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, 43 insertions, 0 deletions

diff --git a/src/gl/texture.cc b/src/gl/texture.cc
new file mode 100644
index 0000000..cd877c9
--- /dev/null
+++ b/src/gl/texture.cc
@@ -0,0 +1,43 @@
+// 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.
+
+#include "src/gl/texture.h"
+
+#include <stdexcept>
+
+#include "src/gl/error.h"
+#include "src/util.h"
+#include "third_party/abseil/absl/strings/str_cat.h"
+#include "third_party/glew/include/GL/glew.h"
+
+namespace gl {
+
+void Texture2d::LoadSubimage(int width, int height, PixelFormat format,
+                             PixelType type, const void* pixels, int level) {
+  gl_internal::CheckThreadSafety();
+
+  if (level >= levels_) {
+    throw std::invalid_argument(
+        absl::StrCat("GL: invalid texture subimage level $0; maximum is $1",
+                     level, levels_ - 1));
+  }
+
+  glTextureSubImage2D(texture_, level, /*xoffset=*/0, /*yoffset=*/0, width,
+                      height, FromEnum(format), FromEnum(type), pixels);
+  // This error check is necessary for a variety of reasons, including a
+  // type/format mismatch.
+  gl_internal::ErrorCheck();
+}
+
+}  // namespace gl