The Flags values used are in Hexadecimal, but first I will have to discuss the binary form. I will kept the number of bits down to 8 bits, cause that is all we will need to work with for the Flags (for the most part anyway). We have all heard at one time or another that the most basic form of computer language is made up of ones and zeros. Well, this is known as the binary digits or bits. The logical values of these binary digits are denoted by 0 and 1. If a bit is 0 (empty) then that bit value will be 0. However, if a bit is 1 (full) then the value would be 2^n. Where the "^" is to the power and "n" is the bit position. For example, 2^2 is two squared which is the same as 2 * 2 = 4. (Note: the "*" means times). Another example, 2^3 is the same as 2 * 2 * 2 = 8. One final one that you need to know is 2^0 = 1. Ok, let's look at bit position with just four bits. bit 3 bit 2 bit 1 bit 0 decimal hexadecimal row 1 0 0 0 0 0 0 row 2 0 0 0 1 1 1 row 3 0 0 1 0 2 2 row 4 0 0 1 1 3 3 row 5 0 1 0 0 4 4 row 6 0 1 0 1 5 5 row 7 0 1 1 0 6 6 row 8 0 1 1 1 7 7 row 9 1 0 0 0 8 8 row 10 1 0 0 1 9 9 row 11 1 0 1 0 10 A row 12 1 0 1 1 11 B row 13 1 1 0 0 12 C row 14 1 1 0 1 13 D row 15 1 1 1 0 14 E row 16 1 1 1 1 15 F You will notice that for 4 bits their positions are 0-3. With the least significant bit on the right and the most significant bit on the left. Let's add up row 6. We have 0 + 2^2 + 0 + 2^0 and this is the same as 0 + 4 + 0 + 1 = 5. With row 16 we get 2^3 + 2^2 + 2^1 + 2^0 = 8 + 4 + 2 + 1 = 15. I just wanted to show you how the decimal values are totaled. You can also think of a bit that is 0 (empty) as off or false, and a bit that is 1 (full) as on or true. So, if a flag value for a SECTOR is 5c then the binary form is: 0 1 0 1 1 1 0 0 \ / \ / 5 c Reading from right to left (bit 0 to bit 7) and comparing it with Section 11. BUILD MAP FORMAT in the BUILDHLP.EXE file which follows: SECTORS bit 0: 1 = parallaxing, 0 = not "P" bit 1: 1 = sloped, 0 = not bit 2: 1 = swap x&y, 0 = not "F" bit 3: 1 = double smooshiness "E" bit 4: 1 = x-flip "F" bit 5: 1 = y-flip "F" bit 6: 1 = Align texture to first wall of sector "R" bits 7-15: reserved So, the Flag 5c uses bits 2, 3, 4, and 6 which tells us that when the sector was made the following keys were pressed F, E, F, and R. WALLS bit 0: 1 = Blocking wall (use with clipmove, getzrange) "B" bit 1: 1 = bottoms of invisible walls swapped, 0 = not "2" bit 2: 1 = align picture on bottom (for doors), 0 = top "O" bit 3: 1 = x-fliped, 0 = normal "F" bit 4: 1 = masking wall, 0 = not "M" bit 5: 1 = 1-way wall, 0 = not "1" bit 6: 1 = Blocking wall (use with hitscan/cliptype 1) "H" bit 7: 1 = Transluscence, 0 = not "T" bit 8: 1 = y-flipped, 0 = normal "F" bit 9: 1 = Transluscence reversing, 0 = normal "T" bits 10-15: reserved SPRITES bit 0: 1 = Blocking sprite (use with clipmove, getzrange) "B" bit 1: 1 = transluscence, 0 = normal "T" bit 2: 1 = x-flipped, 0 = normal "F" bit 3: 1 = y-flipped, 0 = normal "F" bits 5-4: 00 = FACE sprite (default) 01 = WALL sprite (like masked walls) "R" 10 = FLOOR sprite (parallel to ceilings&floors "R" bit 6: 1 = 1-sided sprite, 0 = normal "1" bit 7: 1 = Real centered centering, 0 = foot center "C" bit 8: 1 = Blocking sprite (use with hitscan/cliptype 1) "H" bit 9: 1 = Transluscence reversing, 0 = normal "T" bits 10-14: reserved bit 15: 1 = Invisible sprite, 0 = not no key given Well, I hope that this helps you out in understanding how a map (level) was made. Let me know...good or bad. Created by Bruce A. Benko at webmaster@babtech.com Copyright (C) 1997-98 by Bruce A. Benko