meson: switch gles1 and gles2 to auto options

This allows them to default to false on windows, but default to true
elsewhere. As a side effect turning off shared-glapi now automatically
turns off gles. Shared glapi remains a boolean defaulting to true.

v5: - new in this version

Reviewed-by: Eric Anholt <eric@anholt.net>

meson.build

@@ -70,25 +70,43 @@ endif
 
 with_gles1 = get_option('gles1')
 with_gles2 = get_option('gles2')
+if host_machine.system() == 'windows'
+  if with_gles1 == 'auto'
+    with_gles1 = 'false'
+  endif
+  if with_gles2 == 'auto'
+    with_gles2 = 'false'
+  endif
+endif
 with_opengl = get_option('opengl')
-with_any_opengl = with_opengl or with_gles1 or with_gles2
+with_shared_glapi = get_option('shared-glapi')
-# Only build shared_glapi if at least one OpenGL API is enabled
-with_shared_glapi = get_option('shared-glapi') and with_any_opengl
-
 
 # shared-glapi is required if at least two OpenGL APIs are being built
 if not with_shared_glapi
-  if ((with_gles1 and with_gles2) or (with_gles1 and with_opengl)
+  if ((with_gles1 == 'true' and with_gles2 == 'true') or 
-      or (with_gles2 and with_opengl))
+      (with_gles1 == 'true' and with_opengl) or
+      (with_gles2 == 'true' and with_opengl))
     error('shared-glapi required for building two or more of OpenGL, OpenGL ES 1.x, OpenGL ES 2.x')
   endif
+  with_gles1 = 'false'
+  with_gles2 = 'false'
 endif
 
 # We require OpenGL for OpenGL ES
-if (with_gles1 or with_gles2) and not with_opengl
+if not with_opengl
-  error('building OpenGL ES without OpenGL is not supported.')
+  if (with_gles1 == 'true' or with_gles2 == 'true') and not with_opengl
+    error('building OpenGL ES without OpenGL is not supported.')
+  endif
+  with_gles1 = 'false'
+  with_gles2 = 'false'
 endif
 
+with_gles1 = with_gles1 != 'false'
+with_gles2 = with_gles2 != 'false'
+with_any_opengl = with_opengl or with_gles1 or with_gles2
+# Only build shared_glapi if at least one OpenGL API is enabled
+with_shared_glapi = get_option('shared-glapi') and with_any_opengl
+
 system_has_kms_drm = ['openbsd', 'netbsd', 'freebsd', 'dragonfly', 'linux'].contains(host_machine.system())
 
 dri_drivers = get_option('dri-drivers')

meson_options.txt

@@ -181,14 +181,16 @@ option(
 )
 option(
   'gles1',
-  type : 'boolean',
+  type : 'combo',
-  value : true,
+  value : 'auto',
+  choices : ['auto', 'true', 'false'],
   description : 'Build support for OpenGL ES 1.x'
 )
 option(
   'gles2',
-  type : 'boolean',
+  type : 'combo',
-  value : true,
+  value : 'auto',
+  choices : ['auto', 'true', 'false'],
   description : 'Build support for OpenGL ES 2.x and 3.x'
 )
 option(