[core] Added ConstrainMode::{HeightOnly,WidthAndHeight}

ConstrainMode gives flexibility to our engine to choose between
constraining both vertically and horizontally, or just vertically
(default behavior).

Constrain in both axis means we can no longer pan the map beyond the map
boundaries. This fixes an issue where e.g. annotations disappear upon
crossing the map boundaries.

2 files changed, 50 insertions, 10 deletions

diff --git a/test/miscellaneous/transform.cpp b/test/miscellaneous/transform.cpp
index 426e9e534d..a5c91b84ef 100644
--- a/test/miscellaneous/transform.cpp
+++ b/test/miscellaneous/transform.cpp
@@ -7,13 +7,13 @@ using namespace mbgl;
 
 TEST(Transform, InvalidScale) {
     MockView view;
-    Transform transform(view);
+    Transform transform(view, ConstrainMode::HeightOnly);
 
     ASSERT_DOUBLE_EQ(0, transform.getLatLng().latitude);
     ASSERT_DOUBLE_EQ(0, transform.getLatLng().longitude);
     ASSERT_DOUBLE_EQ(1, transform.getScale());
 
-    transform.setScale(2);
+    transform.setScale(2 << 0);
 
     ASSERT_DOUBLE_EQ(0, transform.getLatLng().latitude);
     ASSERT_DOUBLE_EQ(0, transform.getLatLng().longitude);
@@ -47,13 +47,13 @@ TEST(Transform, InvalidScale) {
 
 TEST(Transform, InvalidLatLng) {
     MockView view;
-    Transform transform(view);
+    Transform transform(view, ConstrainMode::HeightOnly);
 
     ASSERT_DOUBLE_EQ(0, transform.getLatLng().latitude);
     ASSERT_DOUBLE_EQ(0, transform.getLatLng().longitude);
     ASSERT_DOUBLE_EQ(1, transform.getScale());
 
-    transform.setScale(2);
+    transform.setScale(2 << 0);
     transform.setLatLng({ 8, 10 });
 
     ASSERT_DOUBLE_EQ(8, transform.getLatLng().latitude);
@@ -83,13 +83,13 @@ TEST(Transform, InvalidLatLng) {
 
 TEST(Transform, InvalidBearing) {
     MockView view;
-    Transform transform(view);
+    Transform transform(view, ConstrainMode::HeightOnly);
 
     ASSERT_DOUBLE_EQ(0, transform.getLatLng().latitude);
     ASSERT_DOUBLE_EQ(0, transform.getLatLng().longitude);
     ASSERT_DOUBLE_EQ(1, transform.getScale());
 
-    transform.setScale(2);
+    transform.setScale(2 << 0);
     transform.setAngle(2);
 
     ASSERT_DOUBLE_EQ(0, transform.getLatLng().latitude);
@@ -108,10 +108,10 @@ TEST(Transform, InvalidBearing) {
 
 TEST(Transform, PerspectiveProjection) {
     MockView view;
-    Transform transform(view);
+    Transform transform(view, ConstrainMode::HeightOnly);
 
     transform.resize({{ 1000, 1000 }});
-    transform.setScale(1024);
+    transform.setScale(2 << 9);
     transform.setPitch(0.9);
     transform.setLatLng(LatLng(38, -77));
 
@@ -129,7 +129,7 @@ TEST(Transform, PerspectiveProjection) {
     ASSERT_NEAR(-76.75823239205641, loc.longitude, 0.0001);
     ASSERT_NEAR(37.692872969426375, loc.latitude, 0.0001);
 
-    vec2<double> point = transform.getState().latLngToPoint({38.74661326302018, -77.59198961199148});
+    PrecisionPoint point = transform.getState().latLngToPoint({38.74661326302018, -77.59198961199148});
     ASSERT_NEAR(point.x, 0, 0.01);
     ASSERT_NEAR(point.y, 1000, 0.01);
 
@@ -137,3 +137,43 @@ TEST(Transform, PerspectiveProjection) {
     ASSERT_NEAR(point.x, 1000, 0.02);
     ASSERT_NEAR(point.y, 0, 0.02);
 }
+
+TEST(Transform, ConstrainHeightOnly) {
+    MockView view;
+    LatLng loc;
+    LatLngBounds bounds;
+
+    Transform transform(view, ConstrainMode::HeightOnly);
+    transform.resize({{ 1000, 1000 }});
+    transform.setScale(1024);
+
+    transform.setLatLng(bounds.sw);
+    loc = transform.getState().pointToLatLng({ 500, 500 });
+    ASSERT_NEAR(-85.021422866378714, loc.latitude, 0.0001);
+    ASSERT_NEAR(180, std::abs(loc.longitude), 0.0001);
+
+    transform.setLatLng(bounds.ne);
+    loc = transform.getState().pointToLatLng({ 500, 500 });
+    ASSERT_NEAR(85.021422866378742, loc.latitude, 0.0001);
+    ASSERT_NEAR(180, std::abs(loc.longitude), 0.0001);
+}
+
+TEST(Transform, ConstrainWidthAndHeight) {
+    MockView view;
+    LatLng loc;
+    LatLngBounds bounds;
+
+    Transform transform(view, ConstrainMode::WidthAndHeight);
+    transform.resize({{ 1000, 1000 }});
+    transform.setScale(1024);
+
+    transform.setLatLng(bounds.sw);
+    loc = transform.getState().pointToLatLng({ 500, 500 });
+    ASSERT_NEAR(-85.021422866378714, loc.latitude, 0.0001);
+    ASSERT_NEAR(-179.65667724609375, loc.longitude, 0.0001);
+
+    transform.setLatLng(bounds.ne);
+    loc = transform.getState().pointToLatLng({ 500, 500 });
+    ASSERT_NEAR(85.021422866378742, loc.latitude, 0.0001);
+    ASSERT_NEAR(179.65667724609358, std::abs(loc.longitude), 0.0001);
+}
diff --git a/test/style/resource_loading.cpp b/test/style/resource_loading.cpp
index c6f1c1dfae..cdc84e96b2 100644
--- a/test/style/resource_loading.cpp
+++ b/test/style/resource_loading.cpp
@@ -24,7 +24,7 @@ public:
                    FileSource& fileSource,
                    const std::function<void(std::exception_ptr error)>& callback)
         : data_(MapMode::Still, GLContextMode::Unique, view.getPixelRatio()),
-          transform_(view),
+          transform_(view, ConstrainMode::HeightOnly),
           callback_(callback) {
         util::ThreadContext::setFileSource(&fileSource);