- Updated doc/README.opengl

- Better extension handling:
  Distributing own, mangled, glext.h (now myglext.h).
  Resolving glXgetProcAddress[ARB] during runtime now
  (original patch by Robert Osfield).
  Should compile now virtually anywhere.
- Test for existence / working GLU (original patch by Alien).
- Windows often were opened with the wrong visual ID depending on
  the single/double buffering flag. Fixed.

CVS patchset: 7478
CVS date: 2005/04/21 17:37:40

1 files changed, 42 insertions, 30 deletions

diff --git a/m4/opengl.m4 b/m4/opengl.m4
index fdc30751e..82534be91 100644
--- a/m4/opengl.m4
+++ b/m4/opengl.m4
@@ -1,5 +1,5 @@
 dnl
-dnl Check for OpenGL & [Glut | GLU]
+dnl Check for OpenGL & GLU
 dnl
 dnl AM_PATH_OPENGL([ACTION IF FOUND [, ACTION IF NOT FOUND]])
 dnl
@@ -10,46 +10,58 @@ AC_DEFUN([AM_PATH_OPENGL], [
     [enableopengl=$enableval],
     [enableopengl="yes"]
   )
+  AC_ARG_ENABLE(glu, AC_HELP_STRING([--disable-glu], [build OpenGL plugin without GLU (no verbose errors)]),
+    [enableglu=$enableval],
+    [enableglu="yes"]
+  )
 
   if test x$enableopengl = "xyes"; then
     AC_CHECK_LIB(GL, glBegin,
-     [AC_CHECK_HEADER(GL/gl.h,
-       [ac_have_opengl="yes"
-        OPENGL_LIBS="-lGL"
-        dnl check for glut
-        AC_CHECK_LIB(glut, glutInit,
-         [ac_have_glut="yes"
-          GLUT_LIBS="-lglut"
-          AC_DEFINE(HAVE_GLUT,1,[Define this if you have GLut support available])
-          AC_DEFINE(HAVE_OPENGL,1,[Define this if you have OpenGL support available])
-         ],
-         [ac_have_glut="no"
-          dnl fallback, check for GLU
-          AC_CHECK_LIB(GLU, gluPerspective,
-           [ac_have_glu="yes"
-            GLU_LIBS="-lGLU -lm" 
-            AC_DEFINE(HAVE_GLU,1,[Define this if you have GLU support available])
+      [AC_CHECK_LIB(m, tan,
+        [AC_CHECK_HEADER(GL/gl.h,
+          [ac_have_opengl="yes"
+            OPENGL_LIBS="-lGL -lm"
             AC_DEFINE(HAVE_OPENGL,1,[Define this if you have OpenGL support available])
-           ],
-           [ac_have_glu="no"], 
-           [$X_LIBS $X_PRE_LIBS $OPENGL_LIBS -lGLU -lm $X_EXTRA_LIBS]
-          )
-         ], 
-         [$X_LIBS $X_PRE_LIBS -lglut $X_EXTRA_LIBS]
-        )
-       ]
-     )],
-     [],
-     [$X_LIBS $X_PRE_LIBS -lGL $X_EXTRA_LIBS]
+            dnl
+            dnl need to check with some test if this linking with -lGLU actually works...
+            dnl check for GLU
+            dnl
+            if test x$enableglu = "xyes"; then
+              AC_CHECK_LIB(GLU, gluPerspective,
+                [AC_CHECK_HEADER(GL/glu.h,
+                  [AC_MSG_CHECKING([if GLU is sane])
+                    ac_save_LIBS="$LIBS"
+                    LIBS="$X_LIBS $XPRE_LIBS $OPENGL_LIBS -lGLU $X_EXTRA_LIBS"
+                    AC_TRY_LINK([#include <GL/gl.h>
+#include <GL/glu.h>],
+                      [ gluPerspective(45.0f,1.33f,1.0f,1000.0f); glBegin(GL_POINTS); glEnd(); return 0 ],
+                      [ ac_have_glu="yes"
+                        GLU_LIBS="-lGLU" 
+                        AC_DEFINE(HAVE_GLU,1,[Define this if you have GLU support available])
+                        AC_MSG_RESULT(yes)],
+                      [ AC_MSG_RESULT(no)
+                        echo "*** GLU doesn't link with GL; GLU is disabled ***"])
+                    LIBS="$ac_save_LIBS"]
+                )],
+                [], 
+                [$X_LIBS $X_PRE_LIBS $OPENGL_LIBS -lGLU $X_EXTRA_LIBS]
+              )
+            fi
+          ]
+        )],
+        [],
+        [$X_LIBS $X_PRE_LIBS -lGL -lm $X_EXTRA_LIBS]
+      )],
+      [],
+      [$X_LIBS $X_PRE_LIBS $X_EXTRA_LIBS]
     )
-    if test x$ac_have_opengl = "xyes" -a x$ac_have_glut = "xyes" -o x$ac_have_opengl = "xyes" -a x$ac_have_glu = "xyes"; then
+    if test x$ac_have_opengl = "xyes"; then
       ac_use_opengl=yes
     fi
   fi
 
   AC_SUBST(OPENGL_CFLAGS)
   AC_SUBST(OPENGL_LIBS)
-  AC_SUBST(GLUT_LIBS)
   AC_SUBST(GLU_LIBS)
   AM_CONDITIONAL(HAVE_OPENGL, [test x$ac_use_opengl = "xyes"])