fix MSVC OpenGL linkage warnings & mingw linker problems. use SDL.lib also for MinGW.

BBGE/Core.cpp

@@ -1797,7 +1797,7 @@ void Core::setSDLGLAttributes()
 #define GLAPIENTRY
 #endif
 
-#if BBGE_BUILD_OPENGL_DYNAMIC
+#ifdef BBGE_BUILD_OPENGL_DYNAMIC
 #define GL_FUNC(ret,fn,params,call,rt) \
     extern "C" { \
         static ret (GLAPIENTRY *p##fn) params = NULL; \

BBGE/Effects.cpp

@@ -32,9 +32,7 @@ GLuint emptyTexture()											// Create An Empty Texture
 
 	// Create Storage Space For Texture Data (128x128x4)
 	data = (unsigned int*)new GLuint[((quality * quality)* 4 * sizeof(unsigned int))];
-#ifdef BBGE_BUILD_WINDOWS
+	memset(data, 0, ((quality * quality)* 4 * sizeof(unsigned int)));	// Clear Storage Memory
-	ZeroMemory(data,((quality * quality)* 4 * sizeof(unsigned int)));	// Clear Storage Memory
-#endif
 
 #ifdef BBGE_BUILD_OPENGL
 	glGenTextures(1, &txtnumber);								// Create 1 Texture

BBGE/GL/gl.h

@@ -35,9 +35,18 @@ extern "C" {
 #define APIENTRY
 #endif
 
-#ifndef WIN32
+// BBGE HACK:
+// Because Win32 uses __declspec(dllimport) for OpenGL function imports,
+// although Core.cpp defines its own functions using the same names, which are just accessing
+// OpenGL function pointers acquired elsewhere, this leads to inconsistent linkage between
+// declaration in gl.h and the actual function definition in Core.cpp.
+// So, we use this little hack to disable external linkage globally.
+#undef WINGDIAPI
+#define WINGDIAPI extern
+
+/*#ifndef WIN32
 #define WINGDIAPI
-#endif
+#endif*/
 
 #ifndef GLAPI
 # ifdef _WIN32

CMakeLists.txt

@@ -138,11 +138,7 @@ if (NOT SDL_FOUND)
         set(SDLDIR "${EXTLIBDIR}/SDL12")
         set(SDL_INCLUDE_DIR "${SDLDIR}/include" CACHE PATH "SDL include directory" FORCE)
         message(STATUS "Using internal copy of SDL")
-        if(MSVC)
         set(SDL_LIBRARY "${SDLDIR}/lib/win32/SDL.lib" CACHE PATH "Where the SDL library can be found")
-        else(MSVC)
-            set(SDL_LIBRARY "${SDLDIR}/lib/win32/libSDL.dll.a" CACHE PATH "Where the SDL library can be found")
-        endif(MSVC)
     else(MACOSX)
         message(SEND_ERROR "We don't have a prebuilt SDL for this platform.")
     endif(MACOSX)

ExternalLibs/SDL12/lib/win32/libSDL.la

@@ -1,41 +0,0 @@
-# libSDL.la - a libtool library file
-# Generated by ltmain.sh (GNU libtool) 2.2.6
-#
-# Please DO NOT delete this file!
-# It is necessary for linking the library.
-
-# The name that we can dlopen(3).
-dlname='../bin/SDL.dll'
-
-# Names of this library.
-library_names='libSDL.dll.a'
-
-# The name of the static archive.
-old_library='libSDL.a'
-
-# Linker flags that can not go in dependency_libs.
-inherited_linker_flags=''
-
-# Libraries that this one depends upon.
-dependency_libs=' -luser32 -lgdi32 -lwinmm -ldxguid'
-
-# Names of additional weak libraries provided by this library
-weak_library_names=''
-
-# Version information for libSDL.
-current=11
-age=11
-revision=3
-
-# Is this an already installed library?
-installed=yes
-
-# Should we warn about portability when linking against -modules?
-shouldnotlink=no
-
-# Files to dlopen/dlpreopen
-dlopen=''
-dlpreopen=''
-
-# Directory that this library needs to be installed in:
-libdir='/usr/local/lib'