OpenEuphoria

Re: Fastest Print to Screen

• Posted by Ralf Nieuwenhuijsen <nieuwen at XS4ALL.NL> Nov 23, 1998
• 589 views

>I stumbled across "perform.doc" and read that puts ain't the way to go
>for speed. I tried display_text_image() but apparently it would be a
>pain to parse out the sequence I want printed with all the colors in
>between, or maybe it wouldn't.


Putsxy is for graphics modes.
No, you want to poke your data to the memory.
Here's a fast, text-mode only version, it clips at 25,80
But you can easily change the constants.
The code has been tested by me.

-- Fast display_text_image and save_text_image

constant
  BPC = 2,                 -- 2 bytes per char (one for the color)
  CLIP_Y = 25,            -- 25 lines down
  CLIP_X = 80 * BPC,      -- 80 columns right
  VIDEO = #B8000 -1,      -- Use #B0000 for monochrome
  FALSE = 0

global procedure display_text_image (sequence pos, sequence data)
integer skip, max_width, max_height, pos_x, begin, offset
sequence row

  -- Calculating offset
  pos_x = pos[2] * BPC - 1
  offset = pos_x + (pos[1]-1) * CLIP_X + VIDEO

  -- Check if the offset is out-of-bounds
  if offset <= VIDEO then
    skip = VIDEO - offset + 1
    offset = VIDEO - 1
  else
    skip = FALSE
  end if

  -- Set the maximum length for each row
  max_width = CLIP_X - pos_x
  begin = FALSE

  for skip_index = 1 to length(data) do
    if not skip then
      if length(data)-skip_index > CLIP_Y then
        max_height = skip_index + CLIP_Y
      else
        max_height = length(data)
      end if
      for index = skip_index to max_height do
        row = data[index]
        if length(row) > max_width then
          if begin then
            poke (offset, row[begin..begin+max_width])
          else
            poke (offset, row[1..max_width+1])
          end if
        else
          if begin then
            poke(offset,row[begin..length(row)])
          else
            poke (offset, row)
          end if
        end if
        offset = offset + CLIP_X
      end for
      exit
    end if
    if skip < CLIP_X then
        begin = skip
        skip = FALSE
    else
        skip = skip - CLIP_X
    end if
  end for
end procedure

--- End of code