video_core: Eliminate the g_renderer global variable

We move the initialization of the renderer to the core class, while
keeping the creation of it and any other specifics in video_core. This
way we can ensure that the renderer is initialized and doesn't give
unfettered access to the renderer. This also makes dependencies on types
more explicit.

For example, the GPU class doesn't need to depend on the
existence of a renderer, it only needs to care about whether or not it
has a rasterizer, but since it was accessing the global variable, it was
also making the renderer a part of its dependency chain. By adjusting
the interface, we can get rid of this dependency.

19 files changed, 100 insertions, 74 deletions

diff --git a/src/core/core.cpp b/src/core/core.cpp
index 9824769cf..29222baba 100644
--- a/src/core/core.cpp
+++ b/src/core/core.cpp
@@ -18,6 +18,7 @@
 #include "core/loader/loader.h"
 #include "core/settings.h"
 #include "file_sys/vfs_real.h"
+#include "video_core/renderer_base.h"
 #include "video_core/video_core.h"
 
 namespace Core {
@@ -174,7 +175,6 @@ System::ResultStatus System::Init(EmuWindow& emu_window) {
         cpu_cores[index] = std::make_shared<Cpu>(cpu_exclusive_monitor, cpu_barrier, index);
     }
 
-    gpu_core = std::make_unique<Tegra::GPU>();
     telemetry_session = std::make_unique<Core::TelemetrySession>();
     service_manager = std::make_shared<Service::SM::ServiceManager>();
 
@@ -182,10 +182,13 @@ System::ResultStatus System::Init(EmuWindow& emu_window) {
     Service::Init(service_manager);
     GDBStub::Init();
 
-    if (!VideoCore::Init(emu_window)) {
+    renderer = VideoCore::CreateRenderer(emu_window);
+    if (!renderer->Init()) {
         return ResultStatus::ErrorVideoCore;
     }
 
+    gpu_core = std::make_unique<Tegra::GPU>(*renderer->Rasterizer());
+
     // Create threads for CPU cores 1-3, and build thread_to_cpu map
     // CPU core 0 is run on the main thread
     thread_to_cpu[std::this_thread::get_id()] = cpu_cores[0];
@@ -217,7 +220,7 @@ void System::Shutdown() {
                          perf_results.frametime * 1000.0);
 
     // Shutdown emulation session
-    VideoCore::Shutdown();
+    renderer.reset();
     GDBStub::Shutdown();
     Service::Shutdown();
     Kernel::Shutdown();
diff --git a/src/core/core.h b/src/core/core.h
index ed475ac4e..059db4262 100644
--- a/src/core/core.h
+++ b/src/core/core.h
@@ -27,6 +27,10 @@ namespace Service::SM {
 class ServiceManager;
 }
 
+namespace VideoCore {
+class RendererBase;
+}
+
 namespace Core {
 
 class System {
@@ -127,11 +131,26 @@ public:
     /// Gets a CPU interface to the CPU core with the specified index
     Cpu& CpuCore(size_t core_index);
 
-    /// Gets the GPU interface
+    /// Gets a mutable reference to the GPU interface
     Tegra::GPU& GPU() {
         return *gpu_core;
     }
 
+    /// Gets an immutable reference to the GPU interface.
+    const Tegra::GPU& GPU() const {
+        return *gpu_core;
+    }
+
+    /// Gets a mutable reference to the renderer.
+    VideoCore::RendererBase& Renderer() {
+        return *renderer;
+    }
+
+    /// Gets an immutable reference to the renderer.
+    const VideoCore::RendererBase& Renderer() const {
+        return *renderer;
+    }
+
     /// Gets the scheduler for the CPU core that is currently running
     Kernel::Scheduler& CurrentScheduler() {
         return *CurrentCpuCore().Scheduler();
@@ -195,6 +214,7 @@ private:
 
     /// AppLoader used to load the current executing application
     std::unique_ptr<Loader::AppLoader> app_loader;
+    std::unique_ptr<VideoCore::RendererBase> renderer;
     std::unique_ptr<Tegra::GPU> gpu_core;
     std::shared_ptr<Tegra::DebugContext> debug_context;
     Kernel::SharedPtr<Kernel::Process> current_process;
diff --git a/src/core/hle/service/nvdrv/devices/nvdisp_disp0.cpp b/src/core/hle/service/nvdrv/devices/nvdisp_disp0.cpp
index ed69a4325..2b74e6a33 100644
--- a/src/core/hle/service/nvdrv/devices/nvdisp_disp0.cpp
+++ b/src/core/hle/service/nvdrv/devices/nvdisp_disp0.cpp
@@ -30,9 +30,9 @@ void nvdisp_disp0::flip(u32 buffer_handle, u32 offset, u32 format, u32 width, u3
         addr,      offset,   width, height, stride, static_cast<PixelFormat>(format),
         transform, crop_rect};
 
-    Core::System::GetInstance().perf_stats.EndGameFrame();
-
-    VideoCore::g_renderer->SwapBuffers(framebuffer);
+    auto& instance = Core::System::GetInstance();
+    instance.perf_stats.EndGameFrame();
+    instance.Renderer().SwapBuffers(framebuffer);
 }
 
 } // namespace Service::Nvidia::Devices
diff --git a/src/core/hle/service/nvdrv/devices/nvhost_as_gpu.cpp b/src/core/hle/service/nvdrv/devices/nvhost_as_gpu.cpp
index 57b128b40..06151a1ea 100644
--- a/src/core/hle/service/nvdrv/devices/nvhost_as_gpu.cpp
+++ b/src/core/hle/service/nvdrv/devices/nvhost_as_gpu.cpp
@@ -150,15 +150,16 @@ u32 nvhost_as_gpu::UnmapBuffer(const std::vector<u8>& input, std::vector<u8>& ou
 
     LOG_DEBUG(Service_NVDRV, "called, offset=0x{:X}", params.offset);
 
-    auto& gpu = Core::System::GetInstance().GPU();
-
-    auto itr = buffer_mappings.find(params.offset);
-
+    const auto itr = buffer_mappings.find(params.offset);
     ASSERT_MSG(itr != buffer_mappings.end(), "Tried to unmap invalid mapping");
 
+    auto& system_instance = Core::System::GetInstance();
+
     // Remove this memory region from the rasterizer cache.
-    VideoCore::g_renderer->Rasterizer()->FlushAndInvalidateRegion(params.offset, itr->second.size);
+    system_instance.Renderer().Rasterizer()->FlushAndInvalidateRegion(params.offset,
+                                                                      itr->second.size);
 
+    auto& gpu = system_instance.GPU();
     params.offset = gpu.memory_manager->UnmapBuffer(params.offset, itr->second.size);
 
     buffer_mappings.erase(itr->second.offset);
diff --git a/src/core/hle/service/nvflinger/nvflinger.cpp b/src/core/hle/service/nvflinger/nvflinger.cpp
index 5344441e1..0bf51062c 100644
--- a/src/core/hle/service/nvflinger/nvflinger.cpp
+++ b/src/core/hle/service/nvflinger/nvflinger.cpp
@@ -127,9 +127,11 @@ void NVFlinger::Compose() {
         MicroProfileFlip();
 
         if (buffer == boost::none) {
+            auto& system_instance = Core::System::GetInstance();
+
             // There was no queued buffer to draw, render previous frame
-            Core::System::GetInstance().perf_stats.EndGameFrame();
-            VideoCore::g_renderer->SwapBuffers({});
+            system_instance.perf_stats.EndGameFrame();
+            system_instance.Renderer().SwapBuffers({});
             continue;
         }
 
diff --git a/src/core/memory.cpp b/src/core/memory.cpp
index 4b3bb7b31..a8f08e1da 100644
--- a/src/core/memory.cpp
+++ b/src/core/memory.cpp
@@ -326,34 +326,36 @@ void RasterizerMarkRegionCached(Tegra::GPUVAddr gpu_addr, u64 size, bool cached)
 }
 
 void RasterizerFlushVirtualRegion(VAddr start, u64 size, FlushMode mode) {
+    auto& system_instance = Core::System::GetInstance();
+
     // Since pages are unmapped on shutdown after video core is shutdown, the renderer may be
     // null here
-    if (VideoCore::g_renderer == nullptr) {
+    if (!system_instance.IsPoweredOn()) {
         return;
     }
 
     VAddr end = start + size;
 
-    auto CheckRegion = [&](VAddr region_start, VAddr region_end) {
+    const auto CheckRegion = [&](VAddr region_start, VAddr region_end) {
         if (start >= region_end || end <= region_start) {
             // No overlap with region
             return;
         }
 
-        VAddr overlap_start = std::max(start, region_start);
-        VAddr overlap_end = std::min(end, region_end);
+        const VAddr overlap_start = std::max(start, region_start);
+        const VAddr overlap_end = std::min(end, region_end);
 
-        std::vector<Tegra::GPUVAddr> gpu_addresses =
-            Core::System::GetInstance().GPU().memory_manager->CpuToGpuAddress(overlap_start);
+        const std::vector<Tegra::GPUVAddr> gpu_addresses =
+            system_instance.GPU().memory_manager->CpuToGpuAddress(overlap_start);
 
         if (gpu_addresses.empty()) {
             return;
         }
 
-        u64 overlap_size = overlap_end - overlap_start;
+        const u64 overlap_size = overlap_end - overlap_start;
 
         for (const auto& gpu_address : gpu_addresses) {
-            auto* rasterizer = VideoCore::g_renderer->Rasterizer();
+            auto* rasterizer = system_instance.Renderer().Rasterizer();
             switch (mode) {
             case FlushMode::Flush:
                 rasterizer->FlushRegion(gpu_address, overlap_size);
diff --git a/src/core/settings.cpp b/src/core/settings.cpp
index 79e0b347b..a4623223d 100644
--- a/src/core/settings.cpp
+++ b/src/core/settings.cpp
@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include "core/core.h"
 #include "core/gdbstub/gdbstub.h"
 #include "core/hle/service/hid/hid.h"
 #include "core/settings.h"
@@ -19,8 +20,9 @@ void Apply() {
 
     VideoCore::g_toggle_framelimit_enabled = values.toggle_framelimit;
 
-    if (VideoCore::g_renderer) {
-        VideoCore::g_renderer->UpdateCurrentFramebufferLayout();
+    auto& system_instance = Core::System::GetInstance();
+    if (system_instance.IsPoweredOn()) {
+        system_instance.Renderer().UpdateCurrentFramebufferLayout();
     }
 
     Service::HID::ReloadInputDevices();
diff --git a/src/video_core/engines/maxwell_3d.cpp b/src/video_core/engines/maxwell_3d.cpp
index 0e205ed72..a235b543e 100644
--- a/src/video_core/engines/maxwell_3d.cpp
+++ b/src/video_core/engines/maxwell_3d.cpp
@@ -19,8 +19,8 @@ namespace Engines {
 /// First register id that is actually a Macro call.
 constexpr u32 MacroRegistersStart = 0xE00;
 
-Maxwell3D::Maxwell3D(MemoryManager& memory_manager)
-    : memory_manager(memory_manager), macro_interpreter(*this) {}
+Maxwell3D::Maxwell3D(VideoCore::RasterizerInterface& rasterizer, MemoryManager& memory_manager)
+    : memory_manager(memory_manager), rasterizer{rasterizer}, macro_interpreter(*this) {}
 
 void Maxwell3D::CallMacroMethod(u32 method, std::vector<u32> parameters) {
     auto macro_code = uploaded_macros.find(method);
@@ -130,7 +130,7 @@ void Maxwell3D::WriteReg(u32 method, u32 value, u32 remaining_params) {
         break;
     }
 
-    VideoCore::g_renderer->Rasterizer()->NotifyMaxwellRegisterChanged(method);
+    rasterizer.NotifyMaxwellRegisterChanged(method);
 
     if (debug_context) {
         debug_context->OnEvent(Tegra::DebugContext::Event::MaxwellCommandProcessed, nullptr);
@@ -218,7 +218,7 @@ void Maxwell3D::DrawArrays() {
     }
 
     const bool is_indexed{regs.index_array.count && !regs.vertex_buffer.count};
-    VideoCore::g_renderer->Rasterizer()->AccelerateDrawBatch(is_indexed);
+    rasterizer.AccelerateDrawBatch(is_indexed);
 
     // TODO(bunnei): Below, we reset vertex count so that we can use these registers to determine if
     // the game is trying to draw indexed or direct mode. This needs to be verified on HW still -
@@ -393,7 +393,7 @@ void Maxwell3D::ProcessClearBuffers() {
            regs.clear_buffers.R == regs.clear_buffers.B &&
            regs.clear_buffers.R == regs.clear_buffers.A);
 
-    VideoCore::g_renderer->Rasterizer()->Clear();
+    rasterizer.Clear();
 }
 
 } // namespace Engines
diff --git a/src/video_core/engines/maxwell_3d.h b/src/video_core/engines/maxwell_3d.h
index 3c32f1067..4d0ff96a5 100644
--- a/src/video_core/engines/maxwell_3d.h
+++ b/src/video_core/engines/maxwell_3d.h
@@ -17,6 +17,10 @@
 #include "video_core/memory_manager.h"
 #include "video_core/textures/texture.h"
 
+namespace VideoCore {
+class RasterizerInterface;
+}
+
 namespace Tegra::Engines {
 
 #define MAXWELL3D_REG_INDEX(field_name)                                                            \
@@ -24,7 +28,7 @@ namespace Tegra::Engines {
 
 class Maxwell3D final {
 public:
-    explicit Maxwell3D(MemoryManager& memory_manager);
+    explicit Maxwell3D(VideoCore::RasterizerInterface& rasterizer, MemoryManager& memory_manager);
     ~Maxwell3D() = default;
 
     /// Register structure of the Maxwell3D engine.
@@ -818,6 +822,8 @@ public:
     Texture::FullTextureInfo GetStageTexture(Regs::ShaderStage stage, size_t offset) const;
 
 private:
+    VideoCore::RasterizerInterface& rasterizer;
+
     std::unordered_map<u32, std::vector<u32>> uploaded_macros;
 
     /// Macro method that is currently being executed / being fed parameters.
diff --git a/src/video_core/gpu.cpp b/src/video_core/gpu.cpp
index 141e20444..b2a83ce0b 100644
--- a/src/video_core/gpu.cpp
+++ b/src/video_core/gpu.cpp
@@ -7,12 +7,13 @@
 #include "video_core/engines/maxwell_compute.h"
 #include "video_core/engines/maxwell_dma.h"
 #include "video_core/gpu.h"
+#include "video_core/rasterizer_interface.h"
 
 namespace Tegra {
 
-GPU::GPU() {
+GPU::GPU(VideoCore::RasterizerInterface& rasterizer) {
     memory_manager = std::make_unique<MemoryManager>();
-    maxwell_3d = std::make_unique<Engines::Maxwell3D>(*memory_manager);
+    maxwell_3d = std::make_unique<Engines::Maxwell3D>(rasterizer, *memory_manager);
     fermi_2d = std::make_unique<Engines::Fermi2D>(*memory_manager);
     maxwell_compute = std::make_unique<Engines::MaxwellCompute>();
     maxwell_dma = std::make_unique<Engines::MaxwellDMA>(*memory_manager);
diff --git a/src/video_core/gpu.h b/src/video_core/gpu.h
index 08aa75503..440505c9d 100644
--- a/src/video_core/gpu.h
+++ b/src/video_core/gpu.h
@@ -11,6 +11,10 @@
 #include "core/hle/service/nvflinger/buffer_queue.h"
 #include "video_core/memory_manager.h"
 
+namespace VideoCore {
+class RasterizerInterface;
+}
+
 namespace Tegra {
 
 enum class RenderTargetFormat : u32 {
@@ -98,7 +102,7 @@ enum class EngineID {
 
 class GPU final {
 public:
-    GPU();
+    explicit GPU(VideoCore::RasterizerInterface& rasterizer);
     ~GPU();
 
     /// Processes a command list stored at the specified address in GPU memory.
diff --git a/src/video_core/renderer_base.cpp b/src/video_core/renderer_base.cpp
index dbe3edf09..3ca350243 100644
--- a/src/video_core/renderer_base.cpp
+++ b/src/video_core/renderer_base.cpp
@@ -7,6 +7,8 @@
 #include "video_core/renderer_base.h"
 #include "video_core/renderer_opengl/gl_rasterizer.h"
 
+namespace VideoCore {
+
 RendererBase::RendererBase(EmuWindow& window) : render_window{window} {}
 RendererBase::~RendererBase() = default;
 
@@ -21,3 +23,5 @@ void RendererBase::RefreshRasterizerSetting() {
         rasterizer = std::make_unique<RasterizerOpenGL>(render_window);
     }
 }
+
+} // namespace VideoCore
diff --git a/src/video_core/renderer_base.h b/src/video_core/renderer_base.h
index 1cb161b7f..effb9aed3 100644
--- a/src/video_core/renderer_base.h
+++ b/src/video_core/renderer_base.h
@@ -13,6 +13,8 @@
 
 class EmuWindow;
 
+namespace VideoCore {
+
 class RendererBase : NonCopyable {
 public:
     /// Used to reference a framebuffer
@@ -44,7 +46,7 @@ public:
         return m_current_frame;
     }
 
-    VideoCore::RasterizerInterface* Rasterizer() const {
+    RasterizerInterface* Rasterizer() const {
         return rasterizer.get();
     }
 
@@ -52,7 +54,9 @@ public:
 
 protected:
     EmuWindow& render_window; ///< Reference to the render window handle.
-    std::unique_ptr<VideoCore::RasterizerInterface> rasterizer;
+    std::unique_ptr<RasterizerInterface> rasterizer;
     f32 m_current_fps = 0.0f; ///< Current framerate, should be set by the renderer
     int m_current_frame = 0;  ///< Current frame, should be set by the renderer
 };
+
+} // namespace VideoCore
diff --git a/src/video_core/renderer_opengl/renderer_opengl.cpp b/src/video_core/renderer_opengl/renderer_opengl.cpp
index 74383c7cf..50846975f 100644
--- a/src/video_core/renderer_opengl/renderer_opengl.cpp
+++ b/src/video_core/renderer_opengl/renderer_opengl.cpp
@@ -103,7 +103,7 @@ ScopeAcquireGLContext::~ScopeAcquireGLContext() {
     }
 }
 
-RendererOpenGL::RendererOpenGL(EmuWindow& window) : RendererBase{window} {}
+RendererOpenGL::RendererOpenGL(EmuWindow& window) : VideoCore::RendererBase{window} {}
 RendererOpenGL::~RendererOpenGL() = default;
 
 /// Swap buffers (render frame)
diff --git a/src/video_core/renderer_opengl/renderer_opengl.h b/src/video_core/renderer_opengl/renderer_opengl.h
index ab7de41c8..428afa3b7 100644
--- a/src/video_core/renderer_opengl/renderer_opengl.h
+++ b/src/video_core/renderer_opengl/renderer_opengl.h
@@ -41,7 +41,7 @@ private:
     EmuWindow& emu_window;
 };
 
-class RendererOpenGL : public RendererBase {
+class RendererOpenGL : public VideoCore::RendererBase {
 public:
     explicit RendererOpenGL(EmuWindow& window);
     ~RendererOpenGL() override;
diff --git a/src/video_core/video_core.cpp b/src/video_core/video_core.cpp
index 06b13e681..5085ef96b 100644
--- a/src/video_core/video_core.cpp
+++ b/src/video_core/video_core.cpp
@@ -3,37 +3,16 @@
 // Refer to the license.txt file included.
 
 #include <memory>
-#include "common/logging/log.h"
 #include "video_core/renderer_base.h"
 #include "video_core/renderer_opengl/renderer_opengl.h"
 #include "video_core/video_core.h"
 
-////////////////////////////////////////////////////////////////////////////////////////////////////
-// Video Core namespace
-
 namespace VideoCore {
 
-std::unique_ptr<RendererBase> g_renderer; ///< Renderer plugin
-
 std::atomic<bool> g_toggle_framelimit_enabled;
 
-/// Initialize the video core
-bool Init(EmuWindow& emu_window) {
-    g_renderer = std::make_unique<RendererOpenGL>(emu_window);
-    if (g_renderer->Init()) {
-        LOG_DEBUG(Render, "initialized OK");
-    } else {
-        LOG_CRITICAL(Render, "initialization failed !");
-        return false;
-    }
-    return true;
-}
-
-/// Shutdown the video core
-void Shutdown() {
-    g_renderer.reset();
-
-    LOG_DEBUG(Render, "shutdown OK");
+std::unique_ptr<RendererBase> CreateRenderer(EmuWindow& emu_window) {
+    return std::make_unique<RendererOpenGL>(emu_window);
 }
 
 } // namespace VideoCore
diff --git a/src/video_core/video_core.h b/src/video_core/video_core.h
index 519b757f5..7c01c0b8d 100644
--- a/src/video_core/video_core.h
+++ b/src/video_core/video_core.h
@@ -8,25 +8,23 @@
 #include <memory>
 
 class EmuWindow;
-class RendererBase;
-
-////////////////////////////////////////////////////////////////////////////////////////////////////
-// Video Core namespace
 
 namespace VideoCore {
 
-enum class Renderer { Software, OpenGL };
+class RendererBase;
 
-extern std::unique_ptr<RendererBase> g_renderer; ///< Renderer plugin
+enum class Renderer { Software, OpenGL };
 
 // TODO: Wrap these in a user settings struct along with any other graphics settings (often set from
 // qt ui)
 extern std::atomic<bool> g_toggle_framelimit_enabled;
 
-/// Initialize the video core
-bool Init(EmuWindow& emu_window);
-
-/// Shutdown the video core
-void Shutdown();
+/**
+ * Creates a renderer instance.
+ *
+ * @note The returned renderer instance is simply allocated. Its Init()
+ *       function still needs to be called to fully complete its setup.
+ */
+std::unique_ptr<RendererBase> CreateRenderer(EmuWindow& emu_window);
 
 } // namespace VideoCore
diff --git a/src/yuzu/main.cpp b/src/yuzu/main.cpp
index 341867f7b..955353a2c 100644
--- a/src/yuzu/main.cpp
+++ b/src/yuzu/main.cpp
@@ -445,7 +445,7 @@ bool GMainWindow::LoadROM(const QString& filename) {
 
         case Core::System::ResultStatus::ErrorVideoCore:
             QMessageBox::critical(
-                this, tr("An error occured in the video core."),
+                this, tr("An error occurred initializing the video core."),
                 tr("yuzu has encountered an error while running the video core, please see the "
                    "log for more details."
                    "For more information on accessing the log, please see the following page: "
@@ -459,7 +459,7 @@ bool GMainWindow::LoadROM(const QString& filename) {
         default:
             QMessageBox::critical(
                 this, tr("Error while loading ROM!"),
-                tr("An unknown error occured. Please see the log for more details."));
+                tr("An unknown error occurred. Please see the log for more details."));
             break;
         }
         return false;
diff --git a/src/yuzu_cmd/yuzu.cpp b/src/yuzu_cmd/yuzu.cpp
index 5ff6266bf..5911ec177 100644
--- a/src/yuzu_cmd/yuzu.cpp
+++ b/src/yuzu_cmd/yuzu.cpp
@@ -187,7 +187,7 @@ int main(int argc, char** argv) {
         LOG_CRITICAL(Frontend, "Failed to determine system mode!");
         return -1;
     case Core::System::ResultStatus::ErrorVideoCore:
-        LOG_CRITICAL(Frontend, "VideoCore not initialized");
+        LOG_CRITICAL(Frontend, "Failed to initialize VideoCore!");
         return -1;
     case Core::System::ResultStatus::Success:
         break; // Expected case