skyTile.py

#!/usr/bin/python
#
# Fabien Chereau fchereau@eso.org
#

import gzip
import os


def writePolys(pl, f):
    """Write a list of polygons pl into the file f.
    The result is under the form [[[ra1, de1],[ra2, de2],[ra3, de3],[ra4, de4]], [[ra1, de1],[ra2, de2],[ra3, de3]]]"""
    f.write('[')
    for idx, poly in enumerate(pl):
        f.write('[')
        for iv, v in enumerate(poly):
            f.write('[%.8f, %.8f]' % (v[0], v[1]))
            if iv != len(poly) - 1:
                f.write(', ')
        f.write(']')
        if idx != len(pl) - 1:
            f.write(', ')
    f.write(']')


class StructCredits:
    def __init__(self):
        self.short = None
        self.full = None
        self.infoUrl = None
        return

    def outJSON(self, f, levTab):
        if self.short != None:
            f.write(levTab + '\t\t"short": "' + self.short + '",\n')
        if self.full != None:
            f.write(levTab + '\t\t"full": "' + self.full + '",\n')
        if self.infoUrl != None:
            f.write(levTab + '\t\t"infoUrl": "' + self.infoUrl + '",\n')
        f.seek(-2, os.SEEK_CUR)
        f.write('\n')


class SkyImageTile:
    """Contains all the properties needed to describe a multiresolution image tile"""

    def __init__(self):
        self.subTiles = []
        self.imageCredits = StructCredits()
        self.serverCredits = StructCredits()
        self.imageInfo = StructCredits()
        self.imageUrl = None
        self.alphaBlend = None
        self.maxBrightness = None
        return

    def outputJSON(self, prefix='', qCompress=False, maxLevelPerFile=10, outDir=''):
        """Output the tiles tree in the JSON format"""
        fName = outDir + prefix + "x%.2d_%.2d_%.2d.json" % (2 ** self.level, self.i, self.j)

        # Actually write the file with maxLevelPerFile level
        with open(fName, 'w') as f:
            self.__subOutJSON(prefix, qCompress, maxLevelPerFile, f, 0, outDir)

        if (qCompress):
            with open(fName) as ff:
                fout = gzip.GzipFile(fName + ".gz", 'w')
                fout.write(ff.read())
                fout.close()
                os.remove(fName)

    def __subOutJSON(self, prefix, qCompress, maxLevelPerFile, f, curLev, outDir):
        """Write the tile in the file f"""
        levTab = ""
        for i in range(0, curLev):
            levTab += '\t'

        f.write(levTab + '{\n')
        if self.imageInfo.short != None or self.imageInfo.full != None or self.imageInfo.infoUrl != None:
            f.write(levTab + '\t"imageInfo": {\n')
            self.imageInfo.outJSON(f, levTab)
            f.write(levTab + '\t},\n')
        if self.imageCredits.short != None or self.imageCredits.full != None or self.imageCredits.infoUrl != None:
            f.write(levTab + '\t"imageCredits": {\n')
            self.imageCredits.outJSON(f, levTab)
            f.write(levTab + '\t},\n')
        if self.serverCredits.short != None or self.serverCredits.full != None or self.serverCredits.infoUrl != None:
            f.write(levTab + '\t"serverCredits": {\n')
            self.serverCredits.outJSON(f, levTab)
            f.write(levTab + '\t},\n')
        if self.imageUrl:
            f.write(levTab + '\t"imageUrl": "' + self.imageUrl + '",\n')
        f.write(levTab + '\t"worldCoords": ')
        writePolys(self.skyConvexPolygons, f)
        f.write(',\n')
        f.write(levTab + '\t"textureCoords": ')
        writePolys(self.textureCoords, f)
        f.write(',\n')
        if self.maxBrightness:
            f.write(levTab + '\t"maxBrightness": %f,\n' % self.maxBrightness)
        if self.alphaBlend:
            f.write(levTab + '\t"alphaBlend": true,\n')
        f.write(levTab + '\t"minResolution": %f' % self.minResolution)
        if not self.subTiles:
            f.write('\n' + levTab + '}')
            return
        f.write(',\n')
        f.write(levTab + '\t"subTiles": [\n')

        if curLev + 1 < maxLevelPerFile:
            # Write the tiles in the same file
            for st in self.subTiles:
                assert isinstance(st, SkyImageTile)
                st.__subOutJSON(prefix, qCompress, maxLevelPerFile, f, curLev + 1, outDir)
                f.write(',\n')
        else:
            # Write the tiles in a new file
            for st in self.subTiles:
                st.outputJSON(prefix, qCompress, maxLevelPerFile, outDir)
                f.write(levTab + '\t\t{"$ref": "' + prefix + "x%.2d_%.2d_%.2d.json" % (2 ** st.level, st.i, st.j))
                if qCompress:
                    f.write(".gz")
                f.write('"},\n')
        f.seek(-2, os.SEEK_CUR)
        f.write('\n' + levTab + '\t]\n')
        f.write(levTab + '}')