skia2/tools/viewer/ParticlesSlide.cpp
Brian Osman fe49163cd1 Major rewrite of the particle system based on the SkSL interpreter
This removes all of the fixed-function particle affector classes.
Instead, each particle effect just has two SkSL snippets, one for
spawn logic, and one for update logic. Each one gets an inout copy
of the particle struct. Ultimately, this makes the effects much
simpler and smaller, while also being far more flexible (you can
do whatever you want with any values you want). Finally, because
the interpreter is vectorized and a particular effect's scripts
are usually tuned to the specific behaviors desired, it's faster
on basically every effect I compared.

I re-created all of the old effects in the new system. Many just
use pure SkSL (no curves or anything). Some of the old curve and
path/text stuff was very handy, though - so those are now exposed
as external values in the interpreter. Basically, an effect can
have any number of named "bindings" that are a callable thing.
This can be a path, text (shortcut for making fancy paths), curve,
or color curve. The path ones return a float4 with position and
normal, the curves return one or four floats.

... and this transposes all of the particle data storage into
SoA form, so that it can use the much faster interpreter entry
point.

Change-Id: Iebe711c45994c4201041b12d171af976bc5e758e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/222057
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Mike Reed <reed@google.com>
2019-07-25 19:59:03 +00:00

374 lines
12 KiB
C++

/*
* 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 "tools/viewer/ParticlesSlide.h"
#include "modules/particles/include/SkParticleDrawable.h"
#include "modules/particles/include/SkParticleEffect.h"
#include "modules/particles/include/SkParticleSerialization.h"
#include "modules/particles/include/SkReflected.h"
#include "src/core/SkOSFile.h"
#include "src/utils/SkOSPath.h"
#include "tools/Resources.h"
#include "tools/viewer/ImGuiLayer.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 int count_lines(const SkString& s) {
int lines = 1;
for (size_t i = 0; i < s.size(); ++i) {
if (s[i] == '\n') {
++lines;
}
}
return lines;
}
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) override {
IF_OPEN(ImGui::DragFloat(item(name), &f))
}
void visit(const char* name, int& i) override {
IF_OPEN(ImGui::DragInt(item(name), &i))
}
void visit(const char* name, bool& b) override {
IF_OPEN(ImGui::Checkbox(item(name), &b))
}
void visit(const char* name, SkString& s) override {
if (fTreeStack.back()) {
int lines = count_lines(s);
ImGuiInputTextFlags flags = ImGuiInputTextFlags_CallbackResize;
if (lines > 1) {
ImVec2 boxSize(-1.0f, ImGui::GetTextLineHeight() * (lines + 1));
ImGui::InputTextMultiline(item(name), s.writable_str(), s.size() + 1, boxSize,
flags, InputTextCallback, &s);
} else {
ImGui::InputText(item(name), s.writable_str(), s.size() + 1, flags,
InputTextCallback, &s);
}
}
}
void visit(const char* name, int& i, const EnumStringMapping* map, int count) override {
if (fTreeStack.back()) {
const char* curStr = EnumToString(i, map, count);
if (ImGui::BeginCombo(item(name), curStr ? curStr : "Unknown")) {
for (int j = 0; j < count; ++j) {
if (ImGui::Selectable(map[j].fName, i == map[j].fValue)) {
i = map[j].fValue;
}
}
ImGui::EndCombo();
}
}
}
void visit(const char* name, SkPoint& p) override {
if (fTreeStack.back()) {
ImGui::DragFloat2(item(name), &p.fX);
gDragPoints.push_back(&p);
}
}
void visit(const char* name, SkColor4f& c) override {
IF_OPEN(ImGui::ColorEdit4(item(name), c.vec()))
}
#undef IF_OPEN
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 = [baseType, curType, &e](const SkReflected::Type* t) {
if (t->fFactory && (t == baseType || t->isDerivedFrom(baseType)) &&
ImGui::Selectable(t->fName, curType == t)) {
e = t->fFactory();
}
};
SkReflected::VisitTypes(visitType);
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;
};
ParticlesSlide::ParticlesSlide() {
// Register types for serialization
REGISTER_REFLECTED(SkReflected);
SkParticleBinding::RegisterBindingTypes();
SkParticleDrawable::RegisterDrawableTypes();
fName = "Particles";
fPlayPosition.set(200.0f, 200.0f);
}
void ParticlesSlide::loadEffects(const char* dirname) {
fLoaded.reset();
fRunning.reset();
SkOSFile::Iter iter(dirname, ".json");
for (SkString file; iter.next(&file); ) {
LoadedEffect effect;
effect.fName = SkOSPath::Join(dirname, file.c_str());
effect.fParams.reset(new SkParticleEffectParams());
if (auto fileData = SkData::MakeFromFileName(effect.fName.c_str())) {
skjson::DOM dom(static_cast<const char*>(fileData->data()), fileData->size());
SkFromJsonVisitor fromJson(dom.root());
effect.fParams->visitFields(&fromJson);
fLoaded.push_back(effect);
}
}
}
void ParticlesSlide::load(SkScalar winWidth, SkScalar winHeight) {
this->loadEffects(GetResourcePath("particles").c_str());
}
void ParticlesSlide::draw(SkCanvas* canvas) {
canvas->clear(0);
gDragPoints.reset();
gDragPoints.push_back(&fPlayPosition);
// Window to show all loaded effects, and allow playing them
if (ImGui::Begin("Library", nullptr, ImGuiWindowFlags_AlwaysVerticalScrollbar)) {
static bool looped = true;
ImGui::Checkbox("Looped", &looped);
static SkString dirname = GetResourcePath("particles");
ImGuiInputTextFlags textFlags = ImGuiInputTextFlags_CallbackResize;
ImGui::InputText("Directory", dirname.writable_str(), dirname.size() + 1, textFlags,
InputTextCallback, &dirname);
if (ImGui::Button("New")) {
LoadedEffect effect;
effect.fName = SkOSPath::Join(dirname.c_str(), "new.json");
effect.fParams.reset(new SkParticleEffectParams());
fLoaded.push_back(effect);
}
ImGui::SameLine();
if (ImGui::Button("Load")) {
this->loadEffects(dirname.c_str());
}
ImGui::SameLine();
if (ImGui::Button("Save")) {
for (const auto& effect : fLoaded) {
SkFILEWStream fileStream(effect.fName.c_str());
if (fileStream.isValid()) {
SkJSONWriter writer(&fileStream, SkJSONWriter::Mode::kPretty);
SkToJsonVisitor toJson(writer);
writer.beginObject();
effect.fParams->visitFields(&toJson);
writer.endObject();
writer.flush();
fileStream.flush();
} else {
SkDebugf("Failed to open %s\n", effect.fName.c_str());
}
}
}
SkGuiVisitor gui;
for (int i = 0; i < fLoaded.count(); ++i) {
ImGui::PushID(i);
if (fAnimated && ImGui::Button("Play")) {
sk_sp<SkParticleEffect> effect(new SkParticleEffect(fLoaded[i].fParams, fRandom));
effect->start(fAnimationTime, looped);
fRunning.push_back({ fPlayPosition, fLoaded[i].fName, effect });
}
ImGui::SameLine();
ImGui::InputText("##Name", fLoaded[i].fName.writable_str(), fLoaded[i].fName.size() + 1,
textFlags, InputTextCallback, &fLoaded[i].fName);
if (ImGui::TreeNode("##Details")) {
fLoaded[i].fParams->visitFields(&gui);
ImGui::TreePop();
}
ImGui::PopID();
}
}
ImGui::End();
// Another window to show all the running effects
if (ImGui::Begin("Running")) {
for (int i = 0; i < fRunning.count(); ++i) {
ImGui::PushID(i);
bool remove = ImGui::Button("X") || !fRunning[i].fEffect->isAlive();
ImGui::SameLine();
ImGui::Text("%4g, %4g %5d %s", fRunning[i].fPosition.fX, fRunning[i].fPosition.fY,
fRunning[i].fEffect->getCount(), fRunning[i].fName.c_str());
if (remove) {
fRunning.removeShuffle(i);
}
ImGui::PopID();
}
}
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);
}
}
for (const auto& effect : fRunning) {
canvas->save();
canvas->translate(effect.fPosition.fX, effect.fPosition.fY);
effect.fEffect->draw(canvas);
canvas->restore();
}
}
bool ParticlesSlide::animate(double nanos) {
fAnimated = true;
fAnimationTime = 1e-9 * nanos;
for (const auto& effect : fRunning) {
effect.fEffect->update(fAnimationTime);
}
return true;
}
bool ParticlesSlide::onMouse(SkScalar x, SkScalar y, InputState state, ModifierKey modifiers) {
if (gDragIndex == -1) {
if (state == InputState::kDown) {
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 == InputState::kUp) {
gDragIndex = -1;
}
return true;
}
return false;
}