X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Fscreen%2Fextensions.cxx;h=a317bda42fec5d4c996a24f8dc561de627900323;hb=84dd54b33a6d8b35e57c32194b025f79245f35c4;hp=4acf0e260160efcea9e8492fc48f75dc080f1bdf;hpb=ab34b86574c951f5a3ee6edaa5bfe2010c9b6e44;p=simgear.git

diff --git a/simgear/screen/extensions.cxx b/simgear/screen/extensions.cxx
index 4acf0e26..a317bda4 100644
--- a/simgear/screen/extensions.cxx
+++ b/simgear/screen/extensions.cxx
@@ -24,23 +24,19 @@
 
 #include <string.h>
 
-#ifdef WIN32
-#include <windows.h>
-#endif
-
-#if !defined( WIN32 ) && !defined( __APPLE__ )
-#include <dlfcn.h>
-#endif
-
 #include "extensions.hxx"
+#include <simgear/debug/logstream.hxx>
 
-bool SGSearchExtensionsString(char *extString, char *extName) {
+bool SGSearchExtensionsString(const char *extString, const char *extName) {
     // Returns GL_TRUE if the *extName string appears in the *extString string,
     // surrounded by white spaces, or GL_FALSE otherwise.
 
-    char *p, *end;
+    const char *p, *end;
     int n, extNameLen;
 
+    if ((extString == NULL) || (extName == NULL))
+        return false;
+
     extNameLen = strlen(extName);
 
     p=extString;
@@ -64,8 +60,7 @@ bool SGIsOpenGLExtensionSupported(char *extName) {
    // The *extName string must follow the OpenGL extensions naming scheme
    // (ie: "GL_type_extension", like GL_EXT_convolution)
 
-    return SGSearchExtensionsString((char *)glGetString(GL_EXTENSIONS),
-extName);
+    return SGSearchExtensionsString((const char *)glGetString(GL_EXTENSIONS),extName);
 }
 
 #ifdef __APPLE__
@@ -101,4 +96,40 @@ void* macosxGetGLProcAddress(const char *func) {
   return function;
 }
 
+#elif !defined( WIN32 )
+
+void *SGGetGLProcAddress(const char *func) {
+    static void *libHandle = NULL;
+    void *fptr = NULL;
+
+    /*
+     * Clear the error buffer
+     */
+    dlerror();
+
+    /*
+     * Since libGL must be linked to the binary we run on, this is the
+     * right handle. That 'current binary' handle also avoids conflicts which
+     * arise from linking with a different libGL at link time an than later
+     * use the standard libGL at runtime ...
+     */
+    if (libHandle == NULL)
+        libHandle = dlopen(NULL, RTLD_LAZY);
+
+    if (libHandle != NULL) {
+        fptr = dlsym(libHandle, func);
+
+#if defined (__FreeBSD__)
+        const char *error = dlerror();
+#else
+        char *error = dlerror();
 #endif
+        if (error)
+            SG_LOG(SG_GENERAL, SG_INFO, error);
+    }
+
+    return fptr;
+}
+
+#endif
+