Add imgui compilation

3 files changed, 200 insertions, 6 deletions

diff --git a/.gitignore b/.gitignore
index 9042904..5d4ccb4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,5 @@
 
 obj/
 /compile_commands.json
+
+imgui.ini
diff --git a/Makefile b/Makefile
index 98e6346..49823c8 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,5 @@
 CC ?= gcc
+CC ?= g++
 
 SRCDIR ?= src
 INCDIR ?= inc
@@ -6,11 +7,13 @@ OBJDIR ?= obj
 TSTDIR ?= test
 EXMDIR ?= examples
 
-LIBS = -lm
-INCS = -Ithirdparty/cglm/include -Iinc/
+PKGS = sdl2 opengl
+LIBS = -lm $(shell pkg-config --libs $(PKGS))
+INCS = -Ithirdparty/cglm/include -Ithirdparty/ -Iinc/
 
 CFLAGS ?= -D_FORTIFY_SOURCE=2 -Wall -Werror -Wno-error=unused-variable -g -Og
-CFLAGS += -std=gnu23 -fms-extensions -flto
+CFLAGS += -std=gnu23 -fms-extensions -flto $(shell pkg-config --cflags $(PKGS)) -DCIMGUI_USE_OPENGL3 -DCIMGUI_USE_SDL2
+CXXFLAGS += -flto $(shell pkg-config --cflags $(PKGS)) -DCIMGUI_USE_OPENGL3 -DCIMGUI_USE_SDL2 -DIMGUI_IMPL_API='extern "C"'
 
 APP_MAIN_SOURCES = $(SRCDIR)/main.c
 APP_MAIN_OBJS = $(APP_MAIN_SOURCES:%.c=$(OBJDIR)/%.o)
@@ -30,6 +33,8 @@ EXM_OBJS = $(EXM_SOURCES:%.c=$(OBJDIR)/%.o)
 EXM_DEPS = $(EXM_OBJS:%.o=%.d)
 EXM_APPS = $(EXM_SOURCES:%.c=$(OBJDIR)/%)
 
+IMGUI_OBJS = $(OBJDIR)/thirdparty/cimgui/imgui/backends/imgui_impl_sdl2.o $(OBJDIR)/thirdparty/cimgui/imgui/backends/imgui_impl_opengl3.o
+
 -include $(APP_DEPS) $(APP_MAIN_DEPS) $(TST_DEPS) $(EXM_DEPS)
 
 # We don't really need to run the tests for bear to record them
@@ -37,8 +42,14 @@ compile_commands.json: clean Makefile $(APP_SOURCES)
 	@rm -f "$@"
 	bear -- make main
 
-main: $(APP_MAIN_OBJS) $(APP_OBJS)
-	$(CC) $(LDFLAGS) $(CFLAGS) -o $@ $(APP_MAIN_OBJS) $(APP_OBJS) $(LIBS)
+.PHONY: thirdparty/cimgui/cimgui.so
+thirdparty/cimgui/cimgui.so:
+	make -C thirdparty/cimgui
+
+LIBS += -Lthirdparty/cimgui -Wl,-rpath,'$$ORIGIN/thirdparty/cimgui' -lcimgui -lstdc++
+
+main: $(APP_MAIN_OBJS) $(APP_OBJS) thirdparty/cimgui/cimgui.so $(IMGUI_OBJS)
+	$(CC) $(LDFLAGS) $(CFLAGS) -o $@ $(APP_MAIN_OBJS) $(APP_OBJS) $(IMGUI_OBJS) $(LIBS)
 
 $(OBJDIR)/%.o: %.c
 	@mkdir -p $(dir $@)
@@ -55,6 +66,7 @@ $(OBJDIR)/examples/%: $(OBJDIR)/examples/%.o $(APP_OBJS)
 clean:
 	@rm -rf $(OBJDIR)
 	@rm -f main
+	@make -C thirdparty/cimgui clean
 
 test: $(TST_APPS)
 	@echo "Running tests"
@@ -64,3 +76,8 @@ examples: $(EXM_APPS)
 
 .DEFAULT_GOAL := all
 all: main test examples
+
+# Imgui specific compile rules
+$(OBJDIR)/%.o: %.cpp
+	@mkdir -p $(dir $@)
+	$(CXX) $(CXXFLAGS) $(INCS) -Ithirdparty/cimgui/imgui/ -MMD -o $@ -c $<
diff --git a/src/main.c b/src/main.c
index 9f8d151..10cbbfc 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,6 +1,17 @@
 #include "cad.h"
 #include "cad/debug.h"
 
+#define CIMGUI_DEFINE_ENUMS_AND_STRUCTS
+#include "cimgui/cimgui.h"
+#include "cimgui/cimgui_impl.h"
+#include <SDL2/SDL.h>
+
+#include <GL/gl.h>
+#include <GL/glu.h>
+
+#define igGetIO igGetIO_Nil
+SDL_Window *window = NULL;
+
 struct smooth_line {
 	struct component l1;
 	struct component l2;
@@ -151,7 +162,7 @@ void draw_from_constraints(struct constraints *c, struct topology *t, struct can
 	free_drawing(&drawing);
 }
 
-int main(int argc, char *argv[]) {
+int main2(int argc, char *argv[]) {
 	struct constraints constraints = {};
 	struct topology topo = {};
 
@@ -280,4 +291,168 @@ int main(int argc, char *argv[]) {
 
 	free_constraints(&constraints);
 	free_topology(&topo);
+	return 0;
+}
+
+int main(int argc, char* argv[]) {
+
+	if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+		SDL_Log("failed to init: %s", SDL_GetError());
+		return -1;
+	}
+ 
+	// GL 3.0 + GLSL 130
+	const char* glsl_version = "#version 130";
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0);
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
+
+	// and prepare OpenGL stuff
+	SDL_SetHint(SDL_HINT_RENDER_DRIVER, "opengl");
+	SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
+	SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
+	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+	SDL_DisplayMode current;
+	SDL_GetCurrentDisplayMode(0, &current);
+	float main_scale = ImGui_ImplSDL2_GetContentScaleForDisplay(0);
+	SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
+	window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+ 
+	if (window == NULL) {
+		SDL_Log("Failed to create window: %s", SDL_GetError());
+		return -1;
+	}
+
+	SDL_GLContext gl_context = SDL_GL_CreateContext(window);
+	SDL_GL_SetSwapInterval(1);  // enable vsync
+
+
+	// check opengl version sdl uses
+	SDL_Log("opengl version: %s", (char*)glGetString(GL_VERSION));
+
+	// setup imgui
+	igCreateContext(NULL);
+
+	//set docking
+	ImGuiIO* ioptr = igGetIO();
+	ioptr->ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;       // Enable Keyboard Controls
+	ioptr->ConfigFlags |= ImGuiConfigFlags_DockingEnable;
+
+	// Setup scaling
+	ImGuiStyle* style = igGetStyle();
+	ImGuiStyle_ScaleAllSizes(style, main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+	style->FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+	ioptr->ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+	ioptr->ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+
+	ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
+	ImGui_ImplOpenGL3_Init(glsl_version);
+
+	igStyleColorsDark(NULL);
+	//ImFontAtlas_AddFontDefault(io.Fonts, NULL);
+
+
+	bool showDemoWindow = true;
+	bool showAnotherWindow = false;
+	ImVec4 clearColor;
+	clearColor.x = 0.45f;
+	clearColor.y = 0.55f;
+	clearColor.z = 0.60f;
+	clearColor.w = 1.00f;
+
+	bool quit = false;
+	while (!quit)
+	{
+		SDL_Event e;
+
+		// we need to call SDL_PollEvent to let window rendered, otherwise
+		// no window will be shown
+		while (SDL_PollEvent(&e) != 0)
+		{
+			ImGui_ImplSDL2_ProcessEvent(&e);
+			if (e.type == SDL_QUIT)
+				quit = true;
+			if (e.type == SDL_WINDOWEVENT && e.window.event == SDL_WINDOWEVENT_CLOSE && e.window.windowID == SDL_GetWindowID(window))
+				quit = true;
+		}
+
+		// start imgui frame
+		ImGui_ImplOpenGL3_NewFrame();
+		ImGui_ImplSDL2_NewFrame();
+		igNewFrame();
+
+		if (showDemoWindow)
+			igShowDemoWindow(&showDemoWindow);
+
+		// show a simple window that we created ourselves.
+		{
+			static float f = 0.0f;
+			static int counter = 0;
+
+			igBegin("Hello, world!", NULL, 0);
+			igText("This is some useful text");
+			igCheckbox("Demo window", &showDemoWindow);
+			igCheckbox("Another window", &showAnotherWindow);
+
+			igSliderFloat("Float", &f, 0.0f, 1.0f, "%.3f", 0);
+			igColorEdit3("clear color", (float*)&clearColor, 0);
+
+			ImVec2 buttonSize;
+			buttonSize.x = 0;
+			buttonSize.y = 0;
+			if (igButton("Button", buttonSize))
+				counter++;
+			igSameLine(0.0f, -1.0f);
+			igText("counter = %d", counter);
+
+			igText("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / igGetIO()->Framerate, igGetIO()->Framerate);
+			igEnd();
+		}
+
+		if (showAnotherWindow)
+		{
+			igBegin("imgui Another Window", &showAnotherWindow, 0);
+			igText("Hello from imgui");
+			ImVec2 buttonSize;
+			buttonSize.x = 0; buttonSize.y = 0;
+			if (igButton("Close me", buttonSize))
+			{
+				showAnotherWindow = false;
+			}
+			igEnd();
+		}
+
+		// render
+		igRender();
+		SDL_GL_MakeCurrent(window, gl_context);
+		glViewport(0, 0, (int)ioptr->DisplaySize.x, (int)ioptr->DisplaySize.y);
+		glClearColor(clearColor.x, clearColor.y, clearColor.z, clearColor.w);
+		glClear(GL_COLOR_BUFFER_BIT);
+		ImGui_ImplOpenGL3_RenderDrawData(igGetDrawData());
+		if (ioptr->ConfigFlags & ImGuiConfigFlags_ViewportsEnable) {
+			SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+			SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
+			igUpdatePlatformWindows();
+			igRenderPlatformWindowsDefault(NULL,NULL);
+			SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
+		}
+		SDL_GL_SwapWindow(window);
+	}
+
+	// clean up
+	ImGui_ImplOpenGL3_Shutdown();
+	ImGui_ImplSDL2_Shutdown();
+	igDestroyContext(NULL);
+
+	SDL_GL_DeleteContext(gl_context);
+	if (window != NULL)
+	{
+		SDL_DestroyWindow(window);
+		window = NULL;
+	}
+	SDL_Quit();
+
+	return 0;
 }