GUI: More refactoring

src/gui/CMakeLists.txt

@@ -10,13 +10,16 @@ include(pfd)
 set(GUI_SOURCES
     src/draw_grid.cpp
     src/err_window.cpp
+    src/glfw_context.cpp
+    src/imgui_helpers.cpp
     src/goal_window.cpp
     src/grid_info.cpp
     src/grid_window.cpp
     src/main.cpp
     src/picross_file.cpp
     src/settings.cpp
     src/settings_window.cpp
+    src/style.cpp
 )
 
 file(GLOB GUI_HEADERS src/*.h)

src/gui/src/err_window.cpp

@@ -25,7 +25,9 @@ void ErrWindow::visit(bool& can_be_erased)
 {
     ImGui::SetNextWindowSizeConstraints(ImVec2(0, 300), ImVec2(FLT_MAX, 600));
 
-    constexpr ImGuiWindowFlags win_flags = ImGuiWindowFlags_AlwaysAutoResize;
+    constexpr ImGuiWindowFlags win_flags = ImGuiWindowFlags_AlwaysAutoResize
+                                         | ImGuiWindowFlags_NoSavedSettings;
+
     bool is_window_open = true;
     if (!ImGui::Begin(pImpl->title.c_str(), &is_window_open, win_flags))
     {

src/gui/src/glfw_context.cpp

@@ -0,0 +1,78 @@
+#include "glfw_context.h"
+
+
+#include <GLFW/glfw3.h>
+
+
+namespace
+{
+
+// Target OpenGL 3.3 for this project
+constexpr int TARGET_OPENGL_MAJOR = 3;
+constexpr int TARGET_OPENGL_MINOR = 0;
+constexpr bool TARGET_OPENGL_CORE_PROFILE = false;                  // 3.2+ only
+constexpr bool TARGET_OPENGL_FORWARD_COMPATIBILITY = true;          // 3.0 only, recommended for MacOS
+constexpr const char* TARGET_GLSL_VERSION_STR = "#version 130";
+
+// GLFW error handling function
+stdutils::io::ErrorHandler s_glfw_err_handler;
+void glfw_error_callback(int error, const char* description)
+{
+    if(!s_glfw_err_handler) { return; }
+    std::stringstream out;
+    out << "GLFW Error " << error << ": " << description;
+    s_glfw_err_handler(stdutils::io::Severity::ERR, out.str());
+}
+
+} // Anonymous namespace
+
+GLFWWindowContext::GLFWWindowContext(int width, int height, const std::string_view& title, const stdutils::io::ErrorHandler* err_handler)
+    : m_window_ptr(nullptr)
+    , m_glfw_init(false)
+{
+    static bool call_once = false;
+    if (call_once)
+        return;
+    call_once = true;
+
+    if (err_handler)
+    {
+        s_glfw_err_handler = *err_handler;
+        glfwSetErrorCallback(glfw_error_callback);
+    }
+    if (!glfwInit())
+    {
+       if (err_handler) { (*err_handler)(stdutils::io::Severity::FATAL, "GLFW failed to initialize"); }
+        return;
+    }
+    m_glfw_init = true;
+
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, TARGET_OPENGL_MAJOR);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, TARGET_OPENGL_MINOR);
+    if constexpr (TARGET_OPENGL_CORE_PROFILE)
+        glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+    if constexpr (TARGET_OPENGL_FORWARD_COMPATIBILITY)
+        glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+    m_window_ptr = glfwCreateWindow(width, height, title.data(), nullptr, nullptr);
+    if (m_window_ptr == nullptr)
+    {
+        if (err_handler) { (*err_handler)(stdutils::io::Severity::FATAL, "GLFW failed to create the window"); }
+        return;
+    }
+    glfwMakeContextCurrent(m_window_ptr);
+    glfwSwapInterval(1);
+}
+
+GLFWWindowContext::~GLFWWindowContext()
+{
+    if(m_window_ptr)
+        glfwDestroyWindow(m_window_ptr);
+    m_window_ptr = nullptr;
+    if (m_glfw_init)
+        glfwTerminate();
+}
+
+const char* glsl_version()
+{
+    return TARGET_GLSL_VERSION_STR;
+}

src/gui/src/glfw_context.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <stdutils/io.h>
+#include <string_view>
+
+// Wrapper class for GLFW initialization and window
+struct GLFWwindow;
+class GLFWWindowContext
+{
+public:
+    GLFWWindowContext(int width, int height, const std::string_view& title, const stdutils::io::ErrorHandler* err_handler = nullptr);
+    ~GLFWWindowContext();
+    GLFWwindow* window() { return m_window_ptr; }
+
+private:
+    GLFWwindow*     m_window_ptr;
+    bool            m_glfw_init;
+};
+
+const char* glsl_version();

src/gui/src/goal_window.cpp

@@ -25,7 +25,9 @@ void GoalWindow::visit(bool& can_be_erased, Settings& settings)
     const float min_win_height = 80.f + static_cast<float>(height * tile_size);
     ImGui::SetNextWindowSizeConstraints(ImVec2(min_win_width, min_win_height), ImVec2(FLT_MAX, FLT_MAX));
 
-    constexpr ImGuiWindowFlags win_flags = ImGuiWindowFlags_AlwaysAutoResize;
+    constexpr ImGuiWindowFlags win_flags = ImGuiWindowFlags_AlwaysAutoResize
+                                         | ImGuiWindowFlags_NoSavedSettings;
+
     bool is_window_open = true;
     if (!ImGui::Begin(title.c_str(), &is_window_open, win_flags))
     {

src/gui/src/grid_window.cpp

@@ -100,7 +100,9 @@ void GridWindow::visit(bool& can_be_erased, Settings& settings)
     const float min_win_height = 100.f + static_cast<float>(height * tile_size);
     ImGui::SetNextWindowSizeConstraints(ImVec2(min_win_width, min_win_height), ImVec2(FLT_MAX, FLT_MAX));
 
-    constexpr ImGuiWindowFlags win_flags = ImGuiWindowFlags_AlwaysAutoResize;
+    constexpr ImGuiWindowFlags win_flags = ImGuiWindowFlags_AlwaysAutoResize
+                                         | ImGuiWindowFlags_NoSavedSettings;
+
     bool is_window_open = true;
     if (!ImGui::Begin(title.c_str(), &is_window_open, win_flags))
     {

src/gui/src/imgui_helpers.cpp

@@ -0,0 +1,86 @@
+#include "imgui_helpers.h"
+
+#include <imgui_wrap.h>
+#include <imgui_impl_glfw.h>
+#include <imgui_impl_opengl3.h>
+#include <GLFW/glfw3.h>
+#include "glfw_context.h"
+
+
+namespace ImGui
+{
+
+void HelpMarker(const char* desc)
+{
+    ImGui::TextDisabled("(?)");
+    if (ImGui::BeginItemTooltip())
+    {
+        ImGui::PushTextWrapPos(ImGui::GetFontSize() * 35.0f);
+        ImGui::TextUnformatted(desc);
+        ImGui::PopTextWrapPos();
+        ImGui::EndTooltip();
+    }
+}
+
+// Place the window in the working area, that is the position of the viewport minus task bars, menus bars, status bars, etc.
+void SetNextWindowPosAndSize(const WindowLayout& window_layout, ImGuiCond cond)
+{
+    const auto work_tl_corner = ImGui::GetMainViewport()->WorkPos;
+    const auto work_size = ImGui::GetMainViewport()->WorkSize;
+    const ImVec2 tl_corner(window_layout.m_position.x + work_tl_corner.x, window_layout.m_position.y + work_tl_corner.y);
+    ImGui::SetNextWindowPos(tl_corner, cond);
+    ImGui::SetNextWindowSize(to_imgui_vec2(window_layout.window_size(to_screen_size(work_size))), cond);
+}
+
+} // namespace ImGui
+
+DearImGuiContext::DearImGuiContext(GLFWwindow* glfw_window, bool& any_fatal_error) noexcept
+{
+    any_fatal_error = false;
+    try
+    {
+        const bool versions_ok = IMGUI_CHECKVERSION();
+        const auto* ctx = ImGui::CreateContext();
+
+        // Setup Platform/Renderer backends
+        const bool init_glfw = ImGui_ImplGlfw_InitForOpenGL(glfw_window, true);
+        const bool init_opengl3 = ImGui_ImplOpenGL3_Init(glsl_version());
+
+        any_fatal_error = !versions_ok || (ctx == nullptr) || !init_glfw || !init_opengl3;
+    }
+    catch(const std::exception&)
+    {
+        any_fatal_error = true;
+    }
+}
+
+DearImGuiContext::~DearImGuiContext()
+{
+    ImGui_ImplOpenGL3_Shutdown();
+    ImGui_ImplGlfw_Shutdown();
+    ImGui::DestroyContext();
+}
+
+void DearImGuiContext::new_frame() const
+{
+    ImGui_ImplOpenGL3_NewFrame();
+    ImGui_ImplGlfw_NewFrame();
+    ImGui::NewFrame();
+}
+
+void DearImGuiContext::render() const
+{
+    ImGui::Render();
+    ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+}
+
+void DearImGuiContext::backend_info(std::ostream& out) const
+{
+    const ImGuiIO& io = ImGui::GetIO();
+    out << "Dear ImGui " << IMGUI_VERSION
+        << " (Backend platform: " << (io.BackendPlatformName ? io.BackendPlatformName : "NULL")
+        << ", renderer: " << (io.BackendRendererName ? io.BackendRendererName : "NULL") << ")" << std::endl;
+    out << "GLFW " << GLFW_VERSION_MAJOR << "." << GLFW_VERSION_MINOR << "." << GLFW_VERSION_REVISION << std::endl;
+    out << "OpenGL Version " << glGetString(GL_VERSION) << std::endl;
+    out << "OpenGL Renderer " << glGetString(GL_RENDERER) << std::endl;
+}

src/gui/src/imgui_helpers.h

@@ -0,0 +1,46 @@
+#pragma once
+
+#include "screen.h"
+#include "window_layout.h"
+
+#include <imgui_wrap.h>
+
+#include <ostream>
+
+inline ScreenPos to_screen_pos(ImVec2 vec2)
+{
+    return ScreenPos(vec2.x, vec2.y);
+}
+
+inline ScreenSize to_screen_size(ImVec2 vec2)
+{
+    return ScreenSize(vec2.x, vec2.y);
+}
+
+inline ImVec2 to_imgui_vec2(ScreenPos pos)
+{
+    return ImVec2(pos.x, pos.y);
+}
+
+namespace ImGui
+{
+void HelpMarker(const char* desc);          // Function taken from imgui_demo.cpp
+void SetNextWindowPosAndSize(const WindowLayout& window_layout, ImGuiCond cond = 0);
+}
+
+// Do not call this class ImGuiContext because this is an internal class of Dear ImGui
+struct GLFWwindow;
+class DearImGuiContext
+{
+public:
+    explicit DearImGuiContext(GLFWwindow* glfw_window, bool& any_fatal_error) noexcept;
+    ~DearImGuiContext();
+    DearImGuiContext(const DearImGuiContext&) = delete;
+    DearImGuiContext(DearImGuiContext&&) = delete;
+    DearImGuiContext& operator=(const DearImGuiContext&) = delete;
+    DearImGuiContext& operator=(DearImGuiContext&&) = delete;
+
+    void new_frame() const;
+    void render() const;
+    void backend_info(std::ostream& out) const;
+};