From 710391597bc0064c9ad7306bae30752919aca84b Mon Sep 17 00:00:00 2001
From: Emil Sjolander <emilsj@fb.com>
Date: Thu, 22 Dec 2016 02:57:15 -0800
Subject: [PATCH] BREAKING - Change aspect ratio to always be width/height

Summary: Aspect ratio being defined as width/height or height/width depending on the situation it was used in turned out to be very confusing. This diff makes aspect ratio always be defined as width/height irregardless of the usage.

Differential Revision: D4339132

fbshipit-source-id: e5da32750b55ddaf6acaf1cbd7662d86f2b480c3
---
 ReactCommon/yoga/yoga/Yoga.c | 6 +++---
 ReactCommon/yoga/yoga/Yoga.h | 3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/ReactCommon/yoga/yoga/Yoga.c b/ReactCommon/yoga/yoga/Yoga.c
index 4762cee4f..8b1c5fda2 100644
--- a/ReactCommon/yoga/yoga/Yoga.c
+++ b/ReactCommon/yoga/yoga/Yoga.c
@@ -1062,7 +1062,7 @@ static void YGNodeComputeFlexBasisForChild(const YGNodeRef node,
     if (!YGValueIsUndefined(child->style.aspectRatio)) {
       if (!isMainAxisRow && childWidthMeasureMode == YGMeasureModeExactly) {
         child->layout.computedFlexBasis =
-            fmaxf(childWidth * child->style.aspectRatio,
+            fmaxf(childWidth / child->style.aspectRatio,
                   YGNodePaddingAndBorderForAxis(child, YGFlexDirectionColumn));
         return;
       } else if (isMainAxisRow && childHeightMeasureMode == YGMeasureModeExactly) {
@@ -1157,7 +1157,7 @@ static void YGNodeAbsoluteLayoutChild(const YGNodeRef node,
         childWidth = fmaxf(childHeight * child->style.aspectRatio,
                            YGNodePaddingAndBorderForAxis(child, YGFlexDirectionColumn));
       } else if (YGValueIsUndefined(childHeight)) {
-        childHeight = fmaxf(childWidth * child->style.aspectRatio,
+        childHeight = fmaxf(childWidth / child->style.aspectRatio,
                             YGNodePaddingAndBorderForAxis(child, YGFlexDirectionRow));
       }
     }
@@ -1880,7 +1880,7 @@ static void YGNodelayoutImpl(const YGNodeRef node,
         if (!YGValueIsUndefined(currentRelativeChild->style.aspectRatio)) {
           if (isMainAxisRow && childHeightMeasureMode != YGMeasureModeExactly) {
             childHeight =
-                fmaxf(childWidth * currentRelativeChild->style.aspectRatio,
+                fmaxf(childWidth / currentRelativeChild->style.aspectRatio,
                       YGNodePaddingAndBorderForAxis(currentRelativeChild, YGFlexDirectionColumn));
             childHeightMeasureMode = YGMeasureModeExactly;
           } else if (!isMainAxisRow && childWidthMeasureMode != YGMeasureModeExactly) {
diff --git a/ReactCommon/yoga/yoga/Yoga.h b/ReactCommon/yoga/yoga/Yoga.h
index 3bb967271..5e10b503f 100644
--- a/ReactCommon/yoga/yoga/Yoga.h
+++ b/ReactCommon/yoga/yoga/Yoga.h
@@ -151,6 +151,9 @@ YG_NODE_STYLE_PROPERTY(float, MaxHeight, maxHeight);
 
 // Yoga specific properties, not compatible with flexbox specification
 // Aspect ratio control the size of the undefined dimension of a node.
+// Aspect ratio is encoded as a floating point value width/height. e.g. A value of 2 leads to a node
+// with a width twice the size of its height while a value of 0.5 gives the opposite effect.
+//
 // - On a node with a set width/height aspect ratio control the size of the unset dimension
 // - On a node with a set flex basis aspect ratio controls the size of the node in the cross axis if
 // unset