gallium: introduce target directory

Currently there are still at least two functions bundled up inside the
winsys concept:

a) that of a backend resource manager, sometimes capable of performing
   present() operations,

b) the initialization code/routine for the whole driver stack.

The inclusion of (b) makes it difficult to share implementations of
(a) between different drivers.  For instance, a clean xlib winsys
could be of use for software-rasterized VG, GLES, EGL, etc, stacks.
But that is only true as long as there is no dependency from the
winsys to higher level code, as would be the case when we include (b)
in this component.

This change creates a new gallium/targets subtree, specifically for
implementing the glue needed to build individual driver stacks, and
moves that code out of a single example winsys, namely xlib.

Other drivers continue to build unchanged, but hopefully can migrate
to this structure over time.

1 files changed, 104 insertions, 0 deletions

diff --git a/src/gallium/targets/libgl-xlib/xlib.c b/src/gallium/targets/libgl-xlib/xlib.c
new file mode 100644
index 00000000000..7cae0884e84
--- /dev/null
+++ b/src/gallium/targets/libgl-xlib/xlib.c
@@ -0,0 +1,104 @@
+/**************************************************************************
+ * 
+ * Copyright 2007 Tungsten Graphics, Inc., Bismarck, ND., USA
+ * All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ * 
+ * 
+ **************************************************************************/
+
+/*
+ * Authors:
+ *   Keith Whitwell
+ */
+
+#include "state_tracker/xlib_sw_winsys.h"
+#include "xm_winsys.h"
+#include "util/u_debug.h"
+
+
+/* advertise OpenGL support */
+PUBLIC const int st_api_OpenGL = 1;
+
+static void _init( void ) __attribute__((constructor));
+
+/* Build the rendering stack.
+ */
+static void _init( void )
+{
+   struct xm_driver *driver;
+
+   /* Initialize the xlib software winsys.  Later on, once Display and
+    * other parameters are known, this will be used to create the
+    * gallium driver (such as softpipe), etc.
+    */
+   driver = xlib_sw_winsys_init();
+
+   /* Initialize the xlib libgl code, pass in the winsys:
+    */
+   xmesa_set_driver( driver );
+}
+
+
+/***********************************************************************
+ *
+ * Butt-ugly hack to convince the linker not to throw away public GL
+ * symbols (they are all referenced from getprocaddress, I guess).
+ */
+extern void (*linker_foo(const unsigned char *procName))();
+extern void (*glXGetProcAddress(const unsigned char *procName))();
+
+extern void (*linker_foo(const unsigned char *procName))()
+{
+   return glXGetProcAddress(procName);
+}
+
+
+/**
+ * When GLX_INDIRECT_RENDERING is defined, some symbols are missing in
+ * libglapi.a.  We need to define them here.
+ */
+#ifdef GLX_INDIRECT_RENDERING
+
+#define GL_GLEXT_PROTOTYPES
+#include "GL/gl.h"
+#include "glapi/glapi.h"
+#include "glapi/glapitable.h"
+#include "glapi/glapidispatch.h"
+
+#if defined(USE_MGL_NAMESPACE)
+#define NAME(func)  mgl##func
+#else
+#define NAME(func)  gl##func
+#endif
+
+#define DISPATCH(FUNC, ARGS, MESSAGE)		\
+   CALL_ ## FUNC(GET_DISPATCH(), ARGS);
+
+#define RETURN_DISPATCH(FUNC, ARGS, MESSAGE) 	\
+   return CALL_ ## FUNC(GET_DISPATCH(), ARGS);
+
+/* skip normal ones */
+#define _GLAPI_SKIP_NORMAL_ENTRY_POINTS
+#include "glapi/glapitemp.h"
+
+#endif /* GLX_INDIRECT_RENDERING */