mirror of https://git.sr.ht/~rabbits/uxn
82 lines
1.9 KiB
Plaintext
82 lines
1.9 KiB
Plaintext
( draw routines )
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:dev/r fff8 ( std read port )
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:dev/w fff9 ( std write port )
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;x_ 2 ;y_ 2 ;color 1
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;x0 2 ;y0 2 ;x1 2 ;y1 2 ;dx 2 ;dy 2 ;err1 2 ;err2 2
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|0100 @RESET
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( set dev/write to screen )
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#01 =dev/w ( set dev/write to sprite )
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( positive )
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#01 ,color STR
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+0030 ,x0 STR2 +0040 ,y0 STR2
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+0100 ,x1 STR2 +0060 ,y1 STR2
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,line JSR
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#02 ,color STR
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+0020 ,x0 STR2 +0010 ,y0 STR2
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+0090 ,x1 STR2 +0070 ,y1 STR2
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,line JSR
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#03 ,color STR
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+0010 ,x0 STR2 +0040 ,y0 STR2
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+0070 ,x1 STR2 +0060 ,y1 STR2
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,line JSR
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( draw control points )
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#02 ,color STR
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,x0 LDR2 ,y0 LDR2 ,putpixel JSR
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,x1 LDR2 ,y1 LDR2 ,putpixel JSR
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,redraw JSR
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BRK
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@line
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,x0 LDR2 ,x_ STR2 ,y0 LDR2 ,y_ STR2 ( start at x0,y0 )
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,x1 LDR2 ,x0 LDR2 ,diff16sub JSR ,dx STR2 ( int dx = abs[x1 - x0] )
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,y1 LDR2 ,y0 LDR2 ,diff16sub JSR -0001 MULS2 ,dy STR2 ( int dy = -abs[y1 - y0] )
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,dx LDR2 ,dy LDR2 ADDS2 ,err1 STR2 ( int err1 = dx + dy, e2; )
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@lineloop
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,x_ LDR2 ,y_ LDR2 ,putpixel JSR ( draw )
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@line-x
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,err1 LDR2 +0002 MULS2 ,err2 STR2 ( e2 = 2 * err; )
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,err2 LDR2 ,dy LDR2 LTHS2 ,line-y ROT JMP? POP2 ( e2 >= dy )
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,err1 LDR2 ,dy LDR2 ADDS2 ,err1 STR2 ( err1 += dy; )
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,x_ LDR2 +0001 ADDS2 ,x_ STR2 ( y0 += y0 < y1 ? 1 : -1; )
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@line-y
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,err2 LDR2 ,dx LDR2 GTHS2 ,line-end ROT JMP? POP2 ( e2 <= dx )
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,err1 LDR2 ,dx LDR2 ADDS2 ,err1 STR2 ( err1 += dx; )
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,y_ LDR2 +0001 ADDS2 ,y_ STR2 ( y0 += y0 < y1 ? 1 : -1; )
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@line-end
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,x_ LDR2 ,x1 LDR2 NEQS2 ,lineloop ROT JMP? POP2 ( loop )
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RTS
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@redraw
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#0000 IOW2
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#0000 IOW2
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#00 IOW
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#01 IOW
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RTS
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@putpixel
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IOW2 ( y short )
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IOW2 ( x short )
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,color LDR IOW ( color byte )
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#00 IOW ( redraw byte )
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RTS
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@diff16
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OVR2 OVR2 GTH2 ,diff16sub ROT JMP? POP2
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SWP2 @diff16sub SUB2
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RTS
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|c000 @FRAME BRK
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|d000 @ERROR BRK
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|FFF0 [ f2ac 35bb 2b53 ] ( palette )
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|FFFA .RESET .FRAME .ERROR
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