Line Flags
Line flags are settings and properties you can apply to linedefs. These change how the textures are rendered and how players, monsters, and projectiles interact with them. For certain flags, such as the texture scrolls, they only work on the front side of the lindef.
| Flag Bit | Editor Setting | Description |
|---|---|---|
| 0x1 | Impassable | Monsters, players, and projectiles can't cross |
| 0x2 | Block Monsters | Monsters can't cross |
| 0x4 | Double Sided | Textures can be defined for both sides |
| 0x8 | Upper Unpegged | Align upper texture from ceiling origin |
| 0x10 | Lower Unpegged | Align lower texture from ceiling origin |
| 0x20 | Show 1-sided on Automap | Show line as one-sided with automap (good for secrets) |
| 0x40 | Block Sound | Prevent sound from alerting monsters across this linedef (sound can still be heard). In practice two linedefs with this flag are required to successfully prevent an alerting sound from traveling. |
| 0x80 | Never Show on Automap | Never show the linedef on automap |
| 0x100 | Always Show on Automap | Always show the linedef on automap |
| 0x200 | Render Middle Texture | Show middle texture (good for windows and cages) |
| 0x400 | No Occlusion | Explicitly allow geometry behind linedef to be rendered |
| 0x800 | Block Projectiles | Block all projectiles, but not hitscans, from passing |
| 0x1000 | Trigger By Dead Thing | Activate lineaction by monster death or sometimes monster crossing |
| 0x2000 | Switch Flag 1 | Activated when setting up switches |
| 0x4000 | Switch Flag 2 | Activated when setting up switches |
| 0x8000 | Switch Flag 3 | Activated when setting up switches |
| 0x10000 | Switch Check Height | Enable linedef to behave as a switch |
| 0x20000 | Scroll Left | Scroll texture to the left |
| 0x40000 | Scroll Right | Scroll texture to the right |
| 0x80000 | Scroll Up | Scroll texture upward |
| 0x100000 | Scroll Down | Scroll texture downward |
| 0x200000 | Peg Upper Wall Color | Begin upper wall gradient from bottom of upper wall |
| 0x400000 | Peg Lower Wall Color | End lower wall gradient at the top of the lower wall |
| 0x800000 | Use Wall Color Blending | Enable colored gradients on wall, otherwise use thing color for the wall |
| 0x1000000 | Trigger Only Front Side | Linedef action can only be activated from the front side |
| 0x2000000 | Hide Special on Automap | Hide that the linedef can be activated on automap |
| 0x4000000 | Flip Upper Pegged Color | Flip upper wall gradient direction |
| 0x8000000 | Block Player | (Super EX+ only) Line will only block player and not other things |
| 0x40000000 | Mirror Texture Horizontal | Mirror every other texture tile horizontally |
| 0x80000000 | Mirror Texture Vertical | Flip every other texture tile vertically |