OpenGL: Only load the core API by default

See the breaking changes document for more details.

BREAKING-CHANGES.txt

@@ -4,6 +4,28 @@ JUCE breaking changes
 Develop
 =======
 
+Change
+------
+juce::gl::loadFunctions() no longer loads extension functions.
+
+Possible Issues
+---------------
+Code that depended on extension functions being loaded automatically may cease
+to function correctly.
+
+Workaround
+----------
+Extension functions can now be loaded using juce::gl::loadExtensions().
+
+Rationale
+---------
+There are a great number of extension functions, and on some systems these can
+be slow to load (i.e. a second or so). Projects that do not require these
+extension functions should not have to pay for this unnecessary overhead. Now,
+only core functions will be loaded by default, and extensions can be loaded
+explicitly in projects that require such functionality.
+
+
 Change
 ------
 Thread::setPriority() will no longer set a realtime scheduling policy for all

modules/juce_opengl/opengl/juce_gl.cpp

@@ -3784,7 +3784,9 @@
     JUCE_GL_FUNCTIONS_GL_VERSION_4_3_DYNAMIC \
     JUCE_GL_FUNCTIONS_GL_VERSION_4_4_DYNAMIC \
     JUCE_GL_FUNCTIONS_GL_VERSION_4_5_DYNAMIC \
-    JUCE_GL_FUNCTIONS_GL_VERSION_4_6_DYNAMIC \
+    JUCE_GL_FUNCTIONS_GL_VERSION_4_6_DYNAMIC
+
+#define JUCE_EXTENSION_GL_FUNCTIONS \
     JUCE_GL_FUNCTIONS_GL_3DFX_tbuffer \
     JUCE_GL_FUNCTIONS_GL_AMD_debug_output \
     JUCE_GL_FUNCTIONS_GL_AMD_draw_buffers_blend \
@@ -4049,6 +4051,7 @@ JUCE_STATIC_GL_FUNCTIONS
     static returns (KHRONOS_APIENTRY* juce_ ## name) params = nullptr; \
     returns (KHRONOS_APIENTRY* const& ::juce::gl::name) params = juce_ ## name;
 JUCE_DYNAMIC_GL_FUNCTIONS
+JUCE_EXTENSION_GL_FUNCTIONS
 #undef X
 
 void juce::gl::loadFunctions()
@@ -4059,5 +4062,14 @@ void juce::gl::loadFunctions()
    #undef X
 }
 
+void juce::gl::loadExtensions()
+{
+   #define X(returns, name, params) \
+       juce_ ## name = reinterpret_cast<returns (KHRONOS_APIENTRY*) params> (::juce::OpenGLHelpers::getExtensionFunction (#name));
+    JUCE_EXTENSION_GL_FUNCTIONS
+   #undef X
+}
+
 #undef JUCE_STATIC_GL_FUNCTIONS
 #undef JUCE_DYNAMIC_GL_FUNCTIONS
+#undef JUCE_EXTENSION_GL_FUNCTIONS

modules/juce_opengl/opengl/juce_gl.h

@@ -11990,7 +11990,19 @@ enum : GLenum
 #endif
 
 
+/** Load all available functions from the OpenGL core API.
+
+    This will not load extensions!
+*/
 void loadFunctions();
 
+/** Load all available OpenGL extension functions.
+
+    It's probably a good idea to stick to the core API as much as possible.
+    Extensions are not as portable, and it can be a little time-consuming to
+    load all of the extension entry-points.
+*/
+void loadExtensions();
+
 }
 }

modules/juce_opengl/opengl/juce_gles2.cpp

@@ -1253,7 +1253,9 @@
     JUCE_GL_FUNCTIONS_GL_ES_VERSION_2_0_DYNAMIC \
     JUCE_GL_FUNCTIONS_GL_ES_VERSION_3_0_DYNAMIC \
     JUCE_GL_FUNCTIONS_GL_ES_VERSION_3_1_DYNAMIC \
-    JUCE_GL_FUNCTIONS_GL_ES_VERSION_3_2_DYNAMIC \
+    JUCE_GL_FUNCTIONS_GL_ES_VERSION_3_2_DYNAMIC
+
+#define JUCE_EXTENSION_GL_FUNCTIONS \
     JUCE_GL_FUNCTIONS_GL_AMD_framebuffer_multisample_advanced \
     JUCE_GL_FUNCTIONS_GL_AMD_performance_monitor \
     JUCE_GL_FUNCTIONS_GL_ANGLE_framebuffer_blit \
@@ -1392,6 +1394,7 @@ JUCE_STATIC_GL_FUNCTIONS
     static returns (KHRONOS_APIENTRY* juce_ ## name) params = nullptr; \
     returns (KHRONOS_APIENTRY* const& ::juce::gl::name) params = juce_ ## name;
 JUCE_DYNAMIC_GL_FUNCTIONS
+JUCE_EXTENSION_GL_FUNCTIONS
 #undef X
 
 void juce::gl::loadFunctions()
@@ -1402,5 +1405,14 @@ void juce::gl::loadFunctions()
    #undef X
 }
 
+void juce::gl::loadExtensions()
+{
+   #define X(returns, name, params) \
+       juce_ ## name = reinterpret_cast<returns (KHRONOS_APIENTRY*) params> (::juce::OpenGLHelpers::getExtensionFunction (#name));
+    JUCE_EXTENSION_GL_FUNCTIONS
+   #undef X
+}
+
 #undef JUCE_STATIC_GL_FUNCTIONS
 #undef JUCE_DYNAMIC_GL_FUNCTIONS
+#undef JUCE_EXTENSION_GL_FUNCTIONS

modules/juce_opengl/opengl/juce_gles2.h

@@ -5252,7 +5252,19 @@ enum : GLenum
 #endif
 
 
+/** Load all available functions from the OpenGL core API.
+
+    This will not load extensions!
+*/
 void loadFunctions();
 
+/** Load all available OpenGL extension functions.
+
+    It's probably a good idea to stick to the core API as much as possible.
+    Extensions are not as portable, and it can be a little time-consuming to
+    load all of the extension entry-points.
+*/
+void loadExtensions();
+
 }
 }