[SVGDom] Add support for assorted absolute units

experimental/svg/model/SkSVGRenderContext.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCanvas.h"
 #include "SkSVGAttribute.h"
 #include "SkSVGRenderContext.h"
 #include "SkSVGTypes.h"
 
 namespace {
 
 SkScalar length_size_for_type(const SkSize& viewport, SkSVGLengthContext::LengthType t) {
     switch (t) {
     case SkSVGLengthContext::LengthType::kHorizontal:
         return viewport.width();
     case SkSVGLengthContext::LengthType::kVertical:
         return viewport.height();
     case SkSVGLengthContext::LengthType::kOther:
         return SkScalarSqrt(viewport.width() * viewport.height());
     }
 
     SkASSERT(false);  // Not reached.
     return 0;
 }
 

[robertphillips, 2016/08/17 18:39:03]

// These all assume a 90dpi display device.

Do we not want to actually have an fDPI setting on SkSVGLengthContext and then
compute all these explicitly in resolve ?

[f(malita), 2016/08/17 21:04:17]

Done.

+// https://www.w3.org/TR/SVG/coords.html#Units
+constexpr SkScalar kPXMultiplier =  1.00f;

[robertphillips, 2016/08/17 18:39:03]

Isn't the pt multiplier supposed to be DPI/72.272 ?

[f(malita), 2016/08/17 21:04:17]

Done.

+constexpr SkScalar kPTMultiplier =  1.25f;
+constexpr SkScalar kPCMultiplier = 15.00f;
+constexpr SkScalar kINMultiplier = 90.00f;
+constexpr SkScalar kMMMultiplier =  3.543307f;
+constexpr SkScalar kCMMultiplier = kMMMultiplier * 10;
+
 } // anonymous ns
 
 SkScalar SkSVGLengthContext::resolve(const SkSVGLength& l, LengthType t) const {
     switch (l.unit()) {
     case SkSVGLength::Unit::kNumber:
-        // Fall through.
-    case SkSVGLength::Unit::kPX:
         return l.value();
     case SkSVGLength::Unit::kPercentage:
         return l.value() * length_size_for_type(fViewport, t) / 100;
+    case SkSVGLength::Unit::kPX:
+        return l.value() * kPXMultiplier;
+    case SkSVGLength::Unit::kCM:
+        return l.value() * kCMMultiplier;
+    case SkSVGLength::Unit::kMM:
+        return l.value() * kMMMultiplier;
+    case SkSVGLength::Unit::kIN:
+        return l.value() * kINMultiplier;
+    case SkSVGLength::Unit::kPT:
+        return l.value() * kPTMultiplier;
+    case SkSVGLength::Unit::kPC:
+        return l.value() * kPCMultiplier;
     default:
         SkDebugf("unsupported unit type: <%d>\n", l.unit());
         return 0;
     }
 }
 
 SkRect SkSVGLengthContext::resolveRect(const SkSVGLength& x, const SkSVGLength& y,
                                        const SkSVGLength& w, const SkSVGLength& h) const {
     return SkRect::MakeXYWH(
         this->resolve(x, SkSVGLengthContext::LengthType::kHorizontal),
@@ skipping 188 matching lines @@
 
 const SkPaint* SkSVGRenderContext::fillPaint() const {
     const SkSVGPaint::Type paintType = fPresentationContext->fInherited.fFill.get()->type();
     return paintType != SkSVGPaint::Type::kNone ? &fPresentationContext->fFillPaint : nullptr;
 }
 
 const SkPaint* SkSVGRenderContext::strokePaint() const {
     const SkSVGPaint::Type paintType = fPresentationContext->fInherited.fStroke.get()->type();
     return paintType != SkSVGPaint::Type::kNone ? &fPresentationContext->fStrokePaint : nullptr;
 }