From bae1f05038744490082487f8ccc32437b873e5d2 Mon Sep 17 00:00:00 2001
From: Gary Talent <gary@drinkingtea.net>
Date: Sun, 16 May 2021 13:04:32 -0500
Subject: [PATCH] [nostalgia] Add scaffolding for ImGui

---
 .gitignore                             |  1 +
 CMakeLists.txt                         | 13 +++++++--
 conanfile.py                           |  8 +++++-
 deps/imgui/CMakeLists.txt              | 40 ++++++++++++++++++++++++++
 src/nostalgia/core/glfw/CMakeLists.txt | 10 +++++++
 src/nostalgia/core/glfw/core.hpp       |  2 +-
 src/nostalgia/core/glfw/gfx.cpp        |  3 ++
 7 files changed, 72 insertions(+), 5 deletions(-)
 create mode 100644 deps/imgui/CMakeLists.txt

diff --git a/.gitignore b/.gitignore
index d44d4288..5defd653 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,7 @@
 .clangd
 .current_build
 scripts/__pycache__
+deps/imgui/src
 compile_commands.json
 build
 .conanbuild
diff --git a/CMakeLists.txt b/CMakeLists.txt
index eee646c3..91bb4789 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -44,12 +44,19 @@ else()
 endif()
 
 add_subdirectory(deps/ox)
-include_directories(SYSTEM deps/ox/src)
+include_directories(
+	SYSTEM
+		deps/imgui/src
+		deps/ox/src
+)
 
 if(BUILDCORE_TARGET STREQUAL "gba")
 	add_subdirectory(deps/gbastartup)
-elseif(NOSTALGIA_BUILD_STUDIO)
-	add_subdirectory(deps/QDark)
+else()
+	if(NOSTALGIA_BUILD_STUDIO)
+		add_subdirectory(deps/QDark)
+	endif()
+	add_subdirectory(deps/imgui)
 endif()
 
 add_subdirectory(src)
diff --git a/conanfile.py b/conanfile.py
index c5e3caef..35a261d2 100644
--- a/conanfile.py
+++ b/conanfile.py
@@ -2,7 +2,13 @@ from conans import ConanFile, CMake
 
 class NostalgiaConan(ConanFile):
     settings = 'os', 'compiler', 'build_type', 'arch'
-    requires = 'jsoncpp/1.9.4', 'glfw/3.3.4'
+    requires = 'jsoncpp/1.9.4', 'glfw/3.3.4', 'imgui/1.82'
     generators = 'cmake', 'cmake_find_package', 'cmake_paths'
     default_options = {
     }
+
+    def imports(self):
+        self.copy('imgui_impl_glfw.cpp',    dst='../deps/imgui/src', src='./res/bindings')
+        self.copy('imgui_impl_opengl3.cpp', dst='../deps/imgui/src', src='./res/bindings')
+        self.copy('imgui_impl_glfw.h',      dst='../deps/imgui/src', src='./res/bindings')
+        self.copy('imgui_impl_opengl3.h',   dst='../deps/imgui/src', src='./res/bindings')
diff --git a/deps/imgui/CMakeLists.txt b/deps/imgui/CMakeLists.txt
new file mode 100644
index 00000000..01ad6245
--- /dev/null
+++ b/deps/imgui/CMakeLists.txt
@@ -0,0 +1,40 @@
+add_library(
+	imgui-glfw
+		src/imgui_impl_glfw.cpp
+		src/imgui_impl_opengl3.cpp
+)
+
+find_package(glfw3 REQUIRED)
+find_package(imgui REQUIRED)
+
+if(APPLE)
+	target_compile_definitions(
+		imgui-glfw PRIVATE
+			IMGUI_IMPL_OPENGL_LOADER_CUSTOM="OpenGL/gl3.h"
+	)
+endif()
+
+target_link_libraries(
+	imgui-glfw PUBLIC
+		${OPENGL_gl_LIBRARY}
+		glfw::glfw
+		imgui::imgui
+)
+
+if(NOT MSVC)
+	target_compile_options(
+		imgui-glfw PRIVATE
+			-Wno-all
+			-Wno-extra
+			-Wno-old-style-cast
+			-Wno-deprecated-declarations
+	)
+endif()
+
+install(
+	TARGETS
+		imgui-glfw
+	DESTINATION
+		LIBRARY DESTINATION lib/nostalgia
+		ARCHIVE DESTINATION lib/nostalgia
+)
diff --git a/src/nostalgia/core/glfw/CMakeLists.txt b/src/nostalgia/core/glfw/CMakeLists.txt
index 802c7af7..036dc166 100644
--- a/src/nostalgia/core/glfw/CMakeLists.txt
+++ b/src/nostalgia/core/glfw/CMakeLists.txt
@@ -5,10 +5,20 @@ add_library(
 )
 
 find_package(glfw3 REQUIRED)
+find_package(imgui REQUIRED)
+
+if(APPLE)
+	find_package(OpenGL REQUIRED)
+else()
+	set(OPENGL_gl_LIBRARY GL)
+endif()
 
 target_link_libraries(
 	NostalgiaCore-GLFW PUBLIC
+		${OPENGL_gl_LIBRARY}
 		glfw::glfw
+		imgui::imgui
+		imgui-glfw
 		NostalgiaGlUtils
 		NostalgiaCore-Userspace
 )
diff --git a/src/nostalgia/core/glfw/core.hpp b/src/nostalgia/core/glfw/core.hpp
index 9c79e230..eca68d56 100644
--- a/src/nostalgia/core/glfw/core.hpp
+++ b/src/nostalgia/core/glfw/core.hpp
@@ -13,7 +13,7 @@
 namespace nostalgia::core {
 
 struct GlfwImplData {
-	class GLFWwindow *window = nullptr;
+	struct GLFWwindow *window = nullptr;
 	int64_t startTime = 0;
 	bool running = false;
 	event_handler eventHandler = nullptr;
diff --git a/src/nostalgia/core/glfw/gfx.cpp b/src/nostalgia/core/glfw/gfx.cpp
index e41600f5..27978cc4 100644
--- a/src/nostalgia/core/glfw/gfx.cpp
+++ b/src/nostalgia/core/glfw/gfx.cpp
@@ -7,6 +7,8 @@
  */
 
 #include <GLFW/glfw3.h>
+#include <imgui.h>
+#include <imgui_impl_glfw.h>
 
 #include <nostalgia/core/userland/gfx.hpp>
 
@@ -37,6 +39,7 @@ ox::Error initGfx(Context *ctx) noexcept {
 	glfwSetWindowUserPointer(id->window, ctx);
 	glfwMakeContextCurrent(id->window);
 	oxReturnError(renderer::init(ctx));
+	ImGui_ImplGlfw_InitForOpenGL(id->window, true);
 	return OxError(0);
 }