Implement drawing map legends

bin/xmet-spc-render-file

@@ -4,7 +4,11 @@ import argparse
 import cairo
 
 from xmet.db  import Database
-from xmet.spc import SPCOutlookParser, SPCOutlook, SPCOutlookMap
+
+from xmet.spc import SPCOutlookParser, \
+                     SPCOutlook, \
+                     SPCOutlookMap, \
+                     SPCOutlookType
 
 ASSETS = {
     'light': {
@@ -32,6 +36,7 @@ def render_categorical(conus: SPCOutlookMap,
         conus.draw_categories(cr, outlook)
         conus.draw_cities(cr, db)
         conus.draw_logo(cr, assets['logo'])
+        conus.draw_legend(cr, SPCOutlookType.CATEGORICAL)
 
         if args.dark:
             cr.set_source_rgb(1, 1, 1)
@@ -54,6 +59,7 @@ def render_probabilistic(conus: SPCOutlookMap,
         conus.draw_probabilities(cr, outlook, hazard.upper())
         conus.draw_cities(cr, db)
         conus.draw_logo(cr, assets['logo'])
+        conus.draw_legend(cr, SPCOutlookType.PROBABILISTIC)
 
         if args.dark:
             cr.set_source_rgb(1, 1, 1)

lib/xmet/draw.py

@@ -0,0 +1,29 @@
+import math
+import cairo
+
+def draw_rounded_rect(cr: cairo.Context,
+                      x: float,
+                      y: float,
+                      width: float,
+                      height: float,
+                      radius: float):
+    rect_width  = width  - 2 * radius
+    rect_height = height - 2 * radius
+
+    # Upper right
+    cr.arc(x + radius + rect_width, y + radius, radius,
+           -math.pi / 2, 0)
+
+    # Lower right
+    cr.arc(x + radius + rect_width, y + radius + rect_height, radius,
+           0, math.pi / 2)
+
+    # Lower left
+    cr.arc(x + radius, y + radius + rect_height, radius,
+           math.pi / 2, math.pi)
+
+    # Upper right
+    cr.arc(x + radius, y + radius, radius,
+           math.pi, math.pi * 1.5)
+
+    cr.line_to(x + radius + rect_width, y)

lib/xmet/map.py

@@ -88,9 +88,9 @@ class EquirectMap():
         elif city.population >= 500000:
             radius = 3
         elif city.population >= 100000:
-            radius = 2
+            radius = 2.5
         else:
-            radius = 1
+            radius = 1.3
 
         extents = cr.text_extents(city.name)
 

lib/xmet/spc.py

@@ -9,6 +9,7 @@ from xmet.coord import COORD_SYSTEM
 from xmet.city  import City
 from xmet.map   import EquirectMap, MAP_SCREEN_DIMENSIONS, MAP_BOUNDS
 from xmet.afos  import MONTHS, TIMEZONES
+from xmet.draw  import draw_rounded_rect
 
 from pyiem.nws.products._outlook_util import (
     condition_segment,
@@ -64,57 +65,58 @@ RE_POINTS_START = re.compile(r'''
 RE_POINTS = re.compile(r'^(?:\s+\d{8}){1,6}$')
 
 CITIES = {
-    'WA': ('Seattle', 'Spokane'),
-    'OR': ('Portland', 'Eugene', 'Medford'),
     'CA': (
         'Redding', 'Sacramento', 'San Francisco', 'Fresno', 'Santa Barbara',
         'Los Angeles', 'San Diego'
     ),
-    'ID': ('Boise', 'Pocatello'),
-    'NV': ('Elko', 'Reno', 'Las Vegas'),
-    'UT': ('Salt Lake City', 'Cedar City'),
-    'AZ': ('Flagstaff', 'Phoenix', 'Tucson'),
-    'MT': ('Great Falls', 'Missoula', 'Butte', 'Billings'),
-    'WY': ('Sheridan', 'Jackson', 'Casper', 'Cheyenne'),
-    'CO': ('Denver', 'Grand Junction', 'Pueblo', 'Durango'),
-    'NM': ('Santa Fe', 'Albuquerque', 'Las Cruces'),
-    'ND': ('Minot', 'Bismarck', 'Fargo', 'Grand Forks'),
-    'SD': ('Aberdeen', 'Pierre', 'Rapid City', 'Sioux Falls'),
-    'NE': ('Omaha', 'Lincoln', 'McCook', 'Norfolk'),
-    'KS': ('Wichita', 'Colby', 'Liberal', 'Garden City'),
-    'OK': ('Woodward', 'Tulsa', 'Oklahoma City', 'Norman', 'Altus'),
     'TX': (
         'Amarillo', 'Wichita Falls', 'Lubbock', 'Dallas', 'Abilene',
         'Midland', 'Waco', 'Austin', 'San Antonio', 'Houston',
         'Corpus Christi', 'Brownsville'
     ),
-    'LA': ('Shreveport', 'New Orleans', 'Alexandria',),
-    'AR': ('Little Rock', 'Bentonville'),
-    'MO': ('Jefferson City', 'Kansas City'),
-    'IA': ('Des Moines',),
-    'MN': ('Minneapolis', 'Duluth'),
-    'MI': ('Marquette', 'Detroit'),
-    'WI': ('Green Bay', 'Milwaukee'),
-    'IL': ('Chicago', 'Peoria', 'Springfield'),
-    'KY': ('Louisville', 'Paducah', 'Bowling Green'),
-    'TN': ('Nashville', 'Jackson', 'Memphis'),
-    'MS': ('Jackson',),
     'AL': ('Tuscaloosa', 'Mobile'),
-    'GA': ('Atlanta', 'Columbus'),
+    'AR': ('Little Rock', 'Bentonville'),
-    'FL': ('Tallahassee', 'Jacksonville', 'Orlando', 'Tampa', 'Miami'),
+    'AZ': ('Flagstaff', 'Phoenix', 'Tucson'),
-    'SC': ('Columbia', 'Charleston'),
+    'CO': ('Denver', 'Grand Junction', 'Pueblo', 'Durango'),
-    'NC': ('Charlotte', 'Raleigh', 'Wilmington'),
+    'CT': ('Hartford',),
-    'VA': ('Roanoke', 'Richmond'),
-    'WV': ('Charleston',),
     'DC': ('Washington',),
-    'MD': ('Baltimore',),
+    'FL': ('Tallahassee', 'Jacksonville', 'Orlando', 'Tampa', 'Miami'),
-    'OH': ('Columbus', 'Cincinnati'),
+    'GA': ('Atlanta', 'Columbus'),
+    'IA': ('Des Moines',),
+    'ID': ('Boise', 'Pocatello'),
+    'IL': ('Chicago', 'Peoria', 'Springfield'),
     'IN': ('Fort Wayne', 'Indianapolis'),
-    'PA': ('Philadelphia', 'Pittsburgh', 'Scranton'),
+    'KS': ('Wichita', 'Colby', 'Liberal', 'Garden City'),
-    'NY': ('Rochester', 'Buffalo', 'New York'),
+    'KY': ('Louisville', 'Paducah', 'Bowling Green'),
-    'VT': ('Burlington',),
+    'LA': ('Shreveport', 'New Orleans', 'Alexandria',),
+    'MA': ('Boston',),
+    'MD': ('Baltimore',),
     'ME': ('Portland',),
-    'MA': ('Boston',)
+    'MI': ('Marquette', 'Detroit'),
+    'MN': ('Minneapolis', 'Duluth'),
+    'MO': ('Jefferson City', 'Kansas City'),
+    'MS': ('Jackson',),
+    'MT': ('Great Falls', 'Missoula', 'Butte', 'Billings'),
+    'NC': ('Charlotte', 'Raleigh', 'Wilmington'),
+    'ND': ('Minot', 'Bismarck', 'Fargo', 'Grand Forks'),
+    'NE': ('Omaha', 'Lincoln', 'McCook', 'Norfolk'),
+    'NM': ('Santa Fe', 'Albuquerque', 'Las Cruces'),
+    'NV': ('Elko', 'Reno', 'Las Vegas'),
+    'NY': ('Rochester', 'Buffalo', 'New York'),
+    'OH': ('Columbus', 'Cincinnati'),
+    'OK': ('Woodward', 'Tulsa', 'Oklahoma City', 'Norman', 'Altus'),
+    'OR': ('Portland', 'Eugene', 'Medford'),
+    'PA': ('Philadelphia', 'Pittsburgh', 'Scranton'),
+    'SC': ('Columbia', 'Charleston'),
+    'SD': ('Aberdeen', 'Pierre', 'Rapid City', 'Sioux Falls'),
+    'TN': ('Nashville', 'Jackson', 'Memphis'),
+    'UT': ('Salt Lake City', 'Cedar City'),
+    'VA': ('Roanoke', 'Richmond'),
+    'VT': ('Burlington',),
+    'WA': ('Seattle', 'Spokane'),
+    'WI': ('Green Bay', 'Milwaukee'),
+    'WV': ('Charleston',),
+    'WY': ('Sheridan', 'Jackson', 'Casper', 'Cheyenne'),
 }
 
 class SPCOutlookParserException(Exception):
@@ -542,13 +544,114 @@ class SPCOutlookParser():
 
         return self.outlook
 
+class SPCOutlookType(enum.Enum):
+    CATEGORICAL   = 1
+    PROBABILISTIC = 2
+
+class SPCOutlookLegend():
+    MARGIN = 16
+    RADIUS = 16
+
+    COLOR_WIDTH  = 32
+    COLOR_HEIGHT = 32
+
+    FONT_FACE = 'Muli'
+    FONT_SIZE = 16
+
+    def __init__(self, colors: dict[str, tuple[float, float, float]]):
+        self.colors = colors
+
+        self.text_width = 0.0
+        self.width      = None
+        self.height     = None
+
+    def find_size(self, cr: cairo.Context) -> tuple[float, float]:
+        cr.save()
+
+        count = 0
+
+        cr.select_font_face(self.FONT_FACE,
+                            cairo.FONT_SLANT_NORMAL,
+                            cairo.FONT_WEIGHT_BOLD)
+
+        cr.set_font_size(self.FONT_SIZE)
+
+        for key in self.colors:
+            if key is None:
+                continue
+
+            extents = cr.text_extents(str(key))
+
+            if self.text_width < extents.width:
+                self.text_width = extents.width
+
+            count += 1
+
+        self.width  = 3 * self.MARGIN + self.COLOR_WIDTH + self.text_width
+        self.height = self.MARGIN + count * (self.COLOR_HEIGHT + self.MARGIN)
+
+        cr.restore()
+
+        return self.width, self.height
+
+    def draw_item(self, cr: cairo.Context, key: str, x: float, y: float):
+        cr.save()
+
+        cr.set_source_rgb(*self.colors[key])
+        cr.rectangle(x, y, self.COLOR_WIDTH, self.COLOR_HEIGHT)
+        cr.fill()
+
+        cr.set_source_rgb(0, 0, 0)
+        cr.rectangle(x, y, self.COLOR_WIDTH, self.COLOR_HEIGHT)
+        cr.stroke()
+
+        text = str(key)
+
+        extents = cr.text_extents(text)
+
+        cr.move_to(x + self.COLOR_WIDTH + self.MARGIN,
+                   y + self.COLOR_WIDTH / 2 + extents.height / 2)
+
+        cr.show_text(text)
+
+        cr.restore()
+
+    def draw(self, cr: cairo.Context, x: float, y: float):
+        cr.save()
+
+        cr.select_font_face(self.FONT_FACE,
+                            cairo.FONT_SLANT_NORMAL,
+                            cairo.FONT_WEIGHT_BOLD)
+
+        cr.set_font_size(self.FONT_SIZE)
+
+        cr.set_source_rgba(0.2, 0.2, 0.2, 0.5)
+        draw_rounded_rect(cr, x, y, self.width, self.height, self.RADIUS)
+
+        cr.fill()
+
+        i = 0
+
+        for key in self.colors:
+            if key is None:
+                continue
+
+            item_y = y + self.MARGIN + i * (self.COLOR_HEIGHT + self.MARGIN)
+
+            self.draw_item(cr, key, x + self.MARGIN, item_y)
+
+            i += 1
+
+        cr.restore()
+
 class SPCOutlookMap(EquirectMap):
     TEXT_FONT = 'Muli'
 
     LOGO_RATIO  = 75.0 / 275.0
     LOGO_WIDTH  = 360
     LOGO_HEIGHT = LOGO_RATIO * LOGO_WIDTH
-    LOGO_MARGIN = 16
+
+    MARGIN = 16
 
     __category_colors__ = {
         'TSTM': (212/255.0, 240/255.0, 213/255.0),
@@ -581,12 +684,36 @@ class SPCOutlookMap(EquirectMap):
         cr.line_to(4, 4)
         cr.stroke()
 
+    def draw_legend(self,
+                    cr: cairo.Context,
+                    kind: SPCOutlookType):
+        if kind is SPCOutlookType.CATEGORICAL:
+            colors = self.__category_colors__
+        elif kind is SPCOutlookType.PROBABILISTIC:
+            colors = dict()
+
+            for key in self.__probability_colors__:
+                if key is None:
+                    continue
+
+                text = "%d%%" % int(key * 100)
+
+                colors[text] = self.__probability_colors__[key]
+
+        legend = SPCOutlookLegend(colors)
+        size   = legend.find_size(cr)
+
+        x = self.width  - 3 * self.MARGIN - size[0]
+        y = self.height - 6 * self.MARGIN - size[1]
+
+        legend.draw(cr, x, y)
+
     def draw_logo(self, cr: cairo.Context, path: str):
         cr.save()
 
         width  = self.LOGO_WIDTH
         height = width * self.LOGO_RATIO
-        margin = self.LOGO_MARGIN
+        margin = self.MARGIN
 
         x = margin
         y = self.height - height - margin