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optimized highres 4c position calc a bit

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This commit is contained in:
Irmen de Jong 2021-02-26 00:43:51 +01:00
parent cd500fee8c
commit fd11927708
1 changed files with 28 additions and 10 deletions
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38
compiler/res/prog8lib/cx16/gfx2.p8
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@ -812,6 +812,7 @@ _done
chardataptr = charset_addr + (@(sctextptr) as uword)*8
cx16.vaddr(charset_bank, chardataptr, 1, 1)
repeat 8 {
; TODO rewrite this inner loop fully in assembly
position(x,y)
y++
%asm {{
@ -840,7 +841,7 @@ _done
while @(sctextptr) {
chardataptr = charset_addr + (@(sctextptr) as uword)*8
repeat 8 {
; TODO rewrite this inner loop in assembly
; TODO rewrite this inner loop fully in assembly
ubyte charbits = cx16.vpeek(charset_bank, chardataptr)
repeat 8 {
charbits <<= 1
@ -877,15 +878,31 @@ _done
}}
}
sub addr_mul_24_for_highres_4c(uword yy, uword xx) {
; TODO turn into asmsub
asmsub addr_mul_24_for_highres_4c(uword yy @R2, uword xx @R3) clobbers(A, Y) -> uword @R0, uword @R1 {
; yy * 160 + xx/4 (24 bits calculation)
; 24 bits result is in r0 and r1L (highest byte)
cx16.r0 = yy*128
cx16.r2 = yy*32
xx >>= 2
%asm {{
; add r2 and xx to r0 (24-bits)
ldy #5
- asl cx16.r2
rol cx16.r2+1
dey
bne -
lda cx16.r2
sta cx16.r0
lda cx16.r2+1
sta cx16.r0+1
asl cx16.r0
rol cx16.r0+1
asl cx16.r0
rol cx16.r0+1
; xx >>= 2 (xx=R3)
lsr cx16.r3+1
ror cx16.r3
lsr cx16.r3+1
ror cx16.r3
; add r2 and xx (r3) to r0 (24-bits)
stz cx16.r1
clc
lda cx16.r0
@ -898,14 +915,15 @@ _done
inc cx16.r1
+ clc
lda cx16.r0
adc xx
adc cx16.r3
sta cx16.r0
lda cx16.r0+1
adc xx+1
adc cx16.r3+1
sta cx16.r0+1
bcc +
inc cx16.r1
+
rts
}}
}