Limit path approximation recursion depth
bug:15369119
Change-Id: I6f009f5e8790129e1aa8a51e1fc6cdd1415dd617
diff --git a/libs/hwui/PathTessellator.cpp b/libs/hwui/PathTessellator.cpp
index c9921ba..59e15e1 100644
--- a/libs/hwui/PathTessellator.cpp
+++ b/libs/hwui/PathTessellator.cpp
@@ -975,11 +975,14 @@
// Bezier approximation
///////////////////////////////////////////////////////////////////////////////
+// Depth at which recursion is aborted
+#define ABORT_DEPTH 20
+
void PathTessellator::recursiveCubicBezierVertices(
float p1x, float p1y, float c1x, float c1y,
float p2x, float p2y, float c2x, float c2y,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
- Vector<Vertex>& outputVertices) {
+ Vector<Vertex>& outputVertices, int depth) {
float dx = p2x - p1x;
float dy = p2y - p1y;
float d1 = fabs((c1x - p2x) * dy - (c1y - p2y) * dx);
@@ -988,7 +991,7 @@
// multiplying by sqrInvScaleY/X equivalent to multiplying in dimensional scale factors
- if (d * d < thresholdSquared * (dx * dx * sqrInvScaleY + dy * dy * sqrInvScaleX)) {
+ if (depth >= ABORT_DEPTH || d * d < thresholdSquared * (dx * dx * sqrInvScaleY + dy * dy * sqrInvScaleX)) {
// below thresh, draw line by adding endpoint
pushToVector(outputVertices, p2x, p2y);
} else {
@@ -1012,11 +1015,11 @@
recursiveCubicBezierVertices(
p1x, p1y, p1c1x, p1c1y,
mx, my, p1c1c2x, p1c1c2y,
- sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices);
+ sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices, depth + 1);
recursiveCubicBezierVertices(
mx, my, p2c1c2x, p2c1c2y,
p2x, p2y, p2c2x, p2c2y,
- sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices);
+ sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices, depth + 1);
}
}
@@ -1025,12 +1028,12 @@
float bx, float by,
float cx, float cy,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
- Vector<Vertex>& outputVertices) {
+ Vector<Vertex>& outputVertices, int depth) {
float dx = bx - ax;
float dy = by - ay;
float d = (cx - bx) * dy - (cy - by) * dx;
- if (d * d < thresholdSquared * (dx * dx * sqrInvScaleY + dy * dy * sqrInvScaleX)) {
+ if (depth >= ABORT_DEPTH || d * d < thresholdSquared * (dx * dx * sqrInvScaleY + dy * dy * sqrInvScaleX)) {
// below thresh, draw line by adding endpoint
pushToVector(outputVertices, bx, by);
} else {
@@ -1044,9 +1047,9 @@
float my = (acy + bcy) * 0.5f;
recursiveQuadraticBezierVertices(ax, ay, mx, my, acx, acy,
- sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices);
+ sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices, depth + 1);
recursiveQuadraticBezierVertices(mx, my, bx, by, bcx, bcy,
- sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices);
+ sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices, depth + 1);
}
}
diff --git a/libs/hwui/PathTessellator.h b/libs/hwui/PathTessellator.h
index f033470..8ac9a3b 100644
--- a/libs/hwui/PathTessellator.h
+++ b/libs/hwui/PathTessellator.h
@@ -105,7 +105,7 @@
float bx, float by,
float cx, float cy,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
- Vector<Vertex> &outputVertices);
+ Vector<Vertex> &outputVertices, int depth = 0);
/*
endpoints p1, p2
@@ -117,7 +117,7 @@
float p2x, float p2y,
float c2x, float c2y,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
- Vector<Vertex> &outputVertices);
+ Vector<Vertex> &outputVertices, int depth = 0);
};
}; // namespace uirenderer