CDROM: Add seek speedup enhancement

src/core/cdrom.cpp

@@ -684,24 +684,30 @@ TickCount CDROM::GetTicksForRead()
 
 TickCount CDROM::GetTicksForSeek(CDImage::LBA new_lba)
 {
+  static constexpr TickCount MIN_TICKS = 20000;
+
+  if (g_settings.cdrom_seek_speedup == 0)
+    return MIN_TICKS;
+
   const TickCount tps = System::GetTicksPerSecond();
   const CDImage::LBA current_lba = m_secondary_status.motor_on ? m_current_lba : 0;
   const u32 lba_diff = static_cast<u32>((new_lba > current_lba) ? (new_lba - current_lba) : (current_lba - new_lba));
 
-  // Formula from Mednafen.
-  TickCount ticks = std::max<TickCount>(
+  // Original formula based on Mednafen. Still not accurate, doesn't consider the varying number of sectors per track.
+  // TODO: Replace with algorithm based on mechacon behavior.
+  u32 ticks = std::max<u32>(
     20000, static_cast<u32>(
              ((static_cast<u64>(lba_diff) * static_cast<u64>(tps) * static_cast<u64>(1000)) / (72 * 60 * 75)) / 1000));
   if (!m_secondary_status.motor_on)
     ticks += tps;
   if (lba_diff >= 2550)
-    ticks += static_cast<TickCount>((u64(tps) * 300) / 1000);
+    ticks += static_cast<u32>((u64(tps) * 300) / 1000);
   else
   {
     // When paused, the CDC seems to keep reading the disc until it hits the position it's set to, then skip 10-15
     // sectors back (depending on how far into the disc it is). We'll be generous and use 4 sectors, since on average
     // it's probably closer.
-    ticks += GetTicksForRead() * 4u;
+    ticks += static_cast<u32>(GetTicksForRead()) * 4u;
   }
 
   if (m_mode.double_speed != m_current_double_speed)
@@ -714,8 +720,11 @@ TickCount CDROM::GetTicksForSeek(CDImage::LBA new_lba)
     ticks += static_cast<u32>(static_cast<double>(tps) * 0.1);
   }
 
-  Log_DevPrintf("Seek time for %u LBAs: %d", lba_diff, ticks);
-  return ticks;
+  if (g_settings.cdrom_seek_speedup > 1)
+    ticks = std::min<u32>(ticks / g_settings.cdrom_seek_speedup, MIN_TICKS);
+
+  Log_DevPrintf("Seek time for %u LBAs: %u", lba_diff, ticks);
+  return static_cast<u32>(ticks);
 }
 
 TickCount CDROM::GetTicksForStop(bool motor_was_on)

src/core/host_interface.cpp

@@ -558,6 +558,7 @@ void HostInterface::SetDefaultSettings(SettingsInterface& si)
   si.SetBoolValue("CDROM", "LoadImageToRAM", false);
   si.SetBoolValue("CDROM", "MuteCDAudio", false);
   si.SetIntValue("CDROM", "ReadSpeedup", 1);
+  si.SetIntValue("CDROM", "SeekSpeedup", 1);
 
   si.SetStringValue("Audio", "Backend", Settings::GetAudioBackendName(Settings::DEFAULT_AUDIO_BACKEND));
   si.SetIntValue("Audio", "OutputVolume", 100);
@@ -638,7 +639,8 @@ void HostInterface::FixIncompatibleSettings(bool display_osd_messages)
     g_settings.gpu_widescreen_hack = false;
     g_settings.gpu_pgxp_enable = false;
     g_settings.gpu_24bit_chroma_smoothing = false;
-    g_settings.cdrom_read_speedup = false;
+    g_settings.cdrom_read_speedup = 1;
+    g_settings.cdrom_seek_speedup = 1;
     g_settings.cdrom_mute_cd_audio = false;
     g_settings.texture_replacements.enable_vram_write_replacements = false;
     g_settings.bios_patch_fast_boot = false;

src/core/settings.cpp

@@ -255,6 +255,7 @@ void Settings::Load(SettingsInterface& si)
   cdrom_load_image_to_ram = si.GetBoolValue("CDROM", "LoadImageToRAM", false);
   cdrom_mute_cd_audio = si.GetBoolValue("CDROM", "MuteCDAudio", false);
   cdrom_read_speedup = si.GetIntValue("CDROM", "ReadSpeedup", 1);
+  cdrom_seek_speedup = si.GetIntValue("CDROM", "SeekSpeedup", 1);
 
   audio_backend =
     ParseAudioBackend(si.GetStringValue("Audio", "Backend", GetAudioBackendName(DEFAULT_AUDIO_BACKEND)).c_str())
@@ -430,6 +431,7 @@ void Settings::Save(SettingsInterface& si) const
   si.SetBoolValue("CDROM", "LoadImageToRAM", cdrom_load_image_to_ram);
   si.SetBoolValue("CDROM", "MuteCDAudio", cdrom_mute_cd_audio);
   si.SetIntValue("CDROM", "ReadSpeedup", cdrom_read_speedup);
+  si.SetIntValue("CDROM", "SeekSpeedup", cdrom_seek_speedup);
 
   si.SetStringValue("Audio", "Backend", GetAudioBackendName(audio_backend));
   si.SetIntValue("Audio", "OutputVolume", audio_output_volume);

src/core/settings.h

@@ -156,6 +156,7 @@ struct Settings
   bool cdrom_load_image_to_ram = false;
   bool cdrom_mute_cd_audio = false;
   u32 cdrom_read_speedup = 1;
+  u32 cdrom_seek_speedup = 1;
 
   AudioBackend audio_backend = AudioBackend::Cubeb;
   s32 audio_output_volume = 100;

src/core/system.cpp

@@ -885,10 +885,12 @@ bool Initialize(bool force_software_renderer)
   g_mdec.Initialize();
   g_sio.Initialize();
 
+  static constexpr float WARNING_DURATION = 15.0f;
+
   if (g_settings.cpu_overclock_active)
   {
     g_host_interface->AddFormattedOSDMessage(
-      10.0f,
+      WARNING_DURATION,
       g_host_interface->TranslateString("OSDMessage",
                                         "CPU clock speed is set to %u%% (%u / %u). This may result in instability."),
       g_settings.GetCPUOverclockPercent(), g_settings.cpu_overclock_numerator, g_settings.cpu_overclock_denominator);
@@ -896,11 +898,29 @@ bool Initialize(bool force_software_renderer)
   if (g_settings.cdrom_read_speedup > 1)
   {
     g_host_interface->AddFormattedOSDMessage(
-      10.0f,
+      WARNING_DURATION,
       g_host_interface->TranslateString(
         "OSDMessage", "CD-ROM read speedup set to %ux (effective speed %ux). This may result in instability."),
       g_settings.cdrom_read_speedup, g_settings.cdrom_read_speedup * 2);
   }
+  if (g_settings.cdrom_seek_speedup != 1)
+  {
+    if (g_settings.cdrom_seek_speedup == 0)
+    {
+      g_host_interface->AddOSDMessage(
+        g_host_interface->TranslateStdString("OSDMessage",
+                                             "CD-ROM seek speedup set to instant. This may result in instability."),
+        WARNING_DURATION);
+    }
+    else
+    {
+      g_host_interface->AddFormattedOSDMessage(
+        WARNING_DURATION,
+        g_host_interface->TranslateString("OSDMessage",
+                                          "CD-ROM seek speedup set to %ux. This may result in instability."),
+        g_settings.cdrom_seek_speedup);
+    }
+  }
 
   UpdateThrottlePeriod();
   UpdateMemorySaveStateSettings();