Merge "Fast loadInverse() implementation for the common case"
diff --git a/libs/hwui/Matrix.cpp b/libs/hwui/Matrix.cpp
index 9f2014f..061d26a 100644
--- a/libs/hwui/Matrix.cpp
+++ b/libs/hwui/Matrix.cpp
@@ -203,6 +203,34 @@
}
void Matrix4::loadInverse(const Matrix4& v) {
+ // Fast case for common translation matrices
+ if (v.isPureTranslate()) {
+ // Reset the matrix
+ // Unnamed fields are never written to except by
+ // loadIdentity(), they don't need to be reset
+ data[kScaleX] = 1.0f;
+ data[kSkewX] = 0.0f;
+
+ data[kScaleY] = 1.0f;
+ data[kSkewY] = 0.0f;
+
+ data[kScaleZ] = 1.0f;
+
+ data[kPerspective0] = 0.0f;
+ data[kPerspective1] = 0.0f;
+ data[kPerspective2] = 1.0f;
+
+ // No need to deal with kTranslateZ because isPureTranslate()
+ // only returns true when the kTranslateZ component is 0
+ data[kTranslateX] = -v.data[kTranslateX];
+ data[kTranslateY] = -v.data[kTranslateY];
+ data[kTranslateZ] = 0.0f;
+
+ // A "pure translate" matrix can be identity or translation
+ mType = v.getType();
+ return;
+ }
+
double scale = 1.0 /
(v.data[kScaleX] * ((double) v.data[kScaleY] * v.data[kPerspective2] -
(double) v.data[kTranslateY] * v.data[kPerspective1]) +
@@ -212,18 +240,18 @@
(double) v.data[kScaleY] * v.data[kPerspective0]));
data[kScaleX] = (v.data[kScaleY] * v.data[kPerspective2] -
- v.data[kTranslateY] * v.data[kPerspective1]) * scale;
+ v.data[kTranslateY] * v.data[kPerspective1]) * scale;
data[kSkewX] = (v.data[kTranslateX] * v.data[kPerspective1] -
v.data[kSkewX] * v.data[kPerspective2]) * scale;
data[kTranslateX] = (v.data[kSkewX] * v.data[kTranslateY] -
- v.data[kTranslateX] * v.data[kScaleY]) * scale;
+ v.data[kTranslateX] * v.data[kScaleY]) * scale;
data[kSkewY] = (v.data[kTranslateY] * v.data[kPerspective0] -
v.data[kSkewY] * v.data[kPerspective2]) * scale;
data[kScaleY] = (v.data[kScaleX] * v.data[kPerspective2] -
- v.data[kTranslateX] * v.data[kPerspective0]) * scale;
+ v.data[kTranslateX] * v.data[kPerspective0]) * scale;
data[kTranslateY] = (v.data[kTranslateX] * v.data[kSkewY] -
- v.data[kScaleX] * v.data[kTranslateY]) * scale;
+ v.data[kScaleX] * v.data[kTranslateY]) * scale;
data[kPerspective0] = (v.data[kSkewY] * v.data[kPerspective1] -
v.data[kScaleY] * v.data[kPerspective0]) * scale;