Add Dear ImGui for ease of debugging

Author: zao

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "libs/Lua-cURLv3"]
 	path = libs/Lua-cURLv3
 	url = https://github.com/Lua-cURL/Lua-cURLv3.git
+[submodule "dep/imgui"]
+	path = dep/imgui
+	url = https://github.com/ocornut/imgui.git

CMakeLists.txt

@@ -104,6 +104,41 @@ find_package(re2 CONFIG REQUIRED)
 find_package(Threads REQUIRED)
 find_package(ZLIB REQUIRED)
 
+add_library(imgui STATIC
+	dep/imgui/imconfig.h
+	dep/imgui/imgui.cpp
+	dep/imgui/imgui.h
+	dep/imgui/imgui_demo.cpp
+	dep/imgui/imgui_draw.cpp
+	dep/imgui/imgui_internal.h
+	dep/imgui/imgui_tables.cpp
+	dep/imgui/imgui_widgets.cpp
+	dep/imgui/imstb_rectpack.h
+	dep/imgui/imstb_textedit.h
+	dep/imgui/imstb_truetype.h
+	dep/imgui/backends/imgui_impl_glfw.cpp
+	dep/imgui/backends/imgui_impl_glfw.h
+	dep/imgui/backends/imgui_impl_opengl3.cpp
+	dep/imgui/backends/imgui_impl_opengl3.h
+	dep/imgui/backends/imgui_impl_opengl3_loader.h
+	dep/imgui/misc/cpp/imgui_stdlib.cpp
+	dep/imgui/misc/cpp/imgui_stdlib.h
+)
+
+target_compile_definitions(imgui PUBLIC
+	"IMGUI_IMPL_OPENGL_ES2"
+)
+
+target_include_directories(imgui PUBLIC
+	dep/imgui
+	dep/imgui/backends
+)
+
+target_link_libraries(imgui PUBLIC
+    unofficial::angle::libGLESv2
+    glfw
+)
+
 target_include_directories(SimpleGraphic
     PRIVATE
     ${CMAKE_CURRENT_SOURCE_DIR}/dep/glad/include
@@ -141,6 +176,7 @@ target_link_libraries(SimpleGraphic
     unofficial::angle::libGLESv2
     fmt::fmt
     glfw
+    imgui
     ${LUAJIT_LIBRARIES}
     re2::re2
     Threads::Threads

dep/imgui

@@ -14,6 +14,9 @@
 #include <sstream>
 #include <vector>
 
+#include <imgui_impl_glfw.h>
+#include <imgui_impl_opengl3.h>
+
 // =======
 // Classes
 // =======
@@ -747,6 +750,12 @@ void r_renderer_c::Init()
 
 	whiteImage = RegisterShader("@white", 0);
 
+	imguiCtx = ImGui::CreateContext();
+	ImGui::SetCurrentContext(imguiCtx);
+
+	ImGui_ImplGlfw_InitForOpenGL((GLFWwindow*)sys->video->GetWindowHandle(), true);
+	ImGui_ImplOpenGL3_Init("#version 100");
+
 	fonts[F_FIXED] = new r_font_c(this, "Bitstream Vera Sans Mono");
 	fonts[F_VAR] = new r_font_c(this, "Liberation Sans");
 	fonts[F_VAR_BOLD] = new r_font_c(this, "Liberation Sans Bold");
@@ -760,6 +769,10 @@ void r_renderer_c::Shutdown()
 
 	sys->con->Printf("Unloading resources...\n");
 
+	ImGui_ImplOpenGL3_Shutdown();
+	ImGui_ImplGlfw_Shutdown();
+	ImGui::DestroyContext(imguiCtx);
+
 	delete whiteImage;
 
 	for (int f = 0; f < F_NUMFONTS; f++) {
@@ -799,6 +812,9 @@ void r_renderer_c::Shutdown()
 
 void r_renderer_c::BeginFrame()
 {
+	ImGui_ImplOpenGL3_NewFrame();
+	ImGui_ImplGlfw_NewFrame();
+	ImGui::NewFrame();
 	{
 		auto& vid = sys->video->vid;
 		int wNew = VirtualScreenWidth();
@@ -914,6 +930,9 @@ void r_renderer_c::EndFrame()
 
 	glFlush();
 
+	ImGui::Render();
+	ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
 	// Swap output buffers
 	openGL->Swap();
 

engine/render/r_main.cpp

@@ -10,6 +10,8 @@
 
 #define R_MAXSHADERS 65536
 
+#include <imgui.h>
+
 // =======
 // Classes
 // =======
@@ -116,6 +118,8 @@ class r_renderer_c: public r_IRenderer, public conCmdHandler_c {
 
 	r_shaderHnd_c* whiteImage = nullptr;	// White image
 
+	ImGuiContext* imguiCtx = nullptr;
+
 	r_font_c* fonts[F_NUMFONTS] = {}; // Font objects
 
 	col4_t	drawColor = {};		// Current draw color

engine/render/r_main.h

@@ -15,6 +15,8 @@
 #include <optional>
 #include <utility>
 
+#include <imgui.h>
+
 // ====================
 // sys_IVideo Interface
 // ====================
@@ -265,10 +267,16 @@ int sys_video_c::Apply(sys_vidSet_s* set)
 		});
 		glfwSetCharCallback(wnd, [](GLFWwindow* wnd, uint32_t codepoint) {
 			auto sys = (sys_main_c*)glfwGetWindowUserPointer(wnd);
+			if (ImGui::GetIO().WantCaptureKeyboard) {
+				return;
+			}
 			sys->core->KeyEvent(codepoint, KE_CHAR);
 		});
 		glfwSetKeyCallback(wnd, [](GLFWwindow* wnd, int key, int scancode, int action, int mods) {
 			auto sys = (sys_main_c*)glfwGetWindowUserPointer(wnd);
+			if (ImGui::GetIO().WantCaptureKeyboard) {
+				return;
+			}
 			if (byte k = sys->GlfwKeyToKey(key)) {
 				bool is_down = action == GLFW_PRESS || action == GLFW_REPEAT;
 				sys->heldKeyState[k] = is_down;
@@ -281,6 +289,9 @@ int sys_video_c::Apply(sys_vidSet_s* set)
 		});
 		glfwSetMouseButtonCallback(wnd, [](GLFWwindow* wnd, int button, int action, int mods) {
 			auto sys = (sys_main_c*)glfwGetWindowUserPointer(wnd);
+			if (ImGui::GetIO().WantCaptureMouse) {
+				return;
+			}
 			auto video = (sys_video_c*)sys->video;
 			int sg_key;
 			switch(button) {