ImGui: Add TTF font support

We use the Roboto font that we're already shipping for now, although, we could
also support other fonts or have a setting.

UI/EmuScreen.cpp

@@ -27,7 +27,7 @@ using namespace std::placeholders;
 #include "Common/Render/Text/draw_text.h"
 #include "Common/File/FileUtil.h"
 #include "Common/Battery/Battery.h"
-
+#include "Common/File/VFS/VFS.h"
 #include "Common/UI/Root.h"
 #include "Common/UI/UI.h"
 #include "Common/UI/Context.h"
@@ -1646,7 +1646,13 @@ void EmuScreen::renderImDebugger() {
 		if (!imguiInited_) {
 			imguiInited_ = true;
 			imDebugger_ = std::make_unique<ImDebugger>();
-			ImGui_ImplThin3d_Init(draw);
+
+			// Read the TTF font
+			size_t size = 0;
+			uint8_t *fontData = g_VFS.ReadFile("Roboto-Condensed.ttf", &size);
+			// This call works even if fontData is nullptr, in which case the font just won't get loaded.
+			// This takes ownership of the font array.
+			ImGui_ImplThin3d_Init(draw, fontData, size);
 		}
 
 		if (PSP_IsInited()) {

UI/ImDebugger/ImDebugger.cpp

@@ -371,7 +371,6 @@ void ImDebugger::Frame(MIPSDebugInterface *mipsDebug) {
 			ImGui::EndMenu();
 		}
 		if (ImGui::BeginMenu("Window")) {
-			ImGui::Checkbox("Dear ImGUI Demo", &cfg_.demoOpen);
 			ImGui::Checkbox("CPU debugger", &cfg_.disasmOpen);
 			ImGui::Checkbox("Registers", &cfg_.regsOpen);
 			ImGui::Checkbox("Callstacks", &cfg_.callstackOpen);
@@ -382,6 +381,8 @@ void ImDebugger::Frame(MIPSDebugInterface *mipsDebug) {
 			ImGui::EndMenu();
 		}
 		if (ImGui::BeginMenu("Misc")) {
+			ImGui::Checkbox("Dear ImGui Demo", &cfg_.demoOpen);
+			ImGui::Checkbox("ImGui Style editor", &cfg_.styleEditorOpen);
 			if (ImGui::MenuItem("Close Debugger")) {
 				g_Config.bShowImDebugger = false;
 			}
@@ -394,6 +395,10 @@ void ImDebugger::Frame(MIPSDebugInterface *mipsDebug) {
 		ImGui::ShowDemoWindow(&cfg_.demoOpen);
 	}
 
+	if (cfg_.styleEditorOpen) {
+		ImGui::ShowStyleEditor();
+	}
+
 	if (cfg_.disasmOpen) {
 		disasm_.Draw(mipsDebug, &cfg_.disasmOpen, coreState);
 	}

UI/ImDebugger/ImDebugger.h

@@ -59,6 +59,7 @@ struct ImConfig {
 	bool hleModulesOpen = false;
 	bool atracOpen = true;
 	bool structViewerOpen = false;
+	bool styleEditorOpen = false;
 
 	// HLE explorer settings
 	// bool filterByUsed = true;

ext/imgui/imgui_impl_thin3d.cpp

@@ -217,8 +217,16 @@ void ImGui_ImplThin3d_DestroyDeviceObjects() {
 	}
 }
 
-bool ImGui_ImplThin3d_Init(Draw::DrawContext *draw) {
+bool ImGui_ImplThin3d_Init(Draw::DrawContext *draw, const uint8_t *ttf_font, size_t size) {
 	ImGuiIO& io = ImGui::GetIO();
+	if (ttf_font) {
+		io.Fonts->AddFontFromMemoryTTF((void *)ttf_font, size, 18.0f * g_display.dpi_scale_x, nullptr, io.Fonts->GetGlyphRangesDefault());
+	} else {
+		// necessary?
+		io.Fonts->AddFontDefault();
+	}
+	ImGui::GetStyle().ScaleAllSizes(g_display.dpi_scale_x);
+
 	IMGUI_CHECKVERSION();
 	IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
 

ext/imgui/imgui_impl_thin3d.h

@@ -33,8 +33,8 @@
 #include "Common/GPU/thin3d.h"
 #include "Common/Math/lin/matrix4x4.h"
 
-// Called by user code
-IMGUI_IMPL_API bool         ImGui_ImplThin3d_Init(Draw::DrawContext *draw);
+// Called by user code. Takes ownership of the font buffer and later deletes it.
+IMGUI_IMPL_API bool         ImGui_ImplThin3d_Init(Draw::DrawContext *draw, const uint8_t *ttf_font, size_t size);
 IMGUI_IMPL_API void         ImGui_ImplThin3d_Shutdown();
 IMGUI_IMPL_API void         ImGui_ImplThin3d_NewFrame(Draw::DrawContext *draw, Lin::Matrix4x4 drawMatrix);
 IMGUI_IMPL_API void         ImGui_ImplThin3d_RenderDrawData(ImDrawData* draw_data, Draw::DrawContext *draw);