From 59be110c100df4ab8c4aa35cea9def0e43f30e18 Mon Sep 17 00:00:00 2001
From: Dan Paulat <dpaulat@gmail.com>
Date: Fri, 23 Jul 2021 21:30:51 -0500
Subject: [PATCH] Creating OpenGL utility class, consolidating number of OpenGL
 function objects

---
 scwx-qt/scwx-qt.cmake                         |  3 +-
 scwx-qt/source/scwx/qt/map/map_widget.cpp     | 76 ++++++++++++-------
 scwx-qt/source/scwx/qt/map/map_widget.hpp     | 11 +--
 scwx-qt/source/scwx/qt/map/radar_layer.cpp    | 28 ++++---
 scwx-qt/source/scwx/qt/map/radar_layer.hpp    |  4 +-
 scwx-qt/source/scwx/qt/map/triangle_layer.cpp | 21 ++---
 scwx-qt/source/scwx/qt/map/triangle_layer.hpp |  8 +-
 scwx-qt/source/scwx/qt/util/gl.hpp            | 23 ++++++
 .../source/scwx/qt/util/shader_program.cpp    | 15 ++--
 .../source/scwx/qt/util/shader_program.hpp    |  8 +-
 10 files changed, 124 insertions(+), 73 deletions(-)
 create mode 100644 scwx-qt/source/scwx/qt/util/gl.hpp

diff --git a/scwx-qt/scwx-qt.cmake b/scwx-qt/scwx-qt.cmake
index bf1a19d8..57d1d123 100644
--- a/scwx-qt/scwx-qt.cmake
+++ b/scwx-qt/scwx-qt.cmake
@@ -59,7 +59,8 @@ set(SRC_MAP source/scwx/qt/map/map_widget.cpp
             source/scwx/qt/map/radar_layer.cpp
             source/scwx/qt/map/radar_range_layer.cpp
             source/scwx/qt/map/triangle_layer.cpp)
-set(HDR_UTIL source/scwx/qt/util/shader_program.hpp)
+set(HDR_UTIL source/scwx/qt/util/gl.hpp
+             source/scwx/qt/util/shader_program.hpp)
 set(SRC_UTIL source/scwx/qt/util/shader_program.cpp)
 
 set(RESOURCE_FILES scwx-qt.qrc)
diff --git a/scwx-qt/source/scwx/qt/map/map_widget.cpp b/scwx-qt/source/scwx/qt/map/map_widget.cpp
index 67b7b928..4f75673f 100644
--- a/scwx-qt/source/scwx/qt/map/map_widget.cpp
+++ b/scwx-qt/source/scwx/qt/map/map_widget.cpp
@@ -2,6 +2,7 @@
 
 #include <scwx/qt/map/radar_layer.hpp>
 #include <scwx/qt/map/radar_range_layer.hpp>
+#include <scwx/qt/util/gl.hpp>
 
 #include <QApplication>
 #include <QColor>
@@ -31,7 +32,27 @@ static const MapStyle satelliteStreets { "mapbox://styles/mapbox/satellite-stree
 static const std::array<MapStyle, 6> mapboxStyles_ = {
    {streets, outdoors, light, dark, satellite, satelliteStreets}};
 
-MapWidget::MapWidget(const QMapboxGLSettings& settings) : settings_(settings)
+class MapWidgetImpl
+{
+public:
+   explicit MapWidgetImpl(const QMapboxGLSettings& settings) :
+       gl_(), settings_(settings), map_(), lastPos_(), frameDraws_(0)
+   {
+   }
+   ~MapWidgetImpl() = default;
+
+   OpenGLFunctions gl_;
+
+   QMapboxGLSettings          settings_;
+   std::shared_ptr<QMapboxGL> map_;
+
+   QPointF lastPos_;
+
+   uint64_t frameDraws_;
+};
+
+MapWidget::MapWidget(const QMapboxGLSettings& settings) :
+    p(std::make_unique<MapWidgetImpl>(settings))
 {
    setFocusPolicy(Qt::StrongFocus);
 }
@@ -54,7 +75,7 @@ void MapWidget::changeStyle()
 
    auto& styles = mapboxStyles_;
 
-   map_->setStyleUrl(styles[currentStyleIndex].first.c_str());
+   p->map_->setStyleUrl(styles[currentStyleIndex].first.c_str());
    setWindowTitle(QString("Mapbox GL: ") +
                   styles[currentStyleIndex].second.c_str());
 
@@ -68,11 +89,11 @@ void MapWidget::AddLayers()
 {
    // QMapboxGL::addCustomLayer will take ownership of the QScopedPointer
    QScopedPointer<QMapbox::CustomLayerHostInterface> pHost(
-      new RadarLayer(map_));
+      new RadarLayer(p->map_, p->gl_));
 
    QString before = "ferry";
 
-   for (const QString& layer : map_->layerIds())
+   for (const QString& layer : p->map_->layerIds())
    {
       // Draw below tunnels, ferries and roads
       if (layer.startsWith("tunnel") || layer.startsWith("ferry") ||
@@ -83,8 +104,8 @@ void MapWidget::AddLayers()
       }
    }
 
-   map_->addCustomLayer("radar", pHost, before);
-   RadarRangeLayer::Add(map_, before);
+   p->map_->addCustomLayer("radar", pHost, before);
+   RadarRangeLayer::Add(p->map_, before);
 }
 
 void MapWidget::keyPressEvent(QKeyEvent* ev)
@@ -94,7 +115,7 @@ void MapWidget::keyPressEvent(QKeyEvent* ev)
    case Qt::Key_S: changeStyle(); break;
    case Qt::Key_L:
    {
-      for (const QString& layer : map_->layerIds())
+      for (const QString& layer : p->map_->layerIds())
       {
          qDebug() << "Layer: " << layer;
       }
@@ -108,7 +129,7 @@ void MapWidget::keyPressEvent(QKeyEvent* ev)
 
 void MapWidget::mousePressEvent(QMouseEvent* ev)
 {
-   lastPos_ = ev->position();
+   p->lastPos_ = ev->position();
 
    if (ev->type() == QEvent::MouseButtonPress)
    {
@@ -122,11 +143,11 @@ void MapWidget::mousePressEvent(QMouseEvent* ev)
    {
       if (ev->buttons() == Qt::LeftButton)
       {
-         map_->scaleBy(2.0, lastPos_);
+         p->map_->scaleBy(2.0, p->lastPos_);
       }
       else if (ev->buttons() == Qt::RightButton)
       {
-         map_->scaleBy(0.5, lastPos_);
+         p->map_->scaleBy(0.5, p->lastPos_);
       }
    }
 
@@ -135,26 +156,26 @@ void MapWidget::mousePressEvent(QMouseEvent* ev)
 
 void MapWidget::mouseMoveEvent(QMouseEvent* ev)
 {
-   QPointF delta = ev->position() - lastPos_;
+   QPointF delta = ev->position() - p->lastPos_;
 
    if (!delta.isNull())
    {
       if (ev->buttons() == Qt::LeftButton &&
           ev->modifiers() & Qt::ShiftModifier)
       {
-         map_->pitchBy(delta.y());
+         p->map_->pitchBy(delta.y());
       }
       else if (ev->buttons() == Qt::LeftButton)
       {
-         map_->moveBy(delta);
+         p->map_->moveBy(delta);
       }
       else if (ev->buttons() == Qt::RightButton)
       {
-         map_->rotateBy(lastPos_, ev->position());
+         p->map_->rotateBy(p->lastPos_, ev->position());
       }
    }
 
-   lastPos_ = ev->position();
+   p->lastPos_ = ev->position();
    ev->accept();
 }
 
@@ -171,18 +192,21 @@ void MapWidget::wheelEvent(QWheelEvent* ev)
       factor = factor > -1 ? factor : 1 / factor;
    }
 
-   map_->scaleBy(1 + factor, ev->position());
+   p->map_->scaleBy(1 + factor, ev->position());
 
    ev->accept();
 }
 
 void MapWidget::initializeGL()
 {
-   map_.reset(new QMapboxGL(nullptr, settings_, size(), pixelRatio()));
-   connect(map_.get(), SIGNAL(needsRendering()), this, SLOT(update()));
+   makeCurrent();
+   p->gl_.initializeOpenGLFunctions();
+
+   p->map_.reset(new QMapboxGL(nullptr, p->settings_, size(), pixelRatio()));
+   connect(p->map_.get(), SIGNAL(needsRendering()), this, SLOT(update()));
 
    // Set default location to KLSX.
-   map_->setCoordinateZoom(QMapbox::Coordinate(38.6986, -90.6828), 11);
+   p->map_->setCoordinateZoom(QMapbox::Coordinate(38.6986, -90.6828), 11);
 
    QString styleUrl = qgetenv("MAPBOX_STYLE_URL");
    if (styleUrl.isEmpty())
@@ -191,20 +215,20 @@ void MapWidget::initializeGL()
    }
    else
    {
-      map_->setStyleUrl(styleUrl);
+      p->map_->setStyleUrl(styleUrl);
       setWindowTitle(QString("Mapbox GL: ") + styleUrl);
    }
 
-   connect(map_.get(), &QMapboxGL::mapChanged, this, &MapWidget::mapChanged);
+   connect(p->map_.get(), &QMapboxGL::mapChanged, this, &MapWidget::mapChanged);
 }
 
 void MapWidget::paintGL()
 {
-   frameDraws_++;
-   map_->resize(size());
-   map_->setFramebufferObject(defaultFramebufferObject(),
-                              size() * pixelRatio());
-   map_->render();
+   p->frameDraws_++;
+   p->map_->resize(size());
+   p->map_->setFramebufferObject(defaultFramebufferObject(),
+                                 size() * pixelRatio());
+   p->map_->render();
 }
 
 void MapWidget::mapChanged(QMapboxGL::MapChange mapChange)
diff --git a/scwx-qt/source/scwx/qt/map/map_widget.hpp b/scwx-qt/source/scwx/qt/map/map_widget.hpp
index 43837088..6d7f5cb5 100644
--- a/scwx-qt/source/scwx/qt/map/map_widget.hpp
+++ b/scwx-qt/source/scwx/qt/map/map_widget.hpp
@@ -17,12 +17,14 @@ namespace scwx
 namespace qt
 {
 
+class MapWidgetImpl;
+
 class MapWidget : public QOpenGLWidget
 {
    Q_OBJECT
 
 public:
-   MapWidget(const QMapboxGLSettings&);
+   explicit MapWidget(const QMapboxGLSettings&);
    ~MapWidget();
 
 private:
@@ -41,12 +43,7 @@ private:
 
    void AddLayers();
 
-   QPointF lastPos_;
-
-   QMapboxGLSettings          settings_;
-   std::shared_ptr<QMapboxGL> map_;
-
-   uint64_t frameDraws_ = 0;
+   std::unique_ptr<MapWidgetImpl> p;
 
 private slots:
    void mapChanged(QMapboxGL::MapChange);
diff --git a/scwx-qt/source/scwx/qt/map/radar_layer.cpp b/scwx-qt/source/scwx/qt/map/radar_layer.cpp
index 39c2357e..6be1840a 100644
--- a/scwx-qt/source/scwx/qt/map/radar_layer.cpp
+++ b/scwx-qt/source/scwx/qt/map/radar_layer.cpp
@@ -3,8 +3,6 @@
 
 #include <execution>
 
-#include <QOpenGLFunctions_3_3_Core>
-
 #include <boost/log/trivial.hpp>
 #include <boost/range/irange.hpp>
 #include <boost/timer/timer.hpp>
@@ -30,10 +28,11 @@ LatLongToScreenCoordinate(const QMapbox::Coordinate& coordinate);
 class RadarLayerImpl
 {
 public:
-   explicit RadarLayerImpl(std::shared_ptr<QMapboxGL> map) :
+   explicit RadarLayerImpl(std::shared_ptr<QMapboxGL> map,
+                           OpenGLFunctions&           gl) :
        map_(map),
-       gl_(),
-       shaderProgram_(),
+       gl_(gl),
+       shaderProgram_(gl),
        uMVPMatrixLocation_(GL_INVALID_INDEX),
        uMapScreenCoordLocation_(GL_INVALID_INDEX),
        vbo_ {GL_INVALID_INDEX},
@@ -42,13 +41,12 @@ public:
        bearing_ {0.0},
        numVertices_ {0}
    {
-      gl_.initializeOpenGLFunctions();
    }
    ~RadarLayerImpl() = default;
 
    std::shared_ptr<QMapboxGL> map_;
 
-   QOpenGLFunctions_3_3_Core gl_;
+   OpenGLFunctions& gl_;
 
    ShaderProgram shaderProgram_;
    GLint         uMVPMatrixLocation_;
@@ -62,8 +60,8 @@ public:
    GLsizeiptr numVertices_;
 };
 
-RadarLayer::RadarLayer(std::shared_ptr<QMapboxGL> map) :
-    p(std::make_unique<RadarLayerImpl>(map))
+RadarLayer::RadarLayer(std::shared_ptr<QMapboxGL> map, OpenGLFunctions& gl) :
+    p(std::make_unique<RadarLayerImpl>(map, gl))
 {
 }
 RadarLayer::~RadarLayer() = default;
@@ -75,7 +73,7 @@ void RadarLayer::initialize()
 {
    BOOST_LOG_TRIVIAL(debug) << logPrefix_ << "initialize()";
 
-   QOpenGLFunctions_3_3_Core& gl = p->gl_;
+   OpenGLFunctions& gl = p->gl_;
 
    boost::timer::cpu_timer timer;
 
@@ -134,7 +132,7 @@ void RadarLayer::initialize()
       });
    timer.stop();
    BOOST_LOG_TRIVIAL(debug)
-      << "Coordinates calculated in " << timer.format(6, "%ws");
+      << logPrefix_ << "Coordinates calculated in " << timer.format(6, "%ws");
 
    // Calculate vertices
    static std::array<GLfloat, MAX_RADIALS * MAX_DATA_MOMENT_GATES * 6 * 2>
@@ -185,7 +183,7 @@ void RadarLayer::initialize()
    }
    timer.stop();
    BOOST_LOG_TRIVIAL(debug)
-      << "Vertices calculated in " << timer.format(6, "%ws");
+      << logPrefix_ << "Vertices calculated in " << timer.format(6, "%ws");
 
    // Generate a vertex buffer object
    gl.glGenBuffers(1, &p->vbo_);
@@ -205,7 +203,7 @@ void RadarLayer::initialize()
                    GL_STATIC_DRAW);
    timer.stop();
    BOOST_LOG_TRIVIAL(debug)
-      << "Vertices buffered in " << timer.format(6, "%ws");
+      << logPrefix_ << "Vertices buffered in " << timer.format(6, "%ws");
 
    // Set the vertex attributes pointers
    gl.glVertexAttribPointer(
@@ -218,7 +216,7 @@ void RadarLayer::initialize()
 
 void RadarLayer::render(const QMapbox::CustomLayerRenderParameters& params)
 {
-   QOpenGLFunctions_3_3_Core& gl = p->gl_;
+   OpenGLFunctions& gl = p->gl_;
 
    p->shaderProgram_.Use();
 
@@ -249,7 +247,7 @@ void RadarLayer::render(const QMapbox::CustomLayerRenderParameters& params)
 
 void RadarLayer::deinitialize()
 {
-   QOpenGLFunctions_3_3_Core& gl = p->gl_;
+   OpenGLFunctions& gl = p->gl_;
 
    BOOST_LOG_TRIVIAL(debug) << logPrefix_ << "deinitialize()";
 
diff --git a/scwx-qt/source/scwx/qt/map/radar_layer.hpp b/scwx-qt/source/scwx/qt/map/radar_layer.hpp
index c8c3eac0..dce792dc 100644
--- a/scwx-qt/source/scwx/qt/map/radar_layer.hpp
+++ b/scwx-qt/source/scwx/qt/map/radar_layer.hpp
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <scwx/qt/util/gl.hpp>
+
 #include <QMapboxGL>
 
 namespace scwx
@@ -12,7 +14,7 @@ class RadarLayerImpl;
 class RadarLayer : public QMapbox::CustomLayerHostInterface
 {
 public:
-   explicit RadarLayer(std::shared_ptr<QMapboxGL> map);
+   explicit RadarLayer(std::shared_ptr<QMapboxGL> map, OpenGLFunctions& gl);
    ~RadarLayer();
 
    RadarLayer(const RadarLayer&) = delete;
diff --git a/scwx-qt/source/scwx/qt/map/triangle_layer.cpp b/scwx-qt/source/scwx/qt/map/triangle_layer.cpp
index 79c0d191..5b52c342 100644
--- a/scwx-qt/source/scwx/qt/map/triangle_layer.cpp
+++ b/scwx-qt/source/scwx/qt/map/triangle_layer.cpp
@@ -1,7 +1,5 @@
 #include <scwx/qt/map/triangle_layer.hpp>
 
-#include <QOpenGLFunctions_3_3_Core>
-
 #include <boost/log/trivial.hpp>
 
 namespace scwx
@@ -9,13 +7,13 @@ namespace scwx
 namespace qt
 {
 
-static const std::string logPrefix_ = "[scwx::map::triangle_layer] ";
+static const std::string logPrefix_ = "[scwx::qt::map::triangle_layer] ";
 
 class TriangleLayerImpl
 {
 public:
-   explicit TriangleLayerImpl() :
-       gl_(),
+   explicit TriangleLayerImpl(OpenGLFunctions& gl) :
+       gl_(gl),
        shaderProgram_ {GL_INVALID_INDEX},
        vbo_ {GL_INVALID_INDEX},
        vao_ {GL_INVALID_INDEX}
@@ -24,14 +22,17 @@ public:
    }
    ~TriangleLayerImpl() = default;
 
-   QOpenGLFunctions_3_3_Core gl_;
+   OpenGLFunctions& gl_;
 
    GLuint shaderProgram_;
    GLuint vbo_;
    GLuint vao_;
 };
 
-TriangleLayer::TriangleLayer() : p(std::make_unique<TriangleLayerImpl>()) {}
+TriangleLayer::TriangleLayer(OpenGLFunctions& gl) :
+    p(std::make_unique<TriangleLayerImpl>(gl))
+{
+}
 TriangleLayer::~TriangleLayer() = default;
 
 TriangleLayer::TriangleLayer(TriangleLayer&&) noexcept = default;
@@ -39,7 +40,7 @@ TriangleLayer& TriangleLayer::operator=(TriangleLayer&&) noexcept = default;
 
 void TriangleLayer::initialize()
 {
-   QOpenGLFunctions_3_3_Core& gl = p->gl_;
+   OpenGLFunctions& gl = p->gl_;
 
    static const char* vertexShaderSource =
       "#version 330 core\n"
@@ -141,7 +142,7 @@ void TriangleLayer::initialize()
 
 void TriangleLayer::render(const QMapbox::CustomLayerRenderParameters&)
 {
-   QOpenGLFunctions_3_3_Core& gl = p->gl_;
+   OpenGLFunctions& gl = p->gl_;
 
    gl.glUseProgram(p->shaderProgram_);
    gl.glBindVertexArray(p->vao_);
@@ -150,7 +151,7 @@ void TriangleLayer::render(const QMapbox::CustomLayerRenderParameters&)
 
 void TriangleLayer::deinitialize()
 {
-   QOpenGLFunctions_3_3_Core& gl = p->gl_;
+   OpenGLFunctions& gl = p->gl_;
 
    BOOST_LOG_TRIVIAL(debug) << logPrefix_ << "deinitialize()";
 
diff --git a/scwx-qt/source/scwx/qt/map/triangle_layer.hpp b/scwx-qt/source/scwx/qt/map/triangle_layer.hpp
index 7020f4b7..e62701c3 100644
--- a/scwx-qt/source/scwx/qt/map/triangle_layer.hpp
+++ b/scwx-qt/source/scwx/qt/map/triangle_layer.hpp
@@ -1,4 +1,8 @@
-#include <qmapboxgl.hpp>
+#pragma once
+
+#include <scwx/qt/util/gl.hpp>
+
+#include <QMapboxGL>
 
 namespace scwx
 {
@@ -10,7 +14,7 @@ class TriangleLayerImpl;
 class TriangleLayer : public QMapbox::CustomLayerHostInterface
 {
 public:
-   explicit TriangleLayer();
+   explicit TriangleLayer(OpenGLFunctions& gl);
    ~TriangleLayer();
 
    TriangleLayer(const TriangleLayer&) = delete;
diff --git a/scwx-qt/source/scwx/qt/util/gl.hpp b/scwx-qt/source/scwx/qt/util/gl.hpp
new file mode 100644
index 00000000..26e11ef5
--- /dev/null
+++ b/scwx-qt/source/scwx/qt/util/gl.hpp
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <QOpenGLFunctions_3_3_Core>
+
+#define SCWX_GL_CHECK_ERROR()                                                  \
+   {                                                                           \
+      GLenum err;                                                              \
+      while ((err = p->gl_.glGetError()) != GL_NO_ERROR)                       \
+      {                                                                        \
+         BOOST_LOG_TRIVIAL(warning) << logPrefix_ << "GL Error: " << err       \
+                                    << ", " __FILE__ << ":" << __LINE__;       \
+      }                                                                        \
+   }
+
+namespace scwx
+{
+namespace qt
+{
+
+using OpenGLFunctions = QOpenGLFunctions_3_3_Core;
+
+} // namespace qt
+} // namespace scwx
diff --git a/scwx-qt/source/scwx/qt/util/shader_program.cpp b/scwx-qt/source/scwx/qt/util/shader_program.cpp
index 7c00d824..1b707360 100644
--- a/scwx-qt/source/scwx/qt/util/shader_program.cpp
+++ b/scwx-qt/source/scwx/qt/util/shader_program.cpp
@@ -1,7 +1,6 @@
 #include <scwx/qt/util/shader_program.hpp>
 
 #include <QFile>
-#include <QOpenGLFunctions_3_3_Core>
 
 #include <boost/log/trivial.hpp>
 
@@ -15,10 +14,9 @@ static const std::string logPrefix_ = "[scwx::qt::util::shader_program] ";
 class ShaderProgramImpl
 {
 public:
-   explicit ShaderProgramImpl() : gl_(), id_ {GL_INVALID_INDEX}
+   explicit ShaderProgramImpl(OpenGLFunctions& gl) :
+       gl_(gl), id_ {GL_INVALID_INDEX}
    {
-      gl_.initializeOpenGLFunctions();
-
       // Create shader program
       id_ = gl_.glCreateProgram();
    }
@@ -29,12 +27,15 @@ public:
       gl_.glDeleteProgram(id_);
    }
 
-   QOpenGLFunctions_3_3_Core gl_;
+   OpenGLFunctions& gl_;
 
    GLuint id_;
 };
 
-ShaderProgram::ShaderProgram() : p(std::make_unique<ShaderProgramImpl>()) {}
+ShaderProgram::ShaderProgram(OpenGLFunctions& gl) :
+    p(std::make_unique<ShaderProgramImpl>(gl))
+{
+}
 ShaderProgram::~ShaderProgram() = default;
 
 ShaderProgram::ShaderProgram(ShaderProgram&&) noexcept = default;
@@ -50,7 +51,7 @@ bool ShaderProgram::Load(const std::string& vertexPath,
 {
    BOOST_LOG_TRIVIAL(debug) << logPrefix_ << "Load()";
 
-   QOpenGLFunctions_3_3_Core& gl = p->gl_;
+   OpenGLFunctions& gl = p->gl_;
 
    GLint glSuccess;
    bool  success = true;
diff --git a/scwx-qt/source/scwx/qt/util/shader_program.hpp b/scwx-qt/source/scwx/qt/util/shader_program.hpp
index 0703ed68..a10a6f12 100644
--- a/scwx-qt/source/scwx/qt/util/shader_program.hpp
+++ b/scwx-qt/source/scwx/qt/util/shader_program.hpp
@@ -1,14 +1,14 @@
 #pragma once
 
+#include <scwx/qt/util/gl.hpp>
+
 #ifdef _WIN32
-#include <Windows.h>
+#   include <Windows.h>
 #endif
 
 #include <memory>
 #include <string>
 
-#include <GL/gl.h>
-
 namespace scwx
 {
 namespace qt
@@ -19,7 +19,7 @@ class ShaderProgramImpl;
 class ShaderProgram
 {
 public:
-   explicit ShaderProgram();
+   explicit ShaderProgram(OpenGLFunctions& gl);
    ~ShaderProgram();
 
    ShaderProgram(const ShaderProgram&) = delete;