit word
21 : sequence of 16-bit words, terminated by a word < &0020
25 : 2 16-bit words
26 : 1 16-bit word
27 : 4 32-bit words (word-aligned)
28 : 6 32-bit words (word-aligned)
32-bit parameter forms:
9,11 : 1 32-bit words
17 : 1 32-bit word
18 : 3 32-bit words
19 : 3 32-bit words
21 : sequence of 32-bit words, terminated by a word < &00000020
25 : 2 32-bit words
26 : 1 32-bit word
27 : 4 32-bit words
28 : 6 32-bit words
[sh-index] Back to list of manuals
|
| |
