def from_atlas(cls, atlas, chart_id):
# Bounding box variables of the chart
low = Coord(atlas.rows - 1, atlas.cols - 1)
high = Coord(0, 0)
# Search the atlas for the chart and find the bounding
for i in range(atlas.rows):
for j in range(atlas.cols):
tmp_id = atlas[i, j]
if tmp_id == chart_id:
low.x = min(low.x, i)
low.y = min(low.y, j)
high.x = max(high.x, i)
high.y = max(high.y, j)
# Calculate dimensions
height = high.x - low.x + 1
width = high.y - low.y + 1
# Create array for the chart
chart_arr = np.ndarray(shape=(height, width), dtype=Chart.DATA_TYPE)
chart_arr.fill(Chart.EMPTY)
# Copy the chart from the atlas to the array
pixels = 0
for i in range(height):
for j in range(width):
tmp_id = atlas[low.x + i, low.y + j]
if tmp_id == chart_id:
chart_arr[i, j] = Chart.OCCUPIED
pixels += 1
# Create a new Chart object and return it
index = low
chart = Chart.create(chart_arr,
height,
width,
chart_id=chart_id,
index=index,
pixels=pixels)
return chart
