integrate RMLUI library

src/main/cpp/kernel.cpp

@@ -2,12 +2,89 @@
 #include "egl_context.h"
 #include "render_target.h"
 #include "logger.h"
+#include "assets_manager.h"
 #include "aidl/com/omixlab/mosis/IMosisListener.h"
 #include <android/hardware_buffer.h>
+#include <android/asset_manager.h>
+#include <RmlUi/Core.h>
+#include "RmlUi_Renderer_GL3.h"
+#include <ranges>
+#include <span>
 
 using namespace aidl::com::omixlab::mosis;
 using namespace aidl::android::hardware;
 
+class AssetFilesInterface : public Rml::FileInterface
+{
+public:
+    static AssetFilesInterface& Instance()
+    {
+        static AssetFilesInterface instance;
+        return instance;
+    }
+    Rml::FileHandle Open(const Rml::String &path) override
+    {
+        AAssetManager* am = AssetsManager::Native();
+        AAsset* asset = AAssetManager_open(am, path.c_str(), AASSET_MODE_BUFFER);
+        return reinterpret_cast<Rml::FileHandle>(asset);
+    }
+    void Close(Rml::FileHandle file) override
+    {
+        AAsset* asset = reinterpret_cast<AAsset*>(file);
+        AAsset_close(asset);
+    }
+    size_t Read(void *buffer, size_t size, Rml::FileHandle file) override
+    {
+        AAsset* asset = reinterpret_cast<AAsset*>(file);
+        return AAsset_read(asset, buffer, size);
+    }
+    bool Seek(Rml::FileHandle file, long offset, int origin) override
+    {
+        AAsset* asset = reinterpret_cast<AAsset*>(file);
+        off_t new_cursor = AAsset_seek(asset, offset, origin);
+        return new_cursor != -1;
+    }
+    size_t Tell(Rml::FileHandle file) override
+    {
+        AAsset* asset = reinterpret_cast<AAsset*>(file);
+        return AAsset_seek(asset, 0, SEEK_CUR);
+    }
+
+    size_t Length(Rml::FileHandle file) override
+    {
+        AAsset* asset = reinterpret_cast<AAsset*>(file);
+        return AAsset_getLength(asset);
+    }
+
+    bool LoadFile(const Rml::String &path, Rml::String &out_data) override
+    {
+        AAssetManager* am = AssetsManager::Native();
+        AAsset* asset = AAssetManager_open(am, path.c_str(), AASSET_MODE_BUFFER);
+        if (!asset)
+            return false;
+        out_data.resize(AAsset_getLength(asset));
+        auto data_ptr = static_cast<const char*>(AAsset_getBuffer(asset));
+        std::span data = std::span(data_ptr, out_data.size());
+        std::ranges::copy(data, out_data.begin());
+        return true;
+    }
+};
+
+class SystemInterface : public Rml::SystemInterface
+{
+public:
+    static SystemInterface& Instance()
+    {
+        static SystemInterface instance;
+        return instance;
+    }
+    bool LogMessage(Rml::Log::Type type, const Rml::String &message) override
+    {
+        Logger::Log(std::format("RMLUI: {}", message));
+        return true;
+    }
+};
+
 void Kernel::main_loop()
 {
     m_egl_context = std::make_unique<egl::Context>();
@@ -30,12 +107,45 @@ void Kernel::main_loop()
     for (const auto& [pid, l] : m_listeners)
         l->onBufferAvailable(*m_aidl_buffer);
 
+    RenderInterface_GL3 rmlui_render_interface;
+    if (!rmlui_render_interface)
+    {
+        Logger::Log("failed to create render interface");
+        return;
+    }
+    Rml::SetRenderInterface(&rmlui_render_interface);
+    Rml::SetFileInterface(&AssetFilesInterface::Instance());
+    Rml::SetSystemInterface(&SystemInterface::Instance());
+    Rml::Initialise();
+    Rml::Context* context = Rml::CreateContext("default", Rml::Vector2i(1024, 1024));
+    if (!context)
+    {
+        Logger::Log("RMLUI failed to create a context");
+        Rml::Shutdown();
+        return;
+    }
+    Rml::LoadFontFace("Roboto/static/Roboto_Condensed-Regular.ttf");
+    Rml::LoadFontFace("LatoLatin-Regular.ttf");
+
+    // Now we are ready to load our document.
+    Rml::ElementDocument* document = context->LoadDocument("demo.rml");
+    document->Show();
+
     while (true)
     {
         static float angle = 0.0f;
         angle += 0.1f;
+        m_render_target->bind();
         glClearColor(fabs(sin(angle)), 0.0f, 0.0f, 1.0f);
         glClear(GL_COLOR_BUFFER_BIT);
+        glViewport(0, 0, 1024, 1024);
+
+        context->Update();
+        rmlui_render_interface.SetViewport(1024, 1024);
+        rmlui_render_interface.BeginFrame();
+        context->Render();
+        rmlui_render_interface.EndFrame(m_render_target->framebuffer());
+
         glFinish();
         {
             std::lock_guard _lock(m_mutex);
@@ -44,6 +154,7 @@ void Kernel::main_loop()
         }
         std::this_thread::sleep_for(std::chrono::milliseconds(100));
     }
+    Rml::Shutdown();
 }
 
 Kernel::Kernel(const std::shared_ptr<IMosisListener> &listener)