def _build_zoom_mapping(conf=None, MAX_ZOOM=31):
"""Build and return the zoom_to_opacity mapping
"""
if conf is None:
from gheat import MAX_ZOOM, conf # won't use these in testing
zoom_opaque = conf.get('zoom_opaque', '-15')
try:
zoom_opaque = int(zoom_opaque)
except ValueError:
raise ConfigurationError("zoom_opaque must be an integer.")
zoom_transparent = conf.get('zoom_transparent', '15')
try:
zoom_transparent = int(zoom_transparent)
except ValueError:
raise ConfigurationError("zoom_transparent must be an integer.")
num_opacity_steps = zoom_transparent - zoom_opaque
zoom_to_opacity = dict()
if num_opacity_steps < 1: # don't want general fade
for zoom in range(0, MAX_ZOOM + 1):
zoom_to_opacity[zoom] = None
else: # want general fade
opacity_step = OPAQUE / float(num_opacity_steps) # chunk of opacity
for zoom in range(0, MAX_ZOOM + 1):
if zoom <= zoom_opaque:
opacity = OPAQUE
elif zoom >= zoom_transparent:
opacity = TRANSPARENT
else:
opacity = int(OPAQUE - ((zoom - zoom_opaque) * opacity_step))
zoom_to_opacity[zoom] = opacity
return zoom_to_opacity
def _build_zoom_mapping(conf=None, MAX_ZOOM=31):
"""Build and return the zoom_to_opacity mapping
"""
if conf is None:
from gheat import MAX_ZOOM, conf # won't use these in testing
zoom_opaque = conf.get('zoom_opaque', '-15')
try:
zoom_opaque = int(zoom_opaque)
except ValueError:
raise ConfigurationError("zoom_opaque must be an integer.")
zoom_transparent = conf.get('zoom_transparent', '15')
try:
zoom_transparent = int(zoom_transparent)
except ValueError:
raise ConfigurationError("zoom_transparent must be an integer.")
num_opacity_steps = zoom_transparent - zoom_opaque
zoom_to_opacity = dict()
if num_opacity_steps < 1: # don't want general fade
for zoom in range(0, MAX_ZOOM + 1):
zoom_to_opacity[zoom] = None
else: # want general fade
opacity_step = OPAQUE / float(num_opacity_steps) # chunk of opacity
for zoom in range(0, MAX_ZOOM + 1):
if zoom <= zoom_opaque:
opacity = OPAQUE
elif zoom >= zoom_transparent:
opacity = TRANSPARENT
else:
opacity = int(OPAQUE - ((zoom - zoom_opaque) * opacity_step))
zoom_to_opacity[zoom] = opacity
return zoom_to_opacity
def _build_zoom_mapping(conf=None, MAX_ZOOM=31):
"""Build and return the zoom_to_opacity mapping
This is a mapping of zoom levels to opacity levels. It is applied in
addition to any per-pixel alpha from the color scheme.
"""
if conf is None:
from gheat import MAX_ZOOM, conf # won't use these in testing
# Read and validate configuration.
# ================================
zoom_opaque = conf.get('zoom_opaque', '-15')
try:
zoom_opaque = int(zoom_opaque)
except ValueError:
raise ConfigurationError("zoom_opaque must be an integer.")
zoom_transparent = conf.get('zoom_transparent', '15')
try:
zoom_transparent = int(zoom_transparent)
except ValueError:
raise ConfigurationError("zoom_transparent must be an integer.")
# Build the mapping.
# ==================
num_opacity_steps = zoom_transparent - zoom_opaque
zoom_to_opacity = dict()
if num_opacity_steps < 1: # don't want general fade
for zoom in range(0, MAX_ZOOM + 1):
zoom_to_opacity[zoom] = None
else: # want general fade
opacity_step = OPAQUE / float(num_opacity_steps) # chunk of opacity
for zoom in range(0, MAX_ZOOM + 1):
if zoom <= zoom_opaque:
opacity = OPAQUE
elif zoom >= zoom_transparent:
opacity = TRANSPARENT
else:
opacity = int(OPAQUE - ((zoom - zoom_opaque) * opacity_step))
zoom_to_opacity[zoom] = opacity
return zoom_to_opacity
def _build_zoom_mapping(conf=None, MAX_ZOOM=31):
"""Build and return the zoom_to_opacity mapping
This is a mapping of zoom levels to opacity levels. It is applied in
addition to any per-pixel alpha from the color scheme.
"""
if conf is None:
from gheat import MAX_ZOOM, conf # won't use these in testing
# Read and validate configuration.
# ================================
zoom_opaque = conf.get('zoom_opaque', '-15')
try:
zoom_opaque = int(zoom_opaque)
except ValueError:
raise ConfigurationError("zoom_opaque must be an integer.")
zoom_transparent = conf.get('zoom_transparent', '15')
try:
zoom_transparent = int(zoom_transparent)
except ValueError:
raise ConfigurationError("zoom_transparent must be an integer.")
# Build the mapping.
# ==================
num_opacity_steps = zoom_transparent - zoom_opaque
zoom_to_opacity = dict()
if num_opacity_steps < 1: # don't want general fade
for zoom in range(0, MAX_ZOOM + 1):
zoom_to_opacity[zoom] = None
else: # want general fade
opacity_step = OPAQUE / float(num_opacity_steps) # chunk of opacity
for zoom in range(0, MAX_ZOOM + 1):
if zoom <= zoom_opaque:
opacity = OPAQUE
elif zoom >= zoom_transparent:
opacity = TRANSPARENT
else:
opacity = int(OPAQUE - ((zoom - zoom_opaque) * opacity_step))
zoom_to_opacity[zoom] = opacity
return zoom_to_opacity
