Custom textures rewrite (#6452)

* common: Add thread pool from yuzu

* Is really useful for asynchronous operations like shader compilation and custom textures, will be used in following PRs

* core: Improve ImageInterface

* Provide a default implementation so frontends don't have to duplicate code registering the lodepng version

* Add a dds version too which we will use in the next commit

* rasterizer_cache: Rewrite custom textures

* There's just too much to talk about here, look at the PR description for more details

* rasterizer_cache: Implement basic pack configuration file

* custom_tex_manager: Flip dumped textures

* custom_tex_manager: Optimize custom texture hashing

* If no convertions are needed then we can hash the decoded data directly removing the needed for duplicate decode

* custom_tex_manager: Implement asynchronous texture loading

* The file loading and decoding is offloaded into worker threads, while the upload itself still occurs in the main thread to avoid having to manage shared contexts

* Address review comments

* custom_tex_manager: Introduce custom material support

* video_core: Move custom textures to separate directory

* Also split the files to make the code cleaner

* gl_texture_runtime: Generate mipmaps for material

* custom_tex_manager: Prevent memory overflow when preloading

* externals: Add dds-ktx as submodule

* string_util: Return vector from SplitString

* No code benefits from passing it as an argument

* custom_textures: Use json config file

* gl_rasterizer: Only bind material for unit 0

* Address review comments

src/core/frontend/image_interface.cpp

@@ -0,0 +1,65 @@
+// Copyright 2023 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#define DDSKTX_IMPLEMENT
+#include <dds-ktx.h>
+#include <lodepng.h>
+#include "common/file_util.h"
+#include "common/logging/log.h"
+#include "core/frontend/image_interface.h"
+
+namespace Frontend {
+
+bool ImageInterface::DecodePNG(std::vector<u8>& dst, u32& width, u32& height,
+                               std::span<const u8> src) {
+    const u32 lodepng_ret = lodepng::decode(dst, width, height, src.data(), src.size());
+    if (lodepng_ret) {
+        LOG_ERROR(Frontend, "Failed to decode because {}", lodepng_error_text(lodepng_ret));
+        return false;
+    }
+    return true;
+}
+
+bool ImageInterface::DecodeDDS(std::vector<u8>& dst, u32& width, u32& height, ddsktx_format& format,
+                               std::span<const u8> src) {
+    ddsktx_texture_info tc{};
+    const int size = static_cast<int>(src.size());
+
+    if (!ddsktx_parse(&tc, src.data(), size, nullptr)) {
+        LOG_ERROR(Frontend, "Failed to decode");
+        return false;
+    }
+    width = tc.width;
+    height = tc.height;
+    format = tc.format;
+
+    ddsktx_sub_data sub_data{};
+    ddsktx_get_sub(&tc, &sub_data, src.data(), size, 0, 0, 0);
+
+    dst.resize(sub_data.size_bytes);
+    std::memcpy(dst.data(), sub_data.buff, sub_data.size_bytes);
+
+    return true;
+}
+
+bool ImageInterface::EncodePNG(const std::string& path, u32 width, u32 height,
+                               std::span<const u8> src) {
+    std::vector<u8> out;
+    const u32 lodepng_ret = lodepng::encode(out, src.data(), width, height);
+    if (lodepng_ret) {
+        LOG_ERROR(Frontend, "Failed to encode {} because {}", path,
+                  lodepng_error_text(lodepng_ret));
+        return false;
+    }
+
+    FileUtil::IOFile file{path, "wb"};
+    if (file.WriteBytes(out.data(), out.size()) != out.size()) {
+        LOG_ERROR(Frontend, "Failed to save encode to path {}", path);
+        return false;
+    }
+
+    return true;
+}
+
+} // namespace Frontend

src/core/frontend/image_interface.h

@@ -4,21 +4,26 @@
 
 #pragma once
 
+#include <span>
 #include <string>
 #include <vector>
+#include <dds-ktx.h>
 #include "common/common_types.h"
 
 namespace Frontend {
 
+/**
+ * Utility class that provides image decoding/encoding to the custom texture manager.
+ * Can be optionally overriden by frontends to provide a custom implementation.
+ */
 class ImageInterface {
 public:
     virtual ~ImageInterface() = default;
 
-    // Error logging should be handled by the frontend
-    virtual bool DecodePNG(std::vector<u8>& dst, u32& width, u32& height,
-                           const std::string& path) = 0;
-    virtual bool EncodePNG(const std::string& path, const std::vector<u8>& src, u32 width,
-                           u32 height) = 0;
+    virtual bool DecodePNG(std::vector<u8>& dst, u32& width, u32& height, std::span<const u8> src);
+    virtual bool DecodeDDS(std::vector<u8>& dst, u32& width, u32& height, ddsktx_format& format,
+                           std::span<const u8> src);
+    virtual bool EncodePNG(const std::string& path, u32 width, u32 height, std::span<const u8> src);
 };
 
 } // namespace Frontend