From 7ec3343ee6e4fbaedd115b40a2902d9036c6366c Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <mclaughc@outlook.com>
Date: Fri, 27 Sep 2019 00:03:28 +1000
Subject: [PATCH] Timers: Minor fixes

---
 src/pse/gpu.cpp           | 32 ++++++++++++++++----------------
 src/pse/gpu_hw_opengl.cpp |  4 +++-
 src/pse/system.cpp        |  2 +-
 src/pse/timers.cpp        |  1 +
 4 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/src/pse/gpu.cpp b/src/pse/gpu.cpp
index b469e3fda..721f68d71 100644
--- a/src/pse/gpu.cpp
+++ b/src/pse/gpu.cpp
@@ -266,7 +266,7 @@ void GPU::UpdateCRTCConfig()
 void GPU::UpdateSliceTicks()
 {
   // the next event is at the end of the next scanline
-#if 0
+#if 1
   const TickCount ticks_until_next_event = m_crtc_state.ticks_per_scanline - m_crtc_state.current_tick_in_scanline;
 #else
   // or at vblank. this will depend on the timer config..
@@ -296,6 +296,21 @@ void GPU::Execute(TickCount ticks)
     if (m_timers->IsUsingExternalClock(HBLANK_TIMER_INDEX))
       m_timers->AddTicks(HBLANK_TIMER_INDEX, 1);
 
+    // past the end of vblank?
+    if (m_crtc_state.current_scanline >= m_crtc_state.total_scanlines_per_frame)
+    {
+      // flush any pending draws and "scan out" the image
+      FlushRender();
+      UpdateDisplay();
+
+      // start the new frame
+      m_system->IncrementFrameNumber();
+      m_crtc_state.current_scanline = 0;
+
+      if (m_GPUSTAT.vertical_resolution)
+        m_GPUSTAT.drawing_even_line ^= true;
+    }
+
     const bool old_vblank = m_crtc_state.in_vblank;
     const bool new_vblank = m_crtc_state.current_scanline >= m_crtc_state.visible_vertical_resolution;
     if (new_vblank != old_vblank)
@@ -311,22 +326,7 @@ void GPU::Execute(TickCount ticks)
       m_timers->SetGate(HBLANK_TIMER_INDEX, new_vblank);
     }
 
-    // past the end of vblank?
-    if (m_crtc_state.current_scanline >= m_crtc_state.total_scanlines_per_frame)
-    {
-      // flush any pending draws and "scan out" the image
-      FlushRender();
-      UpdateDisplay();
 
-      // start the new frame
-      m_system->IncrementFrameNumber();
-      m_crtc_state.current_scanline = 0;
-      m_crtc_state.in_hblank = false;
-      m_crtc_state.in_vblank = false;
-
-      if (m_GPUSTAT.vertical_resolution)
-        m_GPUSTAT.drawing_even_line ^= true;
-    }
 
     // alternating even line bit in 240-line mode
     if (!m_crtc_state.vertical_resolution)
diff --git a/src/pse/gpu_hw_opengl.cpp b/src/pse/gpu_hw_opengl.cpp
index 5fabe395b..0e40d0557 100644
--- a/src/pse/gpu_hw_opengl.cpp
+++ b/src/pse/gpu_hw_opengl.cpp
@@ -61,7 +61,9 @@ void GPU_HW_OpenGL::RenderUI()
 
   ImGui::End();
 
-  m_stats = {};
+  // skip update when no batches were drawn in that frame.. for now
+  if (m_stats.num_batches > 0)
+    m_stats = {};
 }
 
 void GPU_HW_OpenGL::InvalidateVRAMReadCache()
diff --git a/src/pse/system.cpp b/src/pse/system.cpp
index 3c4390e90..c5fc11412 100644
--- a/src/pse/system.cpp
+++ b/src/pse/system.cpp
@@ -262,11 +262,11 @@ void System::Synchronize()
   const TickCount pending_ticks = m_cpu->GetPendingTicks();
   m_cpu->ResetPendingTicks();
 
-  m_dma->Execute(pending_ticks);
   m_gpu->Execute(pending_ticks);
   m_timers->AddSystemTicks(pending_ticks);
   m_cdrom->Execute(pending_ticks);
   m_pad->Execute(pending_ticks);
+  m_dma->Execute(pending_ticks);
 }
 
 void System::SetDowncount(TickCount downcount)
diff --git a/src/pse/timers.cpp b/src/pse/timers.cpp
index 2e6693847..9045c4fff 100644
--- a/src/pse/timers.cpp
+++ b/src/pse/timers.cpp
@@ -37,6 +37,7 @@ bool Timers::DoState(StateWrapper& sw)
     sw.Do(&cs.counter);
     sw.Do(&cs.target);
     sw.Do(&cs.gate);
+    sw.Do(&cs.use_external_clock);
     sw.Do(&cs.external_counting_enabled);
     sw.Do(&cs.counting_enabled);
   }