From 936d92dfb82c8266909417bae46f9b511e840490 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Mon, 29 Jun 2020 01:51:01 +1000
Subject: [PATCH] System: Add option to force start in software mode

---
 src/core/gpu.cpp    |  6 ------
 src/core/gpu.h      |  3 ---
 src/core/system.cpp | 30 ++++++++++++++++--------------
 src/core/system.h   |  5 +++--
 4 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/src/core/gpu.cpp b/src/core/gpu.cpp
index 0b5a83b76..6382a9478 100644
--- a/src/core/gpu.cpp
+++ b/src/core/gpu.cpp
@@ -63,12 +63,6 @@ void GPU::UpdateSettings()
   UpdateCRTCDisplayParameters();
 }
 
-void GPU::UpdateHardwareType()
-{
-  m_console_is_pal = m_system->IsPALRegion();
-  UpdateCRTCDisplayParameters();
-}
-
 void GPU::Reset()
 {
   SoftReset();
diff --git a/src/core/gpu.h b/src/core/gpu.h
index 889e70c09..065e76ac7 100644
--- a/src/core/gpu.h
+++ b/src/core/gpu.h
@@ -173,9 +173,6 @@ public:
   // Converts window coordinates into horizontal ticks and scanlines. Returns false if out of range. Used for lightguns.
   bool ConvertScreenCoordinatesToBeamTicksAndLines(s32 window_x, s32 window_y, u32* out_tick, u32* out_line) const;
 
-  // Updates hardware type from settings.
-  void UpdateHardwareType();
-
 protected:
   TickCount CRTCTicksToSystemTicks(TickCount crtc_ticks, TickCount fractional_ticks) const;
   TickCount SystemTicksToCRTCTicks(TickCount sysclk_ticks, TickCount* fractional_ticks) const;
diff --git a/src/core/system.cpp b/src/core/system.cpp
index 3d27b7b5a..4c190a644 100644
--- a/src/core/system.cpp
+++ b/src/core/system.cpp
@@ -88,11 +88,7 @@ ConsoleRegion System::GetConsoleRegionForDiscRegion(DiscRegion region)
 
 std::unique_ptr<System> System::Create(HostInterface* host_interface)
 {
-  std::unique_ptr<System> system(new System(host_interface));
-  if (!system->CreateGPU(host_interface->m_settings.gpu_renderer))
-    return {};
-
-  return system;
+  return std::unique_ptr<System>(new System(host_interface));
 }
 
 bool System::RecreateGPU(GPURenderer renderer)
@@ -138,7 +134,7 @@ void System::SetCPUExecutionMode(CPUExecutionMode mode)
 bool System::Boot(const SystemBootParameters& params)
 {
   if (params.state_stream)
-    return DoLoadState(params.state_stream.get(), true);
+    return DoLoadState(params.state_stream.get(), true, params.force_software_renderer);
 
   // Load CD image up and detect region.
   std::unique_ptr<CDImage> media;
@@ -201,11 +197,12 @@ bool System::Boot(const SystemBootParameters& params)
     return false;
   }
 
+  // Component setup.
+  if (!InitializeComponents(params.force_software_renderer))
+    return false;
+
   // Notify change of disc.
   UpdateRunningGame(params.filename.c_str(), media.get());
-
-  // Component setup.
-  InitializeComponents();
   UpdateControllers();
   UpdateMemoryCards();
   Reset();
@@ -243,8 +240,11 @@ bool System::Boot(const SystemBootParameters& params)
   return true;
 }
 
-void System::InitializeComponents()
+bool System::InitializeComponents(bool force_software_renderer)
 {
+  if (!CreateGPU(force_software_renderer ? GPURenderer::Software : GetSettings().gpu_renderer))
+    return false;
+
   m_cpu->Initialize(m_bus.get());
   m_cpu_code_cache->Initialize(this, m_cpu.get(), m_bus.get(), m_cpu_execution_mode == CPUExecutionMode::Recompiler);
   m_bus->Initialize(m_cpu.get(), m_cpu_code_cache.get(), m_dma.get(), m_interrupt_controller.get(), m_gpu.get(),
@@ -260,9 +260,9 @@ void System::InitializeComponents()
   m_timers->Initialize(this, m_interrupt_controller.get(), m_gpu.get());
   m_spu->Initialize(this, m_dma.get(), m_interrupt_controller.get());
   m_mdec->Initialize(this, m_dma.get());
-  m_gpu->UpdateHardwareType();
 
   UpdateThrottlePeriod();
+  return true;
 }
 
 void System::DestroyComponents()
@@ -398,10 +398,10 @@ void System::Reset()
 
 bool System::LoadState(ByteStream* state)
 {
-  return DoLoadState(state, false);
+  return DoLoadState(state, false, false);
 }
 
-bool System::DoLoadState(ByteStream* state, bool init_components)
+bool System::DoLoadState(ByteStream* state, bool init_components, bool force_software_renderer)
 {
   SAVE_STATE_HEADER header;
   if (!state->Read2(&header, sizeof(header)))
@@ -440,7 +440,9 @@ bool System::DoLoadState(ByteStream* state, bool init_components)
 
   if (init_components)
   {
-    InitializeComponents();
+    if (!InitializeComponents(force_software_renderer))
+      return false;
+
     UpdateControllers();
     UpdateMemoryCards();
 
diff --git a/src/core/system.h b/src/core/system.h
index f316c602d..45dba7c5c 100644
--- a/src/core/system.h
+++ b/src/core/system.h
@@ -39,6 +39,7 @@ struct SystemBootParameters
   std::optional<bool> override_fast_boot;
   std::optional<bool> override_fullscreen;
   std::unique_ptr<ByteStream> state_stream;
+  bool force_software_renderer = false;
 };
 
 class System
@@ -145,11 +146,11 @@ public:
 private:
   System(HostInterface* host_interface);
 
-  bool DoLoadState(ByteStream* stream, bool init_components);
+  bool DoLoadState(ByteStream* stream, bool init_components, bool force_software_renderer);
   bool DoState(StateWrapper& sw);
   bool CreateGPU(GPURenderer renderer);
 
-  void InitializeComponents();
+  bool InitializeComponents(bool force_software_renderer);
   void DestroyComponents();
 
   // Active event management