Start with ImGui support

Signed-off-by: falkTX <falktx@falktx.com>

generic/.kdev_include_paths

@@ -0,0 +1,4 @@
+../../dpf/dgl/
+../../dpf/distrho/
+../../DPF/dgl/
+../../DPF/distrho/

opengl/DearImGui.cpp

@@ -0,0 +1,370 @@
+/*
+ * Dear ImGui for DPF
+ * Copyright (C) 2021 Filipe Coelho <falktx@falktx.com>
+ * Copyright (C) 2021 Jean Pierre Cimalando <jp-dev@inbox.ru>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any purpose with
+ * or without fee is hereby granted, provided that the above copyright notice and this
+ * permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+ * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN
+ * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "DearImGui.hpp"
+
+#ifndef IMGUI_SKIP_IMPLEMENTATION
+# define IMGUI_DPF_BACKEND
+# include "DearImGui/imgui.cpp"
+# include "DearImGui/imgui_demo.cpp"
+# include "DearImGui/imgui_draw.cpp"
+# include "DearImGui/imgui_tables.cpp"
+# include "DearImGui/imgui_widgets.cpp"
+# ifdef DGL_USE_OPENGL3
+#  include "DearImGui/imgui_impl_opengl3.cpp"
+# else
+#  include "DearImGui/imgui_impl_opengl2.cpp"
+# endif
+#else
+# ifdef DGL_USE_OPENGL3
+#  include "DearImGui/imgui_impl_opengl3.h"
+# else
+#  include "DearImGui/imgui_impl_opengl2.h"
+# endif
+#endif
+
+START_NAMESPACE_DGL
+
+// --------------------------------------------------------------------------------------------------------------------
+
+int mouseButtonToImGui(int button)
+{
+    switch (button)
+    {
+    case 1:
+        return 0;
+    case 2:
+        return 2;
+    case 3:
+        return 1;
+    default:
+        return -1;
+    }
+}
+
+template <class BaseWidget>
+struct ImGuiWidget<BaseWidget>::PrivateData {
+    ImGuiWidget<BaseWidget>* const self;
+    ImGuiContext* context;
+
+    explicit PrivateData(ImGuiWidget<BaseWidget>* const s)
+        : self(s),
+          context(nullptr)
+    {
+        IMGUI_CHECKVERSION();
+        context = ImGui::CreateContext();
+        ImGui::SetCurrentContext(context);
+
+        const double scaleFactor = self->getTopLevelWidget()->getScaleFactor();
+
+        ImGuiIO& io(ImGui::GetIO());
+        io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
+        io.DisplaySize.x = std::round(scaleFactor * self->getWidth());
+        io.DisplaySize.y = std::round(scaleFactor * self->getHeight());
+        io.IniFilename = nullptr;
+
+        /*
+        io.KeyMap[ImGuiKey_Tab] = '\t';
+        io.KeyMap[ImGuiKey_LeftArrow] = IM_ARRAYSIZE(io.KeysDown) - kKeyLeft;
+        io.KeyMap[ImGuiKey_RightArrow] = IM_ARRAYSIZE(io.KeysDown) - kKeyRight;
+        io.KeyMap[ImGuiKey_UpArrow] = IM_ARRAYSIZE(io.KeysDown) - kKeyUp;
+        io.KeyMap[ImGuiKey_DownArrow] = IM_ARRAYSIZE(io.KeysDown) - kKeyDown;
+        io.KeyMap[ImGuiKey_PageUp] = IM_ARRAYSIZE(io.KeysDown) - kKeyPageUp;
+        io.KeyMap[ImGuiKey_PageDown] = IM_ARRAYSIZE(io.KeysDown) - kKeyPageDown;
+        io.KeyMap[ImGuiKey_Home] = IM_ARRAYSIZE(io.KeysDown) - kKeyHome;
+        io.KeyMap[ImGuiKey_End] = IM_ARRAYSIZE(io.KeysDown) - kKeyEnd;
+        io.KeyMap[ImGuiKey_Insert] = IM_ARRAYSIZE(io.KeysDown) - kKeyInsert;
+        io.KeyMap[ImGuiKey_Delete] = 127;
+        io.KeyMap[ImGuiKey_Backspace] = '\b';
+        io.KeyMap[ImGuiKey_Space] = ' ';
+        io.KeyMap[ImGuiKey_Enter] = '\r';
+        io.KeyMap[ImGuiKey_Escape] = 27;
+        io.KeyMap[ImGuiKey_A] = 'A';
+        io.KeyMap[ImGuiKey_C] = 'C';
+        io.KeyMap[ImGuiKey_V] = 'V';
+        io.KeyMap[ImGuiKey_X] = 'X';
+        io.KeyMap[ImGuiKey_Y] = 'Y';
+        io.KeyMap[ImGuiKey_Z] = 'Z';
+        */
+
+#ifdef DGL_USE_OPENGL3
+        ImGui_ImplOpenGL3_Init();
+#else
+        ImGui_ImplOpenGL2_Init();
+#endif
+    }
+
+    ~PrivateData()
+    {
+        ImGui::SetCurrentContext(context);
+#ifdef DGL_USE_OPENGL3
+        ImGui_ImplOpenGL3_Shutdown();
+#else
+        ImGui_ImplOpenGL2_Shutdown();
+#endif
+        ImGui::DestroyContext(context);
+    }
+
+    DISTRHO_DECLARE_NON_COPYABLE(PrivateData)
+};
+
+// --------------------------------------------------------------------------------------------------------------------
+
+template <class BaseWidget>
+void ImGuiWidget<BaseWidget>::idleCallback()
+{
+    /*
+    bool shouldRepaint;
+
+    if (fImpl->fWasEverPainted)
+    {
+        Impl::Clock::duration elapsed =
+            Impl::Clock::now() - fImpl->fLastRepainted;
+        std::chrono::milliseconds elapsedMs =
+            std::chrono::duration_cast<std::chrono::milliseconds>(elapsed);
+        shouldRepaint = elapsedMs.count() > fImpl->fRepaintIntervalMs;
+    }
+    else
+    {
+        shouldRepaint = true;
+    }
+
+    if (shouldRepaint)
+        repaint();
+    */
+    BaseWidget::repaint();
+}
+
+template <>
+void ImGuiWidget<SubWidget>::onDisplay()
+{
+    ImGui::SetCurrentContext(pData->context);
+
+#ifdef DGL_USE_OPENGL3
+    ImGui_ImplOpenGL3_NewFrame();
+#else
+    ImGui_ImplOpenGL2_NewFrame();
+#endif
+
+    ImGui::NewFrame();
+    onImGuiDisplay();
+    ImGui::Render();
+
+    /*
+    const GraphicsContext& gc(getGraphicsContext());
+    Color::fromHTML("#373").setFor(gc);
+    Rectangle<double> r(0, 0, getWidth(), getHeight());
+    r.draw(gc);
+    */
+
+    if (ImDrawData* const data = ImGui::GetDrawData())
+    {
+        data->DisplayPos.x = -getAbsoluteX();
+        data->DisplayPos.y = getWindow().getHeight() - (getAbsoluteY() + getHeight());
+#ifdef DGL_USE_OPENGL3
+        ImGui_ImplOpenGL3_RenderDrawData(data);
+#else
+        ImGui_ImplOpenGL2_RenderDrawData(data);
+#endif
+    }
+
+    /*
+    fImpl->fLastRepainted = Impl::Clock::now();
+    fImpl->fWasEverPainted = true;
+    */
+}
+
+template <class BaseWidget>
+bool ImGuiWidget<BaseWidget>::onKeyboard(const Widget::KeyboardEvent& event)
+{
+    /*
+    ImGui::SetCurrentContext(pData->context);
+
+    ImGuiIO& io(ImGui::GetIO());
+
+    if (event.press)
+        io.AddInputCharacter(event.key);
+
+    int imGuiKey = event.key;
+    if (imGuiKey >= 0 && imGuiKey < 128)
+    {
+        if (imGuiKey >= 'a' && imGuiKey <= 'z')
+            imGuiKey = imGuiKey - 'a' + 'A';
+        io.KeysDown[imGuiKey] = event.press;
+    }
+
+    return io.WantCaptureKeyboard;
+    */
+
+    return BaseWidget::onKeyboard(event);
+}
+
+template <class BaseWidget>
+bool ImGuiWidget<BaseWidget>::onSpecial(const Widget::SpecialEvent& event)
+{
+    /*
+    ImGui::SetCurrentContext(pData->context);
+
+    ImGuiIO& io(ImGui::GetIO());
+
+    int imGuiKey = IM_ARRAYSIZE(io.KeysDown) - event.key;
+    io.KeysDown[imGuiKey] = event.press;
+
+    switch (event.key)
+    {
+    case kKeyShift:
+        io.KeyShift = event.press;
+        break;
+    case kKeyControl:
+        io.KeyCtrl = event.press;
+        break;
+    case kKeyAlt:
+        io.KeyAlt = event.press;
+        break;
+    case kKeySuper:
+        io.KeySuper = event.press;
+        break;
+    default:
+        break;
+    }
+
+    return io.WantCaptureKeyboard;
+    */
+
+    return BaseWidget::onSpecial(event);
+}
+
+template <class BaseWidget>
+bool ImGuiWidget<BaseWidget>::onMouse(const Widget::MouseEvent& event)
+{
+    ImGui::SetCurrentContext(pData->context);
+
+    ImGuiIO& io(ImGui::GetIO());
+
+    int imGuiButton = mouseButtonToImGui(event.button);
+    if (imGuiButton != -1)
+        io.MouseDown[imGuiButton] = event.press;
+
+    return io.WantCaptureMouse;
+
+    return BaseWidget::onMouse(event);
+}
+
+template <class BaseWidget>
+bool ImGuiWidget<BaseWidget>::onMotion(const Widget::MotionEvent& event)
+{
+    ImGui::SetCurrentContext(pData->context);
+
+    ImGuiIO& io(ImGui::GetIO());
+
+    // FIXME
+    const double scaleFactor = 1; // getScaleFactor();
+    io.MousePos.x = std::round(scaleFactor * event.pos.getX());
+    io.MousePos.y = std::round(scaleFactor * event.pos.getY());
+
+    return BaseWidget::onMotion(event);
+}
+
+template <class BaseWidget>
+bool ImGuiWidget<BaseWidget>::onScroll(const Widget::ScrollEvent& event)
+{
+    ImGui::SetCurrentContext(pData->context);
+
+    ImGuiIO& io(ImGui::GetIO());
+    io.MouseWheel += event.delta.getY();
+    io.MouseWheelH += event.delta.getX();
+
+    return io.WantCaptureMouse;
+
+    return BaseWidget::onScroll(event);
+}
+
+template <class BaseWidget>
+void ImGuiWidget<BaseWidget>::onResize(const Widget::ResizeEvent& event)
+{
+    BaseWidget::onResize(event);
+
+    const double scaleFactor = BaseWidget::getTopLevelWidget()->getScaleFactor();
+
+    const uint width = event.size.getWidth();
+    const uint height = event.size.getHeight();
+
+    ImGui::SetCurrentContext(pData->context);
+
+    ImGuiIO& io(ImGui::GetIO());
+    io.DisplaySize.x = std::round(scaleFactor * width);
+    io.DisplaySize.y = std::round(scaleFactor * height);
+}
+
+// --------------------------------------------------------------------------------------------------------------------
+
+template <class BaseWidget>
+ImGuiWidget<BaseWidget>::~ImGuiWidget()
+{
+    delete pData;
+}
+
+// --------------------------------------------------------------------------------------------------------------------
+// ImGuiSubWidget
+
+template <>
+ImGuiWidget<SubWidget>::ImGuiWidget(Widget* const parent)
+    : SubWidget(parent),
+      pData(new PrivateData(this))
+{
+    getTopLevelWidget()->addIdleCallback(this);
+}
+
+template class ImGuiWidget<SubWidget>;
+
+// --------------------------------------------------------------------------------------------------------------------
+// ImGuiTopLevelWidget
+
+template <>
+ImGuiWidget<TopLevelWidget>::ImGuiWidget(Window& windowToMapTo)
+    : TopLevelWidget(windowToMapTo),
+      pData(new PrivateData(this))
+{
+    TopLevelWidget::addIdleCallback(this);
+}
+
+template class ImGuiWidget<TopLevelWidget>;
+
+// --------------------------------------------------------------------------------------------------------------------
+// ImGuiStandaloneWindow
+
+template <>
+ImGuiWidget<StandaloneWindow>::ImGuiWidget(Application& app)
+    : StandaloneWindow(app),
+      pData(new PrivateData(this))
+{
+    Window::addIdleCallback(this);
+}
+
+template <>
+ImGuiWidget<StandaloneWindow>::ImGuiWidget(Application& app, Window& transientParentWindow)
+    : StandaloneWindow(app, transientParentWindow),
+      pData(new PrivateData(this))
+{
+    Window::addIdleCallback(this);
+}
+
+template class ImGuiWidget<StandaloneWindow>;
+
+// --------------------------------------------------------------------------------------------------------------------
+
+END_NAMESPACE_DGL