Add stub implementations of backend functions

Towards having actual trivial backends, but in general allows backends to not
declare functions they don't care about which is nice and already a net
reduction of actual code.

5 files changed, 115 insertions, 63 deletions

diff --git a/pugl/detail/mac_cairo.m b/pugl/detail/mac_cairo.m
index 143fbb0..1e4149c 100644
--- a/pugl/detail/mac_cairo.m
+++ b/pugl/detail/mac_cairo.m
@@ -21,6 +21,7 @@
 #include "pugl/detail/implementation.h"
 #include "pugl/detail/mac.h"
 #include "pugl/pugl_cairo_backend.h"
+#include "pugl/pugl_stub_backend.h"
 
 #include <cairo-quartz.h>
 
@@ -62,12 +63,6 @@
 @end
 
 static PuglStatus
-puglMacCairoConfigure(PuglView* PUGL_UNUSED(view))
-{
-	return PUGL_SUCCESS;
-}
-
-static PuglStatus
 puglMacCairoCreate(PuglView* view)
 {
 	PuglInternals* impl     = view->impl;
@@ -141,15 +136,6 @@ puglMacCairoLeave(PuglView* view, bool drawing)
 	return PUGL_SUCCESS;
 }
 
-static PuglStatus
-puglMacCairoResize(PuglView* PUGL_UNUSED(view),
-                   int       PUGL_UNUSED(width),
-                   int       PUGL_UNUSED(height))
-{
-	// No need to resize, the surface is created for the drawing context
-	return PUGL_SUCCESS;
-}
-
 static void*
 puglMacCairoGetContext(PuglView* view)
 {
@@ -159,12 +145,12 @@ puglMacCairoGetContext(PuglView* view)
 const PuglBackend* puglCairoBackend(void)
 {
 	static const PuglBackend backend = {
-		puglMacCairoConfigure,
+		puglStubConfigure,
 		puglMacCairoCreate,
 		puglMacCairoDestroy,
 		puglMacCairoEnter,
 		puglMacCairoLeave,
-		puglMacCairoResize,
+		puglStubResize,
 		puglMacCairoGetContext
 	};
 
diff --git a/pugl/detail/mac_gl.m b/pugl/detail/mac_gl.m
index b84f799..6e3c1c6 100644
--- a/pugl/detail/mac_gl.m
+++ b/pugl/detail/mac_gl.m
@@ -21,6 +21,7 @@
 #include "pugl/detail/implementation.h"
 #include "pugl/detail/mac.h"
 #include "pugl/pugl_gl_backend.h"
+#include "pugl/pugl_stub_backend.h"
 
 #ifndef __MAC_10_10
 #define NSOpenGLProfileVersion4_1Core NSOpenGLProfileVersion3_2Core
@@ -94,12 +95,6 @@ typedef NSUInteger NSWindowStyleMask;
 @end
 
 static PuglStatus
-puglMacGlConfigure(PuglView* PUGL_UNUSED(view))
-{
-	return PUGL_SUCCESS;
-}
-
-static PuglStatus
 puglMacGlCreate(PuglView* view)
 {
 	PuglInternals*  impl     = view->impl;
@@ -164,22 +159,16 @@ puglMacGlResize(PuglView* view, int PUGL_UNUSED(width), int PUGL_UNUSED(height))
 	return PUGL_SUCCESS;
 }
 
-static void*
-puglMacGlGetContext(PuglView* PUGL_UNUSED(view))
-{
-	return NULL;
-}
-
 const PuglBackend* puglGlBackend(void)
 {
 	static const PuglBackend backend = {
-		puglMacGlConfigure,
+		puglStubConfigure,
 		puglMacGlCreate,
 		puglMacGlDestroy,
 		puglMacGlEnter,
 		puglMacGlLeave,
 		puglMacGlResize,
-		puglMacGlGetContext
+		puglStubGetContext
 	};
 
 	return &backend;
diff --git a/pugl/detail/win_gl.c b/pugl/detail/win_gl.c
index e8ecedc..d872303 100644
--- a/pugl/detail/win_gl.c
+++ b/pugl/detail/win_gl.c
@@ -21,6 +21,7 @@
 #include "pugl/detail/types.h"
 #include "pugl/detail/win.h"
 #include "pugl/pugl_gl_backend.h"
+#include "pugl/pugl_stub_backend.h"
 
 #include <windows.h>
 
@@ -272,20 +273,6 @@ puglWinGlLeave(PuglView* view, bool drawing)
 	return PUGL_SUCCESS;
 }
 
-static PuglStatus
-puglWinGlResize(PuglView* PUGL_UNUSED(view),
-                int       PUGL_UNUSED(width),
-                int       PUGL_UNUSED(height))
-{
-	return PUGL_SUCCESS;
-}
-
-static void*
-puglWinGlGetContext(PuglView* PUGL_UNUSED(view))
-{
-	return NULL;
-}
-
 PuglGlFunc
 puglGetProcAddress(const char* name)
 {
@@ -309,8 +296,8 @@ puglGlBackend()
 		puglWinGlDestroy,
 		puglWinGlEnter,
 		puglWinGlLeave,
-		puglWinGlResize,
-		puglWinGlGetContext
+		puglStubResize,
+		puglStubGetContext
 	};
 
 	return &backend;
diff --git a/pugl/detail/x11_gl.c b/pugl/detail/x11_gl.c
index f5dbe2c..ea34fc3 100644
--- a/pugl/detail/x11_gl.c
+++ b/pugl/detail/x11_gl.c
@@ -22,6 +22,7 @@
 #include "pugl/detail/x11.h"
 #include "pugl/pugl.h"
 #include "pugl/pugl_gl_backend.h"
+#include "pugl/pugl_stub_backend.h"
 
 #include <GL/gl.h>
 #include <GL/glx.h>
@@ -188,20 +189,6 @@ puglX11GlLeave(PuglView* view, bool drawing)
 	return PUGL_SUCCESS;
 }
 
-static PuglStatus
-puglX11GlResize(PuglView* PUGL_UNUSED(view),
-                int       PUGL_UNUSED(width),
-                int       PUGL_UNUSED(height))
-{
-	return PUGL_SUCCESS;
-}
-
-static void*
-puglX11GlGetContext(PuglView* PUGL_UNUSED(view))
-{
-	return NULL;
-}
-
 PuglGlFunc
 puglGetProcAddress(const char* name)
 {
@@ -216,8 +203,8 @@ const PuglBackend* puglGlBackend(void)
 		puglX11GlDestroy,
 		puglX11GlEnter,
 		puglX11GlLeave,
-		puglX11GlResize,
-		puglX11GlGetContext
+		puglStubResize,
+		puglStubGetContext
 	};
 
 	return &backend;
diff --git a/pugl/pugl_stub_backend.h b/pugl/pugl_stub_backend.h
new file mode 100644
index 0000000..27a961b
--- /dev/null
+++ b/pugl/pugl_stub_backend.h
@@ -0,0 +1,103 @@
+/*
+  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_backend.h Stub backend functions.
+*/
+
+#ifndef PUGL_STUB_BACKEND_H
+#define PUGL_STUB_BACKEND_H
+
+#include "pugl/pugl.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+   @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_STUB_BACKEND_H