Fix JPEGFrameView behavior with Qt DPI scaling.

diff --git a/jpeg_frame_view.cpp b/jpeg_frame_view.cpp
index 1c48d186574ec520725f020190216a7a05a07916..73030ffa2ce02a2b53f5ae23eef3f4b77eb66d22 100644 (file)
--- a/jpeg_frame_view.cpp
+++ b/jpeg_frame_view.cpp
@@ -12,6 +12,7 @@
 #include <utility>
 
 #include <QMouseEvent>
+#include <QScreen>
 
 #include <movit/resource_pool.h>
 #include <movit/init.h>
@@ -324,8 +325,8 @@ void JPEGFrameView::initializeGL()
        chain->finalize();
        check_error();
 
-       overlay_chain.reset(new EffectChain(overlay_width, overlay_height, resource_pool));
-       overlay_input = (movit::FlatInput *)overlay_chain->add_input(new FlatInput(image_format, FORMAT_GRAYSCALE, GL_UNSIGNED_BYTE, overlay_width, overlay_height));
+       overlay_chain.reset(new EffectChain(overlay_base_width, overlay_base_height, resource_pool));
+       overlay_input = (movit::FlatInput *)overlay_chain->add_input(new FlatInput(image_format, FORMAT_GRAYSCALE, GL_UNSIGNED_BYTE, overlay_base_width, overlay_base_height));
 
        overlay_chain->add_output(inout_format, OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED);
        overlay_chain->finalize();
@@ -336,11 +337,15 @@ void JPEGFrameView::resizeGL(int width, int height)
        check_error();
        glViewport(0, 0, width, height);
        check_error();
+
+       // Save these, as width() and height() will lie with DPI scaling.
+       gl_width = width;
+       gl_height = height;
 }
 
 void JPEGFrameView::paintGL()
 {
-       glViewport(0, 0, width(), height());
+       glViewport(0, 0, gl_width, gl_height);
        if (current_frame == nullptr) {
                glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
                glClear(GL_COLOR_BUFFER_BIT);
@@ -352,9 +357,11 @@ void JPEGFrameView::paintGL()
 
        if (overlay_image != nullptr) {
                if (overlay_input_needs_refresh) {
+                       overlay_input->set_width(overlay_width);
+                       overlay_input->set_height(overlay_height);
                        overlay_input->set_pixel_data(overlay_image->bits());
                }
-               glViewport(width() - overlay_width, 0, overlay_width, overlay_height);
+               glViewport(gl_width - overlay_width, 0, overlay_width, overlay_height);
                overlay_chain->render_to_screen();
        }
 }
@@ -392,7 +399,12 @@ void JPEGFrameView::set_overlay(const string &text)
                return;
        }
 
+       float dpr = QGuiApplication::primaryScreen()->devicePixelRatio();
+       overlay_width = lrint(overlay_base_width * dpr);
+       overlay_height = lrint(overlay_base_height * dpr);
+
        overlay_image.reset(new QImage(overlay_width, overlay_height, QImage::Format_Grayscale8));
+       overlay_image->setDevicePixelRatio(dpr);
        overlay_image->fill(0);
        QPainter painter(overlay_image.get());
 
@@ -401,7 +413,7 @@ void JPEGFrameView::set_overlay(const string &text)
        font.setPointSize(12);
        painter.setFont(font);
 
-       painter.drawText(QRectF(0, 0, overlay_width, overlay_height), Qt::AlignCenter, QString::fromStdString(text));
+       painter.drawText(QRectF(0, 0, overlay_base_width, overlay_base_height), Qt::AlignCenter, QString::fromStdString(text));
 
        // Don't refresh immediately; we might not have an OpenGL context here.
        overlay_input_needs_refresh = true;

diff --git a/jpeg_frame_view.h b/jpeg_frame_view.h
index 5ef68d01cb56d50ef7b1677455e2a7fc75fad4a0..585417279ca8ebcfbbed1263abcdcfb6d3f7bbc3 100644 (file)
--- a/jpeg_frame_view.h
+++ b/jpeg_frame_view.h
@@ -65,11 +65,14 @@ private:
        movit::YCbCrInput *ycbcr_input;
        movit::YCbCrFormat ycbcr_format;
 
-       static constexpr int overlay_width = 16, overlay_height = 16;
+       static constexpr int overlay_base_width = 16, overlay_base_height = 16;
+       int overlay_width = overlay_base_width, overlay_height = overlay_base_height;
        std::unique_ptr<QImage> overlay_image;  // If nullptr, no overlay.
        std::unique_ptr<movit::EffectChain> overlay_chain;  // Just to get the overlay on screen in the easiest way possible.
        movit::FlatInput *overlay_input;
        bool overlay_input_needs_refresh = false;
+
+       int gl_width, gl_height;
 };
 
 #endif  // !defined(_JPEG_FRAME_VIEW_H)