Poll for openGL errors.

src/glutils.cpp

@@ -111,3 +111,17 @@ void fmri::renderText(std::string_view text)
         glutBitmapCharacter(font, c);
     }
 }
+
+void fmri::checkGLErrors()
+{
+    while (auto error = glGetError()) {
+        switch (glGetError()) {
+            case GL_NO_ERROR:
+                // Should not get here, but whatever.
+                return;
+
+            default:
+                cerr << "OpenGL error: " << (const char*) glewGetErrorString(error) << endl;
+        }
+    }
+}

src/glutils.hpp

@@ -41,4 +41,9 @@ namespace fmri {
      * @param text The text to draw.
      */
     void renderText(std::string_view text);
+
+    /**
+     * Check if there are OpenGL errors and report them.
+     */
+    void checkGLErrors();
 }

src/main.cpp

@@ -110,6 +110,11 @@ static void updateVisualisers(unsigned int dataset)
     }
 }
 
+static void idleFunc()
+{
+    checkGLErrors();
+}
+
 int main(int argc, char *argv[])
 {
     google::InitGoogleLogging(argv[0]);
@@ -126,7 +131,7 @@ int main(int argc, char *argv[])
 
     // Register callbacks
     glutDisplayFunc(render);
-    glutIdleFunc(glutPostRedisplay);
+    glutIdleFunc(idleFunc);
     glutReshapeFunc(changeWindowSize);
 
     Camera::instance().registerControls();