Hack in crude OSMesa support

Mostly this is quick, "do nothing" ifdefs when built with
SYSTEM=linux-osmesa, to support the off-screen rendering mode of Mesa in
headless tests.  Support in glewinfo and visualinfo is enough to get
them compile, but insufficient for them to run successfully.

auto/Makefile

@@ -200,7 +200,8 @@ $(S.DEST)/glew.c: $(EXT)/.dummy
 	$(BIN)/make_list.pl $(GL_CORE_SPEC) | grep -v '\"GL_VERSION' >> $@
 	$(BIN)/make_list.pl $(GL_EXT_SPEC) >> $@
 	echo -e "\n  return GLEW_OK;\n}\n" >> $@
-	echo -e "\n#if defined(_WIN32)" >> $@
+	echo -e "\n#if defined(GLEW_OSMESA)" >> $@
+	echo -e "\n#elif defined(_WIN32)" >> $@
 	echo -e "\n#if !defined(GLEW_MX)" >> $@
 	$(BIN)/make_def_fun.pl WGL $(WGL_EXT_SPEC) >> $@
 	$(BIN)/make_def_var.pl WGL $(WGL_EXT_SPEC) >> $@
@@ -250,7 +251,8 @@ $(S.DEST)/glew_def.c: $(EXT)/.dummy
 	echo -e "\n#if !defined(GLEW_MX)\n\nGLboolean __GLEW_VERSION_1_1 = GL_FALSE;" >> $@
 	$(BIN)/make_def_var.pl GL $(GL_CORE_SPEC) >> $@
 	$(BIN)/make_def_var.pl GL $(GL_EXT_SPEC) >> $@
-	echo -e "\n#if defined(_WIN32)" >> $@
+	echo -e "\n#if defined(GLEW_OSMESA)" >> $@
+	echo -e "\n#elif defined(_WIN32)" >> $@
 	$(BIN)/make_def_fun.pl WGL $(WGL_EXT_SPEC) >> $@
 	$(BIN)/make_def_var.pl WGL $(WGL_EXT_SPEC) >> $@
 	echo -e "\n#endif /* _WIN32 */" >> $@

auto/src/glew_head.c

@@ -1,6 +1,9 @@
 #include <GL/glew.h>
 
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+#  define GLAPI extern
+#  include <GL/osmesa.h>
+#elif defined(_WIN32)
 #  include <GL/wglew.h>
 #elif !defined(__ANDROID__) && !defined(__native_client__) && !defined(__HAIKU__) && (!defined(__APPLE__) || defined(GLEW_APPLE_GLX))
 #  include <GL/glxew.h>
@@ -137,7 +140,9 @@ void* NSGLGetProcAddress (const GLubyte *name)
 /*
  * Define glewGetProcAddress.
  */
-#if defined(GLEW_REGAL)
+#if defined(GLEW_OSMESA)
+#  define glewGetProcAddress(name) OSMesaGetProcAddress((const char *)name)
+#elif defined(GLEW_REGAL)
 #  define glewGetProcAddress(name) regalGetProcAddress((const GLchar *) name)
 #elif defined(_WIN32)
 #  define glewGetProcAddress(name) wglGetProcAddress((LPCSTR)name)

auto/src/glew_init_tail.c

@@ -34,7 +34,8 @@ GLboolean glewExperimental = GL_FALSE;
 
 #if !defined(GLEW_MX)
 
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+#elif defined(_WIN32)
 extern GLenum GLEWAPIENTRY wglewContextInit (void);
 #elif !defined(__ANDROID__) && !defined(__native_client__) && !defined(__HAIKU__) && (!defined(__APPLE__) || defined(GLEW_APPLE_GLX))
 extern GLenum GLEWAPIENTRY glxewContextInit (void);
@@ -45,7 +46,9 @@ GLenum GLEWAPIENTRY glewInit (void)
   GLenum r;
   r = glewContextInit();
   if ( r != 0 ) return r;
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+  return r;
+#elif defined(_WIN32)
   return wglewContextInit();
 #elif !defined(__ANDROID__) && !defined(__native_client__) && !defined(__HAIKU__) && (!defined(__APPLE__) || defined(GLEW_APPLE_GLX)) /* _UNIX */
   return glxewContextInit();

auto/src/glew_str_wgl.c

@@ -4,7 +4,8 @@
   return ret;
 }
 
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+#elif defined(_WIN32)
 
 #if defined(GLEW_MX)
 GLboolean GLEWAPIENTRY wglewContextIsSupported (const WGLEWContext* ctx, const char* name)

auto/src/glew_utils.c

@@ -30,7 +30,10 @@
 */
 
 #include <GL/glew.h>
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+#  define GLAPI extern
+#  include <GL/osmesa.h>
+#elif defined(_WIN32)
 #  include <GL/wglew.h>
 #elif !defined(__ANDROID__) && !defined(__native_client__) && !defined(__HAIKU__) && (!defined(__APPLE__) || defined(GLEW_APPLE_GLX))
 #  include <GL/glxew.h>

auto/src/glewinfo_head.c

@@ -2,7 +2,10 @@
 #include <stdlib.h>
 #include <string.h>
 #include <GL/glew.h>
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+#define GLAPI extern
+#include <GL/osmesa.h>
+#elif defined(_WIN32)
 #include <GL/wglew.h>
 #elif !defined(__APPLE__) && !defined(__HAIKU__) || defined(GLEW_APPLE_GLX)
 #include <GL/glxew.h>
@@ -17,7 +20,8 @@ static FILE* f;
 #ifdef GLEW_MX
 GLEWContext _glewctx;
 #define glewGetContext() (&_glewctx)
-#ifdef _WIN32
+#if defined(GLEW_OSMESA)
+#elif defined(_WIN32)
 WGLEWContext _wglewctx;
 #define wglewGetContext() (&_wglewctx)
 #elif !defined(__APPLE__) && !defined(__HAIKU__) || defined(GLEW_APPLE_GLX)
@@ -26,7 +30,9 @@ GLXEWContext _glxewctx;
 #endif
 #endif
 
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+GLboolean glewCreateContext ();
+#elif defined(_WIN32)
 GLboolean glewCreateContext (int* pixelformat);
 #elif !defined(__APPLE__) && !defined(__HAIKU__) || defined(GLEW_APPLE_GLX)
 GLboolean glewCreateContext (const char* display, int* visual);
@@ -34,7 +40,7 @@ GLboolean glewCreateContext (const char* display, int* visual);
 GLboolean glewCreateContext ();
 #endif
 
-#if defined(_WIN32) || !defined(__APPLE__) || defined(GLEW_APPLE_GLX)
+#if defined(_WIN32) || !defined(__APPLE__) || defined(GLEW_APPLE_GLX) || !defined(GLEW_OSMESA)
 GLboolean glewParseArgs (int argc, char** argv, char** display, int* visual);
 #endif
 

auto/src/glewinfo_tail.c

@@ -4,7 +4,7 @@
 
 /* ------------------------------------------------------------------------ */
 
-#if defined(_WIN32) || !defined(__APPLE__) || defined(GLEW_APPLE_GLX)
+#if defined(_WIN32) || !defined(__APPLE__) || defined(GLEW_APPLE_GLX) || !defined(GLEW_OSMESA)
 int main (int argc, char** argv)
 #else
 int main (void)
@@ -12,7 +12,7 @@ int main (void)
 {
   GLuint err;
 
-#if defined(_WIN32) || !defined(__APPLE__) || defined(GLEW_APPLE_GLX)
+#if defined(_WIN32) || !defined(__APPLE__) || defined(GLEW_APPLE_GLX) || !defined(GLEW_OSMESA)
   char* display = NULL;
   int visual = -1;
 
@@ -27,7 +27,9 @@ int main (void)
   }
 #endif
 
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+  if (GL_TRUE == glewCreateContext())
+#elif defined(_WIN32)
   if (GL_TRUE == glewCreateContext(&visual))
 #elif defined(__APPLE__) && !defined(GLEW_APPLE_GLX)
   if (GL_TRUE == glewCreateContext())
@@ -44,7 +46,7 @@ int main (void)
   err = glewContextInit(glewGetContext());
 #ifdef _WIN32
   err = err || wglewContextInit(wglewGetContext());
-#elif !defined(__APPLE__) || defined(GLEW_APPLE_GLX)
+#elif !defined(__APPLE__) || defined(GLEW_APPLE_GLX) || !defined(GLEW_OSMESA)
   err = err || glxewContextInit(glxewGetContext());
 #endif
 
@@ -74,7 +76,7 @@ int main (void)
   fprintf(f, "GLEW version %s\n", glewGetString(GLEW_VERSION));
 #if defined(_WIN32)
   fprintf(f, "Reporting capabilities of pixelformat %d\n", visual);
-#elif !defined(__APPLE__) || defined(GLEW_APPLE_GLX)
+#elif !defined(__APPLE__) || defined(GLEW_APPLE_GLX) || !defined(GLEW_OSMESA)
   fprintf(f, "Reporting capabilities of display %s, visual 0x%x\n", 
     display == NULL ? getenv("DISPLAY") : display, visual);
 #endif
@@ -82,7 +84,8 @@ int main (void)
 	  glGetString(GL_RENDERER), glGetString(GL_VENDOR));
   fprintf(f, "OpenGL version %s is supported\n", glGetString(GL_VERSION));
   glewInfo();
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+#elif defined(_WIN32)
   wglewInfo();
 #else
   glxewInfo();
@@ -94,7 +97,7 @@ int main (void)
 
 /* ------------------------------------------------------------------------ */
 
-#if defined(_WIN32) || !defined(__APPLE__) || defined(GLEW_APPLE_GLX)
+#if defined(_WIN32) || !defined(__APPLE__) || defined(GLEW_APPLE_GLX) || !defined(GLEW_OSMESA)
 GLboolean glewParseArgs (int argc, char** argv, char** display, int* visual)
 {
   int p = 0;
@@ -130,7 +133,22 @@ GLboolean glewParseArgs (int argc, char** argv, char** display, int* visual)
 
 /* ------------------------------------------------------------------------ */
 
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+OSMesaContext ctx;
+
+GLboolean glewCreateContext ()
+{
+  ctx = OSMesaCreateContext(OSMESA_RGBA, NULL);
+  if (NULL == ctx) return GL_TRUE;
+  return GL_FALSE;
+}
+
+void glewDestroyContext ()
+{
+  if (NULL != ctx) OSMesaDestroyContext(ctx);
+}
+
+#elif defined(_WIN32)
 
 HWND wnd = NULL;
 HDC dc = NULL;

auto/src/glewinfo_wgl.c

@@ -2,7 +2,8 @@
 
 /* ------------------------------------------------------------------------ */
 
-#ifdef _WIN32
+#if defined(GLEW_OSMESA)
+#elif defined(_WIN32)
 
 static void wglewInfo ()
 {

config/Makefile.linux-osmesa

@@ -0,0 +1,36 @@
+NAME = $(GLEW_NAME)
+CC = cc
+LD = cc
+M_ARCH ?= $(shell uname -m)
+ARCH64 = false
+ifeq (x86_64,${M_ARCH})
+  ARCH64 = true
+endif
+ifeq (ppc64,${M_ARCH})
+  ARCH64 = true
+endif
+ifeq (${ARCH64},true)
+  LDFLAGS.EXTRA = -L/usr/lib64
+  LIBDIR = $(GLEW_DEST)/lib64
+else
+  LDFLAGS.EXTRA = -L/usr/lib
+  LIBDIR = $(GLEW_DEST)/lib
+endif
+LDFLAGS.GL = -lOSMesa
+LDFLAGS.STATIC = -Wl,-Bstatic
+LDFLAGS.DYNAMIC = -Wl,-Bdynamic
+NAME = GLEW
+WARN = -Wall -W
+POPT = -O2
+CFLAGS.EXTRA += -fPIC -DGLEW_OSMESA
+BIN.SUFFIX =
+LIB.SONAME = lib$(NAME).so.$(SO_MAJOR)
+LIB.DEVLNK = lib$(NAME).so
+LIB.SHARED = lib$(NAME).so.$(SO_VERSION)
+LIB.STATIC = lib$(NAME).a
+LDFLAGS.SO = -shared -Wl,-soname=$(LIB.SONAME)
+LIB.SONAME.MX = lib$(NAME)mx.so.$(SO_MAJOR)
+LIB.DEVLNK.MX = lib$(NAME)mx.so
+LIB.SHARED.MX = lib$(NAME)mx.so.$(SO_VERSION)
+LIB.STATIC.MX = lib$(NAME)mx.a
+LDFLAGS.SO.MX = -shared -Wl,-soname=$(LIB.SONAME.MX)

src/visualinfo.c

@@ -34,12 +34,15 @@
 #include <stdlib.h>
 #include <string.h>
 #include <GL/glew.h>
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
-#include <GL/wglew.h>
+#  define GLAPI extern
+#  include <GL/osmesa.h>
+#elif defined(_WIN32)
+#  include <GL/wglew.h>
 #elif defined(__APPLE__) && !defined(GLEW_APPLE_GLX)
-#include <AGL/agl.h>
+#  include <AGL/agl.h>
 #elif !defined(__HAIKU__)
-#include <GL/glxew.h>
+#  include <GL/glxew.h>
 #endif
 
 #ifdef GLEW_MX
@@ -48,7 +51,7 @@ GLEWContext _glewctx;
 #  ifdef _WIN32
 WGLEWContext _wglewctx;
 #    define wglewGetContext() (&_wglewctx)
-#  elif !defined(__APPLE__) && !defined(__HAIKU__) || defined(GLEW_APPLE_GLX)
+#  elif !defined(__APPLE__) && !defined(__HAIKU__) || defined(GLEW_APPLE_GLX) || !defined(GLEW_OSMESA)
 GLXEWContext _glxewctx;
 #    define glxewGetContext() (&_glxewctx)
 #  endif
@@ -62,6 +65,8 @@ typedef struct GLContextStruct
   HGLRC rc;
 #elif defined(__APPLE__) && !defined(GLEW_APPLE_GLX)
   AGLContext ctx, octx;
+#elif defined(GLEW_OSMESA)
+  OSMesaContext ctx;
 #elif !defined(__HAIKU__)
   Display* dpy;
   XVisualInfo* vi;
@@ -130,7 +135,7 @@ main (int argc, char** argv)
   err = glewContextInit(glewGetContext());
 #  ifdef _WIN32
   err = err || wglewContextInit(wglewGetContext());
-#  elif !defined(__APPLE__) && !defined(__HAIKU__) || defined(GLEW_APPLE_GLX)
+#  elif !defined(__APPLE__) && !defined(__HAIKU__) || defined(GLEW_APPLE_GLX) || !defined(GLEW_OSMESA)
   err = err || glxewContextInit(glxewGetContext());
 #  endif
 #else
@@ -189,7 +194,7 @@ main (int argc, char** argv)
 		    (const char*)wglGetExtensionsStringEXT());
   }
 #elif defined(__APPLE__) && !defined(GLEW_APPLE_GLX)
-  
+#elif defined(GLEW_OSMESA)
 #elif defined(__HAIKU__)
 
   /* TODO */
@@ -595,7 +600,7 @@ VisualInfo (GLContext* ctx)
 
 /* ---------------------------------------------------------------------- */
 
-#elif defined(__APPLE__) && !defined(GLEW_APPLE_GLX)
+#elif (defined(__APPLE__) && !defined(GLEW_APPLE_GLX)) || defined(GLEW_OSMESA)
 
 void
 VisualInfo (GLContext* __attribute__((__unused__)) ctx)
@@ -1002,7 +1007,26 @@ VisualInfo (GLContext* ctx)
 
 /* ------------------------------------------------------------------------ */
 
-#if defined(_WIN32)
+#if defined(GLEW_OSMESA)
+void InitContext (GLContext* ctx)
+{
+  ctx->ctx = NULL;
+}
+
+GLboolean CreateContext (GLContext* ctx)
+{
+  if (NULL == ctx) return GL_TRUE;
+  ctx->ctx = OSMesaCreateContext(OSMESA_RGBA, NULL);
+  if (NULL == ctx->ctx) return GL_TRUE;
+  return GL_FALSE;
+}
+
+void DestroyContext (GLContext* ctx)
+{
+  if (NULL == ctx) return;
+  if (NULL != ctx->ctx) OSMesaDestroyContext(ctx->ctx);
+}
+#elif defined(_WIN32)
 
 void InitContext (GLContext* ctx)
 {