github/AmigaExamples
1
0
Fork 0
mirror of https://frontier.innolan.net/github/AmigaExamples.git synced 2026-09-12 15:02:35 +00:00
Code Releases Activity

Minor optimisations

Browse Source
This commit is contained in:
alpine9000
2016-03-29 14:42:42 +11:00
parent e4fd004289
commit a1106476d9
1 changed files with 22 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files
024.simple_text/blittext.s
+22 -11
View File
@@ -21,8 +21,14 @@ DrawText8:
move.w #$0000,BLTALWM(a6) ; mask out extra word used for shifting
move.w #$ffff,BLTADAT(a6) ; preload source mask so only BLTA?WM mask is used
move.l a1,a3
move.l #font,d6
move.l #font,a5
move.l #fontMask,d7
move.w #SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT,d3
if MASKED_FONT==1
move.w #BLIT_SRCA|BLIT_SRCB|BLIT_SRCC|BLIT_DEST|BLIT_LF_MINTERM,d6
else
move.w #BLIT_SRCB|BLIT_SRCC|BLIT_DEST|BLIT_LF_MINTERM,d6
endif
.loop:
clr.l d2
move.b (a3)+,d2 ; get next character
@@ -37,22 +43,27 @@ DrawText8:
rts
DrawChar8:
;; kills d2,d3,d4,d5,a1,a2,a4
;; kills d2,d4,d5,a1,a2,a4
;; d0 - xpos
;; d1 - ypos bytes
;; d2 - char
;; d3 - bytes per font line
;; d6 - bplcon0 value
;; a4 - bitplane
;; a5 - #font
;; d7 - #fontMask
;; calculating the font offset will be simplier when we have a less weird font image
sub.w #'!',d2 ; index = char - '!'
move.w d2,d5
lsr.w #5,d5 ; char / 32 = fontmap line
move.w d5,d4 ;
lsl.w #5,d4 ; line * 32 = start of line
sub.w d4,d2 ; char index in line
lsr.w #5,d5 ; char / 32 = fontmap line
andi.w #$1f,d2 ; char index in line (char index - start of line index)
add.w #1,d5 ; while we have a weird font image, '!' starts on second line
move.l d6,a1 ; #font
mulu.w #SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT,d5
move.l a5,a1 ; #font
mulu.w d3,d5 ; d5 *= #SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT
if MASKED_FONT==1
move.l d7,a2 ; #fontMask
@@ -71,6 +82,8 @@ DrawChar8:
;; d0 - xpos
;; d1 - ypos bytes
;; d2.0 - odd character = 1, even character = 0
;; d3 - bytes per font line
;; d6 - bplcon0 value
;; a4 - display
;; a1 - object
;; a2 - mask
@@ -100,13 +113,11 @@ DrawChar8:
move.w d5,BLTCON1(A6)
if MASKED_FONT==1
ori.w #BLIT_SRCA|BLIT_SRCB|BLIT_SRCC|BLIT_DEST|BLIT_LF_MINTERM,d5
move.l a2,BLTAPTH(a6) ; mask bitplane
else
ori.w #BLIT_SRCB|BLIT_SRCC|BLIT_DEST|BLIT_LF_MINTERM,d5
endif
move.l a1,BLTBPTH(a6) ; source bitplane
or.w d6,d5 ; d5 = BLTCON0 value
move.w d5,BLTCON0(a6) ; set minterm, dma channel and shift
add.l d4,a4 ; dest += XPOS_BYTES