From dfaa057c15180a18f65d86317618a97d683e99c4 Mon Sep 17 00:00:00 2001
From: Hal Canary <halcanary@google.com>
Date: Mon, 27 Nov 2017 09:33:44 -0500
Subject: [PATCH] SkPDF: less tolerance for small circles

BUG=chromium:772953
Change-Id: I9452ac8ad66ab8be26a9388f8c85a1f0e61bd392
Reviewed-on: https://skia-review.googlesource.com/75960
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
---
 gm/circle_sizes.cpp     | 16 ++++++++++++++++
 gn/gm.gni               |  1 +
 src/pdf/SkPDFDevice.cpp |  3 ++-
 3 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 gm/circle_sizes.cpp

diff --git a/gm/circle_sizes.cpp b/gm/circle_sizes.cpp
new file mode 100644
index 0000000000..8ed95dd0ed
--- /dev/null
+++ b/gm/circle_sizes.cpp
@@ -0,0 +1,16 @@
+/*
+ * 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 "gm.h"
+// https://crbug.com/772953
+DEF_SIMPLE_GM(circle_sizes, canvas, 128, 128) {
+    SkPaint p;
+    p.setAntiAlias(true);
+    for (int i = 0; i < 16; ++i) {
+        canvas->drawCircle({14.0f + 32.0f * (i % 4),
+                            14.0f + 32.0f * (i / 4)}, i + 1.0f, p);
+    }
+}
diff --git a/gn/gm.gni b/gn/gm.gni
index 22d562f187..ad542fb976 100644
--- a/gn/gm.gni
+++ b/gn/gm.gni
@@ -60,6 +60,7 @@ gm_sources = [
   "$_gm/bug615686.cpp",
   "$_gm/cgm.c",
   "$_gm/cgms.cpp",
+  "$_gm/circle_sizes.cpp",
   "$_gm/circles.cpp",
   "$_gm/circulararcs.cpp",
   "$_gm/circularclips.cpp",
diff --git a/src/pdf/SkPDFDevice.cpp b/src/pdf/SkPDFDevice.cpp
index 61205ba36d..10ec6911a2 100644
--- a/src/pdf/SkPDFDevice.cpp
+++ b/src/pdf/SkPDFDevice.cpp
@@ -952,8 +952,9 @@ void SkPDFDevice::internalDrawPath(const SkClipStack& clipStack,
     if (!content.entry()) {
         return;
     }
+    constexpr SkScalar kToleranceScale = 0.0625f;  // smaller = better conics (circles).
     SkScalar matrixScale = matrix.mapRadius(1.0f);
-    SkScalar tolerance = matrixScale > 0.0f ? 0.25f / matrixScale : 0.25f;
+    SkScalar tolerance = matrixScale > 0.0f ? kToleranceScale / matrixScale : kToleranceScale;
     bool consumeDegeratePathSegments =
            paint.getStyle() == SkPaint::kFill_Style ||
            (paint.getStrokeCap() != SkPaint::kRound_Cap &&