SkPDF: when drawing stroked path, draw using SVG rules for zero-length segments
The "zeroPath" and emptystroke GMs capture this issue.
This CL changes the following PDF GMs: emptystroke dashing4
lineclosepath dashing3 zeroPath linepath
complexclip3_complex complexclip3_simple roundrects
degeneratesegments filltypes strokerect pathfill
inverse_paths desk_chalkboard.skp
After this change, all PDF GMs look better (closer to 8888).
The dashing4, emptystroke, and zeroPath GMs still need a lot
of work to make them look right.
BUG=538726
Review URL: https://codereview.chromium.org/1374383004
diff --git a/gm/path_stroke_with_zero_length.cpp b/gm/path_stroke_with_zero_length.cpp
new file mode 100644
index 0000000..dc52947
--- /dev/null
+++ b/gm/path_stroke_with_zero_length.cpp
@@ -0,0 +1,54 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkPath.h"
+#include "SkStream.h"
+#include "gm.h"
+
+// Test how short paths are stroked with various caps
+DEF_SIMPLE_GM(path_stroke_with_zero_length, canvas, 240, 120) {
+ SkPath paths[5];
+ paths[0].moveTo(30.0f, 0); // single line segment
+ paths[0].rLineTo(30.0f, 0);
+
+ paths[1].moveTo(90.0f, 0); // single line segment with close
+ paths[1].rLineTo(30.0f, 0);
+ paths[1].close();
+
+ paths[2].moveTo(150.0f, 0); // zero-length line
+ paths[2].rLineTo(0, 0);
+
+ paths[3].moveTo(180.0f, 0); // zero-length line with close
+ paths[3].rLineTo(0, 0);
+ paths[3].close();
+
+ paths[4].moveTo(210.0f, 0); // close only, no line
+ paths[4].close();
+
+ auto drawPaths = [&](const SkPaint& paint) {
+ canvas->translate(0, 30.0f);
+ for (const SkPath& path : paths) {
+ canvas->drawPath(path, paint);
+ }
+ };
+
+ SkAutoCanvasRestore autoCanvasRestore(canvas, true);
+
+ SkPaint butt;
+ butt.setStyle(SkPaint::kStroke_Style);
+ butt.setStrokeWidth(20.0f);
+ butt.setStrokeCap(SkPaint::kButt_Cap);
+ drawPaths(butt);
+
+ SkPaint round(butt);
+ round.setStrokeCap(SkPaint::kRound_Cap);
+ drawPaths(round);
+
+ SkPaint square(butt);
+ square.setStrokeCap(SkPaint::kSquare_Cap);
+ drawPaths(square);
+}
diff --git a/src/pdf/SkPDFDevice.cpp b/src/pdf/SkPDFDevice.cpp
index b6500c1..9134d80 100644
--- a/src/pdf/SkPDFDevice.cpp
+++ b/src/pdf/SkPDFDevice.cpp
@@ -1035,7 +1035,12 @@
if (!content.entry()) {
return;
}
+ bool consumeDegeratePathSegments =
+ paint.getStyle() == SkPaint::kFill_Style ||
+ (paint.getStrokeCap() != SkPaint::kRound_Cap &&
+ paint.getStrokeCap() != SkPaint::kSquare_Cap);
SkPDFUtils::EmitPath(*pathPtr, paint.getStyle(),
+ consumeDegeratePathSegments,
&content.entry()->fContent);
SkPDFUtils::PaintPath(paint.getStyle(), pathPtr->getFillType(),
&content.entry()->fContent);
diff --git a/src/pdf/SkPDFUtils.cpp b/src/pdf/SkPDFUtils.cpp
index fc1bdbe..108f2c1 100644
--- a/src/pdf/SkPDFUtils.cpp
+++ b/src/pdf/SkPDFUtils.cpp
@@ -118,25 +118,27 @@
// static
void SkPDFUtils::EmitPath(const SkPath& path, SkPaint::Style paintStyle,
- SkWStream* content) {
+ bool doConsumeDegerates, SkWStream* content) {
// Filling a path with no area results in a drawing in PDF renderers but
// Chrome expects to be able to draw some such entities with no visible
// result, so we detect those cases and discard the drawing for them.
// Specifically: moveTo(X), lineTo(Y) and moveTo(X), lineTo(X), lineTo(Y).
enum SkipFillState {
- kEmpty_SkipFillState = 0,
- kSingleLine_SkipFillState = 1,
- kNonSingleLine_SkipFillState = 2,
+ kEmpty_SkipFillState,
+ kSingleLine_SkipFillState,
+ kNonSingleLine_SkipFillState,
};
SkipFillState fillState = kEmpty_SkipFillState;
- if (paintStyle != SkPaint::kFill_Style) {
- fillState = kNonSingleLine_SkipFillState;
- }
+ //if (paintStyle != SkPaint::kFill_Style) {
+ // fillState = kNonSingleLine_SkipFillState;
+ //}
SkPoint lastMovePt = SkPoint::Make(0,0);
SkDynamicMemoryWStream currentSegment;
SkPoint args[4];
SkPath::Iter iter(path, false);
- for (SkPath::Verb verb = iter.next(args); verb != SkPath::kDone_Verb; verb = iter.next(args)) {
+ for (SkPath::Verb verb = iter.next(args, doConsumeDegerates);
+ verb != SkPath::kDone_Verb;
+ verb = iter.next(args, doConsumeDegerates)) {
// args gets all the points, even the implicit first point.
switch (verb) {
case SkPath::kMove_Verb:
@@ -146,13 +148,11 @@
break;
case SkPath::kLine_Verb:
AppendLine(args[1].fX, args[1].fY, ¤tSegment);
- if (fillState == kEmpty_SkipFillState) {
- if (args[0] != lastMovePt) {
- fillState = kSingleLine_SkipFillState;
- }
- } else if (fillState == kSingleLine_SkipFillState) {
- fillState = kNonSingleLine_SkipFillState;
+ if ((fillState == kEmpty_SkipFillState) && (args[0] != lastMovePt)) {
+ fillState = kSingleLine_SkipFillState;
+ break;
}
+ fillState = kNonSingleLine_SkipFillState;
break;
case SkPath::kQuad_Verb:
append_quad(args, ¤tSegment);
@@ -165,6 +165,7 @@
for (int i = 0; i < converter.countQuads(); ++i) {
append_quad(&quads[i * 2], ¤tSegment);
}
+ fillState = kNonSingleLine_SkipFillState;
} break;
case SkPath::kCubic_Verb:
AppendCubic(args[1].fX, args[1].fY, args[2].fX, args[2].fY,
@@ -172,10 +173,10 @@
fillState = kNonSingleLine_SkipFillState;
break;
case SkPath::kClose_Verb:
- if (fillState != kSingleLine_SkipFillState) {
+
ClosePath(¤tSegment);
- currentSegment.writeToStream(content);
- }
+
+ currentSegment.writeToStream(content);
currentSegment.reset();
break;
default:
diff --git a/src/pdf/SkPDFUtils.h b/src/pdf/SkPDFUtils.h
index 38f300a..0aa05a0 100644
--- a/src/pdf/SkPDFUtils.h
+++ b/src/pdf/SkPDFUtils.h
@@ -46,7 +46,11 @@
SkScalar dstX, SkScalar dstY, SkWStream* content);
static void AppendRectangle(const SkRect& rect, SkWStream* content);
static void EmitPath(const SkPath& path, SkPaint::Style paintStyle,
- SkWStream* content);
+ bool doConsumeDegerates, SkWStream* content);
+ static void EmitPath(const SkPath& path, SkPaint::Style paintStyle,
+ SkWStream* content) {
+ SkPDFUtils::EmitPath(path, paintStyle, true, content);
+ }
static void ClosePath(SkWStream* content);
static void PaintPath(SkPaint::Style style, SkPath::FillType fill,
SkWStream* content);