Use item type animators for SVG list types where possible

For SVGNumberList and SVGLengthList we can forward the Add() and
CalculateAnimatedValue() operations to each item (== the item type
animator). This may be slightly slower, but avoids duplicating some
fairly hairy code (for SVGLength; SVGNumber is fairly trivial).

Also move some variable declarations closer to their first use. Remove
the redundant 'length' bit from some local variables.

Bug: 1017723
Change-Id: Ia0e5047891b1fa8584ecc65524f724ddfafff696
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2392461Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#804567}

third_party/blink/renderer/core/svg/svg_length_list.cc

@@ -20,7 +20,6 @@
 
 #include "third_party/blink/renderer/core/svg/svg_length_list.h"
 
-#include "third_party/blink/renderer/core/svg/animation/smil_animation_effect_parameters.h"
 #include "third_party/blink/renderer/core/svg/svg_parser_utilities.h"
 #include "third_party/blink/renderer/platform/heap/heap.h"
 
@@ -86,15 +85,10 @@ SVGParsingError SVGLengthList::SetValueAsString(const String& value) {
 
 void SVGLengthList::Add(SVGPropertyBase* other, SVGElement* context_element) {
   auto* other_list = To<SVGLengthList>(other);
-
   if (length() != other_list->length())
     return;
-
-  SVGLengthContext length_context(context_element);
   for (uint32_t i = 0; i < length(); ++i)
-    at(i)->SetValue(
-        at(i)->Value(length_context) + other_list->at(i)->Value(length_context),
-        length_context);
+    at(i)->Add(other_list->at(i), context_element);
 }
 
 SVGLength* SVGLengthList::CreatePaddingItem() const {
@@ -111,44 +105,28 @@ void SVGLengthList::CalculateAnimatedValue(
     SVGElement* context_element) {
   auto* from_list = To<SVGLengthList>(from_value);
   auto* to_list = To<SVGLengthList>(to_value);
+
+  if (!AdjustFromToListValues(from_list, to_list, percentage))
+    return;
+
   auto* to_at_end_of_duration_list =
       To<SVGLengthList>(to_at_end_of_duration_value);
 
-  SVGLengthContext length_context(context_element);
-
-  uint32_t from_length_list_size = from_list->length();
-  uint32_t to_length_list_size = to_list->length();
+  uint32_t from_list_size = from_list->length();
+  uint32_t to_list_size = to_list->length();
   uint32_t to_at_end_of_duration_list_size =
       to_at_end_of_duration_list->length();
 
-  if (!AdjustFromToListValues(from_list, to_list, percentage))
-    return;
-
-  for (uint32_t i = 0; i < to_length_list_size; ++i) {
-    // TODO(shanmuga.m): Support calc for SVGLengthList animation
-    float animated_number = at(i)->Value(length_context);
-    const SVGLength* length_for_unit_type = to_list->at(i);
-    float effective_from = 0;
-    if (from_length_list_size) {
-      if (percentage < 0.5)
-        length_for_unit_type = from_list->at(i);
-      effective_from = from_list->at(i)->Value(length_context);
-    }
-    float effective_to = to_list->at(i)->Value(length_context);
-    float effective_to_at_end =
-        i < to_at_end_of_duration_list_size
-            ? to_at_end_of_duration_list->at(i)->Value(length_context)
-            : 0;
-
-    AnimateAdditiveNumber(parameters, percentage, repeat_count, effective_from,
-                          effective_to, effective_to_at_end, animated_number);
-    // |animated_number| is in user units.
-    CSSPrimitiveValue::UnitType unit_type =
-        length_for_unit_type->IsCalculated()
-            ? CSSPrimitiveValue::UnitType::kUserUnits
-            : length_for_unit_type->NumericLiteralType();
-    at(i)->SetUnitType(unit_type);
-    at(i)->SetValue(animated_number, length_context);
+  const bool needs_neutral_element =
+      !from_list_size || to_list_size != to_at_end_of_duration_list_size;
+  SVGLength* neutral = needs_neutral_element ? CreatePaddingItem() : nullptr;
+  for (uint32_t i = 0; i < to_list_size; ++i) {
+    SVGLength* from = from_list_size ? from_list->at(i) : neutral;
+    SVGLength* to_at_end = i < to_at_end_of_duration_list_size
+                               ? to_at_end_of_duration_list->at(i)
+                               : neutral;
+    at(i)->CalculateAnimatedValue(parameters, percentage, repeat_count, from,
+                                  to_list->at(i), to_at_end, context_element);
   }
 }
 

third_party/blink/renderer/core/svg/svg_number_list.cc

@@ -20,7 +20,6 @@
 
 #include "third_party/blink/renderer/core/svg/svg_number_list.h"
 
-#include "third_party/blink/renderer/core/svg/animation/smil_animation_effect_parameters.h"
 #include "third_party/blink/renderer/core/svg/svg_parser_utilities.h"
 #include "third_party/blink/renderer/platform/heap/heap.h"
 #include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
@@ -65,12 +64,10 @@ SVGParsingError SVGNumberList::SetValueAsString(const String& value) {
 
 void SVGNumberList::Add(SVGPropertyBase* other, SVGElement* context_element) {
   auto* other_list = To<SVGNumberList>(other);
-
   if (length() != other_list->length())
     return;
-
   for (uint32_t i = 0; i < length(); ++i)
-    at(i)->SetValue(at(i)->Value() + other_list->at(i)->Value());
+    at(i)->Add(other_list->at(i), context_element);
 }
 
 void SVGNumberList::CalculateAnimatedValue(
@@ -83,6 +80,10 @@ void SVGNumberList::CalculateAnimatedValue(
     SVGElement* context_element) {
   auto* from_list = To<SVGNumberList>(from_value);
   auto* to_list = To<SVGNumberList>(to_value);
+
+  if (!AdjustFromToListValues(from_list, to_list, percentage))
+    return;
+
   auto* to_at_end_of_duration_list =
       To<SVGNumberList>(to_at_end_of_duration_value);
 
@@ -91,20 +92,16 @@ void SVGNumberList::CalculateAnimatedValue(
   uint32_t to_at_end_of_duration_list_size =
       to_at_end_of_duration_list->length();
 
-  if (!AdjustFromToListValues(from_list, to_list, percentage))
-    return;
-
+  const bool needs_neutral_element =
+      !from_list_size || to_list_size != to_at_end_of_duration_list_size;
+  SVGNumber* neutral = needs_neutral_element ? CreatePaddingItem() : nullptr;
   for (uint32_t i = 0; i < to_list_size; ++i) {
-    float effective_from = from_list_size ? from_list->at(i)->Value() : 0;
-    float effective_to = to_list_size ? to_list->at(i)->Value() : 0;
-    float effective_to_at_end = i < to_at_end_of_duration_list_size
-                                    ? to_at_end_of_duration_list->at(i)->Value()
-                                    : 0;
-
-    float animated = at(i)->Value();
-    AnimateAdditiveNumber(parameters, percentage, repeat_count, effective_from,
-                          effective_to, effective_to_at_end, animated);
-    at(i)->SetValue(animated);
+    SVGNumber* from = from_list_size ? from_list->at(i) : neutral;
+    SVGNumber* to_at_end = i < to_at_end_of_duration_list_size
+                               ? to_at_end_of_duration_list->at(i)
+                               : neutral;
+    at(i)->CalculateAnimatedValue(parameters, percentage, repeat_count, from,
+                                  to_list->at(i), to_at_end, context_element);
   }
 }