FindSDL_gfx: Add module to find another SDL component

Complement the several existing `FindSDL_*` modules.
Follow the pattern of the existing `FindSDL_mixer` module.

Fixes: #12004

Help/manual/cmake-modules.7.rst

@@ -236,6 +236,7 @@ They are normally called through the :command:`find_package` command.
    /module/FindRuby
    /module/FindSDL
    /module/FindSDL_image
+   /module/FindSDL_gfx
    /module/FindSDL_mixer
    /module/FindSDL_net
    /module/FindSDL_sound

Help/module/FindSDL_gfx.rst

@@ -0,0 +1 @@
+.. cmake-module:: ../../Modules/FindSDL_gfx.cmake

Modules/FindSDL_gfx.cmake

@@ -0,0 +1,86 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+#[=======================================================================[.rst:
+FindSDL_gfx
+-----------
+
+.. versionadded:: 3.25
+
+Locate SDL_gfx library
+
+This module defines:
+
+::
+
+  SDL::SDL_gfx, the name of the target to use with target_*() commands
+  SDL_GFX_LIBRARIES, the name of the library to link against
+  SDL_GFX_INCLUDE_DIRS, where to find the headers
+  SDL_GFX_FOUND, if false, do not try to link against
+  SDL_GFX_VERSION_STRING - human-readable string containing the
+                             version of SDL_gfx
+
+``$SDLDIR`` is an environment variable that would correspond to the
+``./configure --prefix=$SDLDIR`` used in building SDL.
+#]=======================================================================]
+
+find_path(SDL_GFX_INCLUDE_DIRS
+  NAMES
+    SDL_framerate.h
+    SDL_gfxBlitFunc.h
+    SDL_gfxPrimitives.h
+    SDL_gfxPrimitives_font.h
+    SDL_imageFilter.h
+    SDL_rotozoom.h
+  HINTS
+    ENV SDLGFXDIR
+    ENV SDLDIR
+  PATH_SUFFIXES SDL
+                # path suffixes to search inside ENV{SDLDIR}
+                include/SDL include/SDL12 include/SDL11 include
+)
+
+if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+  set(VC_LIB_PATH_SUFFIX lib/x64)
+else()
+  set(VC_LIB_PATH_SUFFIX lib/x86)
+endif()
+
+find_library(SDL_GFX_LIBRARIES
+  NAMES SDL_gfx
+  HINTS
+    ENV SDLGFXDIR
+    ENV SDLDIR
+  PATH_SUFFIXES lib ${VC_LIB_PATH_SUFFIX}
+)
+
+if(SDL_GFX_INCLUDE_DIRS AND EXISTS "${SDL_GFX_INCLUDE_DIRS}/SDL_gfxPrimitives.h")
+  file(STRINGS "${SDL_GFX_INCLUDE_DIRS}/SDL_gfxPrimitives.h" SDL_GFX_VERSION_MAJOR_LINE REGEX "^#define[ \t]+SDL_GFXPRIMITIVES_MAJOR[ \t]+[0-9]+$")
+  file(STRINGS "${SDL_GFX_INCLUDE_DIRS}/SDL_gfxPrimitives.h" SDL_GFX_VERSION_MINOR_LINE REGEX "^#define[ \t]+SDL_GFXPRIMITIVES_MINOR[ \t]+[0-9]+$")
+  file(STRINGS "${SDL_GFX_INCLUDE_DIRS}/SDL_gfxPrimitives.h" SDL_GFX_VERSION_PATCH_LINE REGEX "^#define[ \t]+SDL_GFXPRIMITIVES_MICRO[ \t]+[0-9]+$")
+  string(REGEX REPLACE "^#define[ \t]+SDL_GFXPRIMITIVES_MAJOR[ \t]+([0-9]+)$" "\\1" SDL_GFX_VERSION_MAJOR "${SDL_GFX_VERSION_MAJOR_LINE}")
+  string(REGEX REPLACE "^#define[ \t]+SDL_GFXPRIMITIVES_MINOR[ \t]+([0-9]+)$" "\\1" SDL_GFX_VERSION_MINOR "${SDL_GFX_VERSION_MINOR_LINE}")
+  string(REGEX REPLACE "^#define[ \t]+SDL_GFXPRIMITIVES_MICRO[ \t]+([0-9]+)$" "\\1" SDL_GFX_VERSION_PATCH "${SDL_GFX_VERSION_PATCH_LINE}")
+  set(SDL_GFX_VERSION_STRING ${SDL_GFX_VERSION_MAJOR}.${SDL_GFX_VERSION_MINOR}.${SDL_GFX_VERSION_PATCH})
+  unset(SDL_GFX_VERSION_MAJOR_LINE)
+  unset(SDL_GFX_VERSION_MINOR_LINE)
+  unset(SDL_GFX_VERSION_PATCH_LINE)
+  unset(SDL_GFX_VERSION_MAJOR)
+  unset(SDL_GFX_VERSION_MINOR)
+  unset(SDL_GFX_VERSION_PATCH)
+endif()
+
+include(FindPackageHandleStandardArgs)
+
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL_gfx
+                                  REQUIRED_VARS SDL_GFX_LIBRARIES SDL_GFX_INCLUDE_DIRS
+                                  VERSION_VAR SDL_GFX_VERSION_STRING)
+
+if(SDL_gfx_FOUND)
+  if(NOT TARGET SDL::SDL_gfx)
+    add_library(SDL::SDL_gfx INTERFACE IMPORTED)
+    set_target_properties(SDL::SDL_gfx PROPERTIES
+      INTERFACE_INCLUDE_DIRECTORIES "${SDL_GFX_INCLUDE_DIRS}"
+      INTERFACE_LINK_LIBRARIES "${SDL_GFX_LIBRARIES}")
+  endif()
+endif()