1 files changed, 108 insertions, 0 deletions
diff --git a/src/gl/vertex_array.h b/src/gl/vertex_array.h
new file mode 100644
index 0000000..5799c60
--- /dev/null
+++ b/src/gl/vertex_array.h
@@ -0,0 +1,108 @@
+// 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.
+
+// Vertex array objects.
+
+#ifndef GLPLANET_SRC_GL_VERTEX_ARRAY_H_
+#define GLPLANET_SRC_GL_VERTEX_ARRAY_H_
+
+#include <stdint.h>
+
+#include <utility>
+
+#include "src/gl/buffer.h"
+#include "src/gl/error.h"
+#include "third_party/abseil/absl/types/optional.h"
+#include "third_party/glew/include/GL/glew.h"
+
+namespace gl {
+
+enum class VertexAttributeType : GLenum {
+  kByte = GL_BYTE,
+  kShort = GL_SHORT,
+  kInt = GL_INT,
+  kFixed = GL_FIXED,
+  kFloat = GL_FLOAT,
+  kHalfFloat = GL_HALF_FLOAT,
+  kDouble = GL_DOUBLE,
+  kUnsignedByte = GL_UNSIGNED_BYTE,
+  kUnsignedShort = GL_UNSIGNED_SHORT,
+  kUnsignedInt = GL_UNSIGNED_INT,
+  kInt2x10x10x10Rev = GL_INT_2_10_10_10_REV,
+  kUnsignedInt2x10x10x10Rev = GL_UNSIGNED_INT_2_10_10_10_REV,
+  kUnsignedInt10f11f11fRev = GL_UNSIGNED_INT_10F_11F_11F_REV,
+};
+
+// A VAO.
+class VertexArray final {
+ public:
+  explicit VertexArray() noexcept(!(gl_internal::kThreadSafetyChecks ||
+                                    gl_internal::kAggressiveErrorChecking)) {
+    gl_internal::CheckThreadSafety();
+    glCreateVertexArrays(1, &array_);
+    gl_internal::UnnecessaryErrorCheck();
+  }
+
+  VertexArray(VertexArray&&) noexcept = default;
+  VertexArray& operator=(VertexArray&&) noexcept = default;
+
+  ~VertexArray() noexcept(!(gl_internal::kThreadSafetyChecks ||
+                            gl_internal::kAggressiveErrorChecking)) {
+    gl_internal::CheckThreadSafety();
+    glDeleteVertexArrays(1, &array_);
+    gl_internal::UnnecessaryErrorCheck();
+  }
+
+  // Attaches the specified vertex buffer to the VAO.
+  void SetVertexBuffer(VertexBuffer vertices) {
+    gl_internal::CheckThreadSafety();
+    glVertexArrayVertexBuffer(array_, /*bindingindex=*/0, vertices.id(),
+                              /*offset=*/0, vertices.element_size());
+    // This error check is necessary because the elements of the VBO might be
+    // too large for the implementation to handle.
+    gl_internal::ErrorCheck();
+    vertices_ = std::move(vertices);
+  }
+
+  // Specifies the organization of data in the attached VAO.
+  void SetVertexAttributeFormat(int index, int size, VertexAttributeType type,
+                                int offset, bool normalized = false);
+
+  // Attaches the specified element buffer to the VAO. The element buffer must
+  // outlive this VAO.
+  void SetElementBuffer(ElementBuffer elements) noexcept(
+      !(gl_internal::kThreadSafetyChecks ||
+        gl_internal::kAggressiveErrorChecking)) {
+    gl_internal::CheckThreadSafety();
+    glVertexArrayElementBuffer(array_, elements.id());
+    gl_internal::UnnecessaryErrorCheck();
+    elements_ = std::move(elements);
+  }
+
+  // Returns the element buffer attached to this VAO.
+  const ElementBuffer& element_buffer() const noexcept { return elements_; }
+
+  // The GL identifier for this VAO.
+  unsigned int id() const noexcept { return array_; }
+
+ private:
+  GLuint array_;
+
+  VertexBuffer vertices_;
+  ElementBuffer elements_;
+};
+
+}  // namespace gl
+
+#endif  // GLPLANET_SRC_GL_VERTEX_ARRAY_H_