Tried to plot char with descending mode

This commit is contained in:
alpine9000
2016-04-01 15:00:36 +11:00
parent a523a64e24
commit 01846c84fb
3 changed files with 53 additions and 18 deletions
+1 -1
View File
@@ -61,7 +61,7 @@ BlitScroll:
;; d2 - ypos
;; movem.l d2-d5/a0,-(sp)
add.l d1,d2 ;point to end of data for ascending mode
add.l d1,d2 ;point to end of data for descending mode
mulu.w #BITPLANE_WIDTH_BYTES*SCREEN_BIT_DEPTH,d2
add.l d2,a0
+41 -17
View File
@@ -1,6 +1,8 @@
include "includes.i"
xdef BlitChar8
DESCENDING equ 1
BLIT_LF_MINTERM equ $ca ; cookie cut
BLIT_WIDTH_WORDS equ 2 ; blit 2 words to allow shifting
BLIT_WIDTH_BYTES equ 4
@@ -25,7 +27,11 @@ BlitChar8:
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
if DESCENDING==1
move.w #$0000,BLTAFWM(a6) ; mask out extra word used for shifting
else
move.w #$0000,BLTALWM(a6) ; mask out extra word used for shifting
endif
move.w #$ffff,BLTADAT(a6) ; preload source mask so only BLTA?WM mask is used
move.l #font,a5 ; font pointer
move.l #fontMask,d7 ; font mask pointer
@@ -57,22 +63,8 @@ DrawChar8:
add.l #1,d5 ; while we have a weird font image, '!' starts on second line
move.l a5,a1 ; #font
if 1
mulu.w d3,d5 ; d5 *= #FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH*FONT_HEIGHT
else
move.w d5,d3
lsl.w #7,d3 ; d5 *= FONTMAP_WIDTH_BYTES*SCREEN_BIT_DEPTH
move.w d3,d5
add.l d3,d5
add.l d3,d5
add.l d3,d5
add.l d3,d5
add.l d3,d5
add.l d3,d5
add.l d3,d5
add.l d3,d5
add.l d3,d5
endif
if MASKED_FONT==1
move.l d7,a2 ; #fontMask
@@ -97,6 +89,12 @@ DrawChar8:
;; a1 - object
;; a2 - mask
if DESCENDING==1
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*FONTMAP_WIDTH_BYTES)-FONTMAP_WIDTH_BYTES+2,a1
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*FONTMAP_WIDTH_BYTES)-FONTMAP_WIDTH_BYTES+2,a2
endif
move.l d0,d4 ; xpos
move.l d0,d5 ; xpos
lsr.w #3,d4 ; d4 = xpos bytes
@@ -106,24 +104,46 @@ DrawChar8:
btst #0,d2 ; check if odd or even char
beq .evenChar ;
.oddChar
if DESCENDING==1
move.w #$00ff,BLTALWM(a6) ; select the second (odd) character in the word
move.w #$8000,d5
else
subq #8,d5 ; offset the x position for the odd character
move.w #$00FF,BLTAFWM(a6) ; select the second (odd) character in the word
subq #1,a4 ; move the destination pointer left by one byte
endif
bra .continue
.evenChar:
if DESCENDING==1
move.w #$FF00,BLTALWM(a6) ; select the first character in the word
move.w #0,d5
else
move.w #$FF00,BLTAFWM(a6) ; select the first character in the word
endif
.continue:
if DESCENDING==1
ori.l #2,d5
move.w d5,BLTCON1(A6) ; set the shift bits 12-15, bits 00-11 cleared
else
;; this shift will give us the bits to shift (bits 0-3) in bits (12-15) of d5
swap d5 ; d5 << 12
lsr.l #4,d5 ;
move.w d5,BLTCON1(A6) ; set the shift bits 12-15, bits 00-11 cleared
endif;
if MASKED_FONT==1
move.l a2,BLTAPTH(a6) ; mask bitplane
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
@@ -131,6 +151,10 @@ DrawChar8:
add.l d4,a4 ; dest += XPOS_BYTES
add.l d1,a4 ; dest += YPOS_BYTES
if DESCENDING==1
add.l #(FONT_HEIGHT*SCREEN_BIT_DEPTH*BITPLANE_WIDTH_BYTES)-BITPLANE_WIDTH_BYTES+2,a4
endif
move.l a4,BLTCPTH(a6) ; background top left corner
move.l a4,BLTDPTH(a6) ; destination top left corner
+11
View File
@@ -40,6 +40,17 @@ MainLoop:
jsr WaitVerticalBlank
;; jsr InstallPalette
if 0
;; test
move.b #'B',d2
move.l #32,d0 ; xpos
move.l #100,d1 ; ypos
move.l onscreen,a0
jsr BlitChar8
bra MainLoop
;; test
endif
cmp.l #8,shiftcounter
bne .shift