Updated Texture3D to use extension checking to get the relevant 3d texturing

extensions.

NEWS

@@ -31,6 +31,8 @@ OSG News (most significant items from ChangeLog)
 
     osg::AnimationPath improved.
     
+    Support for writing osg::Image's to .rgb format added.
+
 July 2002 - OpenSceneGraph-0.9.0.tar.gz
 
     >>> OpenSceneGraph goes beta - Multitexturing, Occlusion Culling, Particles and much more added!

include/osg/GLExtensions

@@ -70,6 +70,38 @@ inline void* getGLExtensionFuncPtr(const char *funcName,const char *fallbackFunc
     return getGLExtensionFuncPtr(fallbackFuncName);
 }
 
+/** return true if OpenGL "extension" is supported.
+  * note: Must only called within a valid OpenGL context,
+  * undefined behavior may occur otherwise.
+  */
+SG_EXPORT extern const bool isGLUExtensionSupported(const char *extension);
+
+inline void* getGLUExtensionFuncPtr(const char *funcName)
+{
+#if defined(WIN32)
+    return wglGetProcAddress(funcName);
+#elif defined(__DARWIN_OSX__)
+    std::string temp( "_" );
+    temp += funcName;	// Mac OS X prepends an underscore on function names
+    if ( NSIsSymbolNameDefined( temp.c_str() ) )
+    {
+        NSSymbol symbol = NSLookupAndBindSymbol( temp.c_str() );
+        return NSAddressOfSymbol( symbol );
+    } else
+	return NULL;
+#else // all other unixes
+   // Note: although we use shl_load() etc. for Plugins on HP-UX, it's
+   // not neccessary here since we only used them because library
+   // intialization was not taking place with dlopen() which renders
+   // Plugins useless on HP-UX.
+   static void *lib = dlopen("libGLU.so", RTLD_LAZY);
+   if (lib)
+      return dlsym(lib, funcName);
+   else
+      return NULL;
+#endif
+}
+
 }
 
 #endif

src/osg/GLExtensions.cpp

@@ -1,5 +1,6 @@
 
 #include <osg/GL>
+#include <osg/GLU>
 #include <osg/GLExtensions>
 #include <osg/Notify>
 
@@ -51,3 +52,43 @@ const bool osg::isGLExtensionSupported(const char *extension)
 
     return result;
 }
+
+const bool osg::isGLUExtensionSupported(const char *extension)
+{
+    typedef std::set<std::string>  ExtensionSet;
+    static ExtensionSet s_extensionSet;
+    static const char* s_extensions = NULL;
+    if (s_extensions==NULL)
+    {
+        // get the extension list from OpenGL.
+        s_extensions = (const char*)gluGetString(GL_EXTENSIONS);
+        if (s_extensions==NULL) return false;
+
+        // insert the ' ' delimiated extensions words into the extensionSet.
+        const char *startOfWord = s_extensions;
+        const char *endOfWord;
+        while ((endOfWord = strchr(startOfWord,' '))!=NULL)
+        {
+            s_extensionSet.insert(std::string(startOfWord,endOfWord));
+            startOfWord = endOfWord+1;
+        }
+        if (*startOfWord!=0) s_extensionSet.insert(std::string(startOfWord));
+        
+        osg::notify(INFO)<<"OpenGL extensions supported by installed OpenGL drivers are:"<<std::endl;
+        for(ExtensionSet::iterator itr=s_extensionSet.begin();
+            itr!=s_extensionSet.end();
+            ++itr)
+        {
+            osg::notify(INFO)<<"    "<<*itr<<std::endl;
+        }
+            
+    }
+
+    // true if extension found in extensionSet.
+    bool result = s_extensionSet.find(extension)!=s_extensionSet.end();
+
+    if (result) osg::notify(INFO)<<"OpenGL utility library extension '"<<extension<<"' is supported."<<std::endl;
+    else osg::notify(INFO)<<"OpenGL utility library extension '"<<extension<<"' is not supported."<<std::endl;
+
+    return result;
+}

src/osg/Texture3D.cpp

@@ -4,7 +4,13 @@
 #include <osg/GLU>
 #include <osg/Notify>
 
-#define TEMPORARY_COMMENT_OUT_WHILE_ESTABLISHING_X_PLATFORM_SUPPORT_FOR_3D_TEXTURES
+#include <string.h>
+
+typedef void (APIENTRY * GLTexImage3DProc)      ( GLenum target, GLint level, GLenum internalFormat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLenum format, GLenum type, const GLvoid *pixels);
+typedef void (APIENTRY * GLTexSubImage3DProc)   ( GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const GLvoid *pixels);
+typedef void (APIENTRY * GLCopyTexSubImageProc) ( GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLint x, GLint y, GLsizei width, GLsizei height );
+typedef void (APIENTRY * GLUBuild3DMipMapsProc) ( GLenum target, GLint internalFormat, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const GLvoid *data);
+
 
 using namespace osg;
 
@@ -92,6 +98,14 @@ void Texture3D::setImage(Image* image)
 void Texture3D::apply(State& state) const
 {
 
+    static bool s_texturing_supported = strncmp((const char*)glGetString(GL_VERSION),"1.2",3)>=0 ||
+                                        isGLExtensionSupported("GL_EXT_texture3D");
+                                        
+    if (s_texturing_supported)
+    {
+        notify(WARN)<<"Warning: Texture3D::apply(..) failed, 3D texturing is not support by your OpenGL drivers."<<std::endl;
+    }
+
     // get the contextID (user defined ID of 0 upwards) for the 
     // current OpenGL context.
     const uint contextID = state.getContextID();
@@ -158,12 +172,17 @@ void Texture3D::computeInternalFormat() const
 
 void Texture3D::applyTexImage3D(GLenum target, Image* image, State& state, GLsizei& inwidth, GLsizei& inheight, GLsizei& indepth, GLsizei& numMimpmapLevels) const
 {
-#ifndef TEMPORARY_COMMENT_OUT_WHILE_ESTABLISHING_X_PLATFORM_SUPPORT_FOR_3D_TEXTURES
-
     // if we don't have a valid image we can't create a texture!
     if (!image || !image->data())
         return;
 
+    static GLTexImage3DProc s_glTexImage3D = (GLTexImage3DProc) getGLExtensionFuncPtr("glTexImage3D","glTexImage3DEXT");
+    if (!s_glTexImage3D)
+    {
+        notify(WARN) << "Warning:: Texture3D::applyTexImage3D(..) failed, 3D texturing not supported by your OpenGL drivers."<<std::endl;
+        return;
+    }
+
     // get the contextID (user defined ID of 0 upwards) for the 
     // current OpenGL context.
     const uint contextID = state.getContextID();
@@ -187,10 +206,12 @@ void Texture3D::applyTexImage3D(GLenum target, Image* image, State& state, GLsiz
 
     glPixelStorei(GL_UNPACK_ALIGNMENT,image->getPacking());
     
+
+
     if( _min_filter == LINEAR || _min_filter == NEAREST )
     {
         numMimpmapLevels = 1;
-        glTexImage3D( target, 0, _internalFormat,
+        s_glTexImage3D( target, 0, _internalFormat,
             image->s(), image->t(), image->r(), 0,
             (GLenum)image->getPixelFormat(),
             (GLenum)image->getDataType(),
@@ -201,9 +222,16 @@ void Texture3D::applyTexImage3D(GLenum target, Image* image, State& state, GLsiz
         if(!image->isMipmap())
         {
 
+            static GLUBuild3DMipMapsProc s_gluBuild3DMipmaps = (GLUBuild3DMipMapsProc) getGLUExtensionFuncPtr("gluBuild3DMipmaps");
+            if (!s_gluBuild3DMipmaps)
+            {
+                notify(WARN) << "Warning:: Texture3D::applyTexImage3D(..) failed, gluBuild3DMipmaps not supported by your OpenGL drivers."<<std::endl;
+                return;
+            }
+
             numMimpmapLevels = 1;
 
-             gluBuild3DMipmaps( target, _internalFormat,
+             s_gluBuild3DMipmaps( target, _internalFormat,
                  image->s(),image->t(),image->r(),
                  (GLenum)image->getPixelFormat(), (GLenum)image->getDataType(),
                  image->data() );
@@ -227,7 +255,7 @@ void Texture3D::applyTexImage3D(GLenum target, Image* image, State& state, GLsiz
                 if (depth == 0)
                     depth = 1;
 
-                glTexImage3D( target, k, _internalFormat,
+                s_glTexImage3D( target, k, _internalFormat,
                      width, height, depth, 0,
                     (GLenum)image->getPixelFormat(),
                     (GLenum)image->getDataType(),
@@ -245,13 +273,18 @@ void Texture3D::applyTexImage3D(GLenum target, Image* image, State& state, GLsiz
     inheight = image->t();
     indepth  = image->r();
     
-#endif // TEMPORARY_COMMENT_OUT_WHILE_ESTABLISHING_X_PLATFORM_SUPPORT_FOR_3D_TEXTURES
-    
 }
 
 void Texture3D::copyTexSubImage3D(State& state, int xoffset, int yoffset, int zoffset, int x, int y, int width, int height )
 {
-#ifndef TEMPORARY_COMMENT_OUT_WHILE_ESTABLISHING_X_PLATFORM_SUPPORT_FOR_3D_TEXTURES
+    static GLCopyTexSubImageProc s_glCopyTexSubImage3D = (GLCopyTexSubImageProc) getGLExtensionFuncPtr("glCopyTexSubImage3D","glCopyTexSubImage3DEXT");
+    if (!s_glCopyTexSubImage3D)
+    {
+        notify(WARN) << "Warning:: Texture3D::copyTexSubImage3D(..) failed, 3D texture copy sub image not supported by your OpenGL drivers."<<std::endl;
+        return;
+    }
+
+
     const uint contextID = state.getContextID();
 
     // get the globj for the current contextID.
@@ -263,7 +296,7 @@ void Texture3D::copyTexSubImage3D(State& state, int xoffset, int yoffset, int zo
         // we have a valid image
         glBindTexture( GL_TEXTURE_3D, handle );
         applyTexParameters(GL_TEXTURE_3D,state);
-        glCopyTexSubImage3D( GL_TEXTURE_3D, 0, xoffset,yoffset,zoffset, x, y, width, height);
+        s_glCopyTexSubImage3D( GL_TEXTURE_3D, 0, xoffset,yoffset,zoffset, x, y, width, height);
 
         /* Redundant, delete later */
         glBindTexture( GL_TEXTURE_3D, handle );
@@ -276,5 +309,4 @@ void Texture3D::copyTexSubImage3D(State& state, int xoffset, int yoffset, int zo
     {
         notify(WARN)<<"Warning: Texture3D::copyTexSubImage3D(..) failed, cannot not copy to a non existant texture."<<std::endl;
     }
-#endif // TEMPORARY_COMMENT_OUT_WHILE_ESTABLISHING_X_PLATFORM_SUPPORT_FOR_3D_TEXTURES
 }