def get_layer_points_postgis_ogr(self, layer, bbox_str, max_features):
# print("Content-type: text/plain\n\n")
points = []
# "the_geom from (select g.id, g.point as the_geom from gw_tracepoint g where g.point && GeomFromText('POLYGON((-4.275557 50.242394,-4.275557 54.685361,14.115557 54.685361,14.115557 50.242394,-4.275557 50.242394))',4326) order by random() limit 3000) as subquery using unique id using srid=4326"
bbox_arr = [float(x) for x in bbox_str.split(",")]
box_polygon = (
str(bbox_arr[0])
+ " "
+ str(bbox_arr[1])
+ ","
+ str(bbox_arr[0])
+ " "
+ str(bbox_arr[3])
+ ","
+ str(bbox_arr[2])
+ " "
+ str(bbox_arr[3])
+ ","
+ str(bbox_arr[2])
+ " "
+ str(bbox_arr[1])
+ ","
+ str(bbox_arr[0])
+ " "
+ str(bbox_arr[1])
)
# box_polygon = "-4.275557 50.242394, -4.275557 54.685361, 14.115557 54.685361, 14.115557 50.242394, -4.275557 50.242394"
sql = (
"select AsBinary(point) as wkb_geometry from gw_tracepoint where point && GeomFromText('POLYGON(("
+ box_polygon
+ "))',4326) order by random() limit "
+ str(max_features)
)
connProp = "PG: host=localhost dbname='georambling' user='******' password='******'"
conn = ogr.Open(connProp)
result = conn.ExecuteSQL(sql)
ftCnt = result.GetFeatureCount()
printtime("PostGIS query done cnt=" + str(ftCnt))
# print ftCnt
try:
for i in range(0, ftCnt):
feat = result.GetFeature(i)
feat_pt = feat.GetGeometryRef()
point = Point((feat_pt.GetY(), feat_pt.GetX()))
points.append(point)
# printtime('feat(' + str(i) + ') x=' + str(feat_pt.GetX()) + ' y=' + str(feat_pt.GetY()))
except Exception:
# print Exception.message
# print sys.exc_info()
return points
return points
def get_layer_points_postgis(self, layer, bbox_str, max_features):
# print("Content-type: text/plain\n\n")
points = []
name = "mapglow"
dsn = layer.connection # e.g. "host=localhost dbname='dbname' user='******' password='******'"
table = layer.getMetaData("mapglow_table_name")
fid = layer.getMetaData("gml_featureid") # defaults to ogc_fid
geometry = layer.getMetaData("mapglow_table_geom_col") # defaults to the_geom
srid = 4326 # defaults to 4326
encoding = "utf-8" # defaults to utf-8
attribute_cols = "rating" # optional
order = "random()" # optional
# try:
pg = PostGIS(name=name, fid=fid, geometry=geometry, srid=srid, order=order, layer=table, dsn=dsn)
pg.begin()
class Action:
id = None
attributes = None
bbox = [float(x) for x in bbox_str.split(",")]
maxfeatures = max_features
startfeature = None
action = Action()
features = pg.select(action)
# print(str(features[0].get_geo()['coordinates'][0 ]))
ftCnt = features.__len__()
printtime("PostGIS query done cnt=" + str(ftCnt))
# print ftCnt
try:
for i in range(0, ftCnt):
feat = features[i]
feat_pt = feat.get_geo()
point = Point((feat_pt["coordinates"][1], feat_pt["coordinates"][0]))
points.append(point)
# printtime('feat(' + str(i) + ') x=' + str(feat_pt.GetX()) + ' y=' + str(feat_pt.GetY()))
except Exception:
# print Exception.message
# print sys.exc_info()
return points
return points
def startElement(self, name, attrs):
# printtime('startElement=' + name)
if name == "gml:pos":
# Found coordinate: next content will be lon/lat
self.coord_elm = True
elif name == "wfs:FeatureCollection":
self.numberOfFeatures = int(attrs["numberOfFeatures"])
self.skip_count = (self.numberOfFeatures / self.max_features) + 1
printtime(
"max_features="
+ str(self.max_features)
+ " nroffeatures="
+ str(self.numberOfFeatures)
+ " skip_count="
+ str(self.skip_count)
)
def wms_getheatmap_req(self, wms_req):
# http://mapserver.org/ogc/mapscript.html#python-examples
# test url
# http://mapglow.org/wms/?service=WMS&request=GetMap&bbox=4.95,52,5.6,52.3&version=1.1.0&layers=tracepoints&srs=EPSG:4326&format=image/png&width=400&height=400
# print("Content-type: text/plain\n\n")
bbox = wms_req.getValueByName("BBOX")
layer = wms_req.getValueByName("LAYERS")
srs = wms_req.getValueByName("SRS")
width = float(wms_req.getValueByName("WIDTH"))
height = float(wms_req.getValueByName("HEIGHT"))
# CREATE WKT STRING OF POINT COORDS
bbox_arr = bbox.split(",")
wktLL = "POINT(%s %s)" % (bbox_arr[0], bbox_arr[1])
wktUR = "POINT(%s %s)" % (bbox_arr[2], bbox_arr[3])
# CREATE PROJECTION OBJECTS
google = osr.SpatialReference()
google.ImportFromEPSG(900913)
wgs84 = osr.SpatialReference()
wgs84.ImportFromEPSG(4326)
# CREATE OGR POINT OBJECT, ASSIGN PROJECTION, REPROJECT
pointLL = ogr.CreateGeometryFromWkt(wktLL)
pointLL.AssignSpatialReference(google)
pointLL.TransformTo(wgs84)
pointUR = ogr.CreateGeometryFromWkt(wktUR)
pointUR.AssignSpatialReference(google)
pointUR.TransformTo(wgs84)
bbox = "%f,%f,%f,%f" % (pointLL.GetX(), pointLL.GetY(), pointUR.GetX(), pointUR.GetY())
bboxLL = "%f,%f,%f,%f" % (pointLL.GetY(), pointLL.GetX(), pointUR.GetY(), pointUR.GetX())
# Do not use internal WFS (too slow)
# points = self.get_layer_points_wfs(layer, bbox, max_features)
# Get points from the layer (direct layer query)
layerObj = self.map.getLayerByName(layer)
points = []
if layerObj:
# see if layer has configured feature density
# this determines max number of features for Layer query
feature_density = float(layerObj.metadata.get("mapglow_feat_density", "0.002"))
# calculate max features for Layer query
max_features = int(round(feature_density * width * height))
# get array of Point objects from Layer
printtime("START - get points from layer max_features=" + str(max_features))
points = self.get_layer_points(layerObj, bbox, max_features)
printtime("Got " + str(len(points)) + " points from layer")
# No points: generate transparent overlay image using standard MS dispatch
if len(points) <= 0:
mapscript.msIO_installStdoutToBuffer()
# MS does not like the heatmap-style STYLES
wms_req.setParameter("STYLES", "")
self.map.OWSDispatch(wms_req)
print(mapscript.msIO_getStdoutBufferBytes())
return
# Get heatmap algoritm+parms
# Now 1 type in STYLES, e.g. 'heat/seth/red-yellow-green/12/0.5'
# TODO: parameters are heatmap-type specific
(heat, heatmap_type, gradient, radius, decay) = wms_req.getValueByName("STYLES").split("/")
# Just to protect ourselves from blowing up
if int(radius) > 20:
radius = "20"
# check how gradient is specified: either a gradient file or a range of doubles (stop, R, G, B, A)
gradient_path = self.root_dir + "config/gradients/gradient-" + gradient + ".png"
if os.path.exists(gradient_path):
# Gradient as file
gradient_option_name = "--gradient"
gradient_option_value = gradient_path
else:
# Gradient as range of doubles (stop, R, G, B, A), (stop, R, G, B, A),...
# each of value double between 0..1
# e.g. 0,1,1,0,1, 0.75,1,0,0,1, 0.9,1,1,0
gradient_option_name = "--gradient_color_srgba"
gradient_option_value = gradient
# Assemble arguments
args = [
"--web",
"--points_arr",
"--radius",
radius,
"--decay",
decay,
"--width",
wms_req.getValueByName("WIDTH"),
"--height",
wms_req.getValueByName("HEIGHT"),
gradient_option_name,
gradient_option_value,
"--extent",
bboxLL,
]
# Creates and sends the heatmap
main(args, points)
