align static render mode and still image render mode

- static rendering now also runs in a separate thread; you have to start it with map.start(Map::Mode::Static) and join the thread with map.stop() before destructing the Map object
- map.renderStill() takes a callback with will be invoked on the *map* thread, so you'll have to figure out your own method of dispatching back to the main thread.

2 files changed, 27 insertions, 10 deletions

diff --git a/bin/render.cpp b/bin/render.cpp
index 440256b38c..78cb5b59f5 100644
--- a/bin/render.cpp
+++ b/bin/render.cpp
@@ -1,4 +1,5 @@
 #include <mbgl/map/map.hpp>
+#include <mbgl/map/still_image.hpp>
 #include <mbgl/util/image.hpp>
 #include <mbgl/util/std.hpp>
 #include <mbgl/util/io.hpp>
@@ -19,12 +20,13 @@
 
 namespace po = boost::program_options;
 
+#include <uv.h>
+
 #include <cassert>
 #include <cstdlib>
 #include <iostream>
 
 int main(int argc, char *argv[]) {
-
     std::string style_path;
     double lat = 0, lon = 0;
     double zoom = 0;
@@ -33,7 +35,7 @@ int main(int argc, char *argv[]) {
     int width = 512;
     int height = 512;
     double pixelRatio = 1.0;
-    std::string output = "out.png";
+    static std::string output = "out.png";
     std::string cache_file = "cache.sqlite";
     std::vector<std::string> classes;
     std::string token;
@@ -81,6 +83,8 @@ int main(int argc, char *argv[]) {
     HeadlessView view;
     Map map(view, fileSource);
 
+    map.start(Map::Mode::Static);
+
     // Set access token if present
     if (token.size()) {
         map.setAccessToken(std::string(token));
@@ -93,14 +97,24 @@ int main(int argc, char *argv[]) {
     map.setLatLngZoom({ lat, lon }, zoom);
     map.setBearing(bearing);
 
-    // Run the loop. It will terminate when we don't have any further listeners.
-    map.run();
+    uv_async_t *async = new uv_async_t;
+    uv_async_init(uv_default_loop(), async, [](uv_async_t *as, int) {
+        std::unique_ptr<const StillImage> image(reinterpret_cast<const StillImage *>(as->data));
+        uv_close(reinterpret_cast<uv_handle_t *>(as), [](uv_handle_t *handle) {
+            delete reinterpret_cast<uv_async_t *>(handle);
+        });
+
+        const std::string png = util::compress_png(image->width, image->height, image->pixels.get());
+        util::write_file(output, png);
+    });
+
+    map.renderStill([async](std::unique_ptr<const StillImage> image) {
+        async->data = const_cast<StillImage *>(image.release());
+        uv_async_send(async);
+    });
 
-    // Get the data from the GPU.
-    auto pixels = view.readPixels();
+    // This loop will terminate once the async was fired.
+    uv_run(uv_default_loop(), UV_RUN_DEFAULT);
 
-    const unsigned int w = width * pixelRatio;
-    const unsigned int h = height * pixelRatio;
-    const std::string image = util::compress_png(w, h, pixels.get());
-    util::write_file(output, image);
+    map.stop();
 }
diff --git a/bin/render.gyp b/bin/render.gyp
index 316a7f3ed0..b205e7a959 100644
--- a/bin/render.gyp
+++ b/bin/render.gyp
@@ -28,15 +28,18 @@
       'variables' : {
         'cflags_cc': [
           '<@(glfw3_cflags)',
+          '<@(uv_cflags)',
           '<@(boost_cflags)',
         ],
         'ldflags': [
           '<@(glfw3_ldflags)',
+          '<@(uv_ldflags)',
           '<@(boost_ldflags)',
           '-lboost_program_options'
         ],
         'libraries': [
           '<@(glfw3_static_libs)',
+          '<@(uv_static_libs)',
         ],
       },