First steps with Dear ImGui. It's awesome!

src/CMakeLists.txt

@@ -22,18 +22,20 @@ target_compile_features(doompanning PRIVATE cxx_std_17)
 target_link_libraries(doompanning
     PRIVATE dp_common
     PRIVATE imgui
-    )
+)
 
 add_executable(dp_imgui_demo dp_imgui_demo.cc)
 target_compile_features(dp_imgui_demo PRIVATE cxx_std_17)
 target_link_libraries(dp_imgui_demo
     PRIVATE dp_common
     PRIVATE imgui
-    )
+)
 
 add_executable(dp_common_c_test dp_common_c_test.c)
 target_compile_features(dp_common_c_test PRIVATE c_std_11)
-target_link_libraries(dp_common_c_test PRIVATE dp_common)
+target_link_libraries(dp_common_c_test
+    PRIVATE dp_common
+)
 
 add_executable(doomsim doomsim.cc)
 target_compile_features(doomsim PRIVATE cxx_std_17)

src/doompanning.cc

@@ -1,12 +1,15 @@
-#include <cstdlib>
 #include <nng/nng.h>
-
 #include <imgui.h>
 #include <backends/imgui_impl_sdl.h>
 #include <backends/imgui_impl_sdlrenderer.h>
 #include <SDL.h>
 
+#include <cstdlib>
+#include <type_traits>
+#include <vector>
+
 #include "dp_common.h"
+#include "dp_util.hpp"
 
 void dp_sdl_fatal(const char *const msg)
 {
@@ -14,21 +17,80 @@ void dp_sdl_fatal(const char *const msg)
     abort();
 }
 
+struct DoomState
+{
+};
+
+static_assert(std::is_trivial<DoomState>::value, "DoomState must be a trivial type");
+
 struct ControllerContext
 {
     nng_socket pub;
     nng_socket sub;
     SDL_Window *window;
     SDL_Renderer *renderer;
+    std::vector<DoomState> dooms;
+    bool quit = false;
 };
 
+void show_ui(ControllerContext *ctx)
+{
+    const ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui::SetNextWindowPos(ImVec2(main_viewport->WorkPos.x + 20, main_viewport->WorkPos.y + 20), ImGuiCond_FirstUseEver);
+    ImGui::SetNextWindowSize(ImVec2(550, 340), ImGuiCond_FirstUseEver);
+    ImGuiWindowFlags window_flags = ImGuiWindowFlags_MenuBar;
+
+#ifndef IMGUI_DISABLE_DEBUG_TOOLS
+    const bool has_debug_tools = true;
+#else
+    const bool has_debug_tools = false;
+#endif
+    static bool show_app_metrics = false;
+    static bool show_app_debug_log = false;
+
+    if (show_app_metrics)
+        ImGui::ShowMetricsWindow(&show_app_metrics);
+    if (show_app_debug_log)
+        ImGui::ShowDebugLogWindow(&show_app_debug_log);
+
+    // Main body of the Demo window starts here.
+    if (!ImGui::Begin("doompanning controls", nullptr, window_flags))
+    {
+        // Early out if the window is collapsed, as an optimization.
+        ImGui::End();
+        return;
+    }
+
+    ImGui::PushItemWidth(ImGui::GetFontSize() * -12);
+
+    // Menu Bar
+    if (ImGui::BeginMenuBar())
+    {
+        if (ImGui::BeginMenu("Menu"))
+        {
+            ImGui::MenuItem("Quit", "Ctrl+Q", &ctx->quit, true);
+            ImGui::EndMenu();
+        }
+
+        if (ImGui::BeginMenu("Tools"))
+        {
+            ImGui::MenuItem("Dear ImGui Metrics/Debugger", NULL, &show_app_metrics, has_debug_tools);
+            ImGui::MenuItem("Dear ImGui Debug Log", NULL, &show_app_debug_log, has_debug_tools);
+            ImGui::EndMenu();
+        }
+
+        ImGui::EndMenuBar();
+    }
+
+    ImGui::PopItemWidth();
+    ImGui::End();
+}
+
 int doom_controller_loop(ControllerContext *ctx)
 {
     static constexpr ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
-    bool done = false;
-
-    while (!done)
+    while (!ctx->quit)
     {
         SDL_Event event;
         while (SDL_PollEvent(&event))
@@ -36,13 +98,13 @@ int doom_controller_loop(ControllerContext *ctx)
             ImGui_ImplSDL2_ProcessEvent(&event);
 
             if (event.type == SDL_QUIT)
-                done = true;
+                ctx->quit = true;
 
             if (event.type == SDL_WINDOWEVENT
                 && event.window.event == SDL_WINDOWEVENT_CLOSE
                 && event.window.windowID == SDL_GetWindowID(ctx->window))
             {
-                done = true;
+                ctx->quit = true;
             }
         }
 
@@ -51,10 +113,13 @@ int doom_controller_loop(ControllerContext *ctx)
         ImGui_ImplSDL2_NewFrame();
         ImGui::NewFrame();
 
+        // Do ImGui things here
+        show_ui(ctx);
+
         // Rendering
         ImGui::Render();
-        SDL_SetRenderDrawColor(ctx->renderer,
-            (u8)(clear_color.x * 255), (u8)(clear_color.y * 255), (u8)(clear_color.z * 255), (u8)(clear_color.w * 255));
+        auto [r, g, b, a] = imvec4_to_rgba(clear_color);
+        SDL_SetRenderDrawColor(ctx->renderer, r, g, b, a);
         SDL_RenderClear(ctx->renderer);
         ImGui_ImplSDLRenderer_RenderDrawData(ImGui::GetDrawData());
         SDL_RenderPresent(ctx->renderer);
@@ -89,6 +154,7 @@ int main(int argc, char *argv[])
 
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
+    ImGui::GetIO().IniFilename = "doompanning_ui.ini";
     ImGui::StyleColorsDark();
     ImGui_ImplSDL2_InitForSDLRenderer(window, renderer);
     ImGui_ImplSDLRenderer_Init(renderer);
@@ -103,7 +169,8 @@ int main(int argc, char *argv[])
         pubSock,
         subSock,
         window,
-        renderer
+        renderer,
+        {}
     };
 
     int ret = doom_controller_loop(&ctx);

src/doomsim.cc

@@ -7,23 +7,6 @@
 #include <nng/protocol/pubsub0/sub.h>
 #include "dp_common.h"
 
-enum DP_DoomState
-{
-    DP_DS_Ready,
-    DP_DS_Running,
-    DP_DS_Quit,
-    DP_DS_COUNT,
-};
-
-static const char *const DP_DoomState_Strings[DP_DS_COUNT] =
-{
-    "DoomState_Ready",
-    "DoomState_Running",
-    "DoomState_Quit",
-};
-
-#define doomstate_str(s) DP_DoomState_Strings[s]
-
 typedef struct DoomContext DoomContext;
 
 #define DEF_DOOM_STATE_FUNC(fn) int fn(DoomContext *ctx)

src/dp_common.c

@@ -95,3 +95,10 @@ nng_socket make_doom_sub(const char *url)
 
     return sock;
 }
+
+const char *const DP_DoomState_Strings[DP_DS_COUNT] =
+{
+    "DoomState_Ready",
+    "DoomState_Running",
+    "DoomState_Quit",
+};

src/dp_common.h

@@ -28,15 +28,29 @@ static const char *const DoomUrl = "ipc://666_doom.socket"; // dooms publish her
 typedef u32 doomid_t; // unique id for each doom instance
 typedef u16 dmt_t; // for DP_MessageType values
 
-enum DP_MessageType
+typedef enum DP_MessageType
 {
     DP_MT_Invalid,
     DP_MT_DoomReady,
     DP_MT_RunDoom,
     DP_MT_QuitDoom,
     DP_MT_COUNT
-};
+} DP_MessageType;
 
+typedef enum DP_DoomState
+{
+    DP_DS_Ready,
+    DP_DS_Running,
+    DP_DS_Quit,
+    DP_DS_COUNT,
+} DP_DoomState;
+
+extern const char *const DP_DoomState_Strings[DP_DS_COUNT];
+
+static inline const char *doomstate_str(DP_DoomState ds)
+{
+    return DP_DoomState_Strings[ds];
+}
 
 #ifdef __cplusplus
 }

src/dp_common_c_test.c

@@ -5,5 +5,8 @@ int main(int argc, char *argv[])
     (void) argc;
     (void) argv;
     log_info("Hello from C11!");
+
+    for (int i=0; i<DP_DS_COUNT; ++i)
+        log_info("doomstate_str: %d=%s", i, doomstate_str(i));
     return 0;
 }

src/dp_util.hpp

@@ -0,0 +1,19 @@
+#ifndef SRC_DP_UTIL_HPP
+#define SRC_DP_UTIL_HPP
+
+#include <imgui.h>
+#include <tuple>
+#include "dp_types.h"
+
+inline std::tuple<u8, u8, u8, u8> imvec4_to_rgba(const ImVec4 &color)
+{
+    return
+    {
+        color.x * 255,
+        color.y * 255,
+        color.z * 255,
+        color.w * 255,
+    };
+}
+
+#endif // SRC_DP_UTIL_HPP