add BinPack test

src/mbgl/geometry/binpack.hpp

@@ -23,7 +23,11 @@ public:
             if (width <= ref.w && height <= ref.h) {
                 if (smallest == free.end() || (ref.y <= rect.y && ref.x <= rect.x)) {
                     smallest = it;
+                } else {
+                    // Our current "smallest" rect is already closer to 0/0.
                 }
+            } else {
+                // The rect in the free list is not big enough.
             }
         }
 

src/mbgl/util/rect.hpp

@@ -12,10 +12,15 @@ struct Rect {
     T originalW = 0, originalH = 0;
 
     template <typename Number>
-    Rect operator *(Number value) const {
+    inline Rect operator *(Number value) const {
         return Rect(x * value, y * value, w * value, h * value);
     }
 
+    template <typename R>
+    inline bool operator==(const R& r) const {
+        return x == r.x && y == r.y && w == r.w && h == r.h;
+    }
+
     inline bool hasArea() const { return w != 0 && h != 0; }
 };
 }

test/miscellaneous/binpack.cpp

@@ -0,0 +1,51 @@
+#include "../fixtures/util.hpp"
+
+#include <mbgl/geometry/binpack.hpp>
+
+#include <iosfwd>
+#include <array>
+
+namespace mbgl {
+template <typename T> ::std::ostream& operator<<(::std::ostream& os, const Rect<T>& t) {
+    return os << "Rect { " << t.x << ", " << t.y << ", " << t.w << ", " << t.h << " }";
+}
+}
+
+TEST(BinPack, Allocating) {
+    mbgl::BinPack<uint16_t> bin(128, 128);
+    std::array<mbgl::Rect<uint16_t>, 4> rects;
+
+    rects[0] = bin.allocate(32, 48);
+    ASSERT_EQ(mbgl::Rect<uint16_t>(0, 0, 32, 48), rects[0]);
+    rects[1] = bin.allocate(8, 17);
+    ASSERT_EQ(mbgl::Rect<uint16_t>(32, 0, 8, 17), rects[1]);
+    rects[2] = bin.allocate(8, 17);
+    ASSERT_EQ(mbgl::Rect<uint16_t>(0, 48, 8, 17), rects[2]);
+
+    bin.release(rects[0]);
+    rects[0] = bin.allocate(32, 24);
+    ASSERT_EQ(mbgl::Rect<uint16_t>(0, 0, 32, 24), rects[0]);
+    rects[3] = bin.allocate(32, 24);
+    ASSERT_EQ(mbgl::Rect<uint16_t>(32, 17, 32, 24), rects[3]);
+}
+
+
+TEST(BinPack, Full) {
+    mbgl::BinPack<uint16_t> bin(128, 128);
+    std::vector<mbgl::Rect<uint16_t>> rects;
+
+    for (int j = 0; j < 3; j++) {
+        for (int i = 0; i < 256; i++) {
+            auto rect = bin.allocate(8, 8);
+            ASSERT_TRUE(rect.hasArea());
+            rects.push_back(rect);
+        }
+
+        ASSERT_FALSE(bin.allocate(8, 8).hasArea());
+
+        for (auto& rect: rects) {
+            bin.release(rect);
+        }
+        rects.clear();
+    }
+}

test/test.gypi

@@ -41,6 +41,7 @@
         'headless/headless.cpp',
 
         'miscellaneous/clip_ids.cpp',
+        'miscellaneous/binpack.cpp',
         'miscellaneous/bilinear.cpp',
         'miscellaneous/comparisons.cpp',
         'miscellaneous/enums.cpp',