From be05d9634178f73cf6d738cbcdfabd49aab87386 Mon Sep 17 00:00:00 2001
From: Jorg Neves Bliesener <jbliesener@bliesener.com>
Date: Sat, 4 May 2024 23:13:35 +0200
Subject: [PATCH] Enable asset load redirection

---
 src/hello_imgui/hello_imgui_assets.h            | 13 +++++++++++++
 src/hello_imgui/internal/hello_imgui_assets.cpp | 17 +++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/hello_imgui/hello_imgui_assets.h b/src/hello_imgui/hello_imgui_assets.h
index 37930116..d3f1d3c7 100644
--- a/src/hello_imgui/hello_imgui_assets.h
+++ b/src/hello_imgui/hello_imgui_assets.h
@@ -38,6 +38,8 @@ struct AssetFileData
 // You *have* to call FreeAssetFileData to free the memory, except if you use
 // ImGui::GetIO().Fonts->AddFontFromMemoryTTF, which will take ownership of the
 // data and free it for you.
+// This function can be redirected with setLoadAssetFileDataFunction. If not redirected,
+// it calls DefaultLoadAssetFileData.
 AssetFileData LoadAssetFileData(const char *assetPath);
 
 // FreeAssetFileData(AssetFileData *)
@@ -47,6 +49,17 @@ AssetFileData LoadAssetFileData(const char *assetPath);
 void FreeAssetFileData(AssetFileData * assetFileData);
 // @@md
 
+// Function type to redirect asset loads. Function receives a path and 
+// returns an AssetFileData structure. By default, it points to 
+// DefaultLoadAssetFileData.
+typedef AssetFileData (*LoadAssetFileDataFunc)(const char *assetPath);
+
+// Redirect asset loads to user-defined function
+void setLoadAssetFileDataFunction(LoadAssetFileDataFunc func);
+
+// This function actually performs the asset load, as described in
+// LoadAssetFileData 
+AssetFileData DefaultLoadAssetFileData(const char *assetPath);
 
 // @@md#assetFileFullPath
 
diff --git a/src/hello_imgui/internal/hello_imgui_assets.cpp b/src/hello_imgui/internal/hello_imgui_assets.cpp
index 6d6b4f09..92cd325e 100644
--- a/src/hello_imgui/internal/hello_imgui_assets.cpp
+++ b/src/hello_imgui/internal/hello_imgui_assets.cpp
@@ -263,7 +263,7 @@ bool AssetExists(const std::string& assetFilename)
 
 #ifdef HELLOIMGUI_USE_SDL2
 
-AssetFileData LoadAssetFileData(const char *assetPath)
+AssetFileData DefaultLoadAssetFileData(const char *assetPath)
 {
     #ifdef __ANDROID__
     {
@@ -328,7 +328,7 @@ AssetFileData LoadAssetFileData_Impl(const char *assetPath)
     }
 }
 
-AssetFileData LoadAssetFileData(const char *assetPath)
+AssetFileData DefaultLoadAssetFileData(const char *assetPath)
 {
     std::string fullPath = assetFileFullPath(assetPath);
     AssetFileData r = LoadAssetFileData_Impl(fullPath.c_str());
@@ -348,6 +348,19 @@ void FreeAssetFileData(AssetFileData * assetFileData)
     assetFileData = nullptr;
 }
 
+static LoadAssetFileDataFunc loadAssetFileDataFunc = DefaultLoadAssetFileData;
+
+AssetFileData LoadAssetFileData(const char *assetPath)
+{
+    AssetFileData data = loadAssetFileDataFunc(assetPath);
+    return data;
+}
+
+void setLoadAssetFileDataFunction(LoadAssetFileDataFunc newLoadAssetFileDataFunc)
+{
+    loadAssetFileDataFunc = newLoadAssetFileDataFunc;
+}
+
 #endif // #ifdef HELLOIMGUI_USE_SDL2