XProfan

 {$cleq}
 $u thread.Pcu = thread.

proc hDottedLine

    parameters hDC&,x&,y&,xx&,hop&,mtr&,c1&,c2&

    AsmStart hDottedLine

        Parameters hDC&,x&,y&,xx&,hop&,mtr&,c1&,c2&
        .data
        vx	dd	0
        hop 	dd	0
        mtr	dd	0
        .code
        mov esi,para4
        cmp esi,0
        jle eop
        mov esi,para5
        mov hop,esi
        mov esi,para6
        inc esi
        mov mtr,esi
        mov esi,para4

        .while vx<esi

            inc vx
            inc hop
            mov eax,mtr
            cmp hop,eax
            apiece eob
            jg eoa
            mov ebx,vx
            add ebx,para2
            invoke SetPixel,para1,ebx,para3,para7
            jmp cnt
            eoa:
            mov hop,0
            eob:
            mov ebx,vx
            add ebx,para2
            invoke SetPixel,para1,ebx,para3,para8
            cnt:

        .endw

        eop:

    ASMEND

endproc

declare c&,dlgdc&,dlg&
dlg&:=createwindow(0,"",0,0,640,480)
dlgdc&:=external("user32","GetWindowDC",dlg&)

while 1

    thread.start;waitinput;thread.stop

wend

end

proc thread.do

    hDottedLine dlgDC&,0,0,width(dlg&),c&,10,rgb(255,0,0),rgb(255,255,255)
    c&+:case c&==12:c&:=0

endproc