From 79648e1c24eac81f54365bbcb6dbc49ad6b16b1c Mon Sep 17 00:00:00 2001
From: iwubcode <iwubcode@users.noreply.github.com>
Date: Thu, 21 Dec 2023 00:22:16 -0600
Subject: [PATCH] VideoCommon: revert max pixel shader samplers back to 8 for
 Android devices.

It was reported that some games (Zelda Wind Waker and Zelda Twilight Princess but others may also exhibit the issue) have graphical issues with the max pixel samplers set to 16 on some Android devices (ex: Pixel6); since this was increased for a performance heavy feature (custom shaders) just disable it for now.  In the future, this could be handled more elegantly
---
 Source/Core/VideoBackends/Vulkan/ObjectCache.cpp     |  7 +++++++
 Source/Core/VideoCommon/Constants.h                  |  7 +++++++
 .../Runtime/GraphicsModActionFactory.cpp             | 12 ++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/Source/Core/VideoBackends/Vulkan/ObjectCache.cpp b/Source/Core/VideoBackends/Vulkan/ObjectCache.cpp
index c32365f3fc..a27d4457e2 100644
--- a/Source/Core/VideoBackends/Vulkan/ObjectCache.cpp
+++ b/Source/Core/VideoBackends/Vulkan/ObjectCache.cpp
@@ -121,6 +121,12 @@ bool ObjectCache::CreateDescriptorSetLayouts()
        VK_SHADER_STAGE_GEOMETRY_BIT},
   }};
 
+#ifdef ANDROID
+  static const std::array<VkDescriptorSetLayoutBinding, 1> standard_sampler_bindings{{
+      {0, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
+       static_cast<u32>(VideoCommon::MAX_PIXEL_SHADER_SAMPLERS), VK_SHADER_STAGE_FRAGMENT_BIT},
+  }};
+#else
   constexpr u32 MAX_PIXEL_SAMPLER_ARRAY_SIZE = 8;
   constexpr u32 TOTAL_PIXEL_SAMPLER_BINDINGS =
       1 + (VideoCommon::MAX_PIXEL_SHADER_SAMPLERS - MAX_PIXEL_SAMPLER_ARRAY_SIZE);
@@ -139,6 +145,7 @@ bool ObjectCache::CreateDescriptorSetLayouts()
           {14, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1, VK_SHADER_STAGE_FRAGMENT_BIT},
           {15, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1, VK_SHADER_STAGE_FRAGMENT_BIT},
       }};
+#endif
 
   // The dynamic veretex loader's vertex buffer must be last here, for similar reasons
   static const std::array<VkDescriptorSetLayoutBinding, 2> standard_ssbo_bindings{{
diff --git a/Source/Core/VideoCommon/Constants.h b/Source/Core/VideoCommon/Constants.h
index 2d411acead..4f846bdd1b 100644
--- a/Source/Core/VideoCommon/Constants.h
+++ b/Source/Core/VideoCommon/Constants.h
@@ -7,6 +7,13 @@
 
 namespace VideoCommon
 {
+#ifdef ANDROID
+// Some devices seem to have graphical errors when providing 16 pixel samplers
+// given the logic is for a performance heavy feature (custom shaders), will just disable for now
+// TODO: handle this more elegantly
+constexpr u32 MAX_PIXEL_SHADER_SAMPLERS = 8;
+#else
 constexpr u32 MAX_PIXEL_SHADER_SAMPLERS = 16;
+#endif
 constexpr u32 MAX_COMPUTE_SHADER_SAMPLERS = 8;
 }  // namespace VideoCommon
diff --git a/Source/Core/VideoCommon/GraphicsModSystem/Runtime/GraphicsModActionFactory.cpp b/Source/Core/VideoCommon/GraphicsModSystem/Runtime/GraphicsModActionFactory.cpp
index 6ff64aa038..57f7e2f313 100644
--- a/Source/Core/VideoCommon/GraphicsModSystem/Runtime/GraphicsModActionFactory.cpp
+++ b/Source/Core/VideoCommon/GraphicsModSystem/Runtime/GraphicsModActionFactory.cpp
@@ -3,6 +3,9 @@
 
 #include "VideoCommon/GraphicsModSystem/Runtime/GraphicsModActionFactory.h"
 
+#include "Common/Logging/Log.h"
+
+#include "VideoCommon/Constants.h"
 #include "VideoCommon/GraphicsModSystem/Runtime/Actions/CustomPipelineAction.h"
 #include "VideoCommon/GraphicsModSystem/Runtime/Actions/MoveAction.h"
 #include "VideoCommon/GraphicsModSystem/Runtime/Actions/PrintAction.h"
@@ -32,7 +35,16 @@ std::unique_ptr<GraphicsModAction> Create(std::string_view name, const picojson:
   }
   else if (name == "custom_pipeline")
   {
+#ifdef ANDROID
+    // Custom shaders currently need more than 8 pixel samplers
+    // to be used with textures, rather than make things complicated
+    // just disable the feature for Android which has issues
+    ERROR_LOG_FMT(VIDEO, "Android needs more than 8 pixel samplers to function, {} provided",
+                  VideoCommon::MAX_PIXEL_SHADER_SAMPLERS);
+    return nullptr;
+#else
     return CustomPipelineAction::Create(json_data, std::move(library));
+#endif
   }
 
   return nullptr;