From 5cc91dc78bcbc90253210a2e385868d66214537f Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Thu, 10 Sep 2020 12:07:30 +1000
Subject: [PATCH] HostDisplay: Add alignment setting

---
 src/core/host_display.cpp | 35 +++++++++++++++++++++++++++++++++--
 src/core/host_display.h   |  9 +++++++++
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/src/core/host_display.cpp b/src/core/host_display.cpp
index a6b8cc241..5b81ccb4c 100644
--- a/src/core/host_display.cpp
+++ b/src/core/host_display.cpp
@@ -94,7 +94,22 @@ void HostDisplay::CalculateDrawRect(s32 window_width, s32 window_height, s32* ou
         *out_left_padding = 0;
     }
     if (out_top_padding)
-      *out_top_padding = std::max<s32>((window_height - static_cast<s32>(display_height * scale)) / 2, 0);
+    {
+      switch (m_display_alignment)
+      {
+        case Alignment::LeftOrTop:
+          *out_top_padding = 0;
+          break;
+
+        case Alignment::Center:
+          *out_top_padding = std::max<s32>((window_height - static_cast<s32>(display_height * scale)) / 2, 0);
+          break;
+
+        case Alignment::RightOrBottom:
+          *out_top_padding = std::max<s32>(window_height - static_cast<s32>(display_height * scale), 0);
+          break;
+      }
+    }
   }
   else
   {
@@ -104,7 +119,23 @@ void HostDisplay::CalculateDrawRect(s32 window_width, s32 window_height, s32* ou
       scale = std::max(std::floor(scale), 1.0f);
 
     if (out_left_padding)
-      *out_left_padding = std::max<s32>((window_width - static_cast<s32>(display_width * scale)) / 2, 0);
+    {
+      switch (m_display_alignment)
+      {
+        case Alignment::LeftOrTop:
+          *out_left_padding = 0;
+          break;
+
+        case Alignment::Center:
+          *out_left_padding = std::max<s32>((window_width - static_cast<s32>(display_width * scale)) / 2, 0);
+          break;
+
+        case Alignment::RightOrBottom:
+          *out_left_padding = std::max<s32>(window_width - static_cast<s32>(display_width * scale), 0);
+          break;
+      }
+    }
+
     if (out_top_padding)
     {
       if (m_display_integer_scaling)
diff --git a/src/core/host_display.h b/src/core/host_display.h
index d6ab3bca7..58fc3d7ee 100644
--- a/src/core/host_display.h
+++ b/src/core/host_display.h
@@ -31,6 +31,13 @@ public:
     OpenGLES
   };
 
+  enum class Alignment
+  {
+    LeftOrTop,
+    Center,
+    RightOrBottom
+  };
+
   virtual ~HostDisplay();
 
   ALWAYS_INLINE s32 GetWindowWidth() const { return static_cast<s32>(m_window_info.surface_width); }
@@ -122,6 +129,7 @@ public:
   void SetDisplayLinearFiltering(bool enabled) { m_display_linear_filtering = enabled; }
   void SetDisplayTopMargin(s32 height) { m_display_top_margin = height; }
   void SetDisplayIntegerScaling(bool enabled) { m_display_integer_scaling = enabled; }
+  void SetDisplayAlignment(Alignment alignment) { m_display_alignment = alignment; }
 
   /// Sets the software cursor to the specified texture. Ownership of the texture is transferred.
   void SetSoftwareCursor(std::unique_ptr<HostDisplayTexture> texture, float scale = 1.0f);
@@ -187,6 +195,7 @@ protected:
   s32 m_display_texture_view_height = 0;
 
   s32 m_display_top_margin = 0;
+  Alignment m_display_alignment = Alignment::Center;
 
   std::unique_ptr<HostDisplayTexture> m_cursor_texture;
   float m_cursor_texture_scale = 1.0f;