sdl2-compat: README.md: Removed some sdl12-compat things I'd forgotten to delete.

SDLPushPostBot · November 22, 2022, 8:40pm

From a9bf3d25223a2e6589355d843848e08097cd342b Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Tue, 22 Nov 2022 15:39:19 -0500
Subject: [PATCH] README.md: Removed some sdl12-compat things I'd forgotten to
 delete.

---
 README.md | 151 +++++-------------------------------------------------
 1 file changed, 12 insertions(+), 139 deletions(-)

diff --git a/README.md b/README.md
index 6048ce0..e6bed2e 100644
--- a/README.md
+++ b/README.md
@@ -39,14 +39,14 @@ them.
 These are quick-start instructions; there isn't anything out of the ordinary
 here if you're used to using CMake. 
 
-You'll need to use CMake to build sdl12-compat. Download at
+You'll need to use CMake to build sdl2-compat. Download at
 [cmake.org](https://cmake.org/) or install from your package manager
 (`sudo apt-get install cmake` on Ubuntu, etc).
 
 Please refer to the [CMake documentation](https://cmake.org/documentation/)
 for complete details, as platform and build tool details vary.
 
-You'll need a copy of SDL3 to build sdl12-compat, because we need the
+You'll need a copy of SDL3 to build sdl2-compat, because we need the
 SDL3 headers. You can build this from source or install from a package
 manager. Windows and Mac users can download prebuilt binaries from
 [SDL's download page](https://libsdl.org/download-3.0.php); make sure you
@@ -70,7 +70,7 @@ cmake --build build

On Windows or macOS, you might prefer to use CMake’s GUI, but it’s the same
-idea: give it the directory where sdl12-compat is located, click “Configure,”
+idea: give it the directory where sdl2-compat is located, click “Configure,”
choose your favorite compiler, then click “Generate.” Now you have project
files! Click “Open Project” to launch your development environment. Then you
can build however you like with Visual Studio, Xcode, etc.
@@ -118,12 +118,7 @@ cmake --build build32

macOS users can try adding -DCMAKE_OSX_ARCHITECTURES='arm64;x86_64' instead
of -DCMAKE_C_FLAGS=-m32 to make a Universal Binary for both 64-bit Intel and
-Apple Silicon machines. If you have an older (or much older!) version of Xcode,
-you can try to build with “i386” or maybe even “powerpc” for 32-bit Intel or
-PowerPC systems, but Xcode (and macOS itself) has not supported either of
-these for quite some time, and you will likely struggle to get SDL2 to compile
-here in small ways, as well…but with some effort, it’s maybe possible to
-run SDL2 and sdl12-compat on Apple’s abandoned architectures.
+Apple Silicon machines.

Building for older CPU architectures on Windows:

@@ -134,169 +129,47 @@ CMake, when it asks you what compiler to target in the CMake GUI.

Configuration options:

-sdl12-compat has a number of configuration options which can be used to work
+sdl2-compat has a number of configuration options which can be used to work
around issues with individual applications, or to better fit your system or
preferences.

These options are all specified as environment variables, and can be set by
running your application with them set on the command-line, for example:

-SDL12COMPAT_HIGHDPI=1 SDL12COMPAT_OPENGL_SCALING=0 %command%
+SDL2COMPAT_DEBUG_LOGGING=1 SDL2COMPAT_ALLOW_SYSWM=0 %command%

will run %command% with high-dpi monitor support enabled, but OpenGL
scaling support disabled.

(While these environment variables are checked at various times throughout
-the lifetime of the app, sdl12-compat expects these to be set before the
+the lifetime of the app, sdl2-compat expects these to be set before the
process starts and not change during the life of the process, and any
places where changing it later might affect operation is purely accidental
-and might change. That is to say: don’t write an SDL 1.2-based app with
+and might change. That is to say: don’t write an SDL2-based app with
plans to tweak these values on the fly!)

The available options are:

– SDL12COMPAT_DEBUG_LOGGING: (checked at startup)
± SDL2COMPAT_DEBUG_LOGGING: (checked at startup)
If enabled, print debugging messages to stderr. These messages are
mostly useful to developers, or when trying to track down a specific
bug.

– SDL12COMPAT_FAKE_CDROM_PATH: (checked during SDL_Init)

A path to a directory containing MP3 files (named trackXX.mp3, where
XX is a two-digit track number) to be used by applications which play
CD audio. Using an absolute path is recommended: relative paths are
not guaranteed to work correctly.

– SDL12COMPAT_OPENGL_SCALING: (checked during SDL_Init)

Enables scaling of OpenGL applications to the current desktop resolution.
If disabled, applications can change the real screen resolution. This
option is enabled by default, but not all applications are compatible
with it: try changing this if you can only see a black screen.

– SDL12COMPAT_FIX_BORDERLESS_FS_WIN: (checked during SDL_SetVideoMode)

Enables turning borderless windows at the desktop resolution into actual
fullscreen windows (so they’ll go into a separate space on macOS and
properly hide dock windows on other desktop environments, etc).
If disabled, applications may not get the full display to theirselves as
they expect. This option is enabled by default, but this option is here
so it can be manually disabled, in case this causes some negative result
we haven’t anticipated.

– SDL12COMPAT_SCALE_METHOD: (checked during SDL_Init)

Choose the scaling method used when applications render at a non-native
resolution. The options are nearest, for nearest-neighbour sampling
(more pixelated) and linear for bilinear sampling (blurrier).

– SDL12COMPAT_HIGHDPI: (checked during SDL_SetVideoMode)

Advertise the application as supporting high-DPI displays. Enabling
this will usually result in sharper graphics, but on some applications
text and other elements may become very small.

– SDL12COMPAT_SYNC_TO_VBLANK: (checked during SDL_SetVideoMode)

Force the application to sync (or not sync) to the vertical blanking
interval (VSync). When enabled, this will cap the application’s
framerate to the screen’s refresh rate (and may resolve issues with
screen tearing).

– SDL12COMPAT_USE_KEYBOARD_LAYOUT: (checked during SDL_Init)

Make all keyboard input take the current keyboard layout into account.
This may need to be disabled for applications which provide their own
keyboard layout support, or if the position of the keys on the keyboard
is more important than the character they produce. Note that text input
(in most applications) will take the keyboard layout into account
regardless of this option.

– SDL12COMPAT_USE_GAME_CONTROLLERS: (checked during SDL_Init)

Use SDL2’s higher-level Game Controller API to expose joysticks instead of
its lower-level joystick API. The benefit of this is that you can exert
more control over arbitrary hardware (deadzones, button mapping, device
name, etc), and button and axes layouts are consistent (what is physically
located where an Xbox360’s “A” button is will always be SDL 1.2 joystick
button 0, “B” will be 1, etc). The downside is it might not expose all of
a given piece of hardware’s functionality, or simply not make sense in
general…if you need to use a flight stick, for example, you should not
use this hint. If there is no known game controller mapping for a joystick,
and this hint is in use, it will not be listed as an availble device.

– SDL12COMPAT_WINDOW_SCALING: (checked during SDL_SetVideoMode)

When creating non-fullscreen, non-resizable windows, use this variable to
size the window differently. If, for example, you have a 4K monitor and the
game is running in a window the size of a postage stamp, you might set this
to 2 to double the size of the window. Fractional values work, so “1.5”
might be a more-pleasing value on your hardware. You can even shrink the
window with values less than 1.0! When scaling a window like this,
sdl12-compat will use all the usual scaling options
(SDL12COMPAT_OPENGL_SCALING, SDL12COMPAT_SCALE_METHOD, etc). If sdl12-compat
can’t scale the contents of the window for various technical reasons, it
will create the window at the originally-requested size. If this variable
isn’t specified, it defaults to 1.0 (no scaling).

– SDL12COMPAT_MAX_VIDMODE: (checked during SDL_Init)

This is a string in the form of WxH, where W is the maximum width
and H is the maximum height (for example: 640x480). The list of valid
resolutions that will be reported by SDL_ListModes and SDL_VideoModeOK will
not include any dimensions that are wider or taller than these sizes. A size
of zero will be ignored, so for 0x480 a resolution of 1920x480 would be
accepted). If not specified, or set to 0x0, no resolution clamping is done.
This is for old software-rendered games that might always choose the largest
resolution offered, but never conceived of 4K displays. In these cases, it
might be better for them to use a smaller resolution and let sdl12-compat
scale their output up with the GPU.

– SDL_MOUSE_RELATIVE_SCALING: (checked during SDL_SetVideoMode)

If enabled, relative mouse motion is scaled when the application is
running at a non-native resolution. This may be required with some
applications which use their own mouse cursors. See also:
SDL_HINT_MOUSE_RELATIVE_SCALING - SDL Wiki

– SDL12COMPAT_ALLOW_THREADED_DRAWS: (checked during SDL_Init)

Enabled by default.
If disabled, calls to SDL_UpdateRects() from non-main threads are
converted into requests for the main thread to carry out the update later.
The thread that called SDL_SetVideoMode() is treated as the main thread.

– SDL12COMPAT_ALLOW_THREADED_PUMPS: (checked during SDL_Init)

Enabled by default.
If disabled, calls to SDL_PumpEvents() from non-main threads are
completely ignored.
The thread that called SDL_SetVideoMode() is treated as the main thread.

– SDL12COMPAT_ALLOW_SYSWM: (checked during SDL_Init)
± SDL2COMPAT_ALLOW_SYSWM: (checked during SDL_Init)
Enabled by default.
If disabled, SDL_SYSWMEVENT events will not be delivered to the app, and
SDL_GetWMInfo() will fail; this is useful if you have a program that
tries to access X11 directly through SDL’s interfaces, but can survive
without it, becoming compatible with, for example, Wayland, or perhaps

just avoiding a bug in target-specific code. Note that sdl12-compat already
disallows SysWM things unless SDL2 is using its “windows” or “x11” video
backends, because SDL 1.2 didn’t have wide support for its SysWM APIs
outside of Windows and X11 anyhow.

just avoiding a bug in target-specific code.

-# Compatibility issues with OpenGL scaling

-The OpenGL scaling feature of sdl12-compat allows applications which wish to
-run at a non-native screen resolution to do so without changing the system
-resolution. It does this by redirecting OpenGL rendering calls to a “fake”
-backbuffer which is scaled when rendering.

-This works well for simple applications, but for more complicated applications
-which use Frame Buffer Objects, sdl12-compat needs to intercept and redirect
-some OpenGL calls. Applications which access these functions without going
-though SDL (even if via a library) may not successfully render anything, or
-may render incorrectly if OpenGL scaling is enabled.

-In these cases, you can disable OpenGL scaling by setting the environment
-variable:
- -SDL12COMPAT_OPENGL_SCALING=0 -

Compatibility issues with applications directly accessing underlying APIs

Some applications combine the use of SDL with direct access to the underlying
OS or window system. When running these applications on the same OS and SDL
video driver (e.g. a program written for X11 on Linux is run on X11 on Linux),
-sdl12-compat is usually compatible.
+sdl2-compat is usually compatible.

However, if you wish to run an application on a different video driver, the
application will be unable to access the underlying API it is expecting, and