[SkSVGDevice] Add support for more stroke params

experimental/svg/SkSVGDevice.cpp

 /*
  * 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 "SkSVGDevice.h"
 
 #include "SkBitmap.h"
@@ skipping 13 matching lines @@
     return SkStringPrintf("rgb(%u,%u,%u)",
                           SkColorGetR(color),
                           SkColorGetG(color),
                           SkColorGetB(color));
 }
 
 static SkScalar svg_opacity(SkColor color) {
     return SkIntToScalar(SkColorGetA(color)) / SK_AlphaOPAQUE;
 }
 
+// Keep in sync with SkPaint::Cap
+static const char* cap_map[]  = {
+    NULL,    // kButt_Cap (default)
+    "round", // kRound_Cap
+    "square" // kSquare_Cap
+};
+SK_COMPILE_ASSERT(SK_ARRAY_COUNT(cap_map) == SkPaint::kCapCount, missing_cap_map_entry);
+
+static const char* svg_cap(SkPaint::Cap cap) {
+    SkASSERT(cap < SK_ARRAY_COUNT(cap_map));
+    return cap_map[cap];
+}
+
+// Keep in sync with SkPaint::Join
+static const char* join_map[] = {
+    NULL,    // kMiter_Join (default)
+    "round", // kRound_Join
+    "bevel"  // kBevel_Join
+};
+SK_COMPILE_ASSERT(SK_ARRAY_COUNT(join_map) == SkPaint::kJoinCount, missing_join_map_entry);
+
+static const char* svg_join(SkPaint::Join join) {
+    SkASSERT(join < SK_ARRAY_COUNT(join_map));
+    return join_map[join];
+}
+
 static void append_escaped_unichar(SkUnichar c, SkString* text) {
     switch(c) {
     case '&':
         text->append("&amp;");
         break;
     case '"':
         text->append("&quot;");
         break;
     case '\'':
         text->append("&apos;");
@@ skipping 140 matching lines @@
     SkString addLinearGradientDef(const SkShader::GradientInfo& info, const SkShader* shader);
 
     SkXMLWriter*    fWriter;
     ResourceBucket* fResourceBucket;
 };
 
 void SkSVGDevice::AutoElement::addPaint(const SkPaint& paint, const Resources& resources) {
     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 {
+        SkASSERT(style == SkPaint::kStroke_Style);
         this->addAttribute("fill", "none");
     }
 
     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);
+
+        const char* cap = svg_cap(paint.getStrokeCap());
+        if (SkToBool(cap)) {

[mtklein, 2015/02/04 22:46:35]

If you're feeling frisky, these can be

if (const char* cap = svg_cap(paint.getStrokeCap())) {
   this->addAttribute("stroke-linecap", cap);
}

etc.

One of the few ways C++ improved on C.  :P

[f(malita), 2015/02/04 22:50:51]

Done.

+            this->addAttribute("stroke-linecap", cap);
+        }
+
+        const char* join = svg_join(paint.getStrokeJoin());
+        if (SkToBool(join)) {
+            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 {
+         SkASSERT(style == SkPaint::kFill_Style);

[mtklein, 2015/02/04 22:46:35]

May be a stray space here?

[f(malita), 2015/02/04 22:50:51]

Done.

         this->addAttribute("stroke", "none");
     }
 
-    if (SK_AlphaOPAQUE != SkColorGetA(paint.getColor())) {
-        this->addAttribute("opacity", svg_opacity(paint.getColor()));
-    }
-
     if (!resources.fClip.isEmpty()) {
         this->addAttribute("clip-path", resources.fClip);
     }
 }
 
 void SkSVGDevice::AutoElement::addTransform(const SkMatrix& t, const char name[]) {
     if (t.isIdentity()) {
         return;
     }
 
@@ skipping 314 matching lines @@
                                const SkPaint& paint) {
     // todo
     SkDebugf("unsupported operation: drawVertices()\n");
 }
 
 void SkSVGDevice::drawDevice(const SkDraw&, SkBaseDevice*, int x, int y,
                              const SkPaint&) {
     // todo
     SkDebugf("unsupported operation: drawDevice()\n");
 }