Plugins: Improve portability of GL and GLU detection

.. and use macOS' own OpenGL rather than Mesa's.

Related documentation:
https://www.gnu.org/software/autoconf-archive/ax_check_gl.html
https://www.gnu.org/software/autoconf-archive/ax_check_glu.html

Author: hartwork

.github/workflows/linux_and_macos.yml

@@ -106,8 +106,6 @@ jobs:
             jack \
             libpng \
             luajit \
-            mesa \
-            mesa-glu \
             orc \
             pkg-config \
             portaudio \

libvisual-plugins/configure.ac

@@ -181,16 +181,16 @@ if test "$ENABLE_GSTREAMER_PLUGIN" = "yes"; then
   fi
 fi
 
-dnl OpenGL + GLX
+dnl OpenGL + GLU
 AC_ARG_ENABLE([opengl],
   AS_HELP_STRING([--disable-opengl],
     [Do not build actor plugins based using OpenGL/GLU @<:@default=enabled@:>@]),
   [ENABLE_OPENGL_ACTORS=$enableval],
   [ENABLE_OPENGL_ACTORS=yes])
 
 AS_IF([test "$ENABLE_OPENGL_ACTORS" = "yes"], [
-  PKG_CHECK_MODULES([GL], [gl], [HAVE_OPENGL="yes"], [HAVE_OPENGL="no"])
-  PKG_CHECK_MODULES([GLU], [glu], [HAVE_GLU="yes"], [HAVE_GLU="no"; HAVE_OPENGL="no"])
+  AX_CHECK_GL([HAVE_OPENGL="yes"], [HAVE_OPENGL="no"])
+  AX_CHECK_GLU([HAVE_GLU="yes"], [HAVE_GLU="no"; HAVE_OPENGL="no"])
   AS_IF([test "$HAVE_OPENGL" != "yes"], [
     AC_MSG_WARN([*** OpenGL and/or GLU have not been found, see above.
                         Actor plugins using OpenGL will not be built.])

libvisual-plugins/plugins/actor/dancingparticles/actor_dancingparticles.cpp

@@ -31,8 +31,21 @@
 #include <math.h>
 #include <gettext.h>
 
-#include <GL/gl.h>
-#include <GL/glu.h>
+#ifdef HAVE_GL_GL_H
+# include <GL/gl.h>
+#elif defined(HAVE_OPENGL_GL_H)
+# include <OpenGL/gl.h>
+#else
+# error neither GL/gl.h nor OpenGL/gl.h available
+#endif
+
+#if defined(HAVE_GL_GLU_H)
+# include <GL/glu.h>
+#elif defined(HAVE_OPENGL_GLU_H)
+# include <OpenGL/glu.h>
+#else
+# error neither GL/glu.h nor OpenGL/glu.h available
+#endif
 
 #include "gl.h"
 #include "fastmath.h"

libvisual-plugins/plugins/actor/dancingparticles/etoile.h

@@ -1,5 +1,13 @@
 #include <cmath>
-#include <GL/glu.h>
+
+#if defined(HAVE_GL_GLU_H)
+# include <GL/glu.h>
+#elif defined(HAVE_OPENGL_GLU_H)
+# include <OpenGL/glu.h>
+#else
+# error neither GL/glu.h nor OpenGL/glu.h available
+#endif
+
 #include <cstring>
 #include <iostream>
 

libvisual-plugins/plugins/actor/dancingparticles/floatpoint.h

@@ -2,7 +2,15 @@
 #define FLOATPOINT_HH
 
 #include <iostream>
-#include <GL/gl.h>
+
+#ifdef HAVE_GL_GL_H
+# include <GL/gl.h>
+#elif defined(HAVE_OPENGL_GL_H)
+# include <OpenGL/gl.h>
+#else
+# error neither GL/gl.h nor OpenGL/gl.h available
+#endif
+
 using namespace std;
 
 #define myfloat  GLfloat

libvisual-plugins/plugins/actor/lv_gltest/actor_lv_gltest.c

@@ -33,8 +33,21 @@
 #include <math.h>
 #include <gettext.h>
 
-#include <GL/gl.h>
-#include <GL/glu.h>
+#ifdef HAVE_GL_GL_H
+# include <GL/gl.h>
+#elif defined(HAVE_OPENGL_GL_H)
+# include <OpenGL/gl.h>
+#else
+# error neither GL/gl.h nor OpenGL/gl.h available
+#endif
+
+#if defined(HAVE_GL_GLU_H)
+# include <GL/glu.h>
+#elif defined(HAVE_OPENGL_GLU_H)
+# include <OpenGL/glu.h>
+#else
+# error neither GL/glu.h nor OpenGL/glu.h available
+#endif
 
 #include <libvisual/libvisual.h>
 

libvisual-plugins/plugins/actor/madspin/madspin.c

@@ -34,8 +34,13 @@
 
 #include <time.h>
 
-#include <GL/gl.h>
-/*#include <GL/glu.h>*/
+#ifdef HAVE_GL_GL_H
+# include <GL/gl.h>
+#elif defined(HAVE_OPENGL_GL_H)
+# include <OpenGL/gl.h>
+#else
+# error neither GL/gl.h nor OpenGL/gl.h available
+#endif
 
 #include <libvisual/libvisual.h>
 

libvisual-plugins/plugins/actor/nastyfft/actor_nastyfft.c

@@ -27,8 +27,21 @@
 #include <string.h>
 #include <math.h>
 
-#include <GL/gl.h>
-#include <GL/glu.h>
+#ifdef HAVE_GL_GL_H
+# include <GL/gl.h>
+#elif defined(HAVE_OPENGL_GL_H)
+# include <OpenGL/gl.h>
+#else
+# error neither GL/gl.h nor OpenGL/gl.h available
+#endif
+
+#if defined(HAVE_GL_GLU_H)
+# include <GL/glu.h>
+#elif defined(HAVE_OPENGL_GLU_H)
+# include <OpenGL/glu.h>
+#else
+# error neither GL/glu.h nor OpenGL/glu.h available
+#endif
 
 #include <gettext.h>
 

libvisual-plugins/plugins/actor/nebulus/child_data.c

@@ -1,4 +1,10 @@
-#include <GL/gl.h>
+#ifdef HAVE_GL_GL_H
+# include <GL/gl.h>
+#elif defined(HAVE_OPENGL_GL_H)
+# include <OpenGL/gl.h>
+#else
+# error neither GL/gl.h nor OpenGL/gl.h available
+#endif
 
 GLuint childNormals = 6153;
 

libvisual-plugins/plugins/actor/nebulus/face_data.c

@@ -1,4 +1,10 @@
-#include <GL/gl.h>
+#ifdef HAVE_GL_GL_H
+# include <GL/gl.h>
+#elif defined(HAVE_OPENGL_GL_H)
+# include <OpenGL/gl.h>
+#else
+# error neither GL/gl.h nor OpenGL/gl.h available
+#endif
 
 GLuint numVertices = 473;
 GLuint numNormals = 537;