VideoCommon: Add option to use old behavior (Fast Texture Sampling)

Co-authored-by: JosJuice <josjuice@gmail.com>

9 files changed, 40 insertions, 1 deletions

diff --git a/Source/Core/Core/Config/GraphicsSettings.cpp b/Source/Core/Core/Config/GraphicsSettings.cpp
index d1c7b21cf9..d859cab150 100644
--- a/Source/Core/Core/Config/GraphicsSettings.cpp
+++ b/Source/Core/Core/Config/GraphicsSettings.cpp
@@ -150,6 +150,8 @@ const Info<bool> GFX_HACK_EFB_EMULATE_FORMAT_CHANGES{
 const Info<bool> GFX_HACK_VERTEX_ROUDING{{System::GFX, "Hacks", "VertexRounding"}, false};
 const Info<u32> GFX_HACK_MISSING_COLOR_VALUE{{System::GFX, "Hacks", "MissingColorValue"},
                                              0xFFFFFFFF};
+const Info<bool> GFX_HACK_FAST_TEXTURE_SAMPLING{{System::GFX, "Hacks", "FastTextureSampling"},
+                                                false};
 
 // Graphics.GameSpecific
 
diff --git a/Source/Core/Core/Config/GraphicsSettings.h b/Source/Core/Core/Config/GraphicsSettings.h
index cc112722ba..3936b65cd9 100644
--- a/Source/Core/Core/Config/GraphicsSettings.h
+++ b/Source/Core/Core/Config/GraphicsSettings.h
@@ -123,6 +123,7 @@ extern const Info<bool> GFX_HACK_COPY_EFB_SCALED;
 extern const Info<bool> GFX_HACK_EFB_EMULATE_FORMAT_CHANGES;
 extern const Info<bool> GFX_HACK_VERTEX_ROUDING;
 extern const Info<u32> GFX_HACK_MISSING_COLOR_VALUE;
+extern const Info<bool> GFX_HACK_FAST_TEXTURE_SAMPLING;
 
 // Graphics.GameSpecific
 
diff --git a/Source/Core/DolphinQt/Config/Graphics/HacksWidget.cpp b/Source/Core/DolphinQt/Config/Graphics/HacksWidget.cpp
index 2765e2e2fd..4dc302ce1e 100644
--- a/Source/Core/DolphinQt/Config/Graphics/HacksWidget.cpp
+++ b/Source/Core/DolphinQt/Config/Graphics/HacksWidget.cpp
@@ -106,11 +106,14 @@ void HacksWidget::CreateWidgets()
   m_vertex_rounding = new GraphicsBool(tr("Vertex Rounding"), Config::GFX_HACK_VERTEX_ROUDING);
   m_save_texture_cache_state =
       new GraphicsBool(tr("Save Texture Cache to State"), Config::GFX_SAVE_TEXTURE_CACHE_TO_STATE);
+  m_fast_texture_sampling =
+      new GraphicsBool(tr("Fast Texture Sampling"), Config::GFX_HACK_FAST_TEXTURE_SAMPLING);
 
   other_layout->addWidget(m_fast_depth_calculation, 0, 0);
   other_layout->addWidget(m_disable_bounding_box, 0, 1);
   other_layout->addWidget(m_vertex_rounding, 1, 0);
   other_layout->addWidget(m_save_texture_cache_state, 1, 1);
+  other_layout->addWidget(m_fast_texture_sampling, 2, 0);
 
   main_layout->addWidget(efb_box);
   main_layout->addWidget(texture_cache_box);
@@ -276,6 +279,17 @@ void HacksWidget::AddDescriptions()
       "higher internal resolutions. This setting has no effect when native internal "
       "resolution is used.<br><br><dolphin_emphasis>If unsure, leave this "
       "unchecked.</dolphin_emphasis>");
+  static const char TR_FAST_TEXTURE_SAMPLING_DESCRIPTION[] = QT_TR_NOOP(
+      "Use the video backend's built-in texture sampling functionality instead of a manual "
+      "implementation.<br><br>"
+      "This setting can cause potentially improve performance, especially at higher internal "
+      "resolutions; additionally, Anisotropic Filtering currently only works with Fast Texture "
+      "Sampling.<br><br>"
+      "This comes at the cost of graphical issues in some games on certain GPUs, most commonly "
+      "vertical lines on FMVs, as well as lack of emulation of texture wrapping special cases "
+      "(though this also only works at 1x IR or when scaled EFB is disabled, and with custom "
+      "textures disabled) and worse emulation of Level of Detail calculation.<br><br>"
+      "<dolphin_emphasis>If unsure, leave this unchecked.</dolphin_emphasis>");
 
   m_skip_efb_cpu->SetDescription(tr(TR_SKIP_EFB_CPU_ACCESS_DESCRIPTION));
   m_ignore_format_changes->SetDescription(tr(TR_IGNORE_FORMAT_CHANGE_DESCRIPTION));
@@ -291,6 +305,7 @@ void HacksWidget::AddDescriptions()
   m_disable_bounding_box->SetDescription(tr(TR_DISABLE_BOUNDINGBOX_DESCRIPTION));
   m_save_texture_cache_state->SetDescription(tr(TR_SAVE_TEXTURE_CACHE_TO_STATE_DESCRIPTION));
   m_vertex_rounding->SetDescription(tr(TR_VERTEX_ROUNDING_DESCRIPTION));
+  m_fast_texture_sampling->SetDescription(tr(TR_FAST_TEXTURE_SAMPLING_DESCRIPTION));
 }
 
 void HacksWidget::UpdateDeferEFBCopiesEnabled()
diff --git a/Source/Core/DolphinQt/Config/Graphics/HacksWidget.h b/Source/Core/DolphinQt/Config/Graphics/HacksWidget.h
index 2af4a12fea..c34cd27ff8 100644
--- a/Source/Core/DolphinQt/Config/Graphics/HacksWidget.h
+++ b/Source/Core/DolphinQt/Config/Graphics/HacksWidget.h
@@ -26,6 +26,7 @@ private:
   GraphicsBool* m_skip_efb_cpu;
   GraphicsBool* m_ignore_format_changes;
   GraphicsBool* m_store_efb_copies;
+  GraphicsBool* m_defer_efb_copies;
 
   // Texture Cache
   QLabel* m_accuracy_label;
@@ -42,7 +43,7 @@ private:
   GraphicsBool* m_disable_bounding_box;
   GraphicsBool* m_vertex_rounding;
   GraphicsBool* m_save_texture_cache_state;
-  GraphicsBool* m_defer_efb_copies;
+  GraphicsBool* m_fast_texture_sampling;
 
   void CreateWidgets();
   void ConnectWidgets();
diff --git a/Source/Core/VideoCommon/PixelShaderGen.cpp b/Source/Core/VideoCommon/PixelShaderGen.cpp
index bff76d4246..fd9933c2ae 100644
--- a/Source/Core/VideoCommon/PixelShaderGen.cpp
+++ b/Source/Core/VideoCommon/PixelShaderGen.cpp
@@ -537,6 +537,7 @@ void UpdateBoundingBox(float2 rawpos) {{
               fmt::arg("efb_height", EFB_HEIGHT), fmt::arg("efb_scale", I_EFBSCALE));
   }
 
+  if (host_config.manual_texture_sampling)
   {
     if (api_type == APIType::OpenGL || api_type == APIType::Vulkan)
     {
@@ -596,6 +597,21 @@ uint WrapCoord(int coord, uint wrap, int size) {{
               "int2 uv, int layer) {{\n");
   }
 
+  if (!host_config.manual_texture_sampling)
+  {
+    out.Write("  float size_s = float(" I_TEXDIMS "[texmap].x * 128);\n"
+              "  float size_t = float(" I_TEXDIMS "[texmap].y * 128);\n"
+              "  float3 coords = float3(float(uv.x) / size_s, float(uv.y) / size_t, layer);\n");
+    if (api_type == APIType::OpenGL || api_type == APIType::Vulkan)
+    {
+      out.Write("  return iround(255.0 * texture(tex, coords));\n}}\n");
+    }
+    else if (api_type == APIType::D3D)
+    {
+      out.Write("  return iround(255.0 * tex.Sample(tex_samp, coords));\n}}\n");
+    }
+  }
+  else
   {
     out.Write(R"(
   uint texmode0 = samp_texmode0(texmap);
diff --git a/Source/Core/VideoCommon/ShaderGenCommon.cpp b/Source/Core/VideoCommon/ShaderGenCommon.cpp
index 72a7e0d14f..49fd1c9783 100644
--- a/Source/Core/VideoCommon/ShaderGenCommon.cpp
+++ b/Source/Core/VideoCommon/ShaderGenCommon.cpp
@@ -39,6 +39,7 @@ ShaderHostConfig ShaderHostConfig::GetCurrent()
   bits.backend_logic_op = g_ActiveConfig.backend_info.bSupportsLogicOp;
   bits.backend_palette_conversion = g_ActiveConfig.backend_info.bSupportsPaletteConversion;
   bits.enable_validation_layer = g_ActiveConfig.bEnableValidationLayer;
+  bits.manual_texture_sampling = !g_ActiveConfig.bFastTextureSampling;
   return bits;
 }
 
diff --git a/Source/Core/VideoCommon/ShaderGenCommon.h b/Source/Core/VideoCommon/ShaderGenCommon.h
index ebdcda262b..46d34e18c6 100644
--- a/Source/Core/VideoCommon/ShaderGenCommon.h
+++ b/Source/Core/VideoCommon/ShaderGenCommon.h
@@ -169,6 +169,7 @@ union ShaderHostConfig
   BitField<21, 1, bool, u32> backend_logic_op;
   BitField<22, 1, bool, u32> backend_palette_conversion;
   BitField<23, 1, bool, u32> enable_validation_layer;
+  BitField<24, 1, bool, u32> manual_texture_sampling;
 
   static ShaderHostConfig GetCurrent();
 };
diff --git a/Source/Core/VideoCommon/VideoConfig.cpp b/Source/Core/VideoCommon/VideoConfig.cpp
index 255e1722b9..88ec126c7c 100644
--- a/Source/Core/VideoCommon/VideoConfig.cpp
+++ b/Source/Core/VideoCommon/VideoConfig.cpp
@@ -135,6 +135,7 @@ void VideoConfig::Refresh()
   bVertexRounding = Config::Get(Config::GFX_HACK_VERTEX_ROUDING);
   iEFBAccessTileSize = Config::Get(Config::GFX_HACK_EFB_ACCESS_TILE_SIZE);
   iMissingColorValue = Config::Get(Config::GFX_HACK_MISSING_COLOR_VALUE);
+  bFastTextureSampling = Config::Get(Config::GFX_HACK_FAST_TEXTURE_SAMPLING);
 
   bPerfQueriesEnable = Config::Get(Config::GFX_PERF_QUERIES_ENABLE);
 
diff --git a/Source/Core/VideoCommon/VideoConfig.h b/Source/Core/VideoCommon/VideoConfig.h
index d4307c479a..40922b3ecf 100644
--- a/Source/Core/VideoCommon/VideoConfig.h
+++ b/Source/Core/VideoCommon/VideoConfig.h
@@ -135,6 +135,7 @@ struct VideoConfig final
   int iLog = 0;           // CONF_ bits
   int iSaveTargetId = 0;  // TODO: Should be dropped
   u32 iMissingColorValue = 0;
+  bool bFastTextureSampling = false;
 
   // Stereoscopy
   StereoMode stereo_mode{};