Extend sub-pixel rendering support (#2609)

Implements sub-pixel rendering support for the SDL2 renderer. Achieved by replacing drawing functions in `SDLPainter` with their `float` equivalents.

Additionally, the `DrawingContext` size getters now return floating-point values, since before, they would always return an integer value, which didn't account for possible floating-point scale values of the current transform. This helps fix various other graphical glitches.

Fixes #2422.

src/control/mobile_controller.cpp

@@ -84,10 +84,12 @@ MobileController::draw(DrawingContext& context)
   if (!g_config->mobile_controls)
     return;
 
-  if (m_screen_width != context.get_width() || m_screen_height != context.get_height() || m_mobile_controls_scale != g_config->m_mobile_controls_scale)
+  if (m_screen_width != static_cast<int>(context.get_width()) ||
+      m_screen_height != static_cast<int>(context.get_height()) ||
+      m_mobile_controls_scale != g_config->m_mobile_controls_scale)
   {
-    m_screen_width = context.get_width();
-    m_screen_height = context.get_height();
+    m_screen_width = static_cast<int>(context.get_width());
+    m_screen_height = static_cast<int>(context.get_height());
     float width = static_cast<float>(m_screen_width);
     float height = static_cast<float>(m_screen_height);
     m_mobile_controls_scale = g_config->m_mobile_controls_scale;

src/editor/overlay_widget.cpp

@@ -1353,8 +1353,8 @@ EditorOverlayWidget::draw_tile_grid(DrawingContext& context, int tile_size,
   int tm_height = current_tm->get_height() * (32 / tile_size);
   auto cam_translation = m_editor.get_sector()->get_camera().get_translation();
   Rectf draw_rect = Rectf(cam_translation, cam_translation +
-                          Vector(static_cast<float>(context.get_width() - 128),
-                                 static_cast<float>(context.get_height() - 32)));
+                          Vector(context.get_width() - 128.f,
+                                 context.get_height() - 32.f));
   Vector start = sp_to_tp( Vector(draw_rect.get_left(), draw_rect.get_top()), tile_size );
   Vector end = sp_to_tp( Vector(draw_rect.get_right(), draw_rect.get_bottom()), tile_size );
   start.x = std::max(0.0f, start.x);

src/editor/toolbox_widget.cpp

@@ -76,8 +76,8 @@ EditorToolboxWidget::draw(DrawingContext& context)
 {
   //SCREEN_WIDTH SCREEN_HEIGHT
   context.color().draw_filled_rect(Rectf(Vector(static_cast<float>(m_Xpos), 0),
-                                         Vector(static_cast<float>(context.get_width()),
-                                                static_cast<float>(context.get_height()))),
+                                         Vector(context.get_width(),
+                                                context.get_height())),
                                      g_config->editorcolor,
                                      0.0f, LAYER_GUI-10);
   if (m_dragging) {
@@ -97,10 +97,10 @@ EditorToolboxWidget::draw(DrawingContext& context)
   }
 
   context.color().draw_text(Resources::normal_font, _("Tiles"),
-                            Vector(static_cast<float>(context.get_width()), 5),
+                            Vector(context.get_width(), 5),
                             ALIGN_RIGHT, LAYER_GUI, ColorScheme::Menu::default_color);
   context.color().draw_text(Resources::normal_font, _("Objects"),
-                            Vector(static_cast<float>(context.get_width()), 37),
+                            Vector(context.get_width(), 37),
                             ALIGN_RIGHT, LAYER_GUI, ColorScheme::Menu::default_color);
 
   m_rubber->draw(context);

src/gui/dialog.cpp

@@ -189,11 +189,11 @@ void
 Dialog::draw(DrawingContext& context)
 {
   Rectf bg_rect(Vector(static_cast<float>(m_passive ?
-                                          (static_cast<float>(context.get_width()) - m_text_size.width - 20.0f) :
-                                          static_cast<float>(context.get_width()) / 2.0f - m_text_size.width / 2.0f),
+                                          (context.get_width() - m_text_size.width - 20.0f) :
+                                          context.get_width() / 2.0f - m_text_size.width / 2.0f),
                        static_cast<float>(m_passive ?
-                                          (static_cast<float>(context.get_height()) - m_text_size.height - 65.0f) :
-                                          (static_cast<float>(context.get_height()) / 2.0f - m_text_size.height / 2.0f))),
+                                          (context.get_height() - m_text_size.height - 65.0f) :
+                                          (context.get_height() / 2.0f - m_text_size.height / 2.0f))),
                 m_size);
 
   // Draw background rect.

src/gui/notification.cpp

@@ -97,7 +97,7 @@ Notification::draw(DrawingContext& context)
     return;
   }
 
-  m_pos = Vector(static_cast<float>(context.get_width()) - std::max(m_text_size.width, m_mini_text_size.width) - 90.0f,
+  m_pos = Vector(context.get_width() - std::max(m_text_size.width, m_mini_text_size.width) - 90.0f,
                  static_cast<float>(context.get_height() / 12) - m_text_size.height - m_mini_text_size.height + 10.0f);
   Rectf bg_rect(m_pos, m_size);
 

src/interface/control_scrollbar.cpp

@@ -31,7 +31,6 @@ ControlScrollbar::ControlScrollbar() :
   m_covered_region(),
   m_progress(),
   m_rect(),
-  m_scaled_rect(),
   //is_horizontal(),
   last_mouse_pos()
   //zoom_factor()
@@ -43,7 +42,7 @@ ControlScrollbar::ControlScrollbar() :
 void
 ControlScrollbar::draw(DrawingContext& context)
 {
-  m_rect = Rect(0, 0, 10, context.get_height());
+  m_rect = Rectf(0, 0, 10, context.get_height());
 
   context.color().draw_filled_rect(m_rect, Color(0.5f, 0.5f, 0.5f, 1.f), 8, LAYER_GUI);
   context.color().draw_filled_rect(get_bar_rect(),
@@ -86,7 +85,7 @@ ControlScrollbar::on_mouse_button_down(const SDL_MouseButtonEvent& button)
 {
   if (button.button == SDL_BUTTON_LEFT) {
     Vector mouse_pos = VideoSystem::current()->get_viewport().to_logical(button.x, button.y);
-    if (get_bar_rect().contains(int(mouse_pos.x), int(mouse_pos.y))) {
+    if (get_bar_rect().contains(mouse_pos)) {
       m_scrolling = true;
       return true;
     } else {
@@ -112,7 +111,7 @@ ControlScrollbar::on_mouse_motion(const SDL_MouseMotionEvent& motion)
     }
   }*/
 
-  m_hovering = get_bar_rect().contains(int(mouse_pos.x), int(mouse_pos.y));
+  m_hovering = get_bar_rect().contains(mouse_pos);
 
   int new_progress = m_progress + int((mouse_pos.y - last_mouse_pos) * VideoSystem::current()->get_viewport().get_scale().y * float(m_total_region) / float(m_covered_region));
   last_mouse_pos = mouse_pos.y;
@@ -129,22 +128,20 @@ ControlScrollbar::on_mouse_motion(const SDL_MouseMotionEvent& motion)
   }
 }
 
-Rect
+Rectf
 ControlScrollbar::get_bar_rect()
 {
-  return Rect(m_rect.left,
-              m_rect.top + int(float(m_progress)
-                             * float(m_covered_region)
-                             / float(m_total_region)
-                           ),
-              m_rect.right,
-              m_rect.top + int(float(m_progress)
-                             * float(m_covered_region)
-                             / float(m_total_region))
-                         + int(float(m_rect.get_height())
-                             * float(m_covered_region)
-                             / float(m_total_region)
-                           )
+  return Rectf(m_rect.get_left(),
+               m_rect.get_top() + static_cast<float>(m_progress)
+                                * static_cast<float>(m_covered_region)
+                                / static_cast<float>(m_total_region),
+               m_rect.get_right(),
+               m_rect.get_top() + static_cast<float>(m_progress)
+                                * static_cast<float>(m_covered_region)
+                                / static_cast<float>(m_total_region)
+                          + m_rect.get_height()
+                          * static_cast<float>(m_covered_region)
+                          / static_cast<float>(m_total_region)
              );
 }
 

src/interface/control_scrollbar.hpp

@@ -18,7 +18,8 @@
 #define HEADER_SUPERTUX_INTERFACE_CONTROL_SCROLLBAR_HPP
 
 #include "editor/widget.hpp"
-#include "math/rect.hpp"
+
+#include "math/rectf.hpp"
 #include "math/vector.hpp"
 
 class DrawingContext;
@@ -54,16 +55,13 @@ class ControlScrollbar final : public Widget
   int m_progress;
 
   /** The logical position and size of the widget */
-  Rect m_rect;
-
-  /** The position and size of the widget, to scale */
-  Rect m_scaled_rect;
+  Rectf m_rect;
 
   /** `true` of the scroller is horizontal; `false` if it is vertical */
   //bool is_horizontal;
 
 private:
-  Rect get_bar_rect();
+  Rectf get_bar_rect();
 
   float last_mouse_pos;
   //float zoom_factor;

src/math/rect.cpp

@@ -28,6 +28,13 @@ Rect::Rect(const Rectf& other) :
 {
 }
 
+Rectf
+Rect::to_rectf() const
+{
+  return { static_cast<float>(left), static_cast<float>(top),
+           static_cast<float>(get_width()), static_cast<float>(get_height()) };
+}
+
 std::ostream& operator<<(std::ostream& out, const Rect& rect)
 {
   out << "Rect("

src/math/rect.hpp

@@ -98,6 +98,11 @@ class Rect final
             top <= other.top && other.bottom <= bottom);
   }
 
+  const int& get_left() const { return left; }
+  const int& get_right() const { return right; }
+  const int& get_top() const { return top; }
+  const int& get_bottom() const { return bottom; }
+
   int get_width()  const { return right - left; }
   int get_height() const { return bottom - top; }
   Size get_size() const { return Size(right - left, bottom - top); }
@@ -138,9 +143,10 @@ class Rect final
                 bottom + border);
   }
 
+  Rectf to_rectf() const;
   SDL_Rect to_sdl() const
   {
-    return {left, top, get_width(), get_height()};
+    return { left, top, get_width(), get_height() };
   }
 
   bool operator<(const Rect& other) const {

src/math/rectf.cpp

@@ -44,6 +44,13 @@ Rectf::initialize()
   }
 }
 
+Rect
+Rectf::to_rect() const
+{
+  return { static_cast<int>(m_p1.x), static_cast<int>(m_p1.y),
+           static_cast<int>(m_size.width), static_cast<int>(m_size.height) };
+}
+
 std::ostream& operator<<(std::ostream& out, const Rectf& rect)
 {
   out << "Rectf("

src/math/rectf.hpp

@@ -20,6 +20,8 @@
 #include <assert.h>
 #include <iosfwd>
 
+#include <SDL.h>
+
 #include "math/anchor_point.hpp"
 #include "math/sizef.hpp"
 #include "math/vector.hpp"
@@ -69,6 +71,12 @@ class Rectf final
     initialize();
   }
 
+  Rectf(const SDL_FRect& rect) :
+    m_p1(rect.x, rect.y), m_size(rect.w, rect.h)
+  {
+    initialize();
+  }
+
   Rectf(const Rect& rect);
 
   bool operator==(const Rectf& other) const
@@ -125,6 +133,12 @@ class Rectf final
   }
   Sizef get_size() const { return m_size; }
 
+  bool empty() const
+  {
+    return get_width() <= 0 ||
+           get_height() <= 0;
+  }
+
   void move(const Vector& v) { m_p1 += v; }
   Rectf moved(const Vector& v) const { return Rectf(m_p1 + v, m_size); }
 
@@ -179,6 +193,12 @@ class Rectf final
                    p.y - m_p1.y);
   }
 
+  Rect to_rect() const;
+  SDL_FRect to_sdl() const
+  {
+    return { m_p1.x, m_p1.y, m_size.width, m_size.height };
+  }
+
 private:
   /// upper left edge
   Vector m_p1;

src/object/background.cpp

@@ -279,8 +279,8 @@ void
 Background::draw_image(DrawingContext& context, const Vector& pos_)
 {
   const Sizef level(d_gameobject_manager->get_width(), d_gameobject_manager->get_height());
-  const Sizef screen(static_cast<float>(context.get_width()),
-                     static_cast<float>(context.get_height()));
+  const Sizef screen(context.get_width(),
+                     context.get_height());
   const Sizef parallax_image_size((1.0f - m_parallax_speed.x) * screen.width + level.width * m_parallax_speed.x,
                                   (1.0f - m_parallax_speed.y) * screen.height + level.height * m_parallax_speed.y);
 
@@ -301,10 +301,10 @@ Background::draw_image(DrawingContext& context, const Vector& pos_)
 
   if (m_fill)
   {
-    Rectf dstrect(Vector(pos_.x - static_cast<float>(context.get_width()) / 2.0f,
-                         pos_.y - static_cast<float>(context.get_height()) / 2.0f),
-                  Sizef(static_cast<float>(context.get_width()),
-                        static_cast<float>(context.get_height())));
+    Rectf dstrect(Vector(pos_.x - context.get_width() / 2.0f,
+                         pos_.y - context.get_height() / 2.0f),
+                  Sizef(context.get_width(),
+                        context.get_height()));
     canvas.draw_surface_scaled(m_image, dstrect, m_layer);
   }
   else
@@ -384,8 +384,8 @@ Background::draw(DrawingContext& context)
 
   Sizef level_size(d_gameobject_manager->get_width(),
                    d_gameobject_manager->get_height());
-  Sizef screen(static_cast<float>(context.get_width()),
-               static_cast<float>(context.get_height()));
+  Sizef screen(context.get_width(),
+               context.get_height());
   Sizef translation_range = level_size - screen;
   Vector center_offset(context.get_translation().x - translation_range.width  / 2.0f,
                        context.get_translation().y - translation_range.height / 2.0f);