[core] separate Backend from View for headless rendering

5 files changed, 65 insertions, 34 deletions

diff --git a/platform/qt/config.cmake b/platform/qt/config.cmake
index d8ede6b450..6df311f885 100644
--- a/platform/qt/config.cmake
+++ b/platform/qt/config.cmake
@@ -43,8 +43,10 @@ endmacro()
 macro(mbgl_platform_test)
     target_sources(mbgl-test
         PRIVATE test/src/main.cpp
+        PRIVATE platform/qt/test/headless_backend_qt.cpp
         PRIVATE platform/qt/test/headless_view_qt.cpp
         PRIVATE platform/qt/test/qmapboxgl.cpp
+        PRIVATE platform/default/headless_backend.cpp
         PRIVATE platform/default/headless_display.cpp
         PRIVATE platform/default/headless_view.cpp
     )
diff --git a/platform/qt/src/qmapboxgl.cpp b/platform/qt/src/qmapboxgl.cpp
index d0a05301f8..73a1771908 100644
--- a/platform/qt/src/qmapboxgl.cpp
+++ b/platform/qt/src/qmapboxgl.cpp
@@ -813,7 +813,7 @@ QMapboxGLPrivate::QMapboxGLPrivate(QMapboxGL *q, const QMapboxGLSettings &settin
         settings.cacheDatabaseMaximumSize()))
     , threadPool(4)
     , mapObj(std::make_unique<mbgl::Map>(
-        *this, *fileSourceObj, threadPool,
+        *this, *this, getPixelRatio(), *fileSourceObj, threadPool,
         static_cast<mbgl::MapMode>(settings.mapMode()),
         static_cast<mbgl::GLContextMode>(settings.contextMode()),
         static_cast<mbgl::ConstrainMode>(settings.constrainMode()),
@@ -845,6 +845,11 @@ float QMapboxGLPrivate::getPixelRatio() const
     return pixelRatio;
 }
 
+void QMapboxGLPrivate::bind()
+{
+    MBGL_CHECK_ERROR(glBindFramebuffer(GL_FRAMEBUFFER, 0));
+}
+
 std::array<uint16_t, 2> QMapboxGLPrivate::getSize() const
 {
     return {{ static_cast<uint16_t>(size.width()), static_cast<uint16_t>(size.height()) }};
diff --git a/platform/qt/src/qmapboxgl_p.hpp b/platform/qt/src/qmapboxgl_p.hpp
index c35ac4e7ba..5a228896dc 100644
--- a/platform/qt/src/qmapboxgl_p.hpp
+++ b/platform/qt/src/qmapboxgl_p.hpp
@@ -3,6 +3,7 @@
 #include "qmapboxgl.hpp"
 
 #include <mbgl/map/map.hpp>
+#include <mbgl/map/backend.hpp>
 #include <mbgl/map/view.hpp>
 #include <mbgl/platform/default/thread_pool.hpp>
 #include <mbgl/storage/default_file_source.hpp>
@@ -11,7 +12,7 @@
 #include <QObject>
 #include <QSize>
 
-class QMapboxGLPrivate : public QObject, public mbgl::View
+class QMapboxGLPrivate : public QObject, public mbgl::View, public mbgl::Backend
 {
     Q_OBJECT
 
@@ -20,7 +21,8 @@ public:
     virtual ~QMapboxGLPrivate();
 
     // mbgl::View implementation.
-    float getPixelRatio() const final;
+    float getPixelRatio() const;
+    void bind() final;
     std::array<uint16_t, 2> getSize() const final;
     std::array<uint16_t, 2> getFramebufferSize() const final;
 
diff --git a/platform/qt/test/headless_backend_qt.cpp b/platform/qt/test/headless_backend_qt.cpp
new file mode 100644
index 0000000000..3f287ae578
--- /dev/null
+++ b/platform/qt/test/headless_backend_qt.cpp
@@ -0,0 +1,46 @@
+#include <mbgl/platform/default/headless_backend.hpp>
+#include <mbgl/platform/default/headless_display.hpp>
+
+#include <QApplication>
+#include <QGLContext>
+#include <QGLWidget>
+
+#if QT_VERSION >= 0x050000
+#include <QOpenGLContext>
+#endif
+
+namespace mbgl {
+
+gl::glProc HeadlessBackend::initializeExtension(const char* name) {
+#if QT_VERSION >= 0x050000
+        QOpenGLContext* thisContext = QOpenGLContext::currentContext();
+        return thisContext->getProcAddress(name);
+#else
+        const QGLContext* thisContext = QGLContext::currentContext();
+        return reinterpret_cast<mbgl::gl::glProc>(thisContext->getProcAddress(name));
+#endif
+}
+
+void HeadlessBackend::createContext() {
+    static const char* argv[] = { "mbgl" };
+    static int argc = 1;
+    static auto* app = new QApplication(argc, const_cast<char**>(argv));
+
+    Q_UNUSED(app);
+
+    glContext = new QGLWidget;
+}
+
+void HeadlessBackend::destroyContext() {
+    delete glContext;
+}
+
+void HeadlessBackend::activateContext() {
+    glContext->makeCurrent();
+}
+
+void HeadlessBackend::deactivateContext() {
+    glContext->doneCurrent();
+}
+
+} // namespace mbgl
diff --git a/platform/qt/test/headless_view_qt.cpp b/platform/qt/test/headless_view_qt.cpp
index 03ecb741ab..133b4a2371 100644
--- a/platform/qt/test/headless_view_qt.cpp
+++ b/platform/qt/test/headless_view_qt.cpp
@@ -1,6 +1,7 @@
-#include <mbgl/platform/default/headless_display.hpp>
 #include <mbgl/platform/default/headless_view.hpp>
 
+#include <mbgl/gl/gl.hpp>
+
 #include <QApplication>
 #include <QGLContext>
 #include <QGLWidget>
@@ -9,30 +10,13 @@
 #include <QOpenGLContext>
 #endif
 
-namespace mbgl {
-
-gl::glProc HeadlessView::initializeExtension(const char* name) {
-#if QT_VERSION >= 0x050000
-        QOpenGLContext* thisContext = QOpenGLContext::currentContext();
-        return thisContext->getProcAddress(name);
-#else
-        const QGLContext* thisContext = QGLContext::currentContext();
-        return reinterpret_cast<mbgl::gl::glProc>(thisContext->getProcAddress(name));
-#endif
-}
-
-void HeadlessView::createContext() {
-    static const char* argv[] = { "mbgl" };
-    static int argc = 1;
-    static auto* app = new QApplication(argc, const_cast<char**>(argv));
-
-    Q_UNUSED(app);
+#include <cassert>
 
-    glContext = new QGLWidget;
-}
+namespace mbgl {
 
-void HeadlessView::destroyContext() {
-    delete glContext;
+void HeadlessView::bindFramebuffer() {
+    assert(fbo);
+    MBGL_CHECK_ERROR(glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo));
 }
 
 void HeadlessView::resizeFramebuffer() {
@@ -95,12 +79,4 @@ void HeadlessView::clearBuffers() {
     }
 }
 
-void HeadlessView::activateContext() {
-    glContext->makeCurrent();
-}
-
-void HeadlessView::deactivateContext() {
-    glContext->doneCurrent();
-}
-
 } // namespace mbgl