summaryrefslogtreecommitdiff
path: root/src/mbgl
diff options
context:
space:
mode:
authorKonstantin Käfer <mail@kkaefer.com>2017-07-14 12:00:53 +0200
committerKonstantin Käfer <mail@kkaefer.com>2017-07-17 15:02:47 +0200
commit6b954677c0e57b1c1b8201210aa31d956d79c9f3 (patch)
treea905382ef450ffb7a33000f11c55e74c20bd0e7d /src/mbgl
parentfef873f68f6cbe7970d0530b6927ed743495af75 (diff)
downloadqtlocation-mapboxgl-6b954677c0e57b1c1b8201210aa31d956d79c9f3.tar.gz
[core] fix undefined behavior for division through 0
Diffstat (limited to 'src/mbgl')
-rw-r--r--src/mbgl/text/collision_feature.cpp2
-rw-r--r--src/mbgl/text/collision_tile.cpp25
-rw-r--r--src/mbgl/util/math.hpp13
3 files changed, 30 insertions, 10 deletions
diff --git a/src/mbgl/text/collision_feature.cpp b/src/mbgl/text/collision_feature.cpp
index 022ee50644..3eb08da8d1 100644
--- a/src/mbgl/text/collision_feature.cpp
+++ b/src/mbgl/text/collision_feature.cpp
@@ -135,7 +135,7 @@ void CollisionFeature::bboxifyLabel(const GeometryCoordinates& line, GeometryCoo
// This makes our calculation spot-on at scale=2, and on the conservative side for
// lower scales
const float distanceToInnerEdge = std::max(std::fabs(boxDistanceToAnchor - firstBoxOffset) - step / 2, 0.0f);
- float maxScale = labelLength / 2 / distanceToInnerEdge;
+ float maxScale = util::division(labelLength / 2, distanceToInnerEdge, std::numeric_limits<float>::infinity());
// The box maxScale calculations are designed to be conservative on collisions in the scale range
// [1,2]. At scale=1, each box has 50% overlap, and at scale=2, the boxes are lined up edge
diff --git a/src/mbgl/text/collision_tile.cpp b/src/mbgl/text/collision_tile.cpp
index b3fbe6f8a3..cc9b602f08 100644
--- a/src/mbgl/text/collision_tile.cpp
+++ b/src/mbgl/text/collision_tile.cpp
@@ -20,7 +20,11 @@ CollisionTile::CollisionTile(PlacementConfig config_) : config(std::move(config_
rotationMatrix = { { angle_cos, -angle_sin, angle_sin, angle_cos } };
reverseRotationMatrix = { { angle_cos, angle_sin, -angle_sin, angle_cos } };
- perspectiveRatio = 1.0f + 0.5f * ((config.cameraToTileDistance / config.cameraToCenterDistance) - 1.0f);
+ perspectiveRatio =
+ 1.0f +
+ 0.5f * (util::division(config.cameraToTileDistance, config.cameraToCenterDistance, 1.0f) -
+ 1.0f);
+
minScale /= perspectiveRatio;
maxScale /= perspectiveRatio;
@@ -30,22 +34,25 @@ CollisionTile::CollisionTile(PlacementConfig config_) : config(std::move(config_
// purposes, but we still want to use the yStretch approximation
// here because we can't adjust the aspect ratio of the collision
// boxes at render time.
- yStretch = util::max(1.0f, config.cameraToTileDistance / (config.cameraToCenterDistance * std::cos(config.pitch)));
+ yStretch = util::max(
+ 1.0f, util::division(config.cameraToTileDistance,
+ config.cameraToCenterDistance * std::cos(config.pitch), 1.0f));
}
-
float CollisionTile::findPlacementScale(const Point<float>& anchor, const CollisionBox& box, const float boxMaxScale, const Point<float>& blockingAnchor, const CollisionBox& blocking) {
float minPlacementScale = minScale;
// Find the lowest scale at which the two boxes can fit side by side without overlapping.
// Original algorithm:
- float s1 = (blocking.x1 - box.x2) / (anchor.x - blockingAnchor.x); // scale at which new box is to the left of old box
- float s2 = (blocking.x2 - box.x1) / (anchor.x - blockingAnchor.x); // scale at which new box is to the right of old box
- float s3 = (blocking.y1 - box.y2) * yStretch / (anchor.y - blockingAnchor.y); // scale at which new box is to the top of old box
- float s4 = (blocking.y2 - box.y1) * yStretch / (anchor.y - blockingAnchor.y); // scale at which new box is to the bottom of old box
- if (std::isnan(s1) || std::isnan(s2)) s1 = s2 = 1;
- if (std::isnan(s3) || std::isnan(s4)) s3 = s4 = 1;
+ const float s1 = util::division(blocking.x1 - box.x2, anchor.x - blockingAnchor.x,
+ 1.0f); // scale at which new box is to the left of old box
+ const float s2 = util::division(blocking.x2 - box.x1, anchor.x - blockingAnchor.x,
+ 1.0f); // scale at which new box is to the right of old box
+ const float s3 = util::division((blocking.y1 - box.y2) * yStretch, anchor.y - blockingAnchor.y,
+ 1.0f); // scale at which new box is to the top of old box
+ const float s4 = util::division((blocking.y2 - box.y1) * yStretch, anchor.y - blockingAnchor.y,
+ 1.0f); // scale at which new box is to the bottom of old box
float collisionFreeScale = util::min(util::max(s1, s2), util::max(s3, s4));
diff --git a/src/mbgl/util/math.hpp b/src/mbgl/util/math.hpp
index f969ecaedd..eb3c7d0fde 100644
--- a/src/mbgl/util/math.hpp
+++ b/src/mbgl/util/math.hpp
@@ -106,5 +106,18 @@ T smoothstep(T edge0, T edge1, T x) {
return t * t * (T(3) - T(2) * t);
}
+template <typename T>
+inline T division(const T dividend, const T divisor, const T nan) {
+ if (divisor == 0) {
+ if (dividend == 0) {
+ return nan;
+ } else {
+ return std::copysign(std::numeric_limits<T>::infinity(), dividend);
+ }
+ } else {
+ return dividend / divisor;
+ }
+}
+
} // namespace util
} // namespace mbgl