         DOSBox with pixel-perfect scaling
            and aspect-ratio correction
          (alpha 23, for DOSBox rev. 4191)

This  patch  adds  three  modes  of software scaling
based on the 'surface' output type and one  hardware
scaling mode based on the 'opengl' output type:

surfacepp (pixel-perfect):
   Each  emulated  pixel  is  represented as a sharp
   rectangle with  integral  dimensions  m x n  such
   that  m:n  approximates  the desired pixel aspect
   ratio (PAR), which depends on the emulated  reso-
   lution  and  the 'aspect' setting in the [render]
   section.  Whereas the  standard  PARs  are  them-
   selves  ratios  of small integers, this mode will
   yield the exact aspect ratio, provided the output
   resolution is high enough for the game.

surfacenp (near-perfect):
   Upscales the image interpolatively with a minimum
   of artefacts.  This is similar  to  supersampling
   with a normaln<x> scaler beyond the display reso-
   lution and then downscaling to the output  dimen-
   sions via bilinear interpolation.  The new param-
   eter 'surfacenp-sharpness' in the  [sdl]  section
   attenuates  the  amount  of  interpoation.  It is
   measured in percent, from 0 to 100, with the lat-
   ter  value  corresponding to the nearest-neighbor
   method.

surfacenb (nearest-neighbor):
   Equivalent to 'openglnb'.

openglpp (pixel-perfect):
   Same as 'surfacepp', but  using  OpenGL  hardware
   acceleration.     The    new    boolean    option
   `glfullvsync' turns  on  V-Sync  for  full-screen
   OpenGL  output.  Try turing it off if the program
   feels jerky.

The new modes ignore "normal" scalers.

The new value `desktop'  of  the  'windowresolution'
parameter  causes DOSBox to make the window as large
as the display and scaling method permit.

The setting `fullborderless' causes DOSBox  to  emu-
late  fullscreen  mode using a borderless window the
size of the display.

To avoid screen tearing, try specifying

                fullborderless = true

If it does't work or  doesn't  help,  revert  it  to
false and set

                fulldouble = true

for surface output or

                glfullvsync = true

for  `openglpp'.   Depending on the refresh rates of
the native and emulated graphical modes, the  latter
two options may case jerky animation.

With  LCD  displays, make certain always to use your
display's native resolution in  fullscreen.   To  do
that,  and  assuming you have configured the correct
resolution in your OS, specify:

                [sdl]
                fullresolution=desktop

Questions and comments are welcome at the Vogons fo-
rum:

 https://www.vogons.org/viewtopic.php?f=41&t=49160
  [ VIDEO Patch for pixel-perfect scaling (SDL1) ]