Difference between revisions of "Programming:Keyboard redefinition"
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For performance , it is possible to compute directly offset and mask in keyboard buffer with GetMask function.This is usefull for game as IsPressed function can be considered as slow. | For performance , it is possible to compute directly offset and mask in keyboard buffer with GetMask function.This is usefull for game as IsPressed function can be considered as slow. | ||
| − | As SHIFT or CONTROL status can be a | + | As SHIFT or CONTROL status can be a problem , you can inhibate them using IgnoreSHITFCTRL. |
<pre> | <pre> | ||
| Line 49: | Line 49: | ||
ret | ret | ||
| − | ;check if there is a key is down at (HL);only the first key found is returned | + | ;check if there is a key is down at (HL) |
| + | ;only the first key found is returned | ||
;return carry is a key is down | ;return carry is a key is down | ||
;return key code in A : key code = (line*8)+bit | ;return key code in A : key code = (line*8)+bit | ||
| Line 57: | Line 58: | ||
GetPressed | GetPressed | ||
push HL | push HL | ||
| − | ld C,10.loop_col | + | ld C,10 |
| + | .loop_col | ||
ld B,8 | ld B,8 | ||
| − | ld A,(HL++).loop_bit | + | ld A,(HL++) |
| − | rla jr nc,.pressed | + | .loop_bit |
| + | rla | ||
| + | jr nc,.pressed | ||
djnz .loop_bit | djnz .loop_bit | ||
dec C | dec C | ||
| Line 93: | Line 97: | ||
rrca | rrca | ||
rrca | rrca | ||
| − | ld E,A ld D,0 | + | ld E,A |
| + | ld D,0 | ||
add HL,DE | add HL,DE | ||
;so we get the address | ;so we get the address | ||
| − | pop AF | + | pop AF |
| − | + | ||
and 7 | and 7 | ||
inc A | inc A | ||
| Line 105: | Line 109: | ||
.loop | .loop | ||
rra ;get bit in carry | rra ;get bit in carry | ||
| − | djnz .loop | + | djnz .loop |
ccf ;reverse bit | ccf ;reverse bit | ||
pop HL | pop HL | ||
| Line 154: | Line 158: | ||
ENDMODULE</pre> | ENDMODULE</pre> | ||
| + | |||
| + | [[Category:Programming]] | ||
Latest revision as of 03:44, 1 September 2014
Key redefinition library
This is a little library to allow you to scan keyboard, test keys and redefine them.Functions are explained in source code.
Keycodes returned by GetPressed and used for IsPressed/GetMask are the same than firmware keycodes (you know the one you have on disc plate on CPC 664/6128)
For performance , it is possible to compute directly offset and mask in keyboard buffer with GetMask function.This is usefull for game as IsPressed function can be considered as slow.
As SHIFT or CONTROL status can be a problem , you can inhibate them using IgnoreSHITFCTRL.
;simple keyboard module ;no extra functions , just scan and locate a key ;no char buffer , no antibounce, ect... ;SJASM syntax MODULE key ;do a complete key scan and store it at (HL) ;altered : AF - BC - DE Scan push HL ld BC,#F782 out (C),C ld BC,#F40e ld E,B out (C),C ld BC,#F6c0 ld D,B out (C),C ld C,0 out (C),C ld BC,#F792 out (C),C ld A,#40 ld C,#4A .loop ld B,D out (C),A ld B,E ini inc A cp C jr c,.loop ld BC,#F782 out (C),C pop HL ret ;check if there is a key is down at (HL) ;only the first key found is returned ;return carry is a key is down ;return key code in A : key code = (line*8)+bit ;returned code is the same than system ;altered : AF - BC GetPressed push HL ld C,10 .loop_col ld B,8 ld A,(HL++) .loop_bit rla jr nc,.pressed djnz .loop_bit dec C jr nz,.loop_col or A ;no key found ! pop HL ret .pressed dec C ld A,9 sub C add A ;*2 add A ;*4 add A ;*8 dec B or B ;add bit scf ;key found ! pop HL ret ;check if a key is pressed ;A = key code ;HL = 10 byte array scanned with Scan function ;return key state in carry ;altered AF - DE - B IsPressed push HL push AF ; keep bit and %01111000 rrca rrca rrca ld E,A ld D,0 add HL,DE ;so we get the address pop AF and 7 inc A ld B,A ld A,(HL) ;get line .loop rra ;get bit in carry djnz .loop ccf ;reverse bit pop HL ret ;compute offset and mask for a key ;A = key code ;return offset in C and mask in B ;altered AF - BC GetMask ld B,A ;get offset and %01111000 rrca rrca rrca ld C,A ;get mask ld A,B and %00000111 ld B,A ld A,1 jr z,.done .loop add A djnz .loop .done ld B,A ret ;erase SHIFT and CONTROL status ;used when that can be a problem , like with IsPressed ;HL = 10 byte array scanned with Scan function ;altered : AF IgnoreSHITFCTRL push HL inc HL inc HL ld A,(HL) or %10100000 ld (HL),A pop HL ret ENDMODULE
