Rename "backend" headers

Working on Vulkan clarified what has always been slightly smelly about the
design and organization here: not everything that is API specific is really in
a "backend" (a PuglBackend).  The concrete example is puglGetProcAddress(),
which only makes sense for GL and is actually implemented in the "backend"
files.  Arguably puglGetContext() is also such a thing.

So, rename the headers so they can be the place where API-specific things go in
general, which happens to include a backend most of the time.  The stub is a
bit of an exception to this, but whatever.  The includes look tidier this way.

In place of the old headers are compatibility stubs that just emit a warning
and include the new version, which will be maintained for a while.

20 files changed, 234 insertions, 165 deletions

diff --git a/pugl/detail/mac.m b/pugl/detail/mac.m
index 7534281..efa4d78 100644
--- a/pugl/detail/mac.m
+++ b/pugl/detail/mac.m
@@ -24,7 +24,7 @@
 #include "pugl/detail/implementation.h"
 #include "pugl/detail/mac.h"
 #include "pugl/pugl.h"
-#include "pugl/pugl_stub_backend.h"
+#include "pugl/pugl_stub.h"
 
 #import <Cocoa/Cocoa.h>
 
diff --git a/pugl/detail/mac_cairo.m b/pugl/detail/mac_cairo.m
index 1e4149c..6b9f36c 100644
--- a/pugl/detail/mac_cairo.m
+++ b/pugl/detail/mac_cairo.m
@@ -20,8 +20,8 @@
 
 #include "pugl/detail/implementation.h"
 #include "pugl/detail/mac.h"
-#include "pugl/pugl_cairo_backend.h"
-#include "pugl/pugl_stub_backend.h"
+#include "pugl/pugl_cairo.h"
+#include "pugl/pugl_stub.h"
 
 #include <cairo-quartz.h>
 
diff --git a/pugl/detail/mac_gl.m b/pugl/detail/mac_gl.m
index f39c25e..428cc1a 100644
--- a/pugl/detail/mac_gl.m
+++ b/pugl/detail/mac_gl.m
@@ -20,8 +20,8 @@
 
 #include "pugl/detail/implementation.h"
 #include "pugl/detail/mac.h"
-#include "pugl/pugl_gl_backend.h"
-#include "pugl/pugl_stub_backend.h"
+#include "pugl/pugl_gl.h"
+#include "pugl/pugl_stub.h"
 
 #ifndef __MAC_10_10
 #define NSOpenGLProfileVersion4_1Core NSOpenGLProfileVersion3_2Core
diff --git a/pugl/detail/win.c b/pugl/detail/win.c
index d7026ae..9debb6d 100644
--- a/pugl/detail/win.c
+++ b/pugl/detail/win.c
@@ -21,7 +21,7 @@
 #include "pugl/detail/implementation.h"
 #include "pugl/detail/win.h"
 #include "pugl/pugl.h"
-#include "pugl/pugl_stub_backend.h"
+#include "pugl/pugl_stub.h"
 
 #include <windows.h>
 #include <windowsx.h>
diff --git a/pugl/detail/win_cairo.c b/pugl/detail/win_cairo.c
index 27765ec..7966b07 100644
--- a/pugl/detail/win_cairo.c
+++ b/pugl/detail/win_cairo.c
@@ -20,7 +20,7 @@
 
 #include "pugl/detail/types.h"
 #include "pugl/detail/win.h"
-#include "pugl/pugl_cairo_backend.h"
+#include "pugl/pugl_cairo.h"
 
 #include <cairo-win32.h>
 #include <cairo.h>
diff --git a/pugl/detail/win_gl.c b/pugl/detail/win_gl.c
index d872303..ee3b032 100644
--- a/pugl/detail/win_gl.c
+++ b/pugl/detail/win_gl.c
@@ -20,8 +20,8 @@
 
 #include "pugl/detail/types.h"
 #include "pugl/detail/win.h"
-#include "pugl/pugl_gl_backend.h"
-#include "pugl/pugl_stub_backend.h"
+#include "pugl/pugl_gl.h"
+#include "pugl/pugl_stub.h"
 
 #include <windows.h>
 
diff --git a/pugl/detail/x11.c b/pugl/detail/x11.c
index 133436c..9256b2e 100644
--- a/pugl/detail/x11.c
+++ b/pugl/detail/x11.c
@@ -26,7 +26,7 @@
 #include "pugl/detail/types.h"
 #include "pugl/detail/x11.h"
 #include "pugl/pugl.h"
-#include "pugl/pugl_stub_backend.h"
+#include "pugl/pugl_stub.h"
 
 #include <X11/X.h>
 #include <X11/Xatom.h>
diff --git a/pugl/detail/x11_cairo.c b/pugl/detail/x11_cairo.c
index 1c7df6e..523a569 100644
--- a/pugl/detail/x11_cairo.c
+++ b/pugl/detail/x11_cairo.c
@@ -21,7 +21,7 @@
 #include "pugl/detail/types.h"
 #include "pugl/detail/x11.h"
 #include "pugl/pugl.h"
-#include "pugl/pugl_cairo_backend.h"
+#include "pugl/pugl_cairo.h"
 
 #include <X11/Xutil.h>
 #include <cairo-xlib.h>
diff --git a/pugl/detail/x11_gl.c b/pugl/detail/x11_gl.c
index a881510..d325f9d 100644
--- a/pugl/detail/x11_gl.c
+++ b/pugl/detail/x11_gl.c
@@ -21,8 +21,8 @@
 #include "pugl/detail/types.h"
 #include "pugl/detail/x11.h"
 #include "pugl/pugl.h"
-#include "pugl/pugl_gl_backend.h"
-#include "pugl/pugl_stub_backend.h"
+#include "pugl/pugl_gl.h"
+#include "pugl/pugl_stub.h"
 
 #include <GL/glx.h>
 #include <X11/X.h>
diff --git a/pugl/pugl.h b/pugl/pugl.h
index fa75878..d4f079e 100644
--- a/pugl/pugl.h
+++ b/pugl/pugl.h
@@ -719,8 +719,8 @@ typedef struct PuglBackendImpl PuglBackend;
 
    This needs to be called once before creating the window to set the graphics
    backend.  There are two backend accessors included with pugl:
-   puglGlBackend() and puglCairoBackend(), declared in pugl_gl_backend.h and
-   pugl_cairo_backend.h, respectively.
+   puglGlBackend() and puglCairoBackend(), declared in pugl_gl.h and
+   pugl_cairo.h, respectively.
 */
 PUGL_API PuglStatus
 puglSetBackend(PuglView* view, const PuglBackend* backend);
diff --git a/pugl/pugl_cairo.h b/pugl/pugl_cairo.h
new file mode 100644
index 0000000..001bca9
--- /dev/null
+++ b/pugl/pugl_cairo.h
@@ -0,0 +1,42 @@
+/*
+  Copyright 2012-2019 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+/**
+   @file pugl_cairo.h Declaration of Cairo backend accessor.
+*/
+
+#ifndef PUGL_PUGL_CAIRO_H
+#define PUGL_PUGL_CAIRO_H
+
+#include "pugl/pugl.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+   Cairo graphics backend accessor.
+
+   Pass the return value to puglInitBackend() to draw to a view with Cairo.
+*/
+PUGL_API const PuglBackend*
+puglCairoBackend(void);
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif // PUGL_PUGL_CAIRO_H
diff --git a/pugl/pugl_cairo_backend.h b/pugl/pugl_cairo_backend.h
index 9e1a046..3f8cec3 100644
--- a/pugl/pugl_cairo_backend.h
+++ b/pugl/pugl_cairo_backend.h
@@ -14,29 +14,10 @@
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
-/**
-   @file pugl_cairo_backend.h Declaration of Cairo backend accessor.
-*/
-
 #ifndef PUGL_PUGL_CAIRO_BACKEND_H
 #define PUGL_PUGL_CAIRO_BACKEND_H
 
-#include "pugl/pugl.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/**
-   Cairo graphics backend accessor.
-
-   Pass the return value to puglInitBackend() to draw to a view with Cairo.
-*/
-PUGL_API const PuglBackend*
-puglCairoBackend(void);
-
-#ifdef __cplusplus
-}  /* extern "C" */
-#endif
+#warning "This header is deprecated, use pugl/pugl_cairo.h instead."
+#include "pugl/pugl_cairo.h"
 
 #endif // PUGL_PUGL_CAIRO_BACKEND_H
diff --git a/pugl/pugl_gl.h b/pugl/pugl_gl.h
new file mode 100644
index 0000000..7789116
--- /dev/null
+++ b/pugl/pugl_gl.h
@@ -0,0 +1,53 @@
+/*
+  Copyright 2012-2019 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+/**
+   @file pugl_gl.h OpenGL-specific API.
+*/
+
+#ifndef PUGL_PUGL_GL_H
+#define PUGL_PUGL_GL_H
+
+#include "pugl/pugl.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+   OpenGL extension function.
+*/
+typedef void (*PuglGlFunc)(void);
+
+/**
+   Return the address of an OpenGL extension function.
+*/
+PUGL_API PuglGlFunc
+puglGetProcAddress(const char* name);
+
+/**
+   OpenGL graphics backend.
+
+   Pass the return value to puglInitBackend() to draw to a view with OpenGL.
+*/
+PUGL_API const PuglBackend*
+puglGlBackend(void);
+
+#ifdef __cplusplus
+}  /* extern "C" */
+#endif
+
+#endif // PUGL_PUGL_GL_H
diff --git a/pugl/pugl_gl_backend.h b/pugl/pugl_gl_backend.h
index c0e5b08..e1b9a15 100644
--- a/pugl/pugl_gl_backend.h
+++ b/pugl/pugl_gl_backend.h
@@ -14,40 +14,10 @@
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
-/**
-   @file pugl_gl_backend.h Declaration of OpenGL backend accessor.
-*/
-
 #ifndef PUGL_PUGL_GL_BACKEND_H
 #define PUGL_PUGL_GL_BACKEND_H
 
-#include "pugl/pugl.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/**
-   OpenGL extension function.
-*/
-typedef void (*PuglGlFunc)(void);
-
-/**
-   Return the address of an OpenGL extension function.
-*/
-PUGL_API PuglGlFunc
-puglGetProcAddress(const char* name);
-
-/**
-   OpenGL graphics backend.
-
-   Pass the return value to puglInitBackend() to draw to a view with OpenGL.
-*/
-PUGL_API const PuglBackend*
-puglGlBackend(void);
-
-#ifdef __cplusplus
-}  /* extern "C" */
-#endif
+#warning "This header is deprecated, use pugl/pugl_gl.h instead."
+#include "pugl/pugl_gl.h"
 
 #endif // PUGL_PUGL_GL_BACKEND_H
diff --git a/pugl/pugl_stub.h b/pugl/pugl_stub.h
new file mode 100644
index 0000000..40d1036
--- /dev/null
+++ b/pugl/pugl_stub.h
@@ -0,0 +1,113 @@
+/*
+  Copyright 2019 David Robillard <http://drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+/**
+   @file pugl_stub.h Stub backend functions and accessor declaration.
+*/
+
+#ifndef PUGL_PUGL_STUB_H
+#define PUGL_PUGL_STUB_H
+
+#include "pugl/pugl.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+   Stub graphics backend.
+
+   This backend just creates a simple native window without setting up any
+   portable graphics API.
+*/
+PUGL_API
+const PuglBackend*
+puglStubBackend(void);
+
+/**
+   @name Stub backend functions
+
+   Implementations of stub backend functions which do nothing and always return
+   success.  These do not make for a usable backend on their own since the
+   platform implementation would fail to create a window, but are useful for
+   other backends to reuse since not all need non-trivial implementations of
+   every backend function.
+
+   @{
+*/
+
+static inline PuglStatus
+puglStubConfigure(PuglView* view)
+{
+	(void)view;
+	return PUGL_SUCCESS;
+}
+
+static inline PuglStatus
+puglStubCreate(PuglView* view)
+{
+	(void)view;
+	return PUGL_SUCCESS;
+}
+
+static inline PuglStatus
+puglStubDestroy(PuglView* view)
+{
+	(void)view;
+	return PUGL_SUCCESS;
+}
+
+static inline PuglStatus
+puglStubEnter(PuglView* view, bool drawing)
+{
+	(void)view;
+	(void)drawing;
+	return PUGL_SUCCESS;
+}
+
+static inline PuglStatus
+puglStubLeave(PuglView* view, bool drawing)
+{
+	(void)view;
+	(void)drawing;
+	return PUGL_SUCCESS;
+}
+
+static inline PuglStatus
+puglStubResize(PuglView* view, int width, int height)
+{
+	(void)view;
+	(void)width;
+	(void)height;
+	return PUGL_SUCCESS;
+}
+
+static inline void*
+puglStubGetContext(PuglView* view)
+{
+	(void)view;
+	return NULL;
+}
+
+/**
+   @}
+*/
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif // PUGL_PUGL_STUB_H
diff --git a/pugl/pugl_stub_backend.h b/pugl/pugl_stub_backend.h
index 8dba30d..e5aa513 100644
--- a/pugl/pugl_stub_backend.h
+++ b/pugl/pugl_stub_backend.h
@@ -1,5 +1,5 @@
 /*
-  Copyright 2019 David Robillard <http://drobilla.net>
+  Copyright 2012-2019 David Robillard <http://drobilla.net>
 
   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
@@ -14,100 +14,10 @@
   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
-/**
-   @file pugl_stub_backend.h Stub backend functions and accessor declaration.
-*/
-
 #ifndef PUGL_PUGL_STUB_BACKEND_H
 #define PUGL_PUGL_STUB_BACKEND_H
 
-#include "pugl/pugl.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/**
-   Stub graphics backend.
-
-   This backend just creates a simple native window without setting up any
-   portable graphics API.
-*/
-PUGL_API
-const PuglBackend*
-puglStubBackend(void);
-
-/**
-   @name Stub backend functions
-
-   Implementations of stub backend functions which do nothing and always return
-   success.  These do not make for a usable backend on their own since the
-   platform implementation would fail to create a window, but are useful for
-   other backends to reuse since not all need non-trivial implementations of
-   every backend function.
-
-   @{
-*/
-
-static inline PuglStatus
-puglStubConfigure(PuglView* view)
-{
-	(void)view;
-	return PUGL_SUCCESS;
-}
-
-static inline PuglStatus
-puglStubCreate(PuglView* view)
-{
-	(void)view;
-	return PUGL_SUCCESS;
-}
-
-static inline PuglStatus
-puglStubDestroy(PuglView* view)
-{
-	(void)view;
-	return PUGL_SUCCESS;
-}
-
-static inline PuglStatus
-puglStubEnter(PuglView* view, bool drawing)
-{
-	(void)view;
-	(void)drawing;
-	return PUGL_SUCCESS;
-}
-
-static inline PuglStatus
-puglStubLeave(PuglView* view, bool drawing)
-{
-	(void)view;
-	(void)drawing;
-	return PUGL_SUCCESS;
-}
-
-static inline PuglStatus
-puglStubResize(PuglView* view, int width, int height)
-{
-	(void)view;
-	(void)width;
-	(void)height;
-	return PUGL_SUCCESS;
-}
-
-static inline void*
-puglStubGetContext(PuglView* view)
-{
-	(void)view;
-	return NULL;
-}
-
-/**
-   @}
-*/
-
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
+#warning "This header is deprecated, use pugl/pugl_stub.h instead."
+#include "pugl/pugl_stub.h"
 
 #endif // PUGL_PUGL_STUB_BACKEND_H
diff --git a/test/pugl_cairo_test.c b/test/pugl_cairo_test.c
index ca4d368..22f54a4 100644
--- a/test/pugl_cairo_test.c
+++ b/test/pugl_cairo_test.c
@@ -21,7 +21,7 @@
 #include "test_utils.h"
 
 #include "pugl/pugl.h"
-#include "pugl/pugl_cairo_backend.h"
+#include "pugl/pugl_cairo.h"
 
 #include <cairo.h>
 
diff --git a/test/pugl_gl3_test.c b/test/pugl_gl3_test.c
index 80a8912..8dea5a1 100644
--- a/test/pugl_gl3_test.c
+++ b/test/pugl_gl3_test.c
@@ -43,7 +43,7 @@
 
 #include "pugl/gl.h"
 #include "pugl/pugl.h"
-#include "pugl/pugl_gl_backend.h"
+#include "pugl/pugl_gl.h"
 
 #include <math.h>
 #include <stdbool.h>
diff --git a/test/pugl_print_events.c b/test/pugl_print_events.c
index 1a0e079..da486aa 100644
--- a/test/pugl_print_events.c
+++ b/test/pugl_print_events.c
@@ -21,7 +21,7 @@
 #include "test_utils.h"
 
 #include "pugl/pugl.h"
-#include "pugl/pugl_stub_backend.h"
+#include "pugl/pugl_stub.h"
 
 #include <stdbool.h>
 #include <stdio.h>
diff --git a/test/pugl_test.c b/test/pugl_test.c
index 99720d2..e158da2 100644
--- a/test/pugl_test.c
+++ b/test/pugl_test.c
@@ -24,7 +24,7 @@
 
 #include "pugl/gl.h"
 #include "pugl/pugl.h"
-#include "pugl/pugl_gl_backend.h"
+#include "pugl/pugl_gl.h"
 
 #include <math.h>
 #include <stdbool.h>