OpenGL examples: Add error message about ANGLE on Windows

These OpenGL examples require a Desktop OpenGL and will
not build with OpenGL ES 2.0. This means those examples
do not build on Windows with the default configuration
using ANGLE.
ANGLE is wrapping OpenGL ES 2.0 to DirectX and does not support
the full Desktop OpenGL feature set.

Since this is confusing for Windows users that do not know about ANGLE
this patch adds an explicit error message describing the solution.
(configuring Qt with -opengl desktop)

Task-number: QTBUG-28590

Change-Id: I782e6830b9e282ddcc8a2ee0a47faf3579d36aab
Reviewed-by: hjk <[email protected]>
Reviewed-by: Oswald Buddenhagen <[email protected]>

7 files changed, 42 insertions, 0 deletions

diff --git a/examples/opengl/framebufferobject2/framebufferobject2.pro b/examples/opengl/framebufferobject2/framebufferobject2.pro
index d26751ab0e1..3a0dbb4446b 100644
--- a/examples/opengl/framebufferobject2/framebufferobject2.pro
+++ b/examples/opengl/framebufferobject2/framebufferobject2.pro
@@ -10,3 +10,9 @@ INSTALLS += target
 
 
 simulator: warning(This example might not fully work on Simulator platform)
+
+contains(QT_CONFIG, opengles.) {
+    contains(QT_CONFIG, angle): \
+        warning("Qt was built with ANGLE, which provides only OpenGL ES 2.0 on top of DirectX 9.0c")
+    error("This example requires Qt to be configured with -opengl desktop")
+}
diff --git a/examples/opengl/grabber/grabber.pro b/examples/opengl/grabber/grabber.pro
index a60dbbe2dc6..c4c54c7c325 100644
--- a/examples/opengl/grabber/grabber.pro
+++ b/examples/opengl/grabber/grabber.pro
@@ -11,3 +11,9 @@ INSTALLS += target
 
 
 simulator: warning(This example might not fully work on Simulator platform)
+
+contains(QT_CONFIG, opengles.) {
+    contains(QT_CONFIG, angle): \
+        warning("Qt was built with ANGLE, which provides only OpenGL ES 2.0 on top of DirectX 9.0c")
+    error("This example requires Qt to be configured with -opengl desktop")
+}
diff --git a/examples/opengl/hellogl/hellogl.pro b/examples/opengl/hellogl/hellogl.pro
index acaca356350..42913835a21 100644
--- a/examples/opengl/hellogl/hellogl.pro
+++ b/examples/opengl/hellogl/hellogl.pro
@@ -16,3 +16,9 @@ INSTALLS += target
 
 
 simulator: warning(This example might not fully work on Simulator platform)
+
+contains(QT_CONFIG, opengles.) {
+    contains(QT_CONFIG, angle): \
+        warning("Qt was built with ANGLE, which provides only OpenGL ES 2.0 on top of DirectX 9.0c")
+    error("This example requires Qt to be configured with -opengl desktop")
+}
diff --git a/examples/opengl/overpainting/overpainting.pro b/examples/opengl/overpainting/overpainting.pro
index 08fe9b3dae7..141c8cb7ce5 100644
--- a/examples/opengl/overpainting/overpainting.pro
+++ b/examples/opengl/overpainting/overpainting.pro
@@ -15,3 +15,9 @@ target.path = $$[QT_INSTALL_EXAMPLES]/opengl/overpainting
 INSTALLS += target
 
 simulator: warning(This example might not fully work on Simulator platform)
+
+contains(QT_CONFIG, opengles.) {
+    contains(QT_CONFIG, angle): \
+        warning("Qt was built with ANGLE, which provides only OpenGL ES 2.0 on top of DirectX 9.0c")
+    error("This example requires Qt to be configured with -opengl desktop")
+}
diff --git a/examples/opengl/pbuffers/pbuffers.pro b/examples/opengl/pbuffers/pbuffers.pro
index 1a9882c45d8..57bb3aa32ab 100644
--- a/examples/opengl/pbuffers/pbuffers.pro
+++ b/examples/opengl/pbuffers/pbuffers.pro
@@ -11,3 +11,9 @@ target.path = $$[QT_INSTALL_EXAMPLES]/opengl/pbuffers
 INSTALLS += target
 
 simulator: warning(This example might not fully work on Simulator platform)
+
+contains(QT_CONFIG, opengles.) {
+    contains(QT_CONFIG, angle): \
+        warning("Qt was built with ANGLE, which provides only OpenGL ES 2.0 on top of DirectX 9.0c")
+    error("This example requires Qt to be configured with -opengl desktop")
+}
diff --git a/examples/opengl/pbuffers2/pbuffers2.pro b/examples/opengl/pbuffers2/pbuffers2.pro
index 31fd22cced3..c53309d1fa5 100644
--- a/examples/opengl/pbuffers2/pbuffers2.pro
+++ b/examples/opengl/pbuffers2/pbuffers2.pro
@@ -9,3 +9,9 @@ target.path = $$[QT_INSTALL_EXAMPLES]/opengl/pbuffers2
 INSTALLS += target
 
 simulator: warning(This example might not fully work on Simulator platform)
+
+contains(QT_CONFIG, opengles.) {
+    contains(QT_CONFIG, angle): \
+        warning("Qt was built with ANGLE, which provides only OpenGL ES 2.0 on top of DirectX 9.0c")
+    error("This example requires Qt to be configured with -opengl desktop")
+}
diff --git a/examples/opengl/samplebuffers/samplebuffers.pro b/examples/opengl/samplebuffers/samplebuffers.pro
index 5793ea3e68f..d16993adfe4 100644
--- a/examples/opengl/samplebuffers/samplebuffers.pro
+++ b/examples/opengl/samplebuffers/samplebuffers.pro
@@ -9,3 +9,9 @@ INSTALLS += target
 
 
 simulator: warning(This example might not fully work on Simulator platform)
+
+contains(QT_CONFIG, opengles.) {
+    contains(QT_CONFIG, angle): \
+        warning("Qt was built with ANGLE, which provides only OpenGL ES 2.0 on top of DirectX 9.0c")
+    error("This example requires Qt to be configured with -opengl desktop")
+}