From 486b09767fff0741744842174d4d55b3593a19a9 Mon Sep 17 00:00:00 2001
From: Fernando Carmona Varo <ferkiwi@gmail.com>
Date: Wed, 9 Oct 2019 19:37:31 +0200
Subject: [PATCH] Support RETRO_ENVIRONMENT_GET_TARGET_REFRESH_RATE

Add "auto" Framerate option to use the reported framerate from the
frontend targeted refresh rate.

It'll also be set as the new default for the Framerate option.
It'll fallback to 60 FPS if not obtained.
---
 libretro/libretro.c | 41 +++++++++++++++++++++++++----------------
 src/m_menu.c        |  2 +-
 src/m_misc.c        |  2 +-
 3 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/libretro/libretro.c b/libretro/libretro.c
index c74f1e8a..e7babd84 100644
--- a/libretro/libretro.c
+++ b/libretro/libretro.c
@@ -244,54 +244,60 @@ void retro_get_system_av_info(struct retro_system_av_info *info)
 {
   switch(movement_smooth)
   {
-    case 0:
+    case 1:
       info->timing.fps = 35.0;
       break;
-    case 1:
+    case 2:
       info->timing.fps = 40.0;
       break;
-    case 2:
+    case 3:
       info->timing.fps = 50.0;
       break;
-    case 3:
+    case 4:
       info->timing.fps = 60.0;
       break;
-    case 4:
+    case 5:
       info->timing.fps = 70.0;
       break;
-    case 5:
+    case 6:
       info->timing.fps = 72.0;
       break;
-    case 6:
+    case 7:
       info->timing.fps = 75.0;
       break;
-    case 7:
+    case 8:
       info->timing.fps = 90.0;
       break;
-    case 8:
+    case 9:
       info->timing.fps = 100.0;
       break;
-    case 9:
+    case 10:
       info->timing.fps = 119.0;
       break;
-    case 10:
+    case 11:
       info->timing.fps = 120.0;
       break;
-    case 11:
+    case 12:
       info->timing.fps = 140.0;
       break;
-    case 12:
+    case 13:
       info->timing.fps = 144.0;
       break;
-    case 13:
+    case 14:
       info->timing.fps = 240.0;
       break;
-    case 14:
+    case 15:
       info->timing.fps = 244.0;
       break;
+    case 0: // Auto
     default:
-      info->timing.fps = TICRATE;
+    {
+      float target_framerate = 0.0f;
+      if (!environ_cb(RETRO_ENVIRONMENT_GET_TARGET_REFRESH_RATE, &target_framerate))
+        target_framerate = 60.0f;
+      info->timing.fps = target_framerate;
       break;
+    }
   }
   info->timing.sample_rate = 44100.0;
   info->geometry.base_width = SCREENWIDTH;
@@ -1413,6 +1419,9 @@ void R_InitInterpolation(void)
     tic_vars.fps = info.timing.fps;
     tic_vars.frac_step = FRACUNIT * TICRATE / tic_vars.fps;
     tic_vars.sample_step = info.timing.sample_rate / tic_vars.fps;
+
+    if (log_cb)
+      log_cb(RETRO_LOG_INFO, "[libretro]: Framerate set to %.2f FPS\n", info.timing.fps);
   }
   tic_vars.frac = FRACUNIT;
 }
diff --git a/src/m_menu.c b/src/m_menu.c
index 73c5da4c..2f21be34 100644
--- a/src/m_menu.c
+++ b/src/m_menu.c
@@ -2837,7 +2837,7 @@ enum {
 #define G_YA3 (G_YA2 + 16)
 #define GF_X 76
 
-static const char *framerates[] = {"35fps", "40fps", "50fps", "60fps", "70fps", "72fps", "75fps", "90fps", "100fps", "119fps", "120fps", "140fps", "144fps", "240fps", "244fps", NULL};
+static const char *framerates[] = {"Auto", "35fps", "40fps", "50fps", "60fps", "70fps", "72fps", "75fps", "90fps", "100fps", "119fps", "120fps", "140fps", "144fps", "240fps", "244fps", NULL};
 static const char *gamma_lvls[] = {"OFF", "Lv. 1", "Lv. 2", "Lv. 3", "Lv. 4", NULL};
 static const char *mus_external_opts[] = {"Never", "Always", "Only IWAD", NULL};
 
diff --git a/src/m_misc.c b/src/m_misc.c
index 7d869e2a..0b8f9294 100644
--- a/src/m_misc.c
+++ b/src/m_misc.c
@@ -295,7 +295,7 @@ default_t defaults[] =
    def_int,ss_none, NULL, NULL},
   {"usegamma",{&usegamma, NULL},{0, NULL},0,4, //jff 3/6/98 fix erroneous upper limit in range
    def_int,ss_gen, NULL, NULL}, // gamma correction level // killough 1/18/98
-  {"uncapped_framerate", {&movement_smooth, NULL},  {3, NULL},0,14,
+  {"uncapped_framerate", {&movement_smooth, NULL},  {0, NULL},0,15,
    def_int,ss_gen, NULL, NULL},
   {"filter_wall",{(int*)&drawvars.filterwall, NULL},{RDRAW_FILTER_POINT, NULL},
    RDRAW_FILTER_POINT, RDRAW_FILTER_ROUNDED, def_int,ss_gen, NULL, NULL},