ImGuiLayer Class Reference

#include <ImGuiLayer.h>

Inheritance diagram for ImGuiLayer:

Public Types
typedef std::function< void(SkCanvas *)>	SkiaWidgetFunc

Public Member Functions
	ImGuiLayer ()
	~ImGuiLayer () override
void	setScaleFactor (float scaleFactor)
void	skiaWidget (const ImVec2 &size, SkiaWidgetFunc func)
void	onAttach (sk_app::Window *window) override
void	onPrePaint () override
void	onPaint (SkSurface *) override
bool	onMouse (int x, int y, skui::InputState state, skui::ModifierKey modifiers) override
bool	onMouseWheel (float delta, int x, int y, skui::ModifierKey modifiers) override
bool	onKey (skui::Key key, skui::InputState state, skui::ModifierKey modifiers) override
bool	onChar (SkUnichar c, skui::ModifierKey modifiers) override
Public Member Functions inherited from sk_app::Window::Layer
	Layer ()
virtual	~Layer ()=default
bool	getActive ()
void	setActive (bool active)
virtual void	onBackendCreated ()
virtual bool	onTouch (intptr_t owner, skui::InputState, float x, float y)
virtual bool	onFling (skui::InputState state)
virtual bool	onPinch (skui::InputState state, float scale, float x, float y)
virtual void	onUIStateChanged (const SkString &stateName, const SkString &stateValue)
virtual void	onResize (int width, int height)

Detailed Description

Definition at line 133 of file ImGuiLayer.h.

Member Typedef Documentation

SkiaWidgetFunc

typedef std::function<void(SkCanvas*)> ImGuiLayer::SkiaWidgetFunc

Definition at line 140 of file ImGuiLayer.h.

Constructor & Destructor Documentation

ImGuiLayer()

ImGuiLayer::ImGuiLayer

(

)

Definition at line 46 of file ImGuiLayer.cpp.

                       {
    // ImGui initialization:
    ImGui::CreateContext();
    ImGuiIO& io = ImGui::GetIO();
 
    // Keymap...
    io.KeyMap[ImGuiKey_Tab]        = (int)skui::Key::kTab;
    io.KeyMap[ImGuiKey_LeftArrow]  = (int)skui::Key::kLeft;
    io.KeyMap[ImGuiKey_RightArrow] = (int)skui::Key::kRight;
    io.KeyMap[ImGuiKey_UpArrow]    = (int)skui::Key::kUp;
    io.KeyMap[ImGuiKey_DownArrow]  = (int)skui::Key::kDown;
    io.KeyMap[ImGuiKey_PageUp]     = (int)skui::Key::kPageUp;
    io.KeyMap[ImGuiKey_PageDown]   = (int)skui::Key::kPageDown;
    io.KeyMap[ImGuiKey_Home]       = (int)skui::Key::kHome;
    io.KeyMap[ImGuiKey_End]        = (int)skui::Key::kEnd;
    io.KeyMap[ImGuiKey_Delete]     = (int)skui::Key::kDelete;
    io.KeyMap[ImGuiKey_Backspace]  = (int)skui::Key::kBack;
    io.KeyMap[ImGuiKey_Enter]      = (int)skui::Key::kOK;
    io.KeyMap[ImGuiKey_Escape]     = (int)skui::Key::kEscape;
    io.KeyMap[ImGuiKey_A]          = (int)skui::Key::kA;
    io.KeyMap[ImGuiKey_C]          = (int)skui::Key::kC;
    io.KeyMap[ImGuiKey_V]          = (int)skui::Key::kV;
    io.KeyMap[ImGuiKey_X]          = (int)skui::Key::kX;
    io.KeyMap[ImGuiKey_Y]          = (int)skui::Key::kY;
    io.KeyMap[ImGuiKey_Z]          = (int)skui::Key::kZ;
 
    build_ImFontAtlas(*io.Fonts, fFontPaint);
}

~ImGuiLayer()

ImGuiLayer::~ImGuiLayer ( )

override

Definition at line 75 of file ImGuiLayer.cpp.

                        {
    ImGui::DestroyContext();
}

Member Function Documentation

onAttach()

void ImGuiLayer::onAttach ( sk_app::Window *  window )

overridevirtual

Reimplemented from sk_app::Window::Layer.

Definition at line 102 of file ImGuiLayer.cpp.

                                        {
    fWindow = window;
 
#if defined(SK_BUILD_FOR_UNIX)
    ImGuiIO& io = ImGui::GetIO();
    io.ClipboardUserData = fWindow;
    io.GetClipboardTextFn = get_clipboard_text;
    io.SetClipboardTextFn = set_clipboard_text;
#endif
}

onChar()

bool ImGuiLayer::onChar ( SkUnichar  c, skui::ModifierKey  modifiers  )

overridevirtual

Reimplemented from sk_app::Window::Layer.

Definition at line 234 of file ImGuiLayer.cpp.

                                                              {
    ImGuiIO& io = ImGui::GetIO();
    if (io.WantTextInput) {
        if (c > 0 && c < 0x10000) {
            io.AddInputCharacter(c);
        }
        return true;
    }
    return false;
}

onKey()

bool ImGuiLayer::onKey ( skui::Key  key, skui::InputState  state, skui::ModifierKey  modifiers  )

overridevirtual

Reimplemented from sk_app::Window::Layer.

Definition at line 228 of file ImGuiLayer.cpp.

                                                                                   {
    ImGuiIO& io = ImGui::GetIO();
    io.KeysDown[static_cast<int>(key)] = (skui::InputState::kDown == state);
    return io.WantCaptureKeyboard;
}

onMouse()

bool ImGuiLayer::onMouse ( int  x, int  y, skui::InputState  state, skui::ModifierKey  modifiers  )

overridevirtual

Reimplemented from sk_app::Window::Layer.

Definition at line 113 of file ImGuiLayer.cpp.

                                                                                      {
    ImGuiIO& io = ImGui::GetIO();
    io.MousePos.x = static_cast<float>(x);
    io.MousePos.y = static_cast<float>(y);
    if (skui::InputState::kDown == state) {
        io.MouseDown[0] = true;
    } else if (skui::InputState::kUp == state) {
        io.MouseDown[0] = false;
    }
    return io.WantCaptureMouse;
}

onMouseWheel()

bool ImGuiLayer::onMouseWheel ( float  delta, int  x, int  y, skui::ModifierKey  modifiers  )

overridevirtual

Reimplemented from sk_app::Window::Layer.

Definition at line 125 of file ImGuiLayer.cpp.

                                                                              {
    ImGuiIO& io = ImGui::GetIO();
    io.MouseWheel += delta;
    return io.WantCaptureMouse;
}

onPaint()

void ImGuiLayer::onPaint ( SkSurface *  surface )

overridevirtual

Reimplemented from sk_app::Window::Layer.

Definition at line 157 of file ImGuiLayer.cpp.

                                           {
    // This causes ImGui to rebuild vertex/index data based on all immediate-mode commands
    // (widgets, etc...) that have been issued
    ImGui::Render();
 
    // Then we fetch the most recent data, and convert it so we can render with Skia
    const ImDrawData* drawData = ImGui::GetDrawData();
    SkTDArray<SkPoint> pos;
    SkTDArray<SkPoint> uv;
    SkTDArray<SkColor> color;
 
    auto canvas = surface->getCanvas();
 
    for (int i = 0; i < drawData->CmdListsCount; ++i) {
        const ImDrawList* drawList = drawData->CmdLists[i];
 
        // De-interleave all vertex data (sigh), convert to Skia types
        pos.clear(); uv.clear(); color.clear();
        for (int j = 0; j < drawList->VtxBuffer.size(); ++j) {
            const ImDrawVert& vert = drawList->VtxBuffer[j];
            pos.push_back(SkPoint::Make(vert.pos.x, vert.pos.y));
            uv.push_back(SkPoint::Make(vert.uv.x, vert.uv.y));
            color.push_back(vert.col);
        }
        // ImGui colors are RGBA
        SkSwapRB(color.begin(), color.begin(), color.size());
 
        int indexOffset = 0;
 
        // Draw everything with canvas.drawVertices...
        for (int j = 0; j < drawList->CmdBuffer.size(); ++j) {
            const ImDrawCmd* drawCmd = &drawList->CmdBuffer[j];
 
            SkAutoCanvasRestore acr(canvas, true);
 
            // TODO: Find min/max index for each draw, so we know how many vertices (sigh)
            if (drawCmd->UserCallback) {
                drawCmd->UserCallback(drawList, drawCmd);
            } else {
                intptr_t idIndex = (intptr_t)drawCmd->TextureId;
                if (idIndex < fSkiaWidgetFuncs.size()) {
                    // Small image IDs are actually indices into a list of callbacks. We directly
                    // examing the vertex data to deduce the image rectangle, then reconfigure the
                    // canvas to be clipped and translated so that the callback code gets to use
                    // Skia to render a widget in the middle of an ImGui panel.
                    ImDrawIdx rectIndex = drawList->IdxBuffer[indexOffset];
                    SkPoint tl = pos[rectIndex], br = pos[rectIndex + 2];
                    canvas->clipRect(SkRect::MakeLTRB(tl.fX, tl.fY, br.fX, br.fY));
                    canvas->translate(tl.fX, tl.fY);
                    fSkiaWidgetFuncs[idIndex](canvas);
                } else {
                    SkPaint* paint = static_cast<SkPaint*>(drawCmd->TextureId);
                    SkASSERT(paint);
 
                    canvas->clipRect(SkRect::MakeLTRB(drawCmd->ClipRect.x, drawCmd->ClipRect.y,
                                                      drawCmd->ClipRect.z, drawCmd->ClipRect.w));
                    auto vertices = SkVertices::MakeCopy(SkVertices::kTriangles_VertexMode,
                                                         drawList->VtxBuffer.size(),
                                                         pos.begin(), uv.begin(), color.begin(),
                                                         drawCmd->ElemCount,
                                                         drawList->IdxBuffer.begin() + indexOffset);
                    canvas->drawVertices(vertices, SkBlendMode::kModulate, *paint);
                }
                indexOffset += drawCmd->ElemCount;
            }
        }
    }
 
    fSkiaWidgetFuncs.clear();
}

onPrePaint()

void ImGuiLayer::onPrePaint ( )

overridevirtual

Reimplemented from sk_app::Window::Layer.

Definition at line 137 of file ImGuiLayer.cpp.

                            {
    // Update ImGui input
    ImGuiIO& io = ImGui::GetIO();
 
    static double previousTime = 0.0;
    double currentTime = SkTime::GetSecs();
    io.DeltaTime = static_cast<float>(currentTime - previousTime);
    previousTime = currentTime;
 
    io.DisplaySize.x = static_cast<float>(fWindow->width());
    io.DisplaySize.y = static_cast<float>(fWindow->height());
 
    io.KeyAlt   = io.KeysDown[static_cast<int>(skui::Key::kOption)];
    io.KeyCtrl  = io.KeysDown[static_cast<int>(skui::Key::kCtrl)];
    io.KeyShift = io.KeysDown[static_cast<int>(skui::Key::kShift)];
    io.KeySuper = io.KeysDown[static_cast<int>(skui::Key::kSuper)];
 
    ImGui::NewFrame();
}

setScaleFactor()

void ImGuiLayer::setScaleFactor

(

float

scaleFactor

)

Definition at line 79 of file ImGuiLayer.cpp.

                                                 {
    ImGui::GetStyle().ScaleAllSizes(scaleFactor);
 
    ImFontAtlas& atlas = *ImGui::GetIO().Fonts;
    atlas.Clear();
    ImFontConfig cfg;
    cfg.SizePixels = 13 * scaleFactor;
    atlas.AddFontDefault(&cfg);
    build_ImFontAtlas(atlas, fFontPaint);
}

skiaWidget()

void ImGuiLayer::skiaWidget	(	const ImVec2 &	size,
		SkiaWidgetFunc	func
	)

Definition at line 131 of file ImGuiLayer.cpp.

                                                                   {
    intptr_t funcIndex = fSkiaWidgetFuncs.size();
    fSkiaWidgetFuncs.push_back(func);
    ImGui::Image((ImTextureID)funcIndex, size);
}

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The documentation for this class was generated from the following files:

• third_party/skia/tools/viewer/ImGuiLayer.h
• third_party/skia/tools/viewer/ImGuiLayer.cpp