Basic feature implemented. Needs improvement.

src/laybasic/laybasic/layLayoutCanvas.cc

@@ -151,6 +151,7 @@ LayoutCanvas::LayoutCanvas (lay::LayoutViewBase *view)
     m_background (0), m_foreground (0), m_active (0),
     m_oversampling (1),
     m_hrm (false),
+    m_srm (false),
     m_need_redraw (false),
     m_redraw_clearing (false),
     m_redraw_force_update (true),
@@ -201,11 +202,7 @@ LayoutCanvas::~LayoutCanvas ()
 double
 LayoutCanvas::resolution () const
 {
-  if (m_hrm) {
-    return 1.0 / m_oversampling;
-  } else {
-    return 1.0 / (m_oversampling * dpr ());
-  }
+  return (m_srm ? 1.0 : 1.0 / m_oversampling) * (m_hrm ? 1.0 : 1.0 / dpr ());
 }
 
 #if defined(HAVE_QT)
@@ -283,6 +280,16 @@ LayoutCanvas::set_highres_mode (bool hrm)
   }
 }
 
+void
+LayoutCanvas::set_subres_mode (bool srm)
+{
+  if (srm != m_srm) {
+    m_image_cache.clear ();
+    m_srm = srm;
+    do_redraw_all ();
+  }
+}
+
 double
 LayoutCanvas::dpr () const
 {

src/laybasic/laybasic/layLayoutCanvas.h

@@ -277,6 +277,19 @@ public:
     return m_hrm;
   }
 
+  /**
+   *  @brief Set sub resolution mode (sub-pixel resolution in oversampling mode)
+   */
+  void set_subres_mode (bool srm);
+
+  /**
+   *  @brief Gets the sub resolution mode flag
+   */
+  bool subres_mode () const
+  {
+    return m_srm;
+  }
+
   /**
    *  @brief Gets the default device pixel ratio for this canvas
    */
@@ -412,6 +425,7 @@ private:
   std::map<unsigned int, std::vector <lay::ViewOp> > m_scaled_view_ops;
   unsigned int m_oversampling;
   bool m_hrm;
+  bool m_srm;
   double m_gamma;
 
   bool m_need_redraw;

src/laybasic/laybasic/layLayoutViewBase.cc

@@ -790,6 +790,13 @@ LayoutViewBase::configure (const std::string &name, const std::string &value)
     mp_canvas->set_highres_mode (hrm);
     return true;
 
+  } else if (name == cfg_subres_mode) {
+
+    bool srm = false;
+    tl::from_string (value, srm);
+    mp_canvas->set_subres_mode (srm);
+    return true;
+
   } else if (name == cfg_image_cache_size) {
 
     int sz = 0;

src/laybasic/laybasic/layLayoutViewConfig.cc

@@ -114,6 +114,7 @@ public:
     options.push_back (std::pair<std::string, std::string> (cfg_array_border_instances, "false"));
     options.push_back (std::pair<std::string, std::string> (cfg_bitmap_oversampling, "1"));
     options.push_back (std::pair<std::string, std::string> (cfg_highres_mode, "false"));
+    options.push_back (std::pair<std::string, std::string> (cfg_subres_mode, "false"));
     options.push_back (std::pair<std::string, std::string> (cfg_image_cache_size, "1"));
     options.push_back (std::pair<std::string, std::string> (cfg_default_font_size, "0"));
     options.push_back (std::pair<std::string, std::string> (cfg_color_palette, lay::ColorPalette ().to_string ()));

src/laybasic/laybasic/laybasicConfig.h

@@ -126,6 +126,7 @@ static const std::string cfg_tip_window_hidden ("tip-window-hidden");
 
 static const std::string cfg_bitmap_oversampling ("bitmap-oversampling");
 static const std::string cfg_highres_mode ("highres-mode");
+static const std::string cfg_subres_mode ("subres-mode");
 static const std::string cfg_image_cache_size ("image-cache-size");
 static const std::string cfg_default_font_size ("default-font-size");