| /* |
| * Copyright 2019 Google LLC |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "ParticlesSlide.h" |
| |
| #include "SkParticleAffector.h" |
| #include "SkParticleEffect.h" |
| #include "SkParticleEmitter.h" |
| #include "SkParticleSerialization.h" |
| #include "SkReflected.h" |
| |
| #include "imgui.h" |
| |
| using namespace sk_app; |
| |
| namespace { |
| |
| static SkScalar kDragSize = 8.0f; |
| static SkTArray<SkPoint*> gDragPoints; |
| int gDragIndex = -1; |
| |
| } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| static int InputTextCallback(ImGuiInputTextCallbackData* data) { |
| if (data->EventFlag == ImGuiInputTextFlags_CallbackResize) { |
| SkString* s = (SkString*)data->UserData; |
| SkASSERT(data->Buf == s->writable_str()); |
| SkString tmp(data->Buf, data->BufTextLen); |
| s->swap(tmp); |
| data->Buf = s->writable_str(); |
| } |
| return 0; |
| } |
| |
| static ImVec2 map_point(float x, float y, ImVec2 pos, ImVec2 size, float yMin, float yMax) { |
| // Turn y into 0 - 1 value |
| float yNorm = 1.0f - ((y - yMin) / (yMax - yMin)); |
| return ImVec2(pos.x + size.x * x, pos.y + size.y * yNorm); |
| } |
| |
| static void ImGui_DrawCurve(SkScalar* pts) { |
| ImDrawList* drawList = ImGui::GetWindowDrawList(); |
| |
| // Fit our image/canvas to the available width, and scale the height to maintain aspect ratio. |
| float canvasWidth = SkTMax(ImGui::GetContentRegionAvailWidth(), 50.0f); |
| ImVec2 size = ImVec2(canvasWidth, canvasWidth); |
| ImVec2 pos = ImGui::GetCursorScreenPos(); |
| |
| // Background rectangle |
| drawList->AddRectFilled(pos, ImVec2(pos.x + size.x, pos.y + size.y), IM_COL32(0, 0, 0, 128)); |
| |
| // Determine min/max extents |
| float yMin = pts[0], yMax = pts[0]; |
| for (int i = 1; i < 4; ++i) { |
| yMin = SkTMin(yMin, pts[i]); |
| yMax = SkTMax(yMax, pts[i]); |
| } |
| |
| // Grow the extents by 10%, at least 1.0f |
| float grow = SkTMax((yMax - yMin) * 0.1f, 1.0f); |
| |
| yMin -= grow; |
| yMax += grow; |
| |
| ImVec2 a = map_point(0.0f , pts[0], pos, size, yMin, yMax), |
| b = map_point(1 / 3.0f, pts[1], pos, size, yMin, yMax), |
| c = map_point(2 / 3.0f, pts[2], pos, size, yMin, yMax), |
| d = map_point(1.0f , pts[3], pos, size, yMin, yMax); |
| |
| drawList->AddBezierCurve(a, b, c, d, IM_COL32(255, 255, 255, 255), 1.0f); |
| |
| // Draw markers |
| drawList->AddCircle(a, 5.0f, 0xFFFFFFFF); |
| drawList->AddCircle(b, 5.0f, 0xFFFFFFFF); |
| drawList->AddCircle(c, 5.0f, 0xFFFFFFFF); |
| drawList->AddCircle(d, 5.0f, 0xFFFFFFFF); |
| |
| ImGui::SetCursorScreenPos(ImVec2(pos.x, pos.y + size.y)); |
| ImGui::Spacing(); |
| } |
| |
| class SkGuiVisitor : public SkFieldVisitor { |
| public: |
| SkGuiVisitor() { |
| fTreeStack.push_back(true); |
| } |
| |
| #define IF_OPEN(WIDGET) if (fTreeStack.back()) { WIDGET; } |
| |
| void visit(const char* name, float& f, SkField field) override { |
| if (fTreeStack.back()) { |
| if (field.fFlags & SkField::kAngle_Field) { |
| ImGui::SliderAngle(item(name), &f, 0.0f); |
| } else { |
| ImGui::DragFloat(item(name), &f); |
| } |
| } |
| } |
| void visit(const char* name, int& i, SkField) override { |
| IF_OPEN(ImGui::DragInt(item(name), &i)) |
| } |
| void visit(const char* name, bool& b, SkField) override { |
| IF_OPEN(ImGui::Checkbox(item(name), &b)) |
| } |
| void visit(const char* name, SkString& s, SkField) override { |
| if (fTreeStack.back()) { |
| ImGuiInputTextFlags flags = ImGuiInputTextFlags_CallbackResize; |
| ImGui::InputText(item(name), s.writable_str(), s.size() + 1, flags, InputTextCallback, |
| &s); |
| } |
| } |
| |
| void visit(const char* name, SkPoint& p, SkField) override { |
| if (fTreeStack.back()) { |
| ImGui::DragFloat2(item(name), &p.fX); |
| gDragPoints.push_back(&p); |
| } |
| } |
| void visit(const char* name, SkColor4f& c, SkField) override { |
| IF_OPEN(ImGui::ColorEdit4(item(name), c.vec())) |
| } |
| |
| #undef IF_OPEN |
| |
| void visit(const char* name, SkCurve& c, SkField) override { |
| this->enterObject(item(name)); |
| if (fTreeStack.back()) { |
| ImGui::Checkbox("Ranged", &c.fRanged); |
| ImGui::DragFloat4("Min", c.fMin); |
| ImGui_DrawCurve(c.fMin); |
| if (c.fRanged) { |
| ImGui::DragFloat4("Max", c.fMax); |
| ImGui_DrawCurve(c.fMax); |
| } |
| |
| } |
| this->exitObject(); |
| } |
| |
| void visit(sk_sp<SkReflected>& e, const SkReflected::Type* baseType) override { |
| if (fTreeStack.back()) { |
| const SkReflected::Type* curType = e ? e->getType() : nullptr; |
| if (ImGui::BeginCombo("Type", curType ? curType->fName : "Null")) { |
| auto visitType = [curType,&e](const SkReflected::Type* t) { |
| if (ImGui::Selectable(t->fName, curType == t)) { |
| e = t->fFactory(); |
| } |
| }; |
| SkReflected::VisitTypes(visitType, baseType); |
| ImGui::EndCombo(); |
| } |
| } |
| } |
| |
| void enterObject(const char* name) override { |
| if (fTreeStack.back()) { |
| fTreeStack.push_back(ImGui::TreeNodeEx(item(name), |
| ImGuiTreeNodeFlags_AllowItemOverlap)); |
| } else { |
| fTreeStack.push_back(false); |
| } |
| } |
| void exitObject() override { |
| if (fTreeStack.back()) { |
| ImGui::TreePop(); |
| } |
| fTreeStack.pop_back(); |
| } |
| |
| int enterArray(const char* name, int oldCount) override { |
| this->enterObject(item(name)); |
| fArrayCounterStack.push_back(0); |
| fArrayEditStack.push_back(); |
| |
| int count = oldCount; |
| if (fTreeStack.back()) { |
| ImGui::SameLine(); |
| if (ImGui::Button("+")) { |
| ++count; |
| } |
| } |
| return count; |
| } |
| ArrayEdit exitArray() override { |
| fArrayCounterStack.pop_back(); |
| auto edit = fArrayEditStack.back(); |
| fArrayEditStack.pop_back(); |
| this->exitObject(); |
| return edit; |
| } |
| |
| private: |
| const char* item(const char* name) { |
| if (name) { |
| return name; |
| } |
| |
| // We're in an array. Add extra controls and a dynamic label. |
| int index = fArrayCounterStack.back()++; |
| ArrayEdit& edit(fArrayEditStack.back()); |
| fScratchLabel = SkStringPrintf("[%d]", index); |
| |
| ImGui::PushID(index); |
| |
| if (ImGui::Button("X")) { |
| edit.fVerb = ArrayEdit::Verb::kRemove; |
| edit.fIndex = index; |
| } |
| ImGui::SameLine(); |
| if (ImGui::Button("^")) { |
| edit.fVerb = ArrayEdit::Verb::kMoveForward; |
| edit.fIndex = index; |
| } |
| ImGui::SameLine(); |
| if (ImGui::Button("v")) { |
| edit.fVerb = ArrayEdit::Verb::kMoveForward; |
| edit.fIndex = index + 1; |
| } |
| ImGui::SameLine(); |
| |
| ImGui::PopID(); |
| |
| return fScratchLabel.c_str(); |
| } |
| |
| SkSTArray<16, bool, true> fTreeStack; |
| SkSTArray<16, int, true> fArrayCounterStack; |
| SkSTArray<16, ArrayEdit, true> fArrayEditStack; |
| SkString fScratchLabel; |
| }; |
| |
| static sk_sp<SkParticleEffectParams> LoadEffectParams(const char* filename) { |
| sk_sp<SkParticleEffectParams> params(new SkParticleEffectParams()); |
| if (auto fileData = SkData::MakeFromFileName(filename)) { |
| skjson::DOM dom(static_cast<const char*>(fileData->data()), fileData->size()); |
| SkFromJsonVisitor fromJson(dom.root()); |
| params->visitFields(&fromJson); |
| } |
| return params; |
| } |
| |
| ParticlesSlide::ParticlesSlide() { |
| // Register types for serialization |
| REGISTER_REFLECTED(SkReflected); |
| SkParticleAffector::RegisterAffectorTypes(); |
| SkParticleEmitter::RegisterEmitterTypes(); |
| fName = "Particles"; |
| } |
| |
| void ParticlesSlide::load(SkScalar winWidth, SkScalar winHeight) { |
| fEffect.reset(new SkParticleEffect(LoadEffectParams("resources/particles/default.json"))); |
| } |
| |
| void ParticlesSlide::draw(SkCanvas* canvas) { |
| canvas->clear(0); |
| |
| gDragPoints.reset(); |
| if (ImGui::Begin("Particles")) { |
| static char filename[64] = "resources/particles/default.json"; |
| ImGui::InputText("Filename", filename, sizeof(filename)); |
| if (ImGui::Button("Load")) { |
| if (auto newParams = LoadEffectParams(filename)) { |
| fEffect.reset(new SkParticleEffect(std::move(newParams))); |
| } |
| } |
| ImGui::SameLine(); |
| |
| if (ImGui::Button("Save")) { |
| SkFILEWStream fileStream(filename); |
| if (fileStream.isValid()) { |
| SkJSONWriter writer(&fileStream, SkJSONWriter::Mode::kPretty); |
| SkToJsonVisitor toJson(writer); |
| writer.beginObject(); |
| fEffect->getParams()->visitFields(&toJson); |
| writer.endObject(); |
| writer.flush(); |
| fileStream.flush(); |
| } else { |
| SkDebugf("Failed to open file\n"); |
| } |
| } |
| |
| SkGuiVisitor gui; |
| fEffect->getParams()->visitFields(&gui); |
| } |
| ImGui::End(); |
| |
| SkPaint dragPaint; |
| dragPaint.setColor(SK_ColorLTGRAY); |
| dragPaint.setAntiAlias(true); |
| SkPaint dragHighlight; |
| dragHighlight.setStyle(SkPaint::kStroke_Style); |
| dragHighlight.setColor(SK_ColorGREEN); |
| dragHighlight.setStrokeWidth(2); |
| dragHighlight.setAntiAlias(true); |
| for (int i = 0; i < gDragPoints.count(); ++i) { |
| canvas->drawCircle(*gDragPoints[i], kDragSize, dragPaint); |
| if (gDragIndex == i) { |
| canvas->drawCircle(*gDragPoints[i], kDragSize, dragHighlight); |
| } |
| } |
| fEffect->draw(canvas); |
| } |
| |
| bool ParticlesSlide::animate(const SkAnimTimer& timer) { |
| fEffect->update(fRandom, timer); |
| return true; |
| } |
| |
| bool ParticlesSlide::onMouse(SkScalar x, SkScalar y, Window::InputState state, uint32_t modifiers) { |
| if (gDragIndex == -1) { |
| if (state == Window::kDown_InputState) { |
| float bestDistance = kDragSize; |
| SkPoint mousePt = { x, y }; |
| for (int i = 0; i < gDragPoints.count(); ++i) { |
| float distance = SkPoint::Distance(*gDragPoints[i], mousePt); |
| if (distance < bestDistance) { |
| gDragIndex = i; |
| bestDistance = distance; |
| } |
| } |
| return gDragIndex != -1; |
| } |
| } else { |
| // Currently dragging |
| SkASSERT(gDragIndex < gDragPoints.count()); |
| gDragPoints[gDragIndex]->set(x, y); |
| if (state == Window::kUp_InputState) { |
| gDragIndex = -1; |
| } |
| return true; |
| } |
| return false; |
| } |