Drawing polygons on Pebble SDK2 Beta 4 bites me. Running this on Helco's Pebble Simulator - https://github.com/Helco/PebbleLocalSim - draws a nice and tidy triangle (just using 100 points to do it). Running it on my pebble draws some crazy stuff. Moreover, setting NUM_POINTS to 400 causes my pebble to reset and sometimes even enter recovery mode.

poly_crash.c

#include <pebble.h>

static Window *window;
static Layer *poly_layer;

const int NUM_POINTS = 100;

// Draws a simple triangle, just using many points
static GPath *create_poly_path(int num_points) {
  APP_LOG(APP_LOG_LEVEL_DEBUG, "Creating poly path with %d points.", num_points);

  GPoint points[num_points];
  points[0].x = 0;
  points[0].y = 0;
  for (int i = 0; i < num_points - 1; i++) {
    points[i+1].x = -(num_points/2) + i;
    points[i+1].y = 40;
  }
  GPathInfo path_info = {
    num_points,
    points
  };
  return gpath_create(&path_info); 
}

static void poly_layer_update_callback(Layer *layer, GContext* ctx) {
  GRect bounds = layer_get_bounds(layer);
  GPoint center = grect_center_point(&bounds);
  
  GPath *poly_path = create_poly_path(NUM_POINTS);
  APP_LOG(APP_LOG_LEVEL_DEBUG, "Poly path created. Drawing...");

  gpath_move_to(poly_path, center);
  graphics_context_set_fill_color(ctx, GColorWhite);  
  gpath_draw_filled(ctx, poly_path);
  APP_LOG(APP_LOG_LEVEL_DEBUG, "Poly path drawn.");

  gpath_destroy(poly_path);
}

static void init(void) {
  window = window_create();
  window_stack_push(window, true);

  Layer *window_layer = window_get_root_layer(window);
  window_set_background_color(window, GColorBlack);
  window_stack_push(window, true);
  GRect bounds = layer_get_bounds(window_layer);
  poly_layer = layer_create(bounds);
  layer_set_update_proc(poly_layer, poly_layer_update_callback);  
  layer_add_child(window_layer, poly_layer);

  APP_LOG(APP_LOG_LEVEL_DEBUG, "Marking poly layer dirty");
  layer_mark_dirty(poly_layer);
}

static void deinit(void) {
  layer_destroy(poly_layer);
  window_destroy(window);
}

int main(void) {
  init();

  APP_LOG(APP_LOG_LEVEL_DEBUG, "Done initializing, pushed window: %p", window);

  app_event_loop();
  deinit();
}