Added output for a Hypsographic curve.

A small bit of polish.

tests/blessed_images/generated_blessed_images.py

@@ -27,8 +27,9 @@ def main(blessed_images_dir, tests_data_dir):
     draw_temperature_levels_on_file(w, "%s/temperature_28070.png" % blessed_images_dir)
     draw_biome_on_file(w, "%s/biome_28070.png" % blessed_images_dir)
     draw_scatter_plot_on_file(w, "%s/scatter_28070.png" % blessed_images_dir)
+    draw_hypsographic_plot_on_file(w, "%s/hypsographic_28070.png" % blessed_images_dir)
     draw_satellite_on_file(w, "%s/satellite_28070.png" % blessed_images_dir)
-    draw_ancientmap_on_file(w, "%s/ancientmap_28070_factor3.png" % blessed_images_dir, resize_factor=3)
+    draw_ancientmap_on_file(w, "%s/ancientmap_28070_factor2.png" % blessed_images_dir, resize_factor=2)
 
     img = PNGWriter.rgba_from_dimensions(w.width * 2, w.height * 2, "%s/rivers_28070_factor2.png" % blessed_images_dir)
     draw_rivers_on_image(w, img, factor=2)

tests/draw_test.py

@@ -3,7 +3,8 @@
 import numpy
 from worldengine.draw import _biome_colors, draw_simple_elevation, elevation_color, \
     draw_elevation, draw_riversmap, draw_grayscale_heightmap, draw_ocean, draw_precipitation, \
-    draw_world, draw_temperature_levels, draw_biome, draw_scatter_plot, draw_satellite
+    draw_world, draw_temperature_levels, draw_biome, draw_scatter_plot, draw_hypsographic_plot, \
+    draw_satellite
 from worldengine.biome import Biome
 from worldengine.world import World
 from worldengine.image_io import PNGWriter, PNGReader
@@ -154,6 +155,14 @@ def test_draw_scatter_plot(self):
         draw_scatter_plot(w, 512, target)
         self._assert_img_equal("scatter_28070", target)
 
+    def test_draw_hypsographic_plot(self):
+        x_bins = 800
+        y_bins = 600
+        w = World.open_protobuf("%s/seed_28070.world" % self.tests_data_dir)
+        target = PNGWriter.grayscale_from_dimensions(x_bins, y_bins)
+        draw_hypsographic_plot(w, target, x_bins, y_bins)
+        self._assert_img_equal("hypsographic_28070", target)
+
     def test_draw_satellite(self):
         w = World.open_protobuf("%s/seed_28070.world" % self.tests_data_dir)
         target = PNGWriter.rgba_from_dimensions(w.width, w.height)

tests/drawing_functions_test.py

@@ -13,9 +13,10 @@ def setUp(self):
         self.w = World.open_protobuf("%s/seed_28070.world" % self.tests_data_dir)
 
     def test_draw_ancient_map(self):
-        target = PNGWriter.rgba_from_dimensions(self.w.width * 3, self.w.height * 3)
-        draw_ancientmap(self.w, target, resize_factor=3)
-        self._assert_img_equal("ancientmap_28070_factor3", target)
+        factor = int(2)
+        target = PNGWriter.rgba_from_dimensions(self.w.width * factor, self.w.height * factor)
+        draw_ancientmap(self.w, target, resize_factor=factor)
+        self._assert_img_equal("ancientmap_28070_factor%i" % factor, target)
 
     def test_gradient(self):
         self._assert_are_colors_equal((10, 20, 40),

worldengine/cli/main.py

@@ -7,7 +7,7 @@
 from worldengine.draw import draw_ancientmap_on_file, draw_biome_on_file, draw_ocean_on_file, \
     draw_precipitation_on_file, draw_grayscale_heightmap_on_file, draw_simple_elevation_on_file, \
     draw_temperature_levels_on_file, draw_riversmap_on_file, draw_scatter_plot_on_file, \
-    draw_satellite_on_file, draw_icecaps_on_file
+    draw_hypsographic_plot_on_file, draw_satellite_on_file, draw_icecaps_on_file
 from worldengine.plates import world_gen, generate_plates_simulation
 from worldengine.imex import export
 from worldengine.step import Step
@@ -84,18 +84,27 @@ def generate_rivers_map(world, filename):
     draw_riversmap_on_file(world, filename)
     print("+ rivers map generated in '%s'" % filename)
 
-def draw_scatter_plot(world, filename):
-    draw_scatter_plot_on_file(world, filename)
-    print("+ scatter plot generated in '%s'" % filename)
 
-def draw_satellite_map(world, filename):
+def generate_satellite_map(world, filename):
     draw_satellite_on_file(world, filename)
     print("+ satellite map generated in '%s'" % filename)
 
-def draw_icecaps_map(world, filename):
+
+def generate_icecaps_map(world, filename):
     draw_icecaps_on_file(world, filename)
     print("+ icecap map generated in '%s'" % filename)
 
+
+def generate_scatter_plot(world, filename):
+    draw_scatter_plot_on_file(world, filename)
+    print("+ scatter plot generated in '%s'" % filename)
+
+
+def generate_hypsographic_plot(world, filename):
+    draw_hypsographic_plot_on_file(world, filename)
+    print("+ hypsographic plot generated in '%s'" % filename)
+
+
 def generate_plates(seed, world_name, output_dir, width, height,
                     num_plates=10):
     """
@@ -317,12 +326,14 @@ def main():
     g_generate.add_argument('--not-fade-borders', dest='fade_borders', action="store_false",
                                help="Not fade borders",
                                default=True)
-    g_generate.add_argument('--scatter', dest='scatter_plot',
-                            action="store_true", help="generate scatter plot")
     g_generate.add_argument('--sat', dest='satelite_map',
                             action="store_true", help="generate satellite map")
     g_generate.add_argument('--ice', dest='icecaps_map',
                             action="store_true", help="generate ice caps map")
+    g_generate.add_argument('--scatter', dest='scatter_plot',
+                            action="store_true", help="generate scatter plot")
+    g_generate.add_argument('--hypsographic', dest='hypsographic_plot',
+                            action="store_true", help="generate hypsographic curve")
 
     # -----------------------------------------------------
     g_ancient_map = parser.add_argument_group(
@@ -468,7 +479,9 @@ def main():
         for x in range(0,len(humids)):
             humids[x] = 1 - float(humids[x])
     if args.scatter_plot and not generation_operation:
-        usage(error="Scatter plot can be produced only during world generation")
+        usage(error="Scatter plot can be produced only during world generation.")
+    if args.hypsographic_plot and not generation_operation:
+        usage(error="Hypsograpic curve can be produced only during world generation.")
 
     print('Worldengine - a world generator (v. %s)' % VERSION)
     print('-----------------------')
@@ -486,6 +499,7 @@ def main():
         print(' icecaps heightmap    : %s' % args.icecaps_map)
         print(' rivers map           : %s' % args.rivers_map)
         print(' scatter plot         : %s' % args.scatter_plot)
+        print(' hypsographic plot    : %s' % args.hypsographic_plot)
         print(' satellite map        : %s' % args.satelite_map)
         print(' fade borders         : %s' % args.fade_borders)
         if args.temps:
@@ -542,15 +556,18 @@ def main():
         if args.rivers_map:
             generate_rivers_map(world,
             '%s/%s_rivers.png' % (args.output_dir, world_name))
-        if args.scatter_plot:
-            draw_scatter_plot(world,
-            '%s/%s_scatter.png' % (args.output_dir, world_name))    
         if args.satelite_map:
-            draw_satellite_map(world,
+            generate_satellite_map(world,
             '%s/%s_satellite.png' % (args.output_dir, world_name))
         if args.icecaps_map:
-            draw_icecaps_map(world,
+            generate_icecaps_map(world,
             '%s/%s_icecaps.png' % (args.output_dir, world_name))
+        if args.scatter_plot:
+            generate_scatter_plot(world,
+            '%s/%s_scatter.png' % (args.output_dir, world_name))
+        if args.hypsographic_plot:
+            generate_hypsographic_plot(world,
+            '%s/%s_hypsographic.png' % (args.output_dir, world_name))  
 
     elif operation == 'plates':
         print('')  # empty line

worldengine/draw.py

@@ -732,7 +732,49 @@ def draw_scatter_plot(world, size, target):
                 ny = (size - 1) * ((p - min_humidity) / humidity_delta)
 
                 target.set_pixel(int(nx), (size - 1) - int(ny), (r, 128, b, 255))
-
+
+
+def draw_hypsographic_plot(world, target, x_bins, y_bins):
+    # Will draw a Hypsograhpic plot that contains information about the distribution of elevations in the world.
+    # y-axis shows the elevation, x-axis shows how often a certain elevation occurs.
+    # For further details see:
+    #   https://en.wikipedia.org/wiki/Elevation#Hypsography
+    #   http://www.ngdc.noaa.gov/mgg/global/etopo1_surface_histogram.html
+
+    assert int(x_bins) > 0 and int(y_bins) > 0, "Hypsographic curve needs more than 0 bins."
+
+    # set colors
+    color_none = target.get_max_colors()  # white
+    color_full = int(color_none / 2)  # gray
+    color_line = 0  # black
+
+    # Prepare a list of available elevations. Scale them to the y-axis and put them into a sorted list,
+    # smallest point to highest.
+    e = world.elevation['data']
+    e_min = e.min()
+    e_max = e.max()
+    e = (e - e_min) / (e_max - e_min)  # normalize to [0, 1]
+    e *= int(y_bins) - 0.01  # instead of "- 1", small trick to make the last bin contain more than one point
+    e = numpy.sort(e, axis=None)  # flatten the array and order values by height
+    e = e.astype(dtype=numpy.uint16)  # do not round (the graph wouldn't change, just shift)
+
+    # Fill the plot.
+    # Start by calculating how many points of the heightmap have to be represented by a single bin (n).
+    # Then step through the bins and fill in points from highest to lowest. Every bin is set to the average height of
+    # the n points it represents.
+    # Instead of drawing to [y, x] draw to [y_bins - y - 1, x_bins - x - 1] to flip the output in x- and y-direction.
+    n = e.size / float(x_bins)
+    for x in range(x_bins):
+        avg = sum(e[int(x * n):int((x + 1) * n)])
+        avg = int(avg / float(n))  # average height of n height-points
+        for y in range(y_bins):
+            target[y_bins - y - 1, x_bins - x - 1] = color_none if y > avg else color_full
+
+    # Draw sea-level (a black line at sea-level).
+    sea = int(numpy.interp(world.sea_level(), [e_min, e_max], [0, y_bins]))  # map sea-level to appropriate y-position
+    for x in range(x_bins):
+        target[y_bins - sea - 1, x] = color_line
+
 
 # -------------
 # Draw on files
@@ -811,6 +853,14 @@ def draw_scatter_plot_on_file(world, filename):
     img.complete()
 
 
+def draw_hypsographic_plot_on_file(world, filename):
+    x_bins = 800
+    y_bins = 600
+    img = PNGWriter.grayscale_from_dimensions(x_bins, y_bins, filename)
+    draw_hypsographic_plot(world, img, x_bins, y_bins)
+    img.complete()
+
+
 def draw_satellite_on_file(world, filename):
     img = PNGWriter.rgba_from_dimensions(world.width, world.height, filename)
     draw_satellite(world, img)