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authorGravatar caryclark <caryclark@google.com>2016-01-23 05:07:04 -0800
committerGravatar Commit bot <commit-bot@chromium.org>2016-01-23 05:07:04 -0800
commit55d49053d1b6db42e013eb3409ffcfc7e235c685 (patch)
treec424605b65aceb748643ecb9e6b66193f362d54b /gm
parentb714fb0199e8727ef2b6cddbee7eba6046f01554 (diff)
Add svg path arcto
The arcto() used by SVG in Chrome and Android is ported here, using conics instead of cubics. The logic is a direct transposition of the WebKit code. The attached GM includes SVG that draws the same as Skia. R=reed@google.com BUG=skia:3959 GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1613303002 Review URL: https://codereview.chromium.org/1613303002
Diffstat (limited to 'gm')
-rw-r--r--gm/arcto.cpp86
1 files changed, 86 insertions, 0 deletions
diff --git a/gm/arcto.cpp b/gm/arcto.cpp
new file mode 100644
index 0000000000..900c6b30ea
--- /dev/null
+++ b/gm/arcto.cpp
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+#include "SkParsePath.h"
+#include "SkPath.h"
+
+/*
+The arcto test below should draw the same as this SVG:
+(Note that Skia's arcTo Direction parameter value is opposite SVG's sweep value, e.g. 0 / 1)
+
+<svg width="500" height="600">
+<path d="M 50,100 A50,50, 0,0,1, 150,200" style="stroke:#660000; fill:none; stroke-width:2" />
+<path d="M100,100 A50,100, 0,0,1, 200,200" style="stroke:#660000; fill:none; stroke-width:2" />
+<path d="M150,100 A50,50, 45,0,1, 250,200" style="stroke:#660000; fill:none; stroke-width:2" />
+<path d="M200,100 A50,100, 45,0,1, 300,200" style="stroke:#660000; fill:none; stroke-width:2" />
+
+<path d="M150,200 A50,50, 0,1,0, 150,300" style="stroke:#660000; fill:none; stroke-width:2" />
+<path d="M200,200 A50,100, 0,1,0, 200,300" style="stroke:#660000; fill:none; stroke-width:2" />
+<path d="M250,200 A50,50, 45,1,0, 250,300" style="stroke:#660000; fill:none; stroke-width:2" />
+<path d="M300,200 A50,100, 45,1,0, 300,300" style="stroke:#660000; fill:none; stroke-width:2" />
+
+<path d="M250,400 A120,80 0 0,0 250,500"
+ fill="none" stroke="red" stroke-width="5" />
+
+<path d="M250,400 A120,80 0 1,1 250,500"
+ fill="none" stroke="green" stroke-width="5"/>
+
+<path d="M250,400 A120,80 0 1,0 250,500"
+ fill="none" stroke="purple" stroke-width="5"/>
+
+<path d="M250,400 A120,80 0 0,1 250,500"
+ fill="none" stroke="blue" stroke-width="5"/>
+</svg>
+ */
+
+DEF_SIMPLE_GM(arcto, canvas, 500, 600) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kStroke_Style);
+ paint.setStrokeWidth(2);
+ paint.setColor(0xFF660000);
+ canvas->scale(2, 2);
+ SkRect oval = SkRect::MakeXYWH(100, 100, 100, 100);
+ SkPath svgArc;
+
+ for (int angle = 0; angle <= 45; angle += 45) {
+ for (int oHeight = 2; oHeight >= 1; --oHeight) {
+ SkScalar ovalHeight = oval.height() / oHeight;
+ svgArc.moveTo(oval.fLeft, oval.fTop);
+ svgArc.arcTo(oval.width() / 2, ovalHeight, SkIntToScalar(angle), SkPath::kSmall_ArcSize,
+ SkPath::kCW_Direction, oval.right(), oval.bottom());
+ canvas->drawPath(svgArc, paint);
+ svgArc.reset();
+
+ svgArc.moveTo(oval.fLeft + 100, oval.fTop + 100);
+ svgArc.arcTo(oval.width() / 2, ovalHeight, SkIntToScalar(angle), SkPath::kLarge_ArcSize,
+ SkPath::kCCW_Direction, oval.right(), oval.bottom() + 100);
+ canvas->drawPath(svgArc, paint);
+ oval.offset(50, 0);
+ svgArc.reset();
+
+ }
+ }
+
+ paint.setStrokeWidth(5);
+ const SkColor purple = 0xFF800080;
+ const SkColor darkgreen = 0xFF008000;
+ const SkColor colors[] = { SK_ColorRED, darkgreen, purple, SK_ColorBLUE };
+ const char* arcstrs[] = {
+ "M250,400 A120,80 0 0,0 250,500",
+ "M250,400 A120,80 0 1,1 250,500",
+ "M250,400 A120,80 0 1,0 250,500",
+ "M250,400 A120,80 0 0,1 250,500"
+ };
+ int cIndex = 0;
+ for (const char* arcstr : arcstrs) {
+ SkParsePath::FromSVGString(arcstr, &svgArc);
+ paint.setColor(colors[cIndex++]);
+ canvas->drawPath(svgArc, paint);
+ }
+}