[SkSVGDevice] Add support for more stroke params

experimental/svg/SkSVGDevice.cpp

Index: experimental/svg/SkSVGDevice.cpp
diff --git a/experimental/svg/SkSVGDevice.cpp b/experimental/svg/SkSVGDevice.cpp
index 9f4a54a8a8b5f4821be7467548d86de008654f27..3c861f3730f720ebf43a4712677f1ad386ed9216 100644
--- a/experimental/svg/SkSVGDevice.cpp
+++ b/experimental/svg/SkSVGDevice.cpp
@@ -31,6 +31,32 @@ static SkScalar svg_opacity(SkColor color) {
     return SkIntToScalar(SkColorGetA(color)) / SK_AlphaOPAQUE;
 }
 
+// Keep in sync with SkPaint::Cap
+static const char* cap_map[]  = {
+    "",      // kButt_Cap (default)
+    "round", // kRound_Cap
+    "square" // kSquare_Cap
+};
+SK_COMPILE_ASSERT(SK_ARRAY_COUNT(cap_map) == SkPaint::kCapCount, missing_cap_map_entry);
+
+static SkString svg_cap(SkPaint::Cap cap) {

[mtklein, 2015/02/04 22:37:49]

Why don't these just return const char* ?  Seems like addAttribute() likes that
just fine, even prefers it.

[reed1, 2015/02/04 22:42:01]

+1

[f(malita), 2015/02/04 22:43:14]

Done.

+    SkASSERT(cap < SK_ARRAY_COUNT(cap_map));
+    return SkString(cap_map[cap]);
+}
+
+// Keep in sync with SkPaint::Join
+static const char* join_map[] = {
+    "",      // kMiter_Join (default)
+    "round", // kRound_Join
+    "bevel"  // kBevel_Join
+};
+SK_COMPILE_ASSERT(SK_ARRAY_COUNT(join_map) == SkPaint::kJoinCount, missing_join_map_entry);
+
+static SkString svg_join(SkPaint::Join join) {
+    SkASSERT(join < SK_ARRAY_COUNT(join_map));
+    return SkString(join_map[join]);
+}
+
 static void append_escaped_unichar(SkUnichar c, SkString* text) {
     switch(c) {
     case '&':
@@ -191,21 +217,46 @@ void SkSVGDevice::AutoElement::addPaint(const SkPaint& paint, const Resources& r
     SkPaint::Style style = paint.getStyle();
     if (style == SkPaint::kFill_Style || style == SkPaint::kStrokeAndFill_Style) {
         this->addAttribute("fill", resources.fPaintServer);
+
+        if (SK_AlphaOPAQUE != SkColorGetA(paint.getColor())) {
+            this->addAttribute("fill-opacity", svg_opacity(paint.getColor()));
+        }
     } else {
         this->addAttribute("fill", "none");

[mtklein, 2015/02/04 22:37:49]

Can we assert kStroke_Style here?

[f(malita), 2015/02/04 22:43:14]

Done.

     }
 
     if (style == SkPaint::kStroke_Style || style == SkPaint::kStrokeAndFill_Style) {
         this->addAttribute("stroke", resources.fPaintServer);
-        this->addAttribute("stroke-width", paint.getStrokeWidth());
+
+        SkScalar strokeWidth = paint.getStrokeWidth();
+        if (strokeWidth == 0) {
+            // Hairline stroke
+            strokeWidth = 1;
+            this->addAttribute("vector-effect", "non-scaling-stroke");
+        }
+        this->addAttribute("stroke-width", strokeWidth);
+
+        SkString cap = svg_cap(paint.getStrokeCap());
+        if (!cap.isEmpty()) {
+            this->addAttribute("stroke-linecap", cap);
+        }
+
+        SkString join = svg_join(paint.getStrokeJoin());
+        if (!join.isEmpty()) {
+            this->addAttribute("stroke-linejoin", join);
+        }
+
+        if (paint.getStrokeJoin() == SkPaint::kMiter_Join) {
+            this->addAttribute("stroke-miterlimit", paint.getStrokeMiter());
+        }
+
+        if (SK_AlphaOPAQUE != SkColorGetA(paint.getColor())) {
+            this->addAttribute("stroke-opacity", svg_opacity(paint.getColor()));
+        }
     } else {
         this->addAttribute("stroke", "none");

[mtklein, 2015/02/04 22:37:49]

And kFill_Style here?

     }
 
-    if (SK_AlphaOPAQUE != SkColorGetA(paint.getColor())) {
-        this->addAttribute("opacity", svg_opacity(paint.getColor()));
-    }
-
     if (!resources.fClip.isEmpty()) {
         this->addAttribute("clip-path", resources.fClip);
     }