BBC BASIC program to draw a map of Great Britain

bbc_gbmap.bas

REM Requires GXR (or BBC Master) for flood fill
ON ERROR VDU23,1,1,0;0;0;0;:END
MODE 1
REM Swap yellow for green
VDU19,2,2,0,0,0
REM Define dither patterns
VDU23,12,1,0,0,1,1,0,0,1
VDU23,13,2,0,0,2,2,0,0,2
VDU23,14,1,2,2,1,1,2,2,1
REM Country outlines
GCOL 0,3
FOR P% = 1 TO 5
  F% = 1
  READ X%, Y%
  REPEAT
    IF F% = 1 THEN MOVE (X%*4)+230, (Y%*8)+100 ELSE DRAW (X%*4)+230, (Y%*8)+100
    IF F% = 1 THEN F% = 0
    READ X%, Y%
  UNTIL X% < 0
NEXT P%
REM Flood fill
FOR C% = 1 TO 3
  READ P%
  FOR Q% = 1 TO P%
    READ X%, Y%
	IF Q% = 1 THEN A% = X%: B% = Y%
	GCOL 16*C%,0
	PLOT &85,(X%*4)+230, (Y%*8)+100
  NEXT Q%
  REM Labels
  A% = (A%*4)+230: B% = (B%*8)+100
  IF C% = 1 THEN B% = 96: A% = A% - 112: L$ = "England"
  IF C% = 2 THEN B% = 984: A% = A% - 128: L$ = "Scotland"
  IF C% = 3 THEN A% = A% - 304: B% = B% + 16: L$ = "Wales"
  VDU 5
  MOVE A%, B%
  GCOL 0,3
  PRINT L$;
  VDU 4
NEXT C%
REM Turn cursor off
VDU23,1,0;0;0;0;
REPEAT UNTIL FALSE
REM Data for England
DATA 125, 55, 127, 54, 129, 54, 131, 53, 132, 51, 134, 51, 136, 50, 138, 50, 136, 49, 136, 47, 142, 44, 136, 44, 134, 45, 132, 45, 134, 45, 138, 43
DATA 140, 43, 144, 41, 146, 37, 144, 37, 140, 35, 142, 36, 144, 36, 142, 36, 144, 36, 146, 35, 148, 35, 150, 36, 154, 36, 156, 37, 158, 36, 164, 36
DATA 166, 35, 168, 35, 170, 34, 171, 32, 171, 30, 169, 26, 167, 26, 165, 25, 163, 25, 164, 23, 162, 23, 160, 22, 158, 22, 157, 20, 159, 21, 161, 21
DATA 159, 21, 155, 19, 153, 19, 155, 19, 157, 18, 167, 18, 167, 16, 163, 14, 161, 14, 157, 12, 153, 12, 151, 11, 147, 11, 145, 10, 143, 10, 141, 11
DATA 131, 11, 129, 10, 119, 10, 117, 11, 115, 10, 107, 10, 103, 8, 99, 8, 97, 9, 97, 7, 93, 9, 91, 9, 89, 10, 87, 10, 85, 9, 77, 9
DATA 76, 7, 76, 5, 74, 5, 72, 4, 70, 4, 68, 5, 66, 5, 64, 6, 62, 5, 60, 6, 58, 6, 56, 5, 52, 5, 50, 4, 48, 4, 46, 3
DATA 45, 1, 43, 1, 42, 3, 38, 3, 36, 2, 34, 2, 35, 4, 41, 4, 43, 5, 45, 5, 46, 7, 48, 7, 50, 8, 52, 8, 56, 10, 57, 12
DATA 59, 13, 63, 13, 63, 15, 65, 15, 67, 16, 77, 16, 79, 15, 83, 15, 87, 17, 84, 17, 86, 18, 88, 18, 90, 19, 92, 19, 92, 21, 93, 23
DATA 89, 23, 87, 24, 85, 24, 84, 26, 86, 27, 87, 29, 83, 29, 87, 31, 85, 31, 86, 33, 84, 34, 88, 36, 90, 36, 92, 35, 90, 36, 89, 38
DATA 87, 38, 83, 40, 82, 42, 84, 41, 86, 41, 85, 43, 86, 45, 86, 47, 90, 49, 82, 49, 81, 51, 77, 53, 77, 55, 79, 56, 80, 58, 82, 59
DATA 86, 59, 90, 61, 92, 61, 100, 65, 102, 65, 100, 66, 101, 68, 103, 68, 105, 69, 111, 66, 112, 64, 112, 62, 114, 61, 116, 57, 120, 55, 124, 55
DATA 125, 55, -1, -1
DATA 117, 10, 121, 10, 120, 8, 116, 8, 114, 9, 112, 9, 114, 9, 116, 10, 117, 10, -1, -1
REM Data for Scotland
DATA 45, 85, 49, 85, 47, 85, 46, 87, 48, 87, 50, 86, 48, 87, 46, 87, 48, 88, 50, 88, 44, 88, 43, 90, 45, 91, 47, 90, 49, 90, 47, 90
DATA 45, 91, 47, 92, 45, 92, 45, 94, 47, 94, 49, 95, 51, 94, 55, 94, 51, 96, 53, 96, 53, 98, 59, 98, 57, 98, 55, 99, 57, 100, 57, 102
DATA 59, 103, 61, 102, 63, 102, 62, 100, 66, 102, 68, 101, 66, 101, 70, 101, 72, 102, 84, 102, 86, 103, 88, 103, 88, 101, 87, 99, 85, 99, 81, 97
DATA 79, 97, 75, 95, 73, 95, 73, 93, 71, 93, 69, 94, 71, 93, 77, 93, 75, 93, 73, 92, 71, 92, 69, 91, 67, 91, 73, 91, 71, 91, 70, 89
DATA 68, 89, 70, 89, 72, 90, 76, 90, 78, 91, 80, 91, 82, 92, 84, 92, 86, 91, 106, 91, 108, 90, 108, 88, 106, 88, 104, 87, 101, 81, 99, 81
DATA 97, 80, 96, 78, 94, 78, 92, 77, 88, 77, 86, 76, 84, 76, 88, 76, 90, 77, 92, 77, 91, 75, 95, 75, 93, 74, 89, 74, 87, 73, 85, 73
DATA 83, 72, 77, 72, 83, 72, 85, 71, 89, 71, 91, 72, 95, 72, 97, 71, 101, 71, 103, 70, 103, 68, 101, 68, 99, 67, 101, 66, 91, 61, 89, 61
DATA 85, 59, 79, 59, 77, 58, 73, 58, 71, 57, 69, 57, 67, 58, 65, 58, 64, 56, 62, 56, 58, 58, 54, 58, 55, 56, 51, 58, 51, 60, 53, 60
DATA 54, 62, 56, 62, 57, 64, 61, 66, 57, 68, 57, 70, 59, 71, 61, 71, 59, 72, 57, 72, 58, 74, 60, 74, 58, 74, 56, 70, 54, 70, 53, 72
DATA 51, 71, 49, 71, 50, 73, 52, 73, 56, 75, 54, 75, 48, 72, 48, 70, 50, 70, 48, 69, 47, 67, 45, 66, 46, 64, 42, 64, 42, 66, 43, 68
DATA 47, 70, 45, 69, 44, 71, 46, 71, 44, 71, 46, 72, 44, 72, 46, 73, 46, 75, 48, 75, 46, 75, 50, 77, 54, 77, 50, 77, 48, 78, 52, 78
DATA 50, 78, 51, 80, 55, 80, 53, 80, 54, 82, 52, 82, 54, 82, 46, 78, 42, 78, 40, 79, 42, 80, 46, 80, 36, 80, 38, 81, 42, 81, 44, 82
DATA 42, 82, 43, 84, 45, 84, 45, 85, -1, -1
REM Data for Wales
DATA 81, 41, 83, 40, 85, 40, 89, 38, 89, 36, 91, 36, 87, 36, 85, 35, 86, 33, 85, 31, 87, 31, 85, 30, 83, 30, 85, 29, 87, 29, 86, 27
DATA 84, 27, 84, 25, 86, 24, 88, 24, 90, 23, 92, 23, 92, 21, 91, 19, 85, 19, 83, 18, 81, 18, 79, 17, 77, 18, 75, 18, 71, 20, 65, 20
DATA 63, 19, 63, 21, 61, 21, 59, 22, 55, 22, 51, 20, 49, 20, 51, 21, 49, 22, 45, 22, 47, 22, 46, 24, 44, 23, 48, 25, 52, 25, 54, 26
DATA 56, 26, 58, 27, 62, 27, 64, 28, 66, 28, 67, 30, 67, 34, 65, 35, 61, 35, 59, 34, 55, 34, 59, 36, 61, 36, 69, 40, 79, 40, 81, 41
DATA 81, 41, -1, -1
DATA 62, 42, 66, 40, 68, 40, 64, 38, 62, 38, 60, 39, 58, 39, 59, 41, 61, 41, 62, 42, -1, -1
REM Flood fill points for England
DATA 2
DATA 115, 33
DATA 117, 9
REM Flood fill points for Scotland
DATA 1
DATA 70, 79
REM Flood fill points for Wales
DATA 2
DATA 76, 28
DATA 63, 40

bbc_mapdata.py

# Python program to generate the data for the BBC Micro map drawing

import fiona
import math
import os
from rdp import rdp
from polylabel import polylabel

geo_data = []
# Download the Boundary-Line™ GeoPackage from Ordnance Survey at https://osdatahub.os.uk/downloads/open/BoundaryLine
with fiona.open('bdline_gb.gpkg', layer='country_region') as layer:
    minx, miny, maxx, maxy = layer.bounds
    width = maxx - minx
    height = maxy - miny
    aspect = width/height
    xscale = 320 * aspect
    sorted_layer = sorted(layer, key=lambda x: x.properties['Hectares'], reverse=True) # reverse sort by land area
    total_pcount = 0
    for feature in sorted_layer[:3]: # biggest 3 areas will be the 3 countries of Great Britain
        scaled_coords = []
        for polygon in feature.geometry['coordinates']:
            ring = polygon[0] # first ring is exterior ring
            polygon_coords = []
            oldx = -999
            oldy = -999
            first = True
            for c in ring:
                x, y = c
                scaled_x = int(math.ceil((x - minx)*xscale/(maxx - minx)))
                scaled_y = int(math.ceil((y - miny)*128/(maxy - miny)))
                if first:
                    first_x = scaled_x
                    first_y = scaled_y
                    first = False
                if abs(oldx-scaled_x)>1 or abs(oldy-scaled_y)>1: 
                    polygon_coords.append([scaled_x, scaled_y])
                    oldx = scaled_x
                    oldy = scaled_y
            polygon_coords = rdp(polygon_coords)
            if len(polygon_coords) > 1:
                scaled_coords.extend(polygon_coords)
                scaled_coords.append([first_x,first_y])
                scaled_coords.append([-1,-1])
                total_pcount = total_pcount + 1
        geo_data.append({ "name": feature.properties['Name'], "coordinates": scaled_coords })
        
minx = 999
miny = 999
maxx = -999
maxy = -999
fill_block = ""
for g in geo_data:
    line = "REM Data for " + g['name']
    print(line)
    scaled_coords = g['coordinates']
    line = "DATA "
    thislinecount = 0
    for c in scaled_coords:
        x, y = c
        if x == -1 or y == -1:
            thislinecount = 15
        if thislinecount < 15:
            line = line + str(x) + ", " + str(y) + ", "
            thislinecount = thislinecount + 1
        else:
            line = line + str(x) + ", " + str(y)
            thislinecount = 0
            print(line)
            line = "DATA "
        if x > maxx:
            maxx = x
        if y > maxy:
            maxy = y
        if x < minx and x > -1:
            minx = x
        if y < miny and y > -1:
            miny = y
    if thislinecount > 0:
        print(line)
    line = "REM Flood fill points for " + g['name']
    fill_block = fill_block + line + os.linesep
    polygon_coords = []
    pcount = 0
    fill_line = ""
    first = True
    for c in scaled_coords:
        x, y = c
        if x == -1 or y == -1:
            fill_point = polylabel([polygon_coords])
            fill_x, fill_y = fill_point
            if not first:
                fill_line = fill_line + os.linesep
            else:
                first = False
            fill_line = fill_line + "DATA " + str(math.ceil(fill_x)) + ", " + str(math.ceil(fill_y))
            polygon_coords = []
            pcount = pcount + 1
        else:
            polygon_coords.append([x, y])
    line = "DATA " + str(pcount) + os.linesep
    fill_block = fill_block + line + fill_line + os.linesep
print(fill_block)
print("Number of polygons: " + str(total_pcount))
print("Bounds: " + str(minx) + ", " + str(miny) + " - " + str(maxx) + ", " + str(maxy))

py_gbmap.py

# Python program to draw a map of Great Britain

import fiona
import math
import os
from rdp import rdp
from polylabel import polylabel
from graphics import * # graphics.py

geo_data = []
# Download the Boundary-Line™ GeoPackage from Ordnance Survey at https://osdatahub.os.uk/downloads/open/BoundaryLine
with fiona.open('bdline_gb.gpkg', layer='country_region') as layer:
    minx, miny, maxx, maxy = layer.bounds
    width = maxx - minx
    height = maxy - miny
    aspect = width/height
    xscale = 320 * aspect
    sorted_layer = sorted(layer, key=lambda x: x.properties['Hectares'], reverse=True) # reverse sort by land area
    total_pcount = 0
    for feature in sorted_layer[:3]: # biggest 3 areas will be the 3 countries of Great Britain
        scaled_coords = []
        for polygon in feature.geometry['coordinates']:
            ring = polygon[0] # first ring is exterior ring
            polygon_coords = []
            oldx = -999
            oldy = -999
            first = True
            for c in ring:
                x, y = c
                scaled_x = int(math.ceil((x - minx)*xscale/(maxx - minx)))
                scaled_y = int(math.ceil((y - miny)*128/(maxy - miny)))
                if first:
                    first_x = scaled_x
                    first_y = scaled_y
                    first = False
                if abs(oldx-scaled_x)>1 or abs(oldy-scaled_y)>1: 
                    polygon_coords.append([scaled_x, scaled_y])
                    oldx = scaled_x
                    oldy = scaled_y
            polygon_coords = rdp(polygon_coords)
            if len(polygon_coords) > 1:
                scaled_coords.extend(polygon_coords)
                scaled_coords.append([first_x,first_y])
                scaled_coords.append([-1,-1])
                total_pcount = total_pcount + 1
        geo_data.append({ "name": feature.properties['Name'], "coordinates": scaled_coords })
        
win = GraphWin(title = "Map of Great Britain", width = 640, height = 512)
win.setCoords(0,0,639,511)
win.setBackground("black")
country_colours = ["red", "green", "yellow"]
for g in geo_data:
    scaled_coords = g['coordinates']
    polygon_coords = []
    polygon_points = []
    this_colour = country_colours.pop(0)
    first = True
    for c in scaled_coords:
        x, y = c
        if x == -1 or y == -1:
            aPolygon = Polygon(polygon_points)
            aPolygon.setFill(this_colour)
            aPolygon.setOutline("white")
            aPolygon.setWidth(3)
            aPolygon.draw(win)
            if first:
                label_coords = polylabel([polygon_coords])
                label_x, label_y = label_coords
                if g['name'] == "England":
                    label_y = 48
                if g['name'] == "Scotland":
                    label_y = 492
                if g['name'] == "Wales":
                    label_x = label_x - 114
                label_point = Point(label_x, label_y)
                label = Text(label_point, g['name'])
                label.setFace("courier")
                label.setStyle("bold")
                label.setSize(18)
                label.setTextColor("white")
                label.draw(win)
                first = False
            polygon_coords = []
            polygon_points = []
        else:
            polygon_points.append(Point((x*2)+115,(y*4)+50))
            polygon_coords.append([(x*2)+115,(y*4)+50])
            
clickPoint = win.getMouse()