-#ifndef GL_TEXTURE_3D_EXT
-#define GL_PACK_SKIP_IMAGES_EXT 0x806B
-#define GL_PACK_IMAGE_HEIGHT_EXT 0x806C
-#define GL_UNPACK_SKIP_IMAGES_EXT 0x806D
-#define GL_UNPACK_IMAGE_HEIGHT_EXT 0x806E
-#define GL_TEXTURE_3D_EXT 0x806F
-#define GL_PROXY_TEXTURE_3D_EXT 0x8070
-#define GL_TEXTURE_DEPTH_EXT 0x8071
-#define GL_TEXTURE_WRAP_R_EXT 0x8072
-#define GL_MAX_3D_TEXTURE_SIZE_EXT 0x8073
-#define GL_TEXTURE_3D_BINDING_EXT 0x806A
-extern void (GLAPIENTRY *qglTexImage3DEXT)(GLenum target, GLint level, GLenum internalFormat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLenum format, GLenum type, const GLvoid *pixels);
-extern void (GLAPIENTRY *qglTexSubImage3DEXT)(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const GLvoid *pixels);
-extern void (GLAPIENTRY *qglCopyTexSubImage3DEXT)(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLint x, GLint y, GLsizei width, GLsizei height);
+#ifndef GL_TEXTURE_3D
+#define GL_PACK_SKIP_IMAGES 0x806B
+#define GL_PACK_IMAGE_HEIGHT 0x806C
+#define GL_UNPACK_SKIP_IMAGES 0x806D
+#define GL_UNPACK_IMAGE_HEIGHT 0x806E
+#define GL_TEXTURE_3D 0x806F
+#define GL_PROXY_TEXTURE_3D 0x8070
+#define GL_TEXTURE_DEPTH 0x8071
+#define GL_TEXTURE_WRAP_R 0x8072
+#define GL_MAX_3D_TEXTURE_SIZE 0x8073
+#define GL_TEXTURE_BINDING_3D 0x806A
+extern void (GLAPIENTRY *qglTexImage3D)(GLenum target, GLint level, GLenum internalFormat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLenum format, GLenum type, const GLvoid *pixels);
+extern void (GLAPIENTRY *qglTexSubImage3D)(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const GLvoid *pixels);
+extern void (GLAPIENTRY *qglCopyTexSubImage3D)(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLint x, GLint y, GLsizei width, GLsizei height);