1/* 2* Copyright 2017 Google Inc. 3* 4* Use of this source code is governed by a BSD-style license that can be 5* found in the LICENSE file. 6*/ 7 8#ifndef ImGuiLayer_DEFINED 9#define ImGuiLayer_DEFINED 10 11#include "include/core/SkPaint.h" 12#include "include/private/SkTArray.h" 13#include "include/private/SkTPin.h" 14#include "tools/sk_app/Window.h" 15 16#include "imgui.h" 17 18namespace ImGui { 19 20// Helper object for drawing in a widget region, with draggable points 21struct DragCanvas { 22 DragCanvas(const void* id, SkPoint tl = { 0.0f, 0.0f }, SkPoint br = { 1.0f, 1.0f }, 23 float aspect = -1.0f) 24 : fID(0), fDragging(false) { 25 ImGui::PushID(id); 26 fDrawList = ImGui::GetWindowDrawList(); 27 28 // Logical size 29 SkScalar w = SkTAbs(br.fX - tl.fX), 30 h = SkTAbs(br.fY - tl.fY); 31 32 // Determine aspect ratio automatically by default 33 if (aspect < 0) { 34 aspect = h / w; 35 } 36 37 float availWidth = std::max(ImGui::GetContentRegionAvailWidth(), 1.0f); 38 fPos = ImGui::GetCursorScreenPos(); 39 fSize = ImVec2(availWidth, availWidth * aspect); 40 41 SkPoint local[4] = { 42 { tl.fX, tl.fY }, 43 { br.fX, tl.fY }, 44 { tl.fX, br.fY }, 45 { br.fX, br.fY }, 46 }; 47 SkPoint screen[4] = { 48 { fPos.x , fPos.y }, 49 { fPos.x + fSize.x, fPos.y }, 50 { fPos.x , fPos.y + fSize.y }, 51 { fPos.x + fSize.x, fPos.y + fSize.y }, 52 }; 53 fLocalToScreen.setPolyToPoly(local, screen, 4); 54 fScreenToLocal.setPolyToPoly(screen, local, 4); 55 } 56 57 ~DragCanvas() { 58 ImGui::SetCursorScreenPos(ImVec2(fPos.x, fPos.y + fSize.y)); 59 ImGui::Spacing(); 60 ImGui::PopID(); 61 } 62 63 void fillColor(ImU32 color) { 64 fDrawList->AddRectFilled(fPos, ImVec2(fPos.x + fSize.x, fPos.y + fSize.y), color); 65 } 66 67 void dragPoint(SkPoint* p, bool tooltip = false, ImU32 color = 0xFFFFFFFF) { 68 // Transform points from logical coordinates to screen coordinates 69 SkPoint center = fLocalToScreen.mapXY(p->fX, p->fY); 70 71 // Invisible 10x10 button 72 ImGui::PushID(fID++); 73 ImGui::SetCursorScreenPos(ImVec2(center.fX - 5, center.fY - 5)); 74 ImGui::InvisibleButton("", ImVec2(10, 10)); 75 76 if (ImGui::IsItemActive() && ImGui::IsMouseDragging(0)) { 77 // Update screen position to track mouse, clamped to our area 78 ImGuiIO& io = ImGui::GetIO(); 79 center.set(SkTPin(io.MousePos.x, fPos.x, fPos.x + fSize.x), 80 SkTPin(io.MousePos.y, fPos.y, fPos.y + fSize.y)); 81 82 // Update local coordinates for the caller 83 *p = fScreenToLocal.mapXY(center.fX, center.fY); 84 fDragging = true; 85 } 86 87 if (tooltip && ImGui::IsItemHovered()) { 88 ImGui::SetTooltip("x: %.3f\ny: %.3f", p->fX, p->fY); 89 } 90 91 ImGui::PopID(); 92 93 fScreenPoints.push_back(ImVec2(center.fX, center.fY)); 94 fDrawList->AddCircle(fScreenPoints.back(), 5.0f, color); 95 } 96 97 ImDrawList* fDrawList; 98 99 // Location and dimensions (in screen coordinates) 100 ImVec2 fPos; 101 ImVec2 fSize; 102 103 // Screen coordinates of points (for additional user drawing) 104 SkSTArray<4, ImVec2, true> fScreenPoints; 105 106 // To simplify dragPoint 107 SkMatrix fLocalToScreen; 108 SkMatrix fScreenToLocal; 109 110 int fID; 111 bool fDragging; 112}; 113 114} // namespace ImGui 115 116class ImGuiLayer : public sk_app::Window::Layer { 117public: 118 ImGuiLayer(); 119 ~ImGuiLayer() override; 120 121 void setScaleFactor(float scaleFactor); 122 123 typedef std::function<void(SkCanvas*)> SkiaWidgetFunc; 124 void skiaWidget(const ImVec2& size, SkiaWidgetFunc func); 125 126 void onAttach(sk_app::Window* window) override; 127 void onPrePaint() override; 128 void onPaint(SkSurface*) override; 129 bool onMouse(int x, int y, skui::InputState state, skui::ModifierKey modifiers) override; 130 bool onMouseWheel(float delta, skui::ModifierKey modifiers) override; 131 bool onKey(skui::Key key, skui::InputState state, skui::ModifierKey modifiers) override; 132 bool onChar(SkUnichar c, skui::ModifierKey modifiers) override; 133 134private: 135 sk_app::Window* fWindow; 136 SkPaint fFontPaint; 137 SkTArray<SkiaWidgetFunc> fSkiaWidgetFuncs; 138}; 139 140#endif 141