From d7e926fc6342a28b4441df306b525b1aac016fad Mon Sep 17 00:00:00 2001
From: 7oxicshadow <7oxicshadow@googlemail.com>
Date: Sat, 31 Jul 2021 22:38:45 +0100
Subject: [PATCH] ui: Add option for a fixed 16:9 display ratio

---
 ui/xemu-hud.cc     |  2 +-
 ui/xemu-settings.c |  1 +
 ui/xemu-settings.h |  1 +
 ui/xemu.c          | 11 +++++++++--
 4 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/ui/xemu-hud.cc b/ui/xemu-hud.cc
index ab2b764706..d97962c96b 100644
--- a/ui/xemu-hud.cc
+++ b/ui/xemu-hud.cc
@@ -2118,7 +2118,7 @@ static void ShowMainMenu()
                 nv2a_set_surface_scale_factor(rendering_scale+1);
             }
 
-            if (ImGui::Combo("Scaling Mode", &scaling_mode, "Center\0Scale\0Stretch\0")) {
+            if (ImGui::Combo("Scaling Mode", &scaling_mode, "Center\0Scale\0Scale (Widescreen 16:9)\0Stretch\0")) {
                 xemu_settings_set_enum(XEMU_SETTINGS_DISPLAY_SCALE, scaling_mode);
                 xemu_settings_save();
             }
diff --git a/ui/xemu-settings.c b/ui/xemu-settings.c
index 71faba5c11..0c0c8ab975 100644
--- a/ui/xemu-settings.c
+++ b/ui/xemu-settings.c
@@ -81,6 +81,7 @@ struct enum_str_map {
 static const struct enum_str_map display_scale_map[DISPLAY_SCALE__COUNT+1] = {
 	{ DISPLAY_SCALE_CENTER,  "center"  },
 	{ DISPLAY_SCALE_SCALE,   "scale"   },
+	{ DISPLAY_SCALE_WS169,   "scale_ws169" },
 	{ DISPLAY_SCALE_STRETCH, "stretch" },
 	{ 0,                     NULL      },
 };
diff --git a/ui/xemu-settings.h b/ui/xemu-settings.h
index bd0042f01b..2d0b0a7387 100644
--- a/ui/xemu-settings.h
+++ b/ui/xemu-settings.h
@@ -60,6 +60,7 @@ enum DISPLAY_SCALE
 {
     DISPLAY_SCALE_CENTER,
     DISPLAY_SCALE_SCALE,
+    DISPLAY_SCALE_WS169,
     DISPLAY_SCALE_STRETCH,
     DISPLAY_SCALE__COUNT,
     DISPLAY_SCALE_INVALID = -1
diff --git a/ui/xemu.c b/ui/xemu.c
index 3542316108..8eb7e6d6f3 100644
--- a/ui/xemu.c
+++ b/ui/xemu.c
@@ -1165,8 +1165,15 @@ void sdl2_gl_refresh(DisplayChangeListener *dcl)
         scale[0] = (float)tw/(float)ww;
         scale[1] = (float)th/(float)wh;
     } else {
-        // Scale to fit
-        float t_ratio = (float)tw/(float)th;
+        float t_ratio;
+        if (scaling_mode == DISPLAY_SCALE_WS169) {
+            // Scale to fit window using a fixed 16:9 aspect ratio
+            t_ratio = 16.0f/9.0f;
+        } else {
+            // Scale to fit, preserving framebuffer aspect ratio
+            t_ratio = (float)tw/(float)th;
+        }
+
         float w_ratio = (float)ww/(float)wh;
         if (w_ratio >= t_ratio) {
             scale[0] = t_ratio/w_ratio;