9 files changed, 104 insertions, 5 deletions
diff --git a/include/llmr/geometry/sprite_atlas.hpp b/include/llmr/geometry/sprite_atlas.hpp
new file mode 100644
index 0000000000..e6557846af
--- /dev/null
+++ b/include/llmr/geometry/sprite_atlas.hpp
@@ -0,0 +1,68 @@
+#ifndef LLMR_GEOMETRY_SPRITE_ATLAS
+#define LLMR_GEOMETRY_SPRITE_ATLAS
+
+#include <llmr/geometry/binpack.hpp>
+
+#include <string>
+#include <map>
+#include <mutex>
+#include <atomic>
+#include <set>
+
+namespace llmr {
+
+class Sprite;
+
+class SpriteAtlas {
+public:
+    typedef uint16_t dimension;
+
+public:
+    // Add way to construct this from another SpriteAtlas (e.g. with another pixelRatio)
+    SpriteAtlas(dimension width, dimension height);
+    ~SpriteAtlas();
+
+    // Changes the pixel ratio.
+    bool resize(float newRatio);
+
+    // Update uninitialized sprites in this atlas from the given sprite.
+    void update(const Sprite &sprite);
+
+    // Returns the coordinates of the icon. The getter also *creates* new icons in the atlas
+    // if they don't exist, but they'll be default-initialized with a a black circle.
+    Rect<dimension> getIcon(int size, const std::string &name);
+
+    // Updates or creates an icon with a given size and name. The data must be a
+    // a (pixelRatio * size)^2 * 4 byte long RGBA image buffer.
+    Rect<dimension> setIcon(int size, const std::string &name, const std::string &icon);
+
+    // Binds the image buffer of this sprite atlas to the GPU, and uploads data if it is out
+    // of date.
+    void bind(bool linear = false);
+
+    inline float getTextureWidth() const { return width * pixelRatio; }
+    inline float getTextureHeight() const { return height * pixelRatio; }
+
+private:
+    void allocate();
+
+public:
+    const dimension width = 0;
+    const dimension height = 0;
+
+private:
+    std::mutex mtx;
+    float pixelRatio = 1.0f;
+    BinPack<dimension> bin;
+    std::map<int, std::map<std::string, Rect<dimension>>> index;
+    std::set<std::pair<int, std::string>> uninitialized;
+    char *data = nullptr;
+    std::atomic<bool> dirty;
+    uint32_t texture = 0;
+    uint32_t filter = 0;
+    static const int buffer = 1;
+};
+
+};
+
+#endif
diff --git a/include/llmr/map/map.hpp b/include/llmr/map/map.hpp
index 4600e1a967..87d64b0733 100644
--- a/include/llmr/map/map.hpp
+++ b/include/llmr/map/map.hpp
@@ -92,6 +92,7 @@ public:
     inline const TransformState &getState() const { return state; }
     inline const Style &getStyle() const { return style; }
     inline GlyphAtlas &getGlyphAtlas() { return glyphAtlas; }
+    inline SpriteAtlas &getSpriteAtlas() { return spriteAtlas; }
     inline uv_loop_t *getLoop() { return loop; }
     inline time getAnimationTime() const { return animationTime; }
     inline Texturepool &getTexturepool() { return texturepool; }
@@ -143,6 +144,7 @@ private:
     Texturepool texturepool;
     Style style;
     GlyphAtlas glyphAtlas;
+    SpriteAtlas spriteAtlas;
     Painter painter;
 
     std::map<std::string, const std::unique_ptr<Source>> sources;
diff --git a/include/llmr/map/tile_parser.hpp b/include/llmr/map/tile_parser.hpp
index 12f3da8ff2..86545e4f76 100644
--- a/include/llmr/map/tile_parser.hpp
+++ b/include/llmr/map/tile_parser.hpp
@@ -9,13 +9,14 @@ namespace llmr {
 
 class Style;
 class GlyphAtlas;
+class SpriteAtlas;
 
 class LayerDescription;
 class Bucket;
 
 class TileParser {
 public:
-    TileParser(const std::string& data, VectorTileData& tile, const Style& style, GlyphAtlas& glyphAtlas);
+    TileParser(const std::string& data, VectorTileData& tile, const Style& style, GlyphAtlas& glyphAtlas, SpriteAtlas &spriteAtlas);
 
 private:
     bool obsolete() const;
@@ -27,13 +28,14 @@ private:
     std::unique_ptr<Bucket> createIconBucket(const VectorTileLayer& layer, const BucketDescription& bucket_desc);
     std::unique_ptr<Bucket> createTextBucket(const VectorTileLayer& layer, const BucketDescription& bucket_desc);
     template <class Bucket> void addBucketFeatures(Bucket& bucket, const VectorTileLayer& layer, const BucketDescription& bucket_desc);
-    template <class Bucket, typename... Args> void addBucketFeatures(Bucket& bucket, const VectorTileLayer& layer, const BucketDescription& bucket_desc, Args... args);
+    template <class Bucket, typename ...Args> void addBucketFeatures(Bucket& bucket, const VectorTileLayer& layer, const BucketDescription& bucket_desc, Args&& ...args);
 
 private:
     const VectorTile vector_data;
     VectorTileData& tile;
     const Style& style;
     GlyphAtlas& glyphAtlas;
+    SpriteAtlas &spriteAtlas;
     Faces faces;
     Placement placement;
 };
diff --git a/include/llmr/platform/platform.hpp b/include/llmr/platform/platform.hpp
index 4f7b4ed693..dc8f7b5faf 100644
--- a/include/llmr/platform/platform.hpp
+++ b/include/llmr/platform/platform.hpp
@@ -32,8 +32,11 @@ std::shared_ptr<Request> request_http(const std::string &url,
 // Cancels an HTTP request.
 void cancel_request_http(const std::shared_ptr<Request> &req);
 
-// Shows an RGBA image with the specified dimensions in a named window.
+// Shows an alpha image with the specified dimensions in a named window.
 void show_debug_image(std::string name, const char *data, size_t width, size_t height);
+
+// Shows an alpha image with the specified dimensions in a named window.
+void show_color_debug_image(std::string name, const char *data, size_t width, size_t height);
 }
 }
 
diff --git a/include/llmr/renderer/icon_bucket.hpp b/include/llmr/renderer/icon_bucket.hpp
index ce90edce30..0878622ec3 100644
--- a/include/llmr/renderer/icon_bucket.hpp
+++ b/include/llmr/renderer/icon_bucket.hpp
@@ -20,7 +20,7 @@ class IconVertexBuffer;
 class BucketDescription;
 class IconShader;
 class DotShader;
-class Sprite;
+class SpriteAtlas;
 class VectorTileFeature;
 
 class IconBucket : public Bucket {
@@ -31,7 +31,7 @@ public:
     virtual void render(Painter& painter, const std::string& layer_name, const Tile::ID& id);
     virtual bool hasData() const;
 
-    void addFeature(const VectorTileFeature &feature, const std::shared_ptr<Sprite> &sprite);
+    void addFeature(const VectorTileFeature &feature, SpriteAtlas &sprite_atlas);
 
     void drawIcons(IconShader& shader);
     void drawIcons(DotShader& shader);
diff --git a/include/llmr/style/style.hpp b/include/llmr/style/style.hpp
index 8fcb99732e..d9c8c22bda 100644
--- a/include/llmr/style/style.hpp
+++ b/include/llmr/style/style.hpp
@@ -7,6 +7,7 @@
 #include <llmr/style/bucket_description.hpp>
 #include <llmr/style/layer_description.hpp>
 #include <llmr/style/class_description.hpp>
+#include <llmr/geometry/sprite_atlas.hpp>
 
 #include <map>
 #include <vector>
diff --git a/include/llmr/util/math.hpp b/include/llmr/util/math.hpp
index 531a13a1a5..ab8e392c48 100644
--- a/include/llmr/util/math.hpp
+++ b/include/llmr/util/math.hpp
@@ -87,12 +87,28 @@ inline T dist(const S1& a, const S2& b) {
     return c;
 }
 
+template <typename T>
+inline T length(T a, T b) {
+    return std::sqrt(a * a + b * b);
+}
+
 // Take the magnitude of vector a.
 template <typename T = double, typename S>
 inline T mag(const S& a) {
     return std::sqrt(a.x * a.x + a.y * a.y);
 }
 
+template <typename T>
+T clamp(T value, T min, T max) {
+    return value < min ? min : (value > max ? max : value);
+}
+
+template <typename T>
+T smoothstep(T edge0, T edge1, T x) {
+    T t = clamp((x - edge0) / (edge1 - edge0), T(0), T(1));
+    return t * t * (T(3) - T(2) * t);
+}
+
 }
 }
 
diff --git a/include/llmr/util/raster.hpp b/include/llmr/util/raster.hpp
index ccdffeef37..0ad29dc7a2 100644
--- a/include/llmr/util/raster.hpp
+++ b/include/llmr/util/raster.hpp
@@ -32,6 +32,8 @@ public:
     bool needsTransition() const;
     void updateTransitions(time now);
 
+    inline const char *getData() const { return img; }
+
 public:
     // loaded image dimensions
     uint32_t width = 0, height = 0;
diff --git a/include/llmr/util/rect.hpp b/include/llmr/util/rect.hpp
index 56bab2c9c9..2e142c3018 100644
--- a/include/llmr/util/rect.hpp
+++ b/include/llmr/util/rect.hpp
@@ -9,6 +9,11 @@ struct Rect {
     T x = 0, y = 0;
     T w = 0, h = 0;
 
+    template <typename Number>
+    Rect operator *(Number value) const {
+        return Rect(x * value, y * value, w * value, h * value);
+    }
+
     operator bool() const { return w == 0 || h == 0; }
 };
 }