[capture] record and collect SKPs in the CaptureManager during capture

This add basic SkPicture tracking functionality. Followup CLs will target grabbing sub-picture "breakpoints" at specified intervals.

Test: bazel run //example/external_client:use_graphite_metal_capture --keep_going --compilation_mode=dbg
Bug: b/412351769
Change-Id: Iace6b187ce4c6ac10f1496f0ec745d9dcc473aaf
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1033137
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Jorge Betancourt <jmbetancourt@google.com>

Author: jbeta51

example/external_client/src/graphite_metal_capture.cpp

@@ -7,6 +7,7 @@
 
 #include "include/core/SkBitmap.h"
 #include "include/core/SkCanvas.h"
+#include "include/core/SkColor.h"
 #include "include/core/SkImage.h"
 #include "include/core/SkRRect.h"
 #include "include/core/SkRect.h"
@@ -58,11 +59,21 @@ int main(int argc, char *argv[]) {
         return 1;
     }
 
+    sk_sp<SkSurface> surfaceB =
+            SkSurfaces::RenderTarget(recorder.get(), imageInfo);
+    if (!surfaceB) {
+        printf("Could not make second surface from Metal Recorder\n");
+        return 1;
+    }
+
     /* DRAWING */
     context->startCapture();
     printf("Capture started, now to draw\n");
 
     SkCanvas* canvas = surface->getCanvas();
+    SkCanvas* canvasB = surfaceB->getCanvas();
+
+    // Canvas A
     canvas->clear(SK_ColorCYAN);
     SkRRect rrect = SkRRect::MakeRectXY(SkRect::MakeLTRB(10, 20, 50, 70), 10, 10);
 
@@ -72,6 +83,12 @@ int main(int argc, char *argv[]) {
 
     canvas->drawRRect(rrect, paint);
 
+    // Canvas B
+    // TODO (b/412351769): take image snapshot from canvas A and draw into B
+    canvasB->clear(SK_ColorMAGENTA);
+    paint.setColor(SK_ColorBLACK);
+    canvasB->drawCircle(10, 10, 5, paint);
+
     printf("ready to snap the GPU calls\n");
     // Now to send the draws to the GPU
     std::unique_ptr<skgpu::graphite::Recording> recording = recorder->snap();

src/capture/SkCaptureCanvas.cpp

@@ -40,8 +40,8 @@ sk_sp<SkPicture> SkCaptureCanvas::snapPicture() {
     if (!fCapturing) {
         return nullptr;
     }
+    this->detachRecordingCanvas(); // remove the stale recording canvas before the recorder finishes
     auto skp = fRecorder.finishRecordingAsPicture();
-    this->detachRecordingCanvas();  // remove the stale recording canvas
     this->attachRecordingCanvas();
     return skp;
 }
@@ -57,6 +57,10 @@ void SkCaptureCanvas::detachRecordingCanvas() {
     this->removeCanvas(fRecorder.getRecordingCanvas());
 }
 
+void SkCaptureCanvas::onSurfaceDelete() {
+    // TODO (b/412351769): signal to the capture manager that this canvas's surface has been deleted
+}
+
 //////////////////// Function forwarding ///////////////////////
 
 void SkCaptureCanvas::willSave() {
@@ -305,7 +309,3 @@ void SkCaptureCanvas::onDrawEdgeAAImageSet2(const ImageSetEntry set[],
     this->SkNWayCanvas::onDrawEdgeAAImageSet2(
             set, count, dstClips, preViewMatrices, sampling, paint, constraint);
 }
-
-void SkCaptureCanvas::onSurfaceDelete() {
-    // TODO (b/412351769): signal to the capture manager that this canvas's surface has been deleted
-}

src/capture/SkCaptureManager.cpp

@@ -8,6 +8,7 @@
 #include "src/capture/SkCaptureManager.h"
 
 #include "include/core/SkCanvas.h"
+#include "include/private/base/SkDebug.h"
 #include "src/capture/SkCaptureCanvas.h"
 
 #include <memory>
@@ -20,3 +21,20 @@ SkCanvas* SkCaptureManager::makeCaptureCanvas(SkCanvas* canvas) {
     fTrackedCanvases.emplace_back(std::move(newCanvas));
     return rawCanvasPtr;
 }
+
+void SkCaptureManager::snapPictures() {
+    for (auto& canvas : fTrackedCanvases) {
+        if (canvas) {
+            auto picture = canvas->snapPicture();
+            if (picture) {
+                fPictures.emplace_back(picture);
+            }
+        }
+    }
+}
+
+void SkCaptureManager::serializeCapture() {
+    // TODO (412351769): return a serialized file via SkData, for now this will print the contents
+    // of the capture for inspection.
+    SkDebugf("Tracked canvases: %d. SkPictures: %d\n", fTrackedCanvases.size(), fPictures.size());
+}

src/capture/SkCaptureManager.h

@@ -8,6 +8,7 @@
 #ifndef SkCaptureManager_DEFINED
 #define SkCaptureManager_DEFINED
 
+#include "include/core/SkPicture.h"
 #include "include/core/SkRefCnt.h"
 #include "include/private/base/SkTArray.h"
 
@@ -21,19 +22,24 @@ class SkCaptureManager : public SkRefCnt {
     SkCaptureManager();
 
     SkCanvas* makeCaptureCanvas(SkCanvas* canvas);
+    void snapPictures();
+    void serializeCapture();
 
     void toggleCapture(bool capturing) {
+        if (capturing != fIsCurrentlyCapturing && !capturing) {
+            this->snapPictures();
+        }
         fIsCurrentlyCapturing = capturing;
     }
 
     bool isCurrentlyCapturing() const {
         return fIsCurrentlyCapturing;
     }
 
-
 private:
     std::atomic<bool> fIsCurrentlyCapturing = false;
     skia_private::TArray<std::unique_ptr<SkCaptureCanvas>> fTrackedCanvases;
+    skia_private::TArray<sk_sp<SkPicture>>  fPictures;
 };
 
 #endif  // SkCaptureManager_DEFINED

src/gpu/graphite/Context.cpp

@@ -917,6 +917,7 @@ void Context::endCapture() {
     // TODO (b/412351769): Return an SkData block of serialized SKPs and other capture data
     if (fSharedContext->captureManager()) {
         fSharedContext->captureManager()->toggleCapture(false);
+        fSharedContext->captureManager()->serializeCapture();
     }
 }