external: provide the GL_VERSION_* defines in our GL headers.

This fixes a conflicting definition of GLsizeiptr and GLintptr when
Magnum is combined with qopengl.h from Qt on Windows. Khronos has it as
`signed long int`, whereas qopengl.h as ptrdiff_t, which is just `int`.

doc/changelog.dox

@@ -264,6 +264,9 @@ See also:
     for Emscripten (see [mosra/magnum#219](https://github.com/mosra/magnum/issues/219))
 -   Updated the Vcpkg package to work correctly with Vcpkg's own SDL2 (see
     [Microsoft/vcpkg#5730](https://github.com/Microsoft/vcpkg/pull/5730))
+-   Updated bundled GL headers to properly define the `GL_VERSION_*` macros to
+    avoid conflicting `GLintptr` and `GLsizeiptr` type definitions on Windows
+    when using Magnum together with Qt
 
 @subsection changelog-latest-bugfixes Bug fixes
 

src/MagnumExternal/OpenGL/GL/flextGL.h

@@ -93,6 +93,29 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+#define GL_VERSION_1_0 1
+#define GL_VERSION_1_1 1
+#define GL_VERSION_1_2 1
+#define GL_VERSION_1_3 1
+#define GL_VERSION_1_4 1
+#define GL_VERSION_1_5 1
+#define GL_VERSION_2_0 1
+#define GL_VERSION_2_1 1
+#define GL_VERSION_3_0 1
+#define GL_VERSION_3_1 1
+#define GL_VERSION_3_2 1
+#define GL_VERSION_3_3 1
+#define GL_VERSION_4_0 1
+#define GL_VERSION_4_1 1
+#define GL_VERSION_4_2 1
+#define GL_VERSION_4_3 1
+#define GL_VERSION_4_4 1
+#define GL_VERSION_4_5 1
+#define GL_VERSION_4_6 1
+
 /* Data types */
 
 #include <KHR/khrplatform.h>

src/MagnumExternal/OpenGL/GL/flextGL.h.template

@@ -94,6 +94,15 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+@for cat,_ in functions:
+@if cat.startswith('VERSION_'):
+#define GL_@cat 1
+@endif
+@end
+
 /* Data types */
 
 @passthru

src/MagnumExternal/OpenGL/GLES2/Emscripten/flextGLEmscripten.h.template

@@ -56,6 +56,15 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+@for cat,_ in functions:
+@if cat.startswith('ES_VERSION_'):
+#define GL_@cat 1
+@endif
+@end
+
 /* Data types */
 
 @passthru

src/MagnumExternal/OpenGL/GLES2/flextGL.h

@@ -80,6 +80,11 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+#define GL_ES_VERSION_2_0 1
+
 /* Data types */
 
 #include <KHR/khrplatform.h>

src/MagnumExternal/OpenGL/GLES2/flextGL.h.template

@@ -81,6 +81,15 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+@for cat,_ in functions:
+@if cat.startswith('ES_VERSION_'):
+#define GL_@cat 1
+@endif
+@end
+
 /* Data types */
 
 @passthru

src/MagnumExternal/OpenGL/GLES2/flextGLEmscripten.h

@@ -55,6 +55,11 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+#define GL_ES_VERSION_2_0 1
+
 /* Data types */
 
 #include <KHR/khrplatform.h>

src/MagnumExternal/OpenGL/GLES3/Emscripten/flextGLEmscripten.h.template

@@ -61,6 +61,15 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+@for cat,_ in functions:
+@if cat.startswith('ES_VERSION_'):
+#define GL_@cat 1
+@endif
+@end
+
 /* Data types */
 
 @passthru

src/MagnumExternal/OpenGL/GLES3/flextGL.h

@@ -84,6 +84,14 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+#define GL_ES_VERSION_2_0 1
+#define GL_ES_VERSION_3_0 1
+#define GL_ES_VERSION_3_1 1
+#define GL_ES_VERSION_3_2 1
+
 /* Data types */
 
 #include <KHR/khrplatform.h>

src/MagnumExternal/OpenGL/GLES3/flextGL.h.template

@@ -85,6 +85,15 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+@for cat,_ in functions:
+@if cat.startswith('ES_VERSION_'):
+#define GL_@cat 1
+@endif
+@end
+
 /* Data types */
 
 @passthru

src/MagnumExternal/OpenGL/GLES3/flextGLEmscripten.h

@@ -60,6 +60,12 @@ void flextGLInit(Magnum::GL::Context& context);
 #define GLAPI extern
 #endif
 
+/* GL version defines. Needs to be done to avoid conflicting definitions with
+   other GL headers (such as qopengl.h in Qt, which has different definition
+   for GLsizei and GLintptr on Windows) */
+#define GL_ES_VERSION_2_0 1
+#define GL_ES_VERSION_3_0 1
+
 /* Data types */
 
 #include <KHR/khrplatform.h>