[PATCH 4/7] Document graphics handling changes

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

---
 doc/hatari.1          | 13 ++++++++++++-
 doc/manual.html       | 15 +++++++++++++--
 doc/release-notes.txt | 20 +++++++++++++++-----
 doc/todo.txt          |  2 --
 4 files changed, 40 insertions(+), 10 deletions(-)

diff --git a/doc/hatari.1 b/doc/hatari.1
index 99138ad8..d0217dfe 100644
--- a/doc/hatari.1
+++ b/doc/hatari.1
@@ -160,7 +160,18 @@ the slower but more accurate Spectrum512 screen conversion functions
 (0 <= x <= 512, 0=disable)
 .TP
 .B \-z, \-\-zoom <x>
-Zoom (double) low resolution (1=no, 2=yes)
+With Hatari SDL1 build, this can be used only to enable ST/STe low
+resolution doubling (1=no, 2=yes).
+
+With Hatari SDL2 build, ST-low resolution is always doubled, so that
+all resolutions have approximately same starting size. Any zoom factor
+can be used to scale that up (or down), regardless of the selected
+Atari machine or monitor type.
+
+With non-integer zoom factors, linear scaling is used to smooth out
+the output, with integer zoom factors, scaling is done using nearest
+neighboring pixels for sharper output.  This applies also to window
+resizes.
 .TP
 .B \-\-video-timing <x>
 Wakeup State for MMU/GLUE (x=ws1/ws2/ws3/ws4/random,
diff --git a/doc/manual.html b/doc/manual.html
index 3f7b6352..e0ec2c94 100644
--- a/doc/manual.html
+++ b/doc/manual.html
@@ -659,8 +659,19 @@ Spectrum512 screen conversion functions (0 &lt;= x &lt;= 512,
 0=disable)</p>
 <p class="parameter">-z, --zoom
 &lt;x&gt;</p>
-<p class="paramdesc">Zoom (double) low resolution (1=no,
-2=yes)</p>
+<p class="paramdesc">
+With Hatari SDL1 build, this can be used only to enable ST/STe low
+resolution doubling (1=no, 2=yes).
+</p><p class="paramdesc">
+With Hatari SDL2 build, ST-low resolution is always doubled, so that
+all resolutions have approximately same starting size. Any zoom factor
+can be used to scale that up (or down), regardless of the selected
+Atari machine or monitor type.
+</p><p class="paramdesc">
+With non-integer zoom factors, linear scaling is used to smooth out
+the output, with integer zoom factors, scaling is done using nearest
+neighboring pixels for sharper output.  This applies also to window
+resizes.</p>
 <p class="parameter">--video-timing
 &lt;x&gt;</p>
 <p class="paramdesc">Wakeup State for MMU/GLUE (x=ws1/ws2/ws3/ws4/random,
diff --git a/doc/release-notes.txt b/doc/release-notes.txt
index 7c34b90a..cfce3a17 100644
--- a/doc/release-notes.txt
+++ b/doc/release-notes.txt
@@ -3,12 +3,14 @@
                                    --------
                                 Release Notes
 
+
  Development version
  -------------------
 
-Note:
-The following features are deprecated and will be removed in a future release:
-- Support for the SDL 1.2 library (i.e. SDL 2.0 should be used instead)
+Following features are deprecated and will be removed in a future release:
+- Support for the SDL 1.2 library (i.e. SDL 2.x should be used instead)
+- SDL 2.x "bUseSdlRenderer" config and "GPU scaling" GUI options
+  (after HW support for SDL2 is available widely enough)
 - The old UAE CPU core (i.e. the new WinUAE CPU core should be used instead)
 - Python 2 support (Python 2 is end of life in 2020, use Python 3 instead)
 - The "external" disassembler (i.e. use "--disasm uae" instead)
@@ -40,8 +42,16 @@ Emulator:
     and TOS stack overflows in some rare cases
 - Support read-only HD image files, and show error dialogs
   for image file open/lock issues
-- Low/med-rez line doubling uses less CPU and doubled lines in
-  "TV" display mode are now drawn at half intensity, not as black
+- Hatari graphics support:
+  - Low/med-rez line doubling uses less CPU and doubled lines in
+    "TV" display mode are now drawn at half intensity, not as black
+  - SDL2: "--zoom" option accepts any values between 1.0 - 8.0
+  - SDL2: scale quality is autoselected; nearest pixel for sharp
+    output with integer scaling factors, and linear scaling to
+    smooth out issues with non-integer scaling & window resizes.
+  - SDL2: Now redundant "nRenderScaleQuality" config option is
+    removed and "Linear scaling" option in GUI is replaced with
+    the "GPU scaling" option (=bUseSdlRenderer config option)
 - Show mouse grab toggle shortcut key in startup statusbar message
 - Center host mouse to Hatari window on Atari resets and resolution
   changes only when window is focused and mouse pointer is within it
diff --git a/doc/todo.txt b/doc/todo.txt
index db5b88e0..b2ec60f0 100644
--- a/doc/todo.txt
+++ b/doc/todo.txt
@@ -178,8 +178,6 @@ on BerliOS hatari-devel mail thread for more info.)
 	- Line based screen change detection/checks:
 		- blit only changed lines
 		- simpler / faster (LED) overlay handling
-	- x3 and x4 zooming routines for ST-Low resolution
-	  (SDL2 scales to monitor size, so it can be blurry)
 	- Include some fancy zooming routines like 2xSaI or Super-Eagle
 
 - Improve directory handling:
-- 
2.20.1


--------------69CD54D5487FA4DE087D9377
Content-Type: text/x-patch; charset=UTF-8;
 name="0003-Replace-Linear-scaling-GUI-option-with-GPU-scaling-o.patch"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
 filename*0="0003-Replace-Linear-scaling-GUI-option-with-GPU-scaling-o.pa";
 filename*1="tch"