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Simplifying char blit

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alpine9000
2016-04-01 16:23:21 +11:00
parent 21d91bccd4
commit 64bfbef970
1 changed files with 21 additions and 21 deletions
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025.scroll_text/blitchar.s
+21 -21
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@@ -20,39 +20,44 @@ BlitChar8:
;; d1 - ypos
;; d2 - char
movem.l d0-d3/a0-a2,-(sp)
WaitBlitter
;; blitter config that is shared for every character
if MASKED_FONT==1
move.w #FONTMAP_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTAMOD(a6) ; A modulo (only used for masked version)
endif
move.w #FONTMAP_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTBMOD(a6) ; B modulo
move.w #BITPLANE_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTCMOD(a6) ; C modulo
move.w #BITPLANE_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTDMOD(a6) ; D modulo
mulu.w #BITPLANE_WIDTH_BYTES*SCREEN_BIT_DEPTH,d1 ; ypos bytes
move.w #$ffff,BLTAFWM(a6) ; don't mask first word
move.l #font,a1 ; font pointer
move.l #fontMask,a2 ; font mask pointer
lea font(pc),a1 ; font pointer
lea fontMask,a2 ; font mask pointer
sub.w #'!',d2 ; index = char - '!'
move.w d2,d3
lsr.w #5,d3 ; char / 32 = fontmap line
andi.w #$1f,d2 ; char index in line (char index - start of line index)
add.l #1,d3 ; while we have a weird font image, '!' starts on second line
mulu.w #FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT,d3 ; d3 *= #FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT
mulu.w #FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT,d3 ; d3 *= #FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT
if MASKED_FONT==1
add.w d3,a2 ; add y offset in lines to fontMask address
add.l d2,a2 ; add offset into mask
endif
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*FONTMAP_WIDTH_BYTES)-FONTMAP_WIDTH_BYTES+0,a1
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*FONTMAP_WIDTH_BYTES)-FONTMAP_WIDTH_BYTES+0,a1 ; last word - descending mode
add.w d3,a1 ; add y offset in lines to font address
add.w d2,a1 ; add offset into font
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*FONTMAP_WIDTH_BYTES)-FONTMAP_WIDTH_BYTES+0,a2
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*FONTMAP_WIDTH_BYTES)-FONTMAP_WIDTH_BYTES+0,a2 ; last word - descending mode
lsr.w #3,d0 ; d0 = xpos bytes
add.l d0,a0 ; dest += XPOS_BYTES
add.l d1,a0 ; dest += YPOS_BYTES
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*BITPLANE_WIDTH_BYTES)-BITPLANE_WIDTH_BYTES+0,a0 ; last word - descending mode
lsr.w #3,d0 ; d0 = xpos bytes
WaitBlitter
if MASKED_FONT==1
move.w #FONTMAP_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTAMOD(a6) ; A modulo (only used for masked version)
endif
move.w #FONTMAP_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTBMOD(a6) ; B modulo
move.w #BITPLANE_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTCMOD(a6) ; C modulo
move.w #BITPLANE_WIDTH_BYTES-BLIT_WIDTH_BYTES,BLTDMOD(a6) ; D modulo
move.w #$ffff,BLTAFWM(a6) ; don't mask first word
btst #0,d2 ; check if odd or even char
beq .evenChar ;
.oddChar:
@@ -72,11 +77,6 @@ BlitChar8:
endif
move.l a1,BLTBPTH(a6) ; source bitplane
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
move.l a0,BLTCPTH(a6) ; background top left corner
move.l a0,BLTDPTH(a6) ; destination top left corner