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 #include "tools/viewer/ImGuiLayer.h"
9
10 #include "include/core/SkBlendMode.h"
11 #include "include/core/SkCanvas.h"
12 #include "include/core/SkColor.h"
13 #include "include/core/SkImage.h"
14 #include "include/core/SkImageInfo.h"
15 #include "include/core/SkPixmap.h"
16 #include "include/core/SkRect.h"
17 #include "include/core/SkRefCnt.h"
18 #include "include/core/SkSamplingOptions.h"
19 #include "include/core/SkShader.h"
20 #include "include/core/SkSurface.h"
21 #include "include/core/SkSwizzle.h"
22 #include "include/core/SkVertices.h"
23 #include "include/private/base/SkTDArray.h"
24 #include "src/base/SkTime.h"
25 #include "tools/skui/InputState.h"
26 #include "tools/skui/Key.h"
27
28 #include <cstdint>
29
30 using namespace sk_app;
31
build_ImFontAtlas(ImFontAtlas & atlas,SkPaint & fontPaint)32 static void build_ImFontAtlas(ImFontAtlas& atlas, SkPaint& fontPaint) {
33 int w, h;
34 unsigned char* pixels;
35 atlas.GetTexDataAsAlpha8(&pixels, &w, &h);
36 SkImageInfo info = SkImageInfo::MakeA8(w, h);
37 SkPixmap pmap(info, pixels, info.minRowBytes());
38 SkMatrix localMatrix = SkMatrix::Scale(1.0f / w, 1.0f / h);
39 auto fontImage = SkImages::RasterFromPixmap(pmap, nullptr, nullptr);
40 auto fontShader = fontImage->makeShader(SkSamplingOptions(SkFilterMode::kLinear), localMatrix);
41 fontPaint.setShader(fontShader);
42 fontPaint.setColor(SK_ColorWHITE);
43 atlas.TexID = &fontPaint;
44 }
45
ImGuiLayer()46 ImGuiLayer::ImGuiLayer() {
47 // ImGui initialization:
48 ImGui::CreateContext();
49 ImGuiIO& io = ImGui::GetIO();
50
51 // Keymap...
52 io.KeyMap[ImGuiKey_Tab] = (int)skui::Key::kTab;
53 io.KeyMap[ImGuiKey_LeftArrow] = (int)skui::Key::kLeft;
54 io.KeyMap[ImGuiKey_RightArrow] = (int)skui::Key::kRight;
55 io.KeyMap[ImGuiKey_UpArrow] = (int)skui::Key::kUp;
56 io.KeyMap[ImGuiKey_DownArrow] = (int)skui::Key::kDown;
57 io.KeyMap[ImGuiKey_PageUp] = (int)skui::Key::kPageUp;
58 io.KeyMap[ImGuiKey_PageDown] = (int)skui::Key::kPageDown;
59 io.KeyMap[ImGuiKey_Home] = (int)skui::Key::kHome;
60 io.KeyMap[ImGuiKey_End] = (int)skui::Key::kEnd;
61 io.KeyMap[ImGuiKey_Delete] = (int)skui::Key::kDelete;
62 io.KeyMap[ImGuiKey_Backspace] = (int)skui::Key::kBack;
63 io.KeyMap[ImGuiKey_Enter] = (int)skui::Key::kOK;
64 io.KeyMap[ImGuiKey_Escape] = (int)skui::Key::kEscape;
65 io.KeyMap[ImGuiKey_A] = (int)skui::Key::kA;
66 io.KeyMap[ImGuiKey_C] = (int)skui::Key::kC;
67 io.KeyMap[ImGuiKey_V] = (int)skui::Key::kV;
68 io.KeyMap[ImGuiKey_X] = (int)skui::Key::kX;
69 io.KeyMap[ImGuiKey_Y] = (int)skui::Key::kY;
70 io.KeyMap[ImGuiKey_Z] = (int)skui::Key::kZ;
71
72 build_ImFontAtlas(*io.Fonts, fFontPaint);
73 }
74
~ImGuiLayer()75 ImGuiLayer::~ImGuiLayer() {
76 ImGui::DestroyContext();
77 }
78
setScaleFactor(float scaleFactor)79 void ImGuiLayer::setScaleFactor(float scaleFactor) {
80 ImGui::GetStyle() = ImGuiStyle{};
81 ImGui::GetStyle().ScaleAllSizes(scaleFactor);
82
83 ImFontAtlas& atlas = *ImGui::GetIO().Fonts;
84 atlas.Clear();
85 ImFontConfig cfg;
86 cfg.SizePixels = 13 * scaleFactor;
87 atlas.AddFontDefault(&cfg);
88 build_ImFontAtlas(atlas, fFontPaint);
89 }
90
91 #if defined(SK_BUILD_FOR_UNIX)
get_clipboard_text(void * user_data)92 static const char* get_clipboard_text(void* user_data) {
93 Window* w = (Window*)user_data;
94 return w->getClipboardText();
95 }
96
set_clipboard_text(void * user_data,const char * text)97 static void set_clipboard_text(void* user_data, const char* text) {
98 Window* w = (Window*)user_data;
99 w->setClipboardText(text);
100 }
101 #endif
102
onAttach(Window * window)103 void ImGuiLayer::onAttach(Window* window) {
104 fWindow = window;
105
106 #if defined(SK_BUILD_FOR_UNIX)
107 ImGuiIO& io = ImGui::GetIO();
108 io.ClipboardUserData = fWindow;
109 io.GetClipboardTextFn = get_clipboard_text;
110 io.SetClipboardTextFn = set_clipboard_text;
111 #endif
112 }
113
onMouse(int x,int y,skui::InputState state,skui::ModifierKey modifiers)114 bool ImGuiLayer::onMouse(int x, int y, skui::InputState state, skui::ModifierKey modifiers) {
115 ImGuiIO& io = ImGui::GetIO();
116 io.MousePos.x = static_cast<float>(x);
117 io.MousePos.y = static_cast<float>(y);
118 if (skui::InputState::kDown == state) {
119 io.MouseDown[0] = true;
120 } else if (skui::InputState::kUp == state) {
121 io.MouseDown[0] = false;
122 }
123 return io.WantCaptureMouse;
124 }
125
onMouseWheel(float delta,int,int,skui::ModifierKey modifiers)126 bool ImGuiLayer::onMouseWheel(float delta, int, int, skui::ModifierKey modifiers) {
127 ImGuiIO& io = ImGui::GetIO();
128 io.MouseWheel += delta;
129 return io.WantCaptureMouse;
130 }
131
skiaWidget(const ImVec2 & size,SkiaWidgetFunc func)132 void ImGuiLayer::skiaWidget(const ImVec2& size, SkiaWidgetFunc func) {
133 intptr_t funcIndex = fSkiaWidgetFuncs.size();
134 fSkiaWidgetFuncs.push_back(func);
135 ImGui::Image((ImTextureID)funcIndex, size);
136 }
137
onPrePaint()138 void ImGuiLayer::onPrePaint() {
139 // Update ImGui input
140 ImGuiIO& io = ImGui::GetIO();
141
142 static double previousTime = 0.0;
143 double currentTime = SkTime::GetSecs();
144 io.DeltaTime = static_cast<float>(currentTime - previousTime);
145 previousTime = currentTime;
146
147 io.DisplaySize.x = static_cast<float>(fWindow->width());
148 io.DisplaySize.y = static_cast<float>(fWindow->height());
149
150 io.KeyAlt = io.KeysDown[static_cast<int>(skui::Key::kOption)];
151 io.KeyCtrl = io.KeysDown[static_cast<int>(skui::Key::kCtrl)];
152 io.KeyShift = io.KeysDown[static_cast<int>(skui::Key::kShift)];
153 io.KeySuper = io.KeysDown[static_cast<int>(skui::Key::kSuper)];
154
155 ImGui::NewFrame();
156 }
157
onPaint(SkSurface * surface)158 void ImGuiLayer::onPaint(SkSurface* surface) {
159 // This causes ImGui to rebuild vertex/index data based on all immediate-mode commands
160 // (widgets, etc...) that have been issued
161 ImGui::Render();
162
163 // Then we fetch the most recent data, and convert it so we can render with Skia
164 const ImDrawData* drawData = ImGui::GetDrawData();
165 SkTDArray<SkPoint> pos;
166 SkTDArray<SkPoint> uv;
167 SkTDArray<SkColor> color;
168
169 auto canvas = surface->getCanvas();
170
171 for (int i = 0; i < drawData->CmdListsCount; ++i) {
172 const ImDrawList* drawList = drawData->CmdLists[i];
173
174 // De-interleave all vertex data (sigh), convert to Skia types
175 pos.clear(); uv.clear(); color.clear();
176 for (int j = 0; j < drawList->VtxBuffer.size(); ++j) {
177 const ImDrawVert& vert = drawList->VtxBuffer[j];
178 pos.push_back(SkPoint::Make(vert.pos.x, vert.pos.y));
179 uv.push_back(SkPoint::Make(vert.uv.x, vert.uv.y));
180 color.push_back(vert.col);
181 }
182 // ImGui colors are RGBA
183 SkSwapRB(color.begin(), color.begin(), color.size());
184
185 int indexOffset = 0;
186
187 // Draw everything with canvas.drawVertices...
188 for (int j = 0; j < drawList->CmdBuffer.size(); ++j) {
189 const ImDrawCmd* drawCmd = &drawList->CmdBuffer[j];
190
191 SkAutoCanvasRestore acr(canvas, true);
192
193 // TODO: Find min/max index for each draw, so we know how many vertices (sigh)
194 if (drawCmd->UserCallback) {
195 drawCmd->UserCallback(drawList, drawCmd);
196 } else {
197 intptr_t idIndex = (intptr_t)drawCmd->TextureId;
198 if (idIndex < fSkiaWidgetFuncs.size()) {
199 // Small image IDs are actually indices into a list of callbacks. We directly
200 // examing the vertex data to deduce the image rectangle, then reconfigure the
201 // canvas to be clipped and translated so that the callback code gets to use
202 // Skia to render a widget in the middle of an ImGui panel.
203 ImDrawIdx rectIndex = drawList->IdxBuffer[indexOffset];
204 SkPoint tl = pos[rectIndex], br = pos[rectIndex + 2];
205 canvas->clipRect(SkRect::MakeLTRB(tl.fX, tl.fY, br.fX, br.fY));
206 canvas->translate(tl.fX, tl.fY);
207 fSkiaWidgetFuncs[idIndex](canvas);
208 } else {
209 SkPaint* paint = static_cast<SkPaint*>(drawCmd->TextureId);
210 SkASSERT(paint);
211
212 canvas->clipRect(SkRect::MakeLTRB(drawCmd->ClipRect.x, drawCmd->ClipRect.y,
213 drawCmd->ClipRect.z, drawCmd->ClipRect.w));
214 auto vertices = SkVertices::MakeCopy(SkVertices::kTriangles_VertexMode,
215 drawList->VtxBuffer.size(),
216 pos.begin(), uv.begin(), color.begin(),
217 drawCmd->ElemCount,
218 drawList->IdxBuffer.begin() + indexOffset);
219 canvas->drawVertices(vertices, SkBlendMode::kModulate, *paint);
220 }
221 indexOffset += drawCmd->ElemCount;
222 }
223 }
224 }
225
226 fSkiaWidgetFuncs.clear();
227 }
228
onKey(skui::Key key,skui::InputState state,skui::ModifierKey modifiers)229 bool ImGuiLayer::onKey(skui::Key key, skui::InputState state, skui::ModifierKey modifiers) {
230 ImGuiIO& io = ImGui::GetIO();
231 io.KeysDown[static_cast<int>(key)] = (skui::InputState::kDown == state);
232 return io.WantCaptureKeyboard;
233 }
234
onChar(SkUnichar c,skui::ModifierKey modifiers)235 bool ImGuiLayer::onChar(SkUnichar c, skui::ModifierKey modifiers) {
236 ImGuiIO& io = ImGui::GetIO();
237 if (io.WantTextInput) {
238 if (c > 0 && c < 0x10000) {
239 io.AddInputCharacter(c);
240 }
241 return true;
242 }
243 return false;
244 }
245