glplanet, an OpenGL-based planetary rendererHEADmain

glplanet draws Earth like it currently appears from space, putting
nighttime areas in shadow and daytime areas in light. It’s modeled
after Xplanet (http://xplanet.sourceforge.net/), but whereas Xplanet is
entirely a CPU-resident program, glplanet draws using OpenGL. It’s thus
much less resource-intensive, particularly when using high-resolution
textures.

1 files changed, 68 insertions, 0 deletions

diff --git a/src/gl/error.h b/src/gl/error.h
new file mode 100644
index 0000000..a56bae9
--- /dev/null
+++ b/src/gl/error.h
@@ -0,0 +1,68 @@
+// Copyright 2021 Benjamin Barenblat
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+// Error handling and thread-safety checking.
+
+#ifndef GLPLANET_SRC_GL_ERROR_H_
+#define GLPLANET_SRC_GL_ERROR_H_
+
+namespace gl_internal {
+
+#ifdef GLPLANET_DISABLE_GL_THREAD_SAFETY_CHECKS
+constexpr bool kThreadSafetyChecks = false;
+#else
+constexpr bool kThreadSafetyChecks = true;
+#endif
+
+#ifdef GLPLANET_DISABLE_AGGRESSIVE_ERROR_CHECKING
+constexpr bool kAggressiveErrorChecking = false;
+#else
+constexpr bool kAggressiveErrorChecking = true;
+#endif
+
+#ifndef GLPLANET_DISABLE_GL_THREAD_SAFETY_CHECKS
+
+void RecordThreadImpl();
+
+void CheckThreadSafetyImpl();
+
+#endif
+
+// Records the calling thread as the OpenGL thread.
+inline void RecordThread() noexcept(!kThreadSafetyChecks) {
+#ifndef GLPLANET_DISABLE_GL_THREAD_SAFETY_CHECKS
+  RecordThreadImpl();
+#endif
+}
+
+// Throws std::logic_error if the current thread is not the OpenGL thread.
+inline void CheckThreadSafety() noexcept(!kThreadSafetyChecks) {
+#ifndef GLPLANET_DISABLE_GL_THREAD_SAFETY_CHECKS
+  CheckThreadSafetyImpl();
+#endif
+}
+
+// Checks the GL state for errors and throws if an error is present.
+void ErrorCheck();
+
+// As ErrorCheck, but disabled by GLPLANET_DISABLE_AGGRESSIVE_ERROR_CHECKING.
+inline void UnnecessaryErrorCheck() noexcept(!kAggressiveErrorChecking) {
+  if constexpr (kAggressiveErrorChecking) {
+    ErrorCheck();
+  }
+}
+
+}  // namespace gl_internal
+
+#endif  // GLPLANET_SRC_GL_ERROR_H_