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Simplifying char blit

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alpine9000
2016-04-01 16:08:00 +11:00
parent 34bcded682
commit 21d91bccd4
1 changed files with 14 additions and 37 deletions
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025.scroll_text/blitchar.s
+14 -37
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@@ -19,7 +19,7 @@ BlitChar8:
;; d0 - xpos
;; d1 - ypos
;; d2 - char
movem.l d0-d5/a0-a2,-(sp)
movem.l d0-d3/a0-a2,-(sp)
WaitBlitter
;; blitter config that is shared for every character
@@ -34,50 +34,25 @@ BlitChar8:
move.l #font,a1 ; font pointer
move.l #fontMask,a2 ; font mask pointer
bsr DrawChar8 ; draw it
movem.l (sp)+,d0-d5/a0-a2
rts
DrawChar8:
;; kills d2,d4,d5,a0,a1,a2
;; d0 - xpos
;; d1 - ypos bytes
;; d2* - char
;; a0 - bitplane
;; a1 - #font
;; a2 - #fontMask
sub.w #'!',d2 ; index = char - '!'
move.w d2,d5
lsr.w #5,d5 ; char / 32 = fontmap line
andi.w #$1f,d2 ; char index in line (char index - start of line index)
add.l #1,d5 ; while we have a weird font image, '!' starts on second line
mulu.w #FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT,d5 ; d5 *= #FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT
move.w d2,d3
lsr.w #5,d3 ; char / 32 = fontmap line
andi.w #$1f,d2 ; char index in line (char index - start of line index)
add.l #1,d3 ; while we have a weird font image, '!' starts on second line
mulu.w #FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT,d3 ; d3 *= #FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT
if MASKED_FONT==1
add.w d5,a2 ; add y offset in lines to fontMask address
endif
add.w d5,a1 ; add y offset in lines to font address
add.w d2,a1 ; add offset into font
if MASKED_FONT==1
add.w d3,a2 ; add y offset in lines to fontMask address
add.l d2,a2 ; add offset into mask
endif
.blitChar8:
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*FONTMAP_WIDTH_BYTES)-FONTMAP_WIDTH_BYTES+0,a1
add.w d3,a1 ; add y offset in lines to font address
add.w d2,a1 ; add offset into font
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*FONTMAP_WIDTH_BYTES)-FONTMAP_WIDTH_BYTES+0,a2
move.l d0,d4 ; xpos
lsr.w #3,d4 ; d4 = xpos bytes
lsr.w #3,d0 ; d0 = xpos bytes
btst #0,d2 ; check if odd or even char
beq .evenChar ;
.oddChar:
@@ -98,7 +73,7 @@ DrawChar8:
move.l a1,BLTBPTH(a6) ; source bitplane
add.l d4,a0 ; dest += XPOS_BYTES
add.l d0,a0 ; dest += XPOS_BYTES
add.l d1,a0 ; dest += YPOS_BYTES
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*BITPLANE_WIDTH_BYTES)-BITPLANE_WIDTH_BYTES+0,a0
@@ -107,6 +82,8 @@ DrawChar8:
move.l a0,BLTDPTH(a6) ; destination top left corner
move.w #(FONT_HEIGHT*SCREEN_BIT_DEPTH)<<6|(BLIT_WIDTH_WORDS),BLTSIZE(a6) ;rectangle size, starts blit
movem.l (sp)+,d0-d3/a0-a2
rts
font: