Drawing basic line

This commit is contained in:
neauoire 2021-02-12 17:56:17 -08:00
parent 24e67d34da
commit 835123f94a
2 changed files with 28 additions and 6 deletions

View File

@ -63,7 +63,6 @@ pushbyte(Uint8 b, int lit)
void void
pushshort(Uint16 s, int lit) pushshort(Uint16 s, int lit)
{ {
printf("%04x[%d]\n", s, lit);
if(lit) { if(lit) {
pushbyte(0x03, 0); pushbyte(0x03, 0);
pushbyte(0x02, 0); pushbyte(0x02, 0);

View File

@ -4,20 +4,24 @@
:dev/w fff9 ( std write port ) :dev/w fff9 ( std write port )
;x_ 2 ;y_ 2 ;x0 2 ;y0 2 ;x1 2 ;y1 2 ;color 1 ;x_ 2 ;y_ 2 ;x0 2 ;y0 2 ;x1 2 ;y1 2 ;color 1
;dx 2 ;dy 2 ;err 2 ;err2 2 ;dx 2 ;dy 2 ;err 2 ;err2 2
|0100 @RESET |0100 @RESET
( set dev/write to screen ) ( set dev/write to screen )
,01 ,dev/w STR ,01 ,dev/w STR
,01 ,color STR ,01 ,color STR
+0030 ,x0 STR^ +0040 ,y0 STR^
+0050 ,x1 STR^ +0060 ,y1 STR^
( init positions ) ,line JSR
,0020 ,x0 STR^ ,0018 ,y0 STR^
,0060 ,x1 STR^ ,0048 ,y1 STR^
,x0 LDR^ ,x_ STR^ ,y0 LDR^ ,y_ STR^
,02 ,color STR
+0020 ,x0 STR^ +0010 ,y0 STR^
+0060 ,x1 STR^ +0070 ,y1 STR^
,line JSR
( draw control points ) ( draw control points )
,02 ,color STR ,02 ,color STR
@ -28,6 +32,25 @@
BRK BRK
@line
,x0 LDR^ ,x_ STR^ ,y0 LDR^ ,y_ STR^ ( start at x0,y0 )
,x1 LDR^ ,x0 LDR^ ,diff16sub JSR ,dx STR^ ( int dx = abs[x1 - x0] )
,y1 LDR^ ,y0 LDR^ ,diff16sub JSR -0001 MUL!^ ,dy STR^ ( int dy = -abs[y1 - y0] )
,dx LDR^ ,dy LDR^ ADD!^ ,err STR^ ( int err = dx + dy, e2; )
@loop
,x_ LDR^ ,y_ LDR^ ,putpixel JSR ( draw )
,err LDR^ +0002 MUL!^ ,err2 STR^ ( e2 = 2 * err; )
,err2 LDR^ ,dy LDR^ LTH!^ ,continue1 ROT JMP? POP^ ( e2 >= dy )
,err LDR^ ,dy LDR^ ADD!^ ,err STR^ ( err += dy; )
,x_ LDR^ +0001 ADD!^ ,x_ STR^ ( y0 += y0 < y1 ? 1 : -1; )
@continue1
,err2 LDR^ ,dx LDR^ GTH!^ ,continue2 ROT JMP? POP^ ( e2 <= dx )
,err LDR^ ,dx LDR^ ADD!^ ,err STR^ ( err += dx; )
,y_ LDR^ +0001 ADD!^ ,y_ STR^ ( y0 += y0 < y1 ? 1 : -1; )
@continue2
,x_ LDR^ ,x1 LDR^ LTH!^ ,loop ROT JMP? POP^ ( loop )
RTS
@redraw @redraw
,0000 IOW^ ,0000 IOW^
,0000 IOW^ ,0000 IOW^