Resurrect pathfinder in viewer and rename to "bisect"

Bug: skia:
Change-Id: If8d2f46b8f27fefc3a0f983eb649654e0fb4afcb
Reviewed-on: https://skia-review.googlesource.com/108685
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

6 files changed, 208 insertions, 172 deletions

diff --git a/BUILD.gn b/BUILD.gn
index f50f7be1c4..240ba78c10 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1947,6 +1947,7 @@ if (skia_enable_tools) {
         bundle_ios_data = true
       }
       sources = [
+        "tools/viewer/BisectSlide.cpp",
         "tools/viewer/GMSlide.cpp",
         "tools/viewer/ImGuiLayer.cpp",
         "tools/viewer/ImageSlide.cpp",
diff --git a/gn/samples.gni b/gn/samples.gni
index 48c580c2a3..135cf78013 100644
--- a/gn/samples.gni
+++ b/gn/samples.gni
@@ -68,7 +68,6 @@ samples_sources = [
   "$_samplecode/SamplePathText.cpp",
   "$_samplecode/SamplePathClip.cpp",
   "$_samplecode/SamplePathEffects.cpp",
-  "$_samplecode/SamplePathFinder.cpp",
   "$_samplecode/SamplePathFuzz.cpp",
   "$_samplecode/SamplePathOverstroke.cpp",
   "$_samplecode/SamplePdfFileViewer.cpp",
diff --git a/samplecode/SamplePathFinder.cpp b/samplecode/SamplePathFinder.cpp
deleted file mode 100644
index d53c40bb5e..0000000000
--- a/samplecode/SamplePathFinder.cpp
+++ /dev/null
@@ -1,164 +0,0 @@
-/*
- * Copyright 2017 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SampleCode.h"
-#include "SkCanvas.h"
-#include "SkCommandLineFlags.h"
-#include "SkDOM.h"
-#include "SkSVGDOM.h"
-#include "SkOSPath.h"
-#include "SkPath.h"
-#include "SkPicture.h"
-#include "SkStream.h"
-#include <stack>
-
-/**
- * This is a simple utility designed to extract the paths from an SKP file and then isolate a single
- * one of them. Use the 'x' and 'X' keys to guide a binary search:
- *
- *   'x': Throw out half the paths.
- *   'X': Toggle which half gets tossed and which half is kept.
- *   'Z': Back up one level.
- *   'D': Dump the path.
- */
-class PathFinderView : public SampleView, public SkCanvas {
-public:
-    PathFinderView(const char name[] = nullptr)
-        : SkCanvas(4096, 4096, nullptr)
-        , fFilename(name) {
-        SkFILEStream stream(fFilename.c_str());
-        if (!stream.isValid()) {
-            SkDebugf("invalid input file at \"%s\"\n", fFilename.c_str());
-            return;
-        }
-        if (fFilename.endsWith(".svg")) {
-            SkDOM xml;
-            if (!xml.build(stream)) {
-                SkDebugf("XML parsing failed: \"%s\"\n", fFilename.c_str());
-                return;
-            }
-            sk_sp<SkSVGDOM> svg = SkSVGDOM::MakeFromDOM(xml);
-            if (!svg) {
-                SkDebugf("couldn't load svg at \"%s\"\n", fFilename.c_str());
-                return;
-            }
-            svg->setContainerSize(SkSize::Make(500, 500));
-            svg->render(this);
-        } else {
-            sk_sp<SkPicture> pic = SkPicture::MakeFromStream(&stream);
-            if (!pic) {
-                SkDebugf("couldn't load skp at \"%s\"\n", fFilename.c_str());
-                return;
-            }
-            pic->playback(this);
-        }
-    }
-
-    ~PathFinderView() override {}
-
-private:
-    // Called through SkPicture::playback during construction.
-    void onDrawPath(const SkPath& path, const SkPaint& paint) override {
-        fPaths.push_back() = {path, paint, this->getTotalMatrix()};
-    }
-
-    // overrides from SkEventSink
-    bool onQuery(SkEvent* evt) override {
-        if (SampleCode::TitleQ(*evt)) {
-            SkString name("PATHFINDER:");
-            const char* basename = strrchr(fFilename.c_str(), SkOSPath::SEPARATOR);
-            name.append(basename ? basename+1: fFilename.c_str());
-            SampleCode::TitleR(evt, name.c_str());
-            return true;
-        }
-        SkUnichar key;
-        if (SampleCode::CharQ(*evt, &key)) {
-            if (this->handleKeystroke(key)) {
-                return true;
-            }
-        }
-        return this->INHERITED::onQuery(evt);
-    }
-
-    bool handleKeystroke(SkUnichar key) {
-        switch (key) {
-            case 'X':
-                if (!fTossedPaths.empty()) {
-                    SkTSwap(fPaths, fTossedPaths);
-                    if ('X' == fTrail.back()) {
-                        fTrail.pop_back();
-                    } else {
-                        fTrail.push_back('X');
-                    }
-                }
-                return true;
-            case 'x':
-                if (fPaths.count() > 1) {
-                    int midpt = (fPaths.count() + 1) / 2;
-                    fPathHistory.emplace(fPaths, fTossedPaths);
-                    fTossedPaths.reset(fPaths.begin() + midpt, fPaths.count() - midpt);
-                    fPaths.resize_back(midpt);
-                    fTrail.push_back('x');
-                }
-                return true;
-            case 'Z': {
-                if (!fPathHistory.empty()) {
-                    fPaths = fPathHistory.top().first;
-                    fTossedPaths = fPathHistory.top().second;
-                    fPathHistory.pop();
-                    char ch;
-                    do {
-                        ch = fTrail.back();
-                        fTrail.pop_back();
-                    } while (ch != 'x');
-                }
-                return true;
-            }
-            case 'D':
-                SkDebugf("SampleApp --pathfinder %s", fFilename.c_str());
-                if (!fTrail.empty()) {
-                    SkDebugf(" --keys ");
-                    for (char ch : fTrail) {
-                        SkDebugf("%c", ch);
-                    }
-                }
-                SkDebugf("\n");
-                for (const FoundPath& foundPath : fPaths) {
-                    foundPath.fPath.dump();
-                }
-                return true;
-        }
-        return false;
-    }
-
-    void onDrawContent(SkCanvas* canvas) override {
-        for (const FoundPath& path : fPaths) {
-            SkAutoCanvasRestore acr(canvas, true);
-            canvas->concat(path.fViewMatrix);
-            canvas->drawPath(path.fPath, path.fPaint);
-        }
-    }
-
-    struct FoundPath {
-        SkPath     fPath;
-        SkPaint    fPaint;
-        SkMatrix   fViewMatrix;
-    };
-
-    SkString              fFilename;
-    SkTArray<FoundPath>   fPaths;
-    SkTArray<FoundPath>   fTossedPaths;
-    SkTArray<char>        fTrail;
-
-    std::stack<std::pair<SkTArray<FoundPath>, SkTArray<FoundPath>>> fPathHistory;
-
-    typedef SampleView INHERITED;
-};
-
-SampleView* CreateSamplePathFinderView(const char filename[]) {
-    return new PathFinderView(filename);
-}
diff --git a/tools/viewer/BisectSlide.cpp b/tools/viewer/BisectSlide.cpp
new file mode 100644
index 0000000000..63e69d278c
--- /dev/null
+++ b/tools/viewer/BisectSlide.cpp
@@ -0,0 +1,130 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "BisectSlide.h"
+
+#include "SkDOM.h"
+#include "SkOSPath.h"
+#include "SkPicture.h"
+#include "SkStream.h"
+#include "../experimental/svg/model/SkSVGDOM.h"
+
+sk_sp<BisectSlide> BisectSlide::Create(const char filepath[]) {
+    SkFILEStream stream(filepath);
+    if (!stream.isValid()) {
+        SkDebugf("BISECT: invalid input file at \"%s\"\n", filepath);
+        return nullptr;
+    }
+
+    sk_sp<BisectSlide> bisect(new BisectSlide(filepath));
+    if (bisect->fFilePath.endsWith(".svg")) {
+        SkDOM xml;
+        if (!xml.build(stream)) {
+            SkDebugf("BISECT: XML parsing failed: \"%s\"\n", filepath);
+            return nullptr;
+        }
+        sk_sp<SkSVGDOM> svg = SkSVGDOM::MakeFromDOM(xml);
+        if (!svg) {
+            SkDebugf("BISECT: couldn't load svg at \"%s\"\n", filepath);
+            return nullptr;
+        }
+        svg->setContainerSize(SkSize::Make(bisect->getDimensions()));
+        svg->render(bisect.get());
+    } else {
+        sk_sp<SkPicture> skp = SkPicture::MakeFromStream(&stream);
+        if (!skp) {
+            SkDebugf("BISECT: couldn't load skp at \"%s\"\n", filepath);
+            return nullptr;
+        }
+        skp->playback(bisect.get());
+    }
+
+    return bisect;
+}
+
+BisectSlide::BisectSlide(const char filepath[])
+        : SkCanvas(4096, 4096, nullptr)
+        , fFilePath(filepath) {
+    const char* basename = strrchr(fFilePath.c_str(), SkOSPath::SEPARATOR);
+    fName.printf("BISECT_%s", basename ? basename + 1 : fFilePath.c_str());
+}
+
+// Called through SkPicture::playback only during creation.
+void BisectSlide::onDrawPath(const SkPath& path, const SkPaint& paint) {
+    SkRect bounds;
+    SkIRect ibounds;
+    this->getTotalMatrix().mapRect(&bounds, path.getBounds());
+    bounds.roundOut(&ibounds);
+    fDrawBounds.join(ibounds);
+    fFoundPaths.push_back() = {path, paint, this->getTotalMatrix()};
+}
+
+bool BisectSlide::onChar(SkUnichar c) {
+    switch (c) {
+        case 'X':
+            if (!fTossedPaths.empty()) {
+                SkTSwap(fFoundPaths, fTossedPaths);
+                if ('X' == fTrail.back()) {
+                    fTrail.pop_back();
+                } else {
+                    fTrail.push_back('X');
+                }
+            }
+            return true;
+
+        case 'x':
+            if (fFoundPaths.count() > 1) {
+                int midpt = (fFoundPaths.count() + 1) / 2;
+                fPathHistory.emplace(fFoundPaths, fTossedPaths);
+                fTossedPaths.reset(fFoundPaths.begin() + midpt, fFoundPaths.count() - midpt);
+                fFoundPaths.resize_back(midpt);
+                fTrail.push_back('x');
+            }
+            return true;
+
+        case 'Z': {
+            if (!fPathHistory.empty()) {
+                fFoundPaths = fPathHistory.top().first;
+                fTossedPaths = fPathHistory.top().second;
+                fPathHistory.pop();
+                char ch;
+                do {
+                    ch = fTrail.back();
+                    fTrail.pop_back();
+                } while (ch != 'x');
+            }
+            return true;
+        }
+
+        case 'D':
+            SkDebugf("viewer --bisect %s", fFilePath.c_str());
+            if (!fTrail.empty()) {
+                SkDebugf(" ");
+                for (char ch : fTrail) {
+                    SkDebugf("%c", ch);
+                }
+            }
+            SkDebugf("\n");
+            for (const FoundPath& foundPath : fFoundPaths) {
+                foundPath.fPath.dump();
+            }
+            return true;
+    }
+
+    return false;
+}
+
+void BisectSlide::draw(SkCanvas* canvas) {
+    SkAutoCanvasRestore acr(canvas, true);
+    canvas->translate(-fDrawBounds.left(), -fDrawBounds.top());
+
+    for (const FoundPath& path : fFoundPaths) {
+        SkAutoCanvasRestore acr(canvas, true);
+        canvas->concat(path.fViewMatrix);
+        canvas->drawPath(path.fPath, path.fPaint);
+    }
+}
diff --git a/tools/viewer/BisectSlide.h b/tools/viewer/BisectSlide.h
new file mode 100644
index 0000000000..c5300c6396
--- /dev/null
+++ b/tools/viewer/BisectSlide.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef BisectSlide_DEFINED
+#define BisectSlide_DEFINED
+
+#include "SkCanvas.h"
+#include "SkPath.h"
+#include "Slide.h"
+#include <stack>
+
+/**
+ * This is a simple utility designed to extract the paths from an SKP file and then isolate a single
+ * one of them via bisect. Use the 'x' and 'X' keys to guide a binary search:
+ *
+ *   'x': Throw out half the paths.
+ *   'X': Toggle which half gets tossed and which half is kept.
+ *   'Z': Back up one level.
+ *   'D': Dump the path.
+ */
+class BisectSlide : public Slide, public SkCanvas {
+public:
+    static sk_sp<BisectSlide> Create(const char filepath[]);
+
+    // Slide overrides.
+    SkISize getDimensions() const override { return fDrawBounds.size(); }
+    bool onChar(SkUnichar c) override;
+    void draw(SkCanvas* canvas) override;
+
+private:
+    BisectSlide(const char filepath[]);
+
+    // SkCanvas override called only during creation.
+    void onDrawPath(const SkPath& path, const SkPaint& paint) override;
+
+    struct FoundPath {
+        SkPath fPath;
+        SkPaint fPaint;
+        SkMatrix fViewMatrix;
+    };
+
+    SkString fFilePath;
+    SkIRect fDrawBounds = SkIRect::MakeEmpty();
+    SkTArray<FoundPath> fFoundPaths;
+    SkTArray<FoundPath> fTossedPaths;
+    SkTArray<char> fTrail;
+    std::stack<std::pair<SkTArray<FoundPath>, SkTArray<FoundPath>>> fPathHistory;
+};
+
+#endif
diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index c412218939..6582490d50 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -7,6 +7,7 @@
 
 #include "Viewer.h"
 
+#include "BisectSlide.h"
 #include "GMSlide.h"
 #include "ImageSlide.h"
 #include "Resources.h"
@@ -82,6 +83,8 @@ static DEFINE_string2(backend, b, "sw", "Backend to use. Allowed values are " BA
 
 static DEFINE_int32(msaa, 1, "Number of subpixel samples. 0 for no HW antialiasing.");
 
+DEFINE_string(bisect, "", "Path to a .skp or .svg file to bisect.");
+
 DECLARE_int32(threads)
 
 const char* kBackendTypeStrings[sk_app::Window::kBackendTypeCount] = {
@@ -478,23 +481,36 @@ Viewer::Viewer(int argc, char** argv, void* platformData)
 void Viewer::initSlides() {
     fAllSlideNames = Json::Value(Json::arrayValue);
 
+    // Bisect slide.
+    if (!FLAGS_bisect.isEmpty()) {
+        sk_sp<BisectSlide> bisect = BisectSlide::Create(FLAGS_bisect[0]);
+        if (bisect && !SkCommandLineFlags::ShouldSkip(FLAGS_match, bisect->getName().c_str())) {
+            if (FLAGS_bisect.count() >= 2) {
+                for (const char* ch = FLAGS_bisect[1]; *ch; ++ch) {
+                    bisect->onChar(*ch);
+                }
+            }
+            fSlides.push_back(std::move(bisect));
+        }
+    }
+
+    // GMs
+    int firstGM = fSlides.count();
     const skiagm::GMRegistry* gms(skiagm::GMRegistry::Head());
     while (gms) {
         std::unique_ptr<skiagm::GM> gm(gms->factory()(nullptr));
 
         if (!SkCommandLineFlags::ShouldSkip(FLAGS_match, gm->getName())) {
             sk_sp<Slide> slide(new GMSlide(gm.release()));
-            fSlides.push_back(slide);
+            fSlides.push_back(std::move(slide));
         }
 
         gms = gms->next();
     }
-
-    // reverse array
-    for (int i = 0; i < fSlides.count()/2; ++i) {
-        sk_sp<Slide> temp = fSlides[i];
-        fSlides[i] = fSlides[fSlides.count() - i - 1];
-        fSlides[fSlides.count() - i - 1] = temp;
+    // reverse gms
+    int numGMs = fSlides.count() - firstGM;
+    for (int i = 0; i < numGMs/2; ++i) {
+        std::swap(fSlides[firstGM + i], fSlides[fSlides.count() - i - 1]);
     }
 
     // samples