foundations for background caching

app/render/renderinstance.cpp

@@ -0,0 +1,79 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2019 Olive Team
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+***/
+
+#include "renderinstance.h"
+
+#include <QDebug>
+
+RenderInstance::RenderInstance(const int& width,
+                               const int& height,
+                               const olive::PixelFormat& format,
+                               const olive::RenderMode& mode) :
+  width_(width),
+  height_(height),
+  format_(format),
+  mode_(mode)
+{
+}
+
+bool RenderInstance::Start()
+{
+  // Create OpenGL context (automatically destroys any existing if there is one)
+  if (!ctx_.create()) {
+    qWarning() << tr("Failed to create OpenGL context in thread %1").arg(reinterpret_cast<quintptr>(this));
+    return false;
+  }
+
+  // Create offscreen surface
+  surface_.create();
+
+  // Make context current on that surface
+  if (!ctx_.makeCurrent(&surface_)) {
+    qWarning() << tr("Failed to makeCurrent() on offscreen surface in thread %1").arg(reinterpret_cast<quintptr>(this));
+    surface_.destroy();
+    return false;
+  }
+
+  buffer_.Create(&ctx_, format_, width_, height_);
+
+  return true;
+}
+
+void RenderInstance::Stop()
+{
+  // Destroy buffer
+  buffer_.Destroy();
+
+  // Release OpenGL context
+  ctx_.doneCurrent();
+
+  // Destroy offscreen surface
+  surface_.destroy();
+}
+
+bool RenderInstance::IsStarted()
+{
+  return buffer_.IsCreated();
+}
+
+TextureBuffer *RenderInstance::buffer()
+{
+  return &buffer_;
+}