OpenEuphoria

Re: mode 18 text writing

• Posted by "Cuny, David" <ATB.DCUNY at HW1.CAHWNET.GOV> Mar 21, 1997
• 1206 views

I've figured the my text writing function for mode 18 out. Turns out it's
embarassingly easy: just write out a bunch of blocks (ASCII 219) to the
screen first, and then OR the text.

Here's the code, if anyone cares. The same call is used three times; I only
change the color used, and the OR flag:

 -- CODE STARTS HERE

include graphics.e
include machine.e
include get.e

procedure display( integer row, integer col,
                    integer fColor, integer bColor, sequence text )

    integer   len
    sequence  inReg, outReg
    object    lowMem

    len = length( text )
    lowMem = allocate_low( len )    -- get memory
    inReg = repeat( 0, 10 )         -- initialize register list

    -- first, write a string of solid blocks.
    -- this could just as well be done with a puts()

    poke( lowMem, repeat( 219, len ) )      -- solid blocks

    inReg[REG_AX] = #1301                   -- tty string write
    inReg[REG_BX] = fColor                  -- video page/color
    inReg[REG_CX] = len                     -- number of characters to print
    inReg[REG_DX] = row*#100+col            -- position of cursor
    inReg[REG_ES] = floor(lowMem / 16)      -- segment of text string
    inReg[REG_BP] = remainder(lowMem, 16)   -- offset of text string
    outReg = dos_interrupt( #10, inReg )    -- bios call


    -- OR the string to the background color, leaving a black mask
    poke( lowMem, text )

    inReg[REG_BX] = #F0 + bColor            -- video page/color
    outReg = dos_interrupt( #10, inReg )    -- bios call

    -- OR the string to the mask, leaving the foreground color
    poke( lowMem, text )

    inReg[REG_BX] = #F0 + fColor            -- video page/color
    outReg = dos_interrupt( #10, inReg )    -- bios call


    free_low( lowMem )  -- free the memory

end procedure


integer result
result = graphics_mode( 18 )
display( 1, 1, WHITE, GREEN, "Hi there" )
display( 2, 1, BLUE, CYAN, "Hi there" )
result = wait_key()
result = graphics_mode( 1 )



 -- CODE ENDS HERE

Thanks for thinking about it.

 -- David Cuny