Initial ImGui integration in the engine

still a bit hacky, but shows imgui windows that can be clicked etc

neo/CMakeLists.txt

@@ -743,15 +743,18 @@ set(src_imgui
 	libs/imgui/backends/imgui_impl_sdl2.cpp
 	libs/imgui/backends/imgui_impl_opengl2.cpp
 	
+	libs/imgui/imgui.h
 	libs/imgui/imgui.cpp
 	libs/imgui/imgui_draw.cpp
 	libs/imgui/imgui_tables.cpp
 	libs/imgui/imgui_widgets.cpp
 	
 	libs/imgui/imgui_demo.cpp
+	
+	sys/sys_imgui.h
+	sys/sys_imgui.cpp
 )
 
-add_globbed_headers(src_imgui "libs/imgui")
 
 set(src_game
 	game/AF.cpp

neo/framework/Common.cpp

@@ -50,6 +50,8 @@ If you have questions concerning this license or the applicable additional terms
 #include "tools/compilers/aas/AASFileManager.h"
 #include "tools/edit_public.h"
 
+#include "sys/sys_imgui.h"
+
 #include "framework/Common.h"
 
 #include "GameCallbacks_local.h"
@@ -2426,6 +2428,9 @@ void idCommonLocal::Frame( void ) {
 
 		eventLoop->RunEventLoop();
 
+		// DG: prepare new ImGui frame - I guess this is a good place, as all new events should be available?
+		D3::ImGuiHooks::NewFrame();
+
 		com_frameTime = com_ticNumber * USERCMD_MSEC;
 
 		idAsyncNetwork::RunFrame();

neo/renderer/tr_backend.cpp

@@ -26,6 +26,7 @@ If you have questions concerning this license or the applicable additional terms
 ===========================================================================
 */
 #include "sys/platform.h"
+#include "sys/sys_imgui.h"
 
 #include "renderer/tr_local.h"
 
@@ -597,6 +598,8 @@ const void	RB_SwapBuffers( const void *data ) {
 			qglEnable( GL_SCISSOR_TEST );
 	}
 
+	D3::ImGuiHooks::EndFrame();
+
 	// force a gl sync if requested
 	if ( r_finish.GetBool() ) {
 		qglFinish();

neo/sys/events.cpp

@@ -39,6 +39,7 @@ If you have questions concerning this license or the applicable additional terms
 #include "renderer/tr_local.h"
 
 #include "sys/sys_public.h"
+#include "sys/sys_imgui.h"
 
 #if !SDL_VERSION_ATLEAST(2, 0, 0)
 #define SDL_Keycode SDLKey
@@ -1124,6 +1125,8 @@ sysEvent_t Sys_GetEvent() {
 
 	// loop until there is an event we care about (will return then) or no more events
 	while(SDL_PollEvent(&ev)) {
+		D3::ImGuiHooks::ProcessEvent(&ev);
+
 		switch (ev.type) {
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 		case SDL_WINDOWEVENT:

neo/sys/glimp.cpp

@@ -33,6 +33,8 @@ If you have questions concerning this license or the applicable additional terms
 
 #include "renderer/tr_local.h"
 
+#include "sys/sys_imgui.h"
+
 #if defined(_WIN32) && defined(ID_ALLOW_TOOLS)
 #include "sys/win32/win_local.h"
 #include <SDL_syswm.h>
@@ -575,6 +577,8 @@ try_again:
 		return false;
 	}
 
+	D3::ImGuiHooks::Init(window, context);
+
 	return true;
 }
 
@@ -594,6 +598,9 @@ GLimp_Shutdown
 ===================
 */
 void GLimp_Shutdown() {
+
+	D3::ImGuiHooks::Shutdown();
+
 	common->Printf("Shutting down OpenGL subsystem\n");
 
 #if SDL_VERSION_ATLEAST(2, 0, 0)

neo/sys/sys_imgui.cpp

@@ -0,0 +1,182 @@
+
+#if 1 // FIXME: introduce D3_ENABLE_IMGUI or similar from cmake? or use IMGUI_DISABLE? either way, no imgui for SDL1.2
+
+#include "sys_imgui.h"
+
+#include <SDL.h>
+
+#include "../libs/imgui/backends/imgui_impl_opengl2.h"
+#include "../libs/imgui/backends/imgui_impl_sdl2.h"
+
+#include "framework/Common.h"
+#include "renderer/qgl.h"
+
+
+namespace D3 {
+namespace ImGuiHooks {
+
+ImGuiContext* imguiCtx = NULL;
+static bool haveNewFrame = false;
+
+// using void* instead of SDL_Window and SDL_GLContext to avoid dragging SDL headers into sys_imgui.h
+bool Init(void* sdlWindow, void* sdlGlContext)
+{
+	SDL_Window* win = (SDL_Window*)sdlWindow;
+	SDL_GL_MakeCurrent(win, (SDL_GLContext)sdlGlContext); // XXX: really?
+	//SDL_GLContext glctx = (SDL_GLContext)sdlGlContext;
+	SDL_GL_SetSwapInterval(1); // XXX: really?
+
+	common->Printf( "Initializing ImGui\n" );
+
+	// Setup Dear ImGui context
+	IMGUI_CHECKVERSION();
+	imguiCtx = ImGui::CreateContext();
+	if (imguiCtx == NULL) {
+		common->Warning("Failed to create ImGui Context!\n");
+		return false;
+	}
+	ImGuiIO& io = ImGui::GetIO(); (void)io;
+	io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
+	io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+
+	// Setup Dear ImGui style
+	ImGui::StyleColorsDark();
+	//ImGui::StyleColorsLight();
+
+	// Setup Platform/Renderer backends
+	if (!ImGui_ImplSDL2_InitForOpenGL(win, sdlGlContext)) {
+		ImGui::DestroyContext(imguiCtx);
+		imguiCtx = NULL;
+		common->Warning("Failed to initialize ImGui SDL platform backend!\n");
+		return false;
+	}
+
+	if (!ImGui_ImplOpenGL2_Init()) {
+		ImGui_ImplSDL2_Shutdown();
+		ImGui::DestroyContext(imguiCtx);
+		imguiCtx = NULL;
+		common->Warning("Failed to initialize ImGui OpenGL renderer backend!\n");
+		return false;
+	}
+
+	// Load Fonts
+	// - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
+	// - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
+	// - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
+	// - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
+	// - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
+	// - Read 'docs/FONTS.md' for more instructions and details.
+	// - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
+	//io.Fonts->AddFontDefault();
+	//io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
+	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
+	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
+	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
+	//ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
+	//IM_ASSERT(font != nullptr);
+
+	return true;
+}
+
+void Shutdown()
+{
+	common->Printf( "Shutting down ImGui\n" );
+
+	ImGui_ImplOpenGL2_Shutdown();
+	ImGui_ImplSDL2_Shutdown();
+	ImGui::DestroyContext(imguiCtx);
+}
+
+void NewFrame()
+{
+	// Start the Dear ImGui frame
+	ImGui_ImplOpenGL2_NewFrame();
+	ImGui_ImplSDL2_NewFrame();
+	ImGui::NewFrame();
+	haveNewFrame = true;
+
+	// XXX hack for testing:
+	static bool show_another_window = false;
+	static bool show_demo_window = true;
+
+	if(show_demo_window)
+		ImGui::ShowDemoWindow(&show_demo_window);
+
+
+	{
+		static float f = 0.0f;
+		static int counter = 0;
+
+		ImGuiIO& io = ImGui::GetIO();
+
+		ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+
+		ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
+		ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
+		ImGui::Checkbox("Another Window", &show_another_window);
+
+		ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
+		//ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
+
+		if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+			counter++;
+		ImGui::SameLine();
+		ImGui::Text("counter = %d", counter);
+
+		ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
+		ImGui::End();
+	}
+
+	if(show_another_window) {
+		ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
+		ImGui::Text("Hello from another window!");
+		if (ImGui::Button("Close Me"))
+			show_another_window = false;
+		ImGui::End();
+	}
+}
+
+bool ProcessEvent(const void* sdlEvent)
+{
+	return ImGui_ImplSDL2_ProcessEvent( (const SDL_Event*)sdlEvent );
+}
+
+void EndFrame()
+{
+	// I think this can happen if we're not coming from idCommon::Frame() but screenshot or sth
+	if (!haveNewFrame) {
+		NewFrame();
+	}
+	haveNewFrame = false;
+	ImGui::Render();
+	ImGuiIO& io = ImGui::GetIO();
+	//qglViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
+	//ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+	//qglClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
+	//qglClear(GL_COLOR_BUFFER_BIT);
+
+	qglDisable( GL_VERTEX_PROGRAM_ARB );
+	qglDisable( GL_FRAGMENT_PROGRAM_ARB );
+
+	GLint curArrayBuffer = 0, curElemBuffer = 0;
+	qglGetIntegerv( GL_ARRAY_BUFFER_BINDING_ARB, &curArrayBuffer );
+	qglGetIntegerv( GL_ELEMENT_ARRAY_BUFFER_BINDING_ARB, &curElemBuffer );
+
+	qglBindBufferARB( GL_ARRAY_BUFFER_ARB, 0 );
+	qglBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, 0 );
+
+
+	ImDrawData* drawData = ImGui::GetDrawData();
+	ImGui_ImplOpenGL2_RenderDrawData( drawData );
+
+	if( curArrayBuffer != 0 ) {
+		qglBindBufferARB( GL_ARRAY_BUFFER_ARB, curArrayBuffer );
+	}
+	if( curElemBuffer != 0 ) {
+		qglBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, curElemBuffer );
+	}
+}
+
+}} //namespace D3::ImGuiHooks
+
+#endif // D3_ENABLE_IMGUI

neo/sys/sys_imgui.h

@@ -0,0 +1,57 @@
+
+
+#ifndef NEO_SYS_SYS_IMGUI_H_
+#define NEO_SYS_SYS_IMGUI_H_
+
+#include "../libs/imgui/imgui.h"
+
+namespace D3 {
+namespace ImGuiHooks {
+
+#ifndef IMGUI_DISABLE
+
+extern ImGuiContext* imguiCtx; // this is only here so IsImguiEnabled() can use it inline
+
+inline bool IsImguiEnabled()
+{
+	return imguiCtx != NULL;
+}
+
+// using void* instead of SDL_Window and SDL_GLContext to avoid dragging SDL headers into sys_imgui.h
+extern bool Init(void* sdlWindow, void* sdlGlContext);
+
+extern void Shutdown();
+
+extern void NewFrame();
+
+extern bool ProcessEvent(const void* sdlEvent);
+
+extern void EndFrame();
+
+#else // IMGUI_DISABLE - just stub out everything
+
+inline bool IsImguiEnabled()
+{
+	return false;
+}
+
+// using void* instead of SDL_Window and SDL_GLContext to avoid dragging SDL headers into sys_imgui.h
+inline bool Init(void* sdlWindow, void* sdlGlContext)
+{
+	return false;
+}
+
+inline void Shutdown() {}
+
+inline void NewFrame() {}
+
+inline bool ProcessEvent(const void* sdlEvent) { return false; }
+
+inline void EndFrame() {}
+
+#endif
+
+}} //namespace D3::ImGuiHooks
+
+
+#endif /* NEO_SYS_SYS_IMGUI_H_ */