emscripten support

emscripten/main.cpp

@@ -0,0 +1,154 @@
+#include <emscripten/emscripten.h>
+#include <GL/glfw.h>
+#include <cstdio>
+#include <cstdlib>
+#include <cmath>
+
+#include <llmr/llmr.hpp>
+#include <llmr/map/tile.hpp>
+
+bool dirty = true;
+
+class MapView;
+
+static MapView *view;
+
+class MapView {
+public:
+    MapView() :
+        dirty(true),
+        platform(new llmr::platform(this)),
+        painter(new llmr::painter(platform)),
+        map(new llmr::map(platform, painter)) {
+
+        // Initialize GLFW
+        if (!glfwInit()) {
+            fprintf(stderr, "Failed to initialize GLFW\n");
+            exit(1);
+        }
+
+        int width, height;
+        emscripten_get_canvas_size(&width, &height, NULL);
+
+        glfwSetMousePosCallback(mousemove);
+        glfwSetMouseButtonCallback(mouseclick);
+        glfwSetMouseWheelCallback(scroll);
+
+        // Open a window and create its OpenGL context
+        if (!glfwOpenWindow(width, height, 8, 8, 8, 8, 16, 8, GLFW_WINDOW)) {
+            fprintf(stderr, "Failed to open GLFW window\n");
+
+            glfwTerminate();
+            exit(1);
+        }
+
+        painter->setup();
+        painter->resize(width, height);
+
+    }
+
+    ~MapView() {
+        delete map;
+        delete painter;
+        delete platform;
+        glfwTerminate();
+    }
+
+    static void mousemove(int x, int y) {
+        if (view->tracking) {
+            view->map->moveBy(x - view->last_x, y - view->last_y);
+        }
+        view->last_x = x;
+        view->last_y = y;
+    }
+
+    static void scroll(float pos) {
+        double delta = pos;
+
+        bool is_wheel = delta != 0 && fmod(delta, 4.000244140625) == 0;
+
+        double absdelta = delta < 0 ? -delta : delta;
+        double scale = 2.0 / (1.0 + exp(-absdelta / 100.0));
+
+        // Make the scroll wheel a bit slower.
+        // if (!is_wheel) {
+        //     scale = (scale - 1.0) / 2.0 + 1.0;
+        // }
+
+        // Zooming out.
+        if (delta < 0 && scale != 0) {
+            scale = 1.0 / scale;
+        }
+
+        view->map->scaleBy(scale, view->last_x, view->last_y);
+    }
+
+    static void mouseclick(int button, int action) {
+        if (button == GLFW_MOUSE_BUTTON_1) {
+            view->tracking = action == GLFW_PRESS;
+        }
+    }
+
+    int run() {
+        emscripten_set_main_loop(render, 60, 1);
+        return 0;
+    }
+
+    static void render() {
+        if (view->dirty) {
+            view->map->render();
+            // glClearColor(1, 1, 0, 1);
+            // glClear(GL_COLOR_BUFFER_BIT);
+
+            view->dirty = false;
+        }
+    }
+
+    bool dirty;
+    double last_x, last_y;
+    bool tracking;
+
+
+    llmr::platform *platform;
+    llmr::painter *painter;
+    llmr::map *map;
+
+};
+
+
+void llmr::platform::restart() {
+    view->dirty = true;
+}
+
+void ontileload(void* custom, void* bytes, int length) {
+    fprintf(stderr, "data loaded successfully: length: %d\n", length);
+    llmr::tile *tile = (llmr::tile *)custom;
+    tile->setData((uint8_t *)bytes, length);
+    if (tile->parse()) {
+        view->map->tileLoaded(tile);
+        return;
+    }
+}
+
+void ontileerror(void* custom) {
+    fprintf(stderr, "data load error\n");
+    llmr::tile *tile = (llmr::tile *)custom;
+    view->map->tileFailed(tile);
+}
+
+void llmr::platform::request(tile *tile) {
+    const char *urlTemplate = "http://api.tiles.mapbox.com/v3/mapbox.mapbox-streets-v4/%d/%d/%d.vector.pbf";
+    char urlString[255];
+    snprintf(urlString, 255, urlTemplate, tile->z, tile->x, tile->y);
+    fprintf(stderr, "requesting %s\n", urlString);
+
+    emscripten_async_wget_data(urlString, tile, ontileload, ontileerror);
+}
+
+
+int main() {
+    view = new MapView();
+    int ret = view->run();
+    delete view;
+    return ret;
+}

emscripten/main.html

@@ -0,0 +1,9 @@
+<body>
+<script>
+var canvas = document.createElement('canvas');
+canvas.width = 600;
+canvas.height = 400;
+document.body.appendChild(canvas);
+Module = { canvas: canvas };
+</script>
+<script src="main.js"></script>