1 files changed, 92 insertions, 0 deletions
diff --git a/source/gui.cpp b/source/gui.cpp
new file mode 100644
index 0000000..15beb90
--- /dev/null
+++ b/source/gui.cpp
@@ -0,0 +1,92 @@
+/**
+ * @file gui.cpp
+ * @brief Contains code for GUI-related logic.
+ *
+ * Copyright (C) 2021 Clyne Sullivan
+ *
+ * Distributed under the GNU GPL v3 or later. You should have received a copy of
+ * the GNU General Public License along with this program.
+ * If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "imgui.h"
+#include "backends/imgui_impl_sdl.h"
+#include "backends/imgui_impl_opengl2.h"
+
+#include "config.h"
+
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_opengl.h>
+
+ImFont *font = nullptr;
+static ImGuiIO *io = nullptr;
+static SDL_Window *window = nullptr;
+static decltype(SDL_GL_CreateContext(nullptr)) gl_context;
+
+bool guiInitialize()
+{
+    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
+        printf("Error: %s\n", SDL_GetError());
+        return false;
+    }
+
+    // Setup window
+    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
+    SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
+    window = SDL_CreateWindow("stmdsp gui",
+        SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+        WINDOW_WIDTH, WINDOW_HEIGHT,
+        SDL_WINDOW_OPENGL /*| SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI*/);
+    gl_context = SDL_GL_CreateContext(window);
+    SDL_GL_MakeCurrent(window, gl_context);
+    SDL_GL_SetSwapInterval(1); // Enable vsync
+
+    // Setup Dear ImGui context
+    IMGUI_CHECKVERSION();
+    ImGui::CreateContext();
+    io = &ImGui::GetIO();
+    io->ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
+    font = io->Fonts->AddFontFromFileTTF("fonts/Roboto-Medium.ttf", 20);
+    ImGui::StyleColorsLight();
+
+    ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
+    ImGui_ImplOpenGL2_Init();
+
+    return true;
+}
+
+void guiRender(void (*func)())
+{
+   glViewport(0, 0, (int)io->DisplaySize.x, (int)io->DisplaySize.y);
+   glClearColor(1, 1, 1, 1);
+   glClear(GL_COLOR_BUFFER_BIT);
+   func();
+   SDL_GL_SwapWindow(window);
+}
+
+void guiHandleEvents(bool& done)
+{
+    SDL_Event event;
+    for (SDL_Event event; SDL_PollEvent(&event);) {
+        ImGui_ImplSDL2_ProcessEvent(&event);
+        if (event.type == SDL_QUIT)
+            done = true;
+        if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
+            done = true;
+    }
+}
+
+void guiShutdown()
+{
+    ImGui_ImplOpenGL2_Shutdown();
+    ImGui_ImplSDL2_Shutdown();
+    ImGui::DestroyContext();
+
+    SDL_GL_DeleteContext(gl_context);
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+}
+