Remove FindSDL2 find-module, use sdl2-config.cmake instead
This requires SDL >= 2.0.4.
Since <https://bugzilla.libsdl.org/show_bug.cgi?id=2464> was fixed in
SDL 2.0.4, SDL behaves as a CMake "config-file package", even if it was
not itself built using CMake: it installs a sdl2-config.cmake file to
${libdir}/cmake/SDL2, which tells CMake where to find SDL's headers and
library, analogous to a pkg-config .pc file.
As a result, we no longer need to copy/paste a "find-module package"
to be able to find a system copy of SDL >= 2.0.4 with find_package(SDL2).
Find-module packages are now discouraged by the CMake developers, in
favour of having upstream projects behave as config-file packages.
This results in a small API change: FindSDL2 used to set SDL2_INCLUDE_DIR
and SDL2_LIBRARY, but the standard behaviour for config-file packages is
to set <name>_INCLUDE_DIRS and <name>_LIBRARIES. Use the CONFIG keyword
to make sure we search in config-file package mode, and will not find a
FindSDL2.cmake in some other directory that implements the old interface.
In addition to deleting redundant code, this avoids some assumptions in
FindSDL2 about the layout of a SDL installation. The current libsdl2-dev
package in Debian breaks those assumptions; this is considered a bug
and will hopefully be fixed soon, but it illustrates how fragile these
assumptions can be. We can be more robust against different installation
layouts by relying on SDL's own CMake integration.
When linking to a copy of CMake in a non-standard location, users can
now set the SDL2_DIR or CMAKE_PREFIX_PATH environment variable to point
to it; previously, these users would have used the SDL2DIR environment
variable. This continues to be unnecessary if using matching system-wide
installations of CMake and SDL2, for example both from Debian.
.\" This program is free software; you can redistribute it and/or modify
.\" it under the terms of the GNU General Public License as published by
.\" the Free Software Foundation; either version 2 of the License, or
.\" (at your option) any later version.
.\"
.\" This program is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
.\" GNU General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public License
.\" along with this program; if not, write to the Free Software
.\" Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
.\"
.\" .
.\" .
.TH "hedgewars" "6" "" "hedgewars" ""
.SH "NAME"
Hedgewars \- a free turn based strategy game
.SH "SYNOPSIS"
.
.B hedgewars
[\fIOPTION\fR...]
[\fICONNECTSTRING\fR]
.
.SH "DESCRIPTION"
Each player controls a team of several hedgehogs. During the course of the game, players take turns with one of their hedgehogs. They then use whatever tools and weapons are available to attack and kill the opponents' hedgehogs, thereby winning the game. Hedgehogs may move around the terrain in a variety of ways, normally by walking and jumping but also by using particular tools such as the "Rope" or "Parachute", to move to otherwise inaccessible areas. Each turn is time\-limited to ensure that players do not hold up the game with excessive thinking or moving.
.SH "OPTIONS"
.
.TP
\fB\-\-help\fR
Displays help and exits
.TP
\fB\-\-config-dir=PATH\fR
Custom path for configuration data and user data
.TP
\fB\-\-data-dir=PATH\fR
Custom path to the game data folder
.SH "CONNECTSTRING"
.
If a CONNECTSTRING (e.g. "hwplay://netserver.hedgewars.org") is supplied, then hedgewars will try to connect to the specified destination on start.
.
.SH "COPYRIGHT"
.
Copyright \(co 2004\-2018 Andrey Korotaev, Igor Ulyanov
.br
This is Free Software; this software is licensed under the GPL version 2, as published by the Free Software Foundation.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
.