From 04240aa855768974740001ca1395c7b5ae2aab81 Mon Sep 17 00:00:00 2001
From: sergystepanov <sergystepanov@gmail.com>
Date: Sat, 27 Jun 2026 14:56:50 +0300
Subject: [PATCH] Use sub-frame emulation precision

---
 pkg/worker/caged/libretro/frontend.go          | 6 +++---
 pkg/worker/caged/libretro/nanoarch/nanoarch.go | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/pkg/worker/caged/libretro/frontend.go b/pkg/worker/caged/libretro/frontend.go
index adf52cec..c0857e24 100644
--- a/pkg/worker/caged/libretro/frontend.go
+++ b/pkg/worker/caged/libretro/frontend.go
@@ -24,7 +24,7 @@ type Emulator interface {
 	SetDataCb(func([]byte))
 	LoadCore(name string)
 	LoadGame(path string) error
-	FPS() int
+	FPS() float64
 	Flipped() bool
 	Rotation() uint
 	PixFormat() uint32
@@ -309,7 +309,7 @@ func (f *Frontend) Start() {
 	// The main loop of Libretro
 
 	// calculate the exact duration required for a frame (e.g., 16.666ms = 60 FPS)
-	targetFrameTime := time.Second / time.Duration(f.nano.VideoFramerate())
+	targetFrameTime := time.Duration(float64(time.Second) / f.nano.VideoFramerate())
 
 	// stop sleeping and start spinning in the remaining 1ms
 	const spinThreshold = 1 * time.Millisecond
@@ -380,7 +380,7 @@ func (f *Frontend) LoadGame(path string) error {
 
 func (f *Frontend) AspectRatio() float32          { return f.nano.AspectRatio() }
 func (f *Frontend) AudioSampleRate() int          { return f.nano.AudioSampleRate() }
-func (f *Frontend) FPS() int                      { return f.nano.VideoFramerate() }
+func (f *Frontend) FPS() float64                  { return f.nano.VideoFramerate() }
 func (f *Frontend) Flipped() bool                 { return f.nano.IsGL() }
 func (f *Frontend) FrameSize() (int, int)         { return f.nano.BaseWidth(), f.nano.BaseHeight() }
 func (f *Frontend) HasSave() bool                 { return os.Exists(f.HashPath()) }
diff --git a/pkg/worker/caged/libretro/nanoarch/nanoarch.go b/pkg/worker/caged/libretro/nanoarch/nanoarch.go
index 5d34dca3..0e36801e 100644
--- a/pkg/worker/caged/libretro/nanoarch/nanoarch.go
+++ b/pkg/worker/caged/libretro/nanoarch/nanoarch.go
@@ -147,7 +147,7 @@ func NewNano(localPath string) *Nanoarch {
 
 func (n *Nanoarch) AspectRatio() float32             { return float32(n.sys.av.geometry.aspect_ratio) }
 func (n *Nanoarch) AudioSampleRate() int             { return int(n.sys.av.timing.sample_rate) }
-func (n *Nanoarch) VideoFramerate() int              { return int(n.sys.av.timing.fps) }
+func (n *Nanoarch) VideoFramerate() float64          { return float64(n.sys.av.timing.fps) }
 func (n *Nanoarch) IsPortrait() bool                 { return 90 == n.Rot%180 }
 func (n *Nanoarch) KbMouseSupport() bool             { return n.meta.KbMouseSupport }
 func (n *Nanoarch) BaseWidth() int                   { return int(n.sys.av.geometry.base_width) }