function create_64_and_32_from_128(&$t128)
{
$t32_i = 0;
# 32x32 tile pixel index
$t64_i = 0;
# 64x64 tile pixel index
$t128_i = 0;
# 128x128 tile pixel index
$t32 = str_repeat("", 32 * 32 / 8);
$t64 = str_repeat("", 64 * 64 / 8);
for ($y = 0; $y < 32; ++$y) {
for ($x = 0; $x < 4; ++$x) {
# pull values from t128
$p00 = ord($t128[$t128_i]);
$p01 = ord($t128[$t128_i + T128_RB]);
$p02 = ord($t128[$t128_i + T128_RB2]);
$p03 = ord($t128[$t128_i + T128_RB3]);
++$t128_i;
$p10 = ord($t128[$t128_i]);
$p11 = ord($t128[$t128_i + T128_RB]);
$p12 = ord($t128[$t128_i + T128_RB2]);
$p13 = ord($t128[$t128_i + T128_RB3]);
++$t128_i;
$p20 = ord($t128[$t128_i]);
$p21 = ord($t128[$t128_i + T128_RB]);
$p22 = ord($t128[$t128_i + T128_RB2]);
$p23 = ord($t128[$t128_i + T128_RB3]);
++$t128_i;
$p30 = ord($t128[$t128_i]);
$p31 = ord($t128[$t128_i + T128_RB]);
$p32 = ord($t128[$t128_i + T128_RB2]);
$p33 = ord($t128[$t128_i + T128_RB3]);
++$t128_i;
# downsample to 64x64
$d64_00 = downsample($p00, $p10, $p01, $p11);
$t64[$t64_i] = chr($d64_00);
$d64_01 = downsample($p02, $p12, $p03, $p13);
$t64[$t64_i + T64_RB] = chr($d64_01);
++$t64_i;
$d64_10 = downsample($p20, $p30, $p21, $p31);
$t64[$t64_i] = chr($d64_10);
$d64_11 = downsample($p22, $p32, $p23, $p33);
$t64[$t64_i + T64_RB] = chr($d64_11);
++$t64_i;
# downsample to 32x32
$t32[$t32_i] = chr(downsample($d64_00, $d64_10, $d64_01, $d64_11));
++$t32_i;
}
# finished a row. move pixel pointers to next row
$t128_i += T128_RB3;
# skip three row (we wrote 4 rows at once, advancing one)
$t64_i += T64_RB;
# skip a row (we wrote two rows at once, advancing one)
}
return array($t64, $t32);
}
function create_tile_from_quadrant($quad)
{
# set the pixel index we're copying from
$pi = $quad % 2 * 16;
$pi += floor($quad / 2) * 4096;
$t32_i = 0;
# 32x32 tile pixel index
$t64_i = 0;
# 64x64 tile pixel index
$t128_i = 0;
# 128x128 tile pixel index
$t32 = str_repeat("", 32 * 32 / 8);
$t64 = str_repeat("", 64 * 64 / 8);
$t128 = str_repeat("", 128 * 128 / 8);
for ($y = 0; $y < 32; ++$y) {
for ($x = 0; $x < 4; ++$x) {
# xy
$p00 = $GLOBALS['pixels'][$pi];
$p01 = $GLOBALS['pixels'][$pi + PIXELS_RB];
$p02 = $GLOBALS['pixels'][$pi + PIXELS_RB2];
$p03 = $GLOBALS['pixels'][$pi + PIXELS_RB3];
++$pi;
$p10 = $GLOBALS['pixels'][$pi];
$p11 = $GLOBALS['pixels'][$pi + PIXELS_RB];
$p12 = $GLOBALS['pixels'][$pi + PIXELS_RB2];
$p13 = $GLOBALS['pixels'][$pi + PIXELS_RB3];
++$pi;
$p20 = $GLOBALS['pixels'][$pi];
$p21 = $GLOBALS['pixels'][$pi + PIXELS_RB];
$p23 = $GLOBALS['pixels'][$pi + PIXELS_RB3];
$p22 = $GLOBALS['pixels'][$pi + PIXELS_RB2];
++$pi;
$p30 = $GLOBALS['pixels'][$pi];
$p31 = $GLOBALS['pixels'][$pi + PIXELS_RB];
$p32 = $GLOBALS['pixels'][$pi + PIXELS_RB2];
$p33 = $GLOBALS['pixels'][$pi + PIXELS_RB3];
++$pi;
# save directly into t128
$t128[$t128_i] = chr($p00);
$t128[$t128_i + T128_RB] = chr($p01);
$t128[$t128_i + T128_RB2] = chr($p02);
$t128[$t128_i + T128_RB3] = chr($p03);
++$t128_i;
$t128[$t128_i] = chr($p10);
$t128[$t128_i + T128_RB] = chr($p11);
$t128[$t128_i + T128_RB2] = chr($p12);
$t128[$t128_i + T128_RB3] = chr($p13);
++$t128_i;
$t128[$t128_i] = chr($p20);
$t128[$t128_i + T128_RB] = chr($p21);
$t128[$t128_i + T128_RB2] = chr($p22);
$t128[$t128_i + T128_RB3] = chr($p23);
++$t128_i;
$t128[$t128_i] = chr($p30);
$t128[$t128_i + T128_RB] = chr($p31);
$t128[$t128_i + T128_RB2] = chr($p32);
$t128[$t128_i + T128_RB3] = chr($p33);
++$t128_i;
# downsample to 64x64
$d64_00 = downsample($p00, $p10, $p01, $p11);
$t64[$t64_i] = chr($d64_00);
$d64_01 = downsample($p02, $p12, $p03, $p13);
$t64[$t64_i + T64_RB] = chr($d64_01);
++$t64_i;
$d64_10 = downsample($p20, $p30, $p21, $p31);
$t64[$t64_i] = chr($d64_10);
$d64_11 = downsample($p22, $p32, $p23, $p33);
$t64[$t64_i + T64_RB] = chr($d64_11);
++$t64_i;
# downsample to 32x32
$t32[$t32_i] = chr(downsample($d64_00, $d64_10, $d64_01, $d64_11));
++$t32_i;
}
# finished a row. move pixels pointer to next row
$pi += T128_RB + PIXELS_RB3;
# go forwards the other half of this row, and the 3 rows we finished
$t128_i += T128_RB3;
# skip three row (we wrote 4 rows at once, advancing one)
$t64_i += T64_RB;
# skip a row (we wrote two rows at once, advancing one)
}
/*
print("quad: $quad\n");
print("first pixel from pixels: " . $GLOBALS['pixels'][0] . "\n");
print("Pixels:\n");
print_table($GLOBALS['pixels'], 64, PIXELS_RB);
print("t128:\n");
print_table($t128, 64, T128_RB);
print("t64:\n");
print_table($t64, 32, T64_RB);
print("t32:\n");
print_table($t32, 16, T32_RB);
exit();
*/
#print_full_table($t32, 32, T32_RB);
#exit();
return array($t128, $t64, $t32);
}
