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.

1 files changed, 113 insertions, 0 deletions

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