meson: Add options to control drm, sdl2, jpeg dependencies of cam

Previously it was not possible to control these dependencies, they were
always used if found. Furthermore, libjpeg was unnecessarily added as a
dependency even if sdl2 was not found. Fix that by introducing three
options to control the dependencies.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

meson_options.txt

@@ -16,6 +16,21 @@ option('cam',
         value : 'auto',
         description : 'Compile the cam test application')
 
+option('cam-output-kms',
+        type : 'feature',
+        value : 'auto',
+        description : 'Enable KMS output in the cam application')
+
+option('cam-output-sdl2',
+        type : 'feature',
+        value : 'auto',
+        description : 'Enable SDL2 output in the cam application')
+
+option('cam-jpeg',
+        type : 'feature',
+        value : 'auto',
+        description : 'Enable JPEG support in the cam application')
+
 option('documentation',
         type : 'feature',
         value : 'auto',

src/apps/cam/meson.build

@@ -17,9 +17,18 @@ cam_sources = files([
 
 cam_cpp_args = [apps_cpp_args]
 
-libdrm = dependency('libdrm', required : false)
-libjpeg = dependency('libjpeg', required : false)
-libsdl2 = dependency('SDL2', required : false)
+cam_deps = [
+    libatomic,
+    libcamera_public,
+    libevent,
+    libthreads,
+    libyaml,
+    libtiff,
+]
+
+libdrm = dependency('libdrm', required : get_option('cam-output-kms'))
+libsdl2 = dependency('SDL2', required : get_option('cam-output-sdl2'))
+libjpeg = dependency('libjpeg', required : get_option('cam-jpeg'))
 
 if libdrm.found()
     cam_cpp_args += [ '-DHAVE_KMS' ]
@@ -27,6 +36,9 @@ if libdrm.found()
         'drm.cpp',
         'kms_sink.cpp'
     ])
+    cam_deps += [
+        libdrm,
+    ]
 endif
 
 if libsdl2.found()
@@ -37,28 +49,24 @@ if libsdl2.found()
         'sdl_texture_1plane.cpp',
         'sdl_texture_yuv.cpp',
     ])
+    cam_deps += [
+        libsdl2,
+    ]
 
     if libjpeg.found()
         cam_cpp_args += ['-DHAVE_LIBJPEG']
         cam_sources += files([
             'sdl_texture_mjpg.cpp'
         ])
+        cam_deps += [
+            libjpeg,
+        ]
     endif
 endif
 
 cam  = executable('cam', cam_sources,
                   link_with : apps_lib,
-                  dependencies : [
-                      libatomic,
-                      libcamera_public,
-                      libdrm,
-                      libevent,
-                      libjpeg,
-                      libsdl2,
-                      libtiff,
-                      libthreads,
-                      libyaml,
-                  ],
+                  dependencies : cam_deps,
                   cpp_args : cam_cpp_args,
                   install : true,
                   install_tag : 'bin')