GPU: Set line width at higher internal resolutions

src/core/gpu_hw_opengl.cpp

@@ -19,6 +19,7 @@ bool GPU_HW_OpenGL::Initialize(System* system, DMA* dma, InterruptController* in
   if (!GPU_HW::Initialize(system, dma, interrupt_controller, timers))
     return false;
 
+  SetMaxResolutionScale();
   CreateFramebuffer();
   CreateVertexBuffer();
   if (!CompilePrograms())
@@ -103,6 +104,24 @@ std::tuple<s32, s32> GPU_HW_OpenGL::ConvertToFramebufferCoordinates(s32 x, s32 y
   return std::make_tuple(x, static_cast<s32>(static_cast<s32>(VRAM_HEIGHT) - y));
 }
 
+void GPU_HW_OpenGL::SetMaxResolutionScale()
+{
+  GLint max_texture_size = VRAM_WIDTH;
+  glGetIntegerv(GL_MAX_TEXTURE_SIZE, &max_texture_size);
+  Log_InfoPrintf("Max texture size: %dx%d", max_texture_size, max_texture_size);
+  const int max_texture_scale = max_texture_size / VRAM_WIDTH;
+
+  std::array<int, 2> line_width_range = {{1, 1}};
+  glGetIntegerv(GL_ALIASED_LINE_WIDTH_RANGE, line_width_range.data());
+  Log_InfoPrintf("Max line width: %d", line_width_range[1]);
+
+  const u32 max_resolution_scale = std::min(max_texture_scale, line_width_range[1]);
+  Log_InfoPrintf("Maximum resolution scale is %u", max_resolution_scale);
+  m_system->GetSettings().max_gpu_resolution_scale = max_resolution_scale;
+  m_system->GetSettings().gpu_resolution_scale =
+    std::min(m_system->GetSettings().gpu_resolution_scale, max_resolution_scale);
+}
+
 void GPU_HW_OpenGL::CreateFramebuffer()
 {
   // save old vram texture/fbo, in case we're changing scale
@@ -550,6 +569,7 @@ void GPU_HW_OpenGL::FlushRender()
   glDisable(GL_DEPTH_TEST);
   glEnable(GL_SCISSOR_TEST);
   glDepthMask(GL_FALSE);
+  glLineWidth(static_cast<float>(m_resolution_scale));
   SetProgram();
   SetViewport();
   SetScissor();

src/core/gpu_hw_opengl.h

@@ -37,6 +37,7 @@ private:
 
   std::tuple<s32, s32> ConvertToFramebufferCoordinates(s32 x, s32 y);
 
+  void SetMaxResolutionScale();
   void CreateFramebuffer();
   void ClearFramebuffer();
   void DestroyFramebuffer();

src/core/settings.h

@@ -12,6 +12,7 @@ struct Settings
 
   GPUBackend gpu_backend = GPUBackend::OpenGL;
   u32 gpu_resolution_scale = 1;
+  u32 max_gpu_resolution_scale = 1;
   
   // TODO: Controllers, memory cards, etc.
 };

src/duckstation/sdl_interface.cpp

@@ -524,7 +524,7 @@ void SDLInterface::RenderMainMenuBar()
       if (ImGui::BeginMenu("Internal Resolution"))
       {
         const u32 current_internal_resolution = m_system->GetSettings().gpu_resolution_scale;
-        for (u32 scale = 1; scale <= 16; scale++)
+        for (u32 scale = 1; scale <= m_system->GetSettings().max_gpu_resolution_scale; scale++)
         {
           if (ImGui::MenuItem(
                 TinyString::FromFormat("%ux (%ux%u)", scale, scale * GPU::VRAM_WIDTH, scale * GPU::VRAM_HEIGHT),