Merge pull request #423 from mapbox/coalesce-texture-uploads

Upload textures at the beginning of a frame

include/mbgl/geometry/glyph_atlas.hpp

@@ -32,6 +32,7 @@ public:
                             const SDFGlyph& glyph);
     void removeGlyphs(uint64_t tile_id);
     void bind();
+    void upload();
 
 public:
     const uint16_t width = 0;

include/mbgl/geometry/sprite_atlas.hpp

@@ -41,10 +41,12 @@ public:
     // NEVER CALL THIS FUNCTION FROM THE RENDER THREAD! it is blocking.
     Rect<dimension> waitForImage(const std::string &name, const Sprite &sprite);
 
-    // Binds the image buffer of this sprite atlas to the GPU, and uploads data if it is out
-    // of date.
+    // Binds the image buffer of this sprite atlas to the GPU.
     void bind(bool linear = false);
 
+    // Uploads the image buffer to the GPU if it is out of date.
+    void upload();
+
     inline float getWidth() const { return width; }
     inline float getHeight() const { return height; }
     inline float getTextureWidth() const { return width * pixelRatio; }

src/geometry/glyph_atlas.cpp

@@ -120,6 +120,20 @@ void GlyphAtlas::removeGlyphs(uint64_t tile_id) {
     }
 }
 
+void GlyphAtlas::upload() {
+    if (dirty) {
+        bind();
+
+        std::lock_guard<std::mutex> lock(mtx);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, data);
+        dirty = false;
+
+#if defined(DEBUG)
+        // platform::show_debug_image("Glyph Atlas", data, width, height);
+#endif
+    }
+}
+
 void GlyphAtlas::bind() {
     if (!texture) {
         glGenTextures(1, &texture);
@@ -131,14 +145,4 @@ void GlyphAtlas::bind() {
     } else {
         glBindTexture(GL_TEXTURE_2D, texture);
     }
-
-    if (dirty) {
-        std::lock_guard<std::mutex> lock(mtx);
-        glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, data);
-        dirty = false;
-
-#if defined(DEBUG)
-        // platform::show_debug_image("Glyph Atlas", data, width, height);
-#endif
-    }
 };

src/geometry/sprite_atlas.cpp

@@ -196,13 +196,11 @@ void SpriteAtlas::update(const Sprite &sprite) {
 }
 
 void SpriteAtlas::bind(bool linear) {
-    bool first = false;
     if (!texture) {
         glGenTextures(1, &texture);
         glBindTexture(GL_TEXTURE_2D, texture);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-        first = true;
     } else {
         glBindTexture(GL_TEXTURE_2D, texture);
     }
@@ -213,12 +211,17 @@ void SpriteAtlas::bind(bool linear) {
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, filter_val);
         filter = filter_val;
     }
+}
 
+void SpriteAtlas::upload() {
     if (dirty) {
+        bool exists = texture;
+        bind(filter); // Make sure we don't change the filter value.
+
         std::lock_guard<std::mutex> lock(mtx);
         allocate();
 
-        if (first) {
+        if (!exists) {
             glTexImage2D(
                 GL_TEXTURE_2D, // GLenum target
                 0, // GLint level
@@ -248,7 +251,7 @@ void SpriteAtlas::bind(bool linear) {
 #endif
         dirty = false;
     }
-};
+}
 
 SpriteAtlas::~SpriteAtlas() {
     std::lock_guard<std::mutex> lock(mtx);

src/map/map.cpp

@@ -558,6 +558,10 @@ void Map::render() {
 #if defined(DEBUG)
     std::vector<std::string> debug;
 #endif
+
+    glyphAtlas->upload();
+    spriteAtlas->upload();
+
     painter.clear();
 
     painter.resetFramebuffer();