[core] Use a separate atlas and store for annotation sprites

Fixes #1488

2 files changed, 12 insertions, 3 deletions

diff --git a/src/mbgl/sprite/sprite_atlas.cpp b/src/mbgl/sprite/sprite_atlas.cpp
index 45b0511c68..ae71f18f03 100644
--- a/src/mbgl/sprite/sprite_atlas.cpp
+++ b/src/mbgl/sprite/sprite_atlas.cpp
@@ -24,9 +24,7 @@ SpriteAtlas::SpriteAtlas(dimension width_, dimension height_, float pixelRatio_,
       pixelRatio(pixelRatio_),
       store(store_),
       bin(width_, height_),
-      data(std::make_unique<uint32_t[]>(pixelWidth * pixelHeight)),
       dirty(true) {
-    std::fill(data.get(), data.get() + pixelWidth * pixelHeight, 0);
 }
 
 Rect<SpriteAtlas::dimension> SpriteAtlas::allocateImage(const size_t pixel_width, const size_t pixel_height) {
@@ -103,6 +101,11 @@ SpriteAtlasPosition SpriteAtlas::getPosition(const std::string& name, bool repea
 }
 
 void SpriteAtlas::copy(const Holder& holder, const bool wrap) {
+    if (!data) {
+        data = std::make_unique<uint32_t[]>(pixelWidth * pixelHeight);
+        std::fill(data.get(), data.get() + pixelWidth * pixelHeight, 0);
+    }
+
     const uint32_t *srcData = reinterpret_cast<const uint32_t *>(holder.texture->data.data());
     if (!srcData) return;
     const vec2<uint32_t> srcSize { holder.texture->pixelWidth, holder.texture->pixelHeight };
@@ -189,6 +192,10 @@ void SpriteAtlas::updateDirty() {
 }
 
 void SpriteAtlas::bind(bool linear) {
+    if (!data) {
+        return; // Empty atlas
+    }
+
     if (!texture) {
         MBGL_CHECK_ERROR(glGenTextures(1, &texture));
         MBGL_CHECK_ERROR(glBindTexture(GL_TEXTURE_2D, texture));
diff --git a/src/mbgl/sprite/sprite_atlas.hpp b/src/mbgl/sprite/sprite_atlas.hpp
index 0d86279e2d..0e3e8cf225 100644
--- a/src/mbgl/sprite/sprite_atlas.hpp
+++ b/src/mbgl/sprite/sprite_atlas.hpp
@@ -66,6 +66,8 @@ public:
     inline dimension getTextureWidth() const { return pixelWidth; }
     inline dimension getTextureHeight() const { return pixelHeight; }
     inline float getPixelRatio() const { return pixelRatio; }
+
+    // Only for use in tests.
     inline const uint32_t* getData() const { return data.get(); }
 
 private:
@@ -90,7 +92,7 @@ private:
     BinPack<dimension> bin;
     std::map<Key, Holder> images;
     std::set<std::string> uninitialized;
-    const std::unique_ptr<uint32_t[]> data;
+    std::unique_ptr<uint32_t[]> data;
     std::atomic<bool> dirty;
     bool fullUploadRequired = true;
     GLuint texture = 0;