From 858f39827da29203cad8b631194f92863a3729d5 Mon Sep 17 00:00:00 2001
From: Connor McLaughlin <stenzek@gmail.com>
Date: Sun, 1 Nov 2020 22:54:03 +1000
Subject: [PATCH] GPU/HW: Add 'Disable Edge Blending' variants of texture
 filters

---
 src/core/gpu_hw_shadergen.cpp | 23 +++++++++++++++++++----
 src/core/settings.cpp         |  7 +++++--
 src/core/types.h              |  3 +++
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/src/core/gpu_hw_shadergen.cpp b/src/core/gpu_hw_shadergen.cpp
index 47788bb01..3de476be4 100644
--- a/src/core/gpu_hw_shadergen.cpp
+++ b/src/core/gpu_hw_shadergen.cpp
@@ -167,8 +167,9 @@ std::string GPU_HW_ShaderGen::GenerateBatchVertexShader(bool textured)
 void GPU_HW_ShaderGen::WriteBatchTextureFilter(std::stringstream& ss, GPUTextureFilter texture_filter)
 {
   // JINC2 and xBRZ shaders originally from beetle-psx, modified to support filtering mask channel.
-  if (texture_filter == GPUTextureFilter::Bilinear)
+  if (texture_filter == GPUTextureFilter::Bilinear || texture_filter == GPUTextureFilter::BilinearBinAlpha)
   {
+    DefineMacro(ss, "BINALPHA", texture_filter == GPUTextureFilter::BilinearBinAlpha);
     ss << R"(
 void FilteredSampleFromVRAM(uint4 texpage, float2 coords, float4 uv_limits,
                             out float4 texcol, out float ialpha)
@@ -200,11 +201,16 @@ void FilteredSampleFromVRAM(uint4 texpage, float2 coords, float4 uv_limits,
   // Compensate for partially transparent sampling.
   if (ialpha > 0.0)
     texcol.rgb /= float3(ialpha, ialpha, ialpha);
+
+#if BINALPHA
+  ialpha = (ialpha >= 0.5) ? 1.0 : 0.0;
+#endif
 }
 )";
   }
-  else if (texture_filter == GPUTextureFilter::JINC2)
+  else if (texture_filter == GPUTextureFilter::JINC2 || texture_filter == GPUTextureFilter::JINC2BinAlpha)
   {
+    DefineMacro(ss, "BINALPHA", texture_filter == GPUTextureFilter::JINC2BinAlpha);
     ss << R"(
 CONSTANT float JINC2_WINDOW_SINC = 0.44;
 CONSTANT float JINC2_SINC = 0.82;
@@ -347,11 +353,16 @@ void FilteredSampleFromVRAM(uint4 texpage, float2 coords, float4 uv_limits,
     // Compensate for partially transparent sampling.
     if (ialpha > 0.0)
       texcol.rgb /= float3(ialpha, ialpha, ialpha);
+
+#if BINALPHA
+  ialpha = (ialpha >= 0.5) ? 1.0 : 0.0;
+#endif
 }
 )";
   }
-  else if (texture_filter == GPUTextureFilter::xBR)
+  else if (texture_filter == GPUTextureFilter::xBR || texture_filter == GPUTextureFilter::xBRBinAlpha)
   {
+    DefineMacro(ss, "BINALPHA", texture_filter == GPUTextureFilter::xBRBinAlpha);
     ss << R"(
 CONSTANT int BLEND_NONE = 0;
 CONSTANT int BLEND_NORMAL = 1;
@@ -626,6 +637,10 @@ void FilteredSampleFromVRAM(uint4 texpage, float2 coords, float4 uv_limits,
   // Compensate for partially transparent sampling.
   if (ialpha > 0.0)
     texcol.rgb /= float3(ialpha, ialpha, ialpha);
+
+#if BINALPHA
+  ialpha = (ialpha >= 0.5) ? 1.0 : 0.0;
+#endif
 }
 
 #undef P
@@ -1172,7 +1187,7 @@ std::string GPU_HW_ShaderGen::GenerateVRAMCopyFragmentShader()
 {
   // TODO: This won't currently work because we can't bind the texture to both the shader and framebuffer.
   const bool msaa = false;
-  
+
   std::stringstream ss;
   WriteHeader(ss);
   WriteCommonFunctions(ss);
diff --git a/src/core/settings.cpp b/src/core/settings.cpp
index 945308742..ffa1dc155 100644
--- a/src/core/settings.cpp
+++ b/src/core/settings.cpp
@@ -513,10 +513,13 @@ const char* Settings::GetRendererDisplayName(GPURenderer renderer)
   return s_gpu_renderer_display_names[static_cast<int>(renderer)];
 }
 
-static constexpr auto s_texture_filter_names = make_array("Nearest", "Bilinear", "JINC2", "xBR");
+static constexpr auto s_texture_filter_names =
+  make_array("Nearest", "Bilinear", "BilinearBinAlpha", "JINC2", "JINC2BinAlpha", "xBR", "xBRBinAlpha");
 static constexpr auto s_texture_filter_display_names =
   make_array(TRANSLATABLE("GPUTextureFilter", "Nearest-Neighbor"), TRANSLATABLE("GPUTextureFilter", "Bilinear"),
-             TRANSLATABLE("GPUTextureFilter", "JINC2"), TRANSLATABLE("GPUTextureFilter", "xBR"));
+             TRANSLATABLE("GPUTextureFilter", "Bilinear (No Edge Blending)"), TRANSLATABLE("GPUTextureFilter", "JINC2"),
+             TRANSLATABLE("GPUTextureFilter", "JINC2 (No Edge Blending)"), TRANSLATABLE("GPUTextureFilter", "xBR"),
+             TRANSLATABLE("GPUTextureFilter", "xBR (No Edge Blending)"));
 
 std::optional<GPUTextureFilter> Settings::ParseTextureFilterName(const char* str)
 {
diff --git a/src/core/types.h b/src/core/types.h
index 700df5c4b..90f2cef82 100644
--- a/src/core/types.h
+++ b/src/core/types.h
@@ -67,8 +67,11 @@ enum class GPUTextureFilter : u8
 {
   Nearest,
   Bilinear,
+  BilinearBinAlpha,
   JINC2,
+  JINC2BinAlpha,
   xBR,
+  xBRBinAlpha,
   Count
 };