objects/oCeilingTrap/step.gml

From spelunky.gmk, Spelunky Classic 1.1's source, © 2008, 2009 Derek Yu and Mossmouth, LLC, shown whole under the Spelunky User License v1.1b. Extracted by spelunky.ai's tools, an unofficial fan project, one file per script or event; the // ==== lines are the extractor's, naming each action of the event. Some scripts are others' work that Derek Yu credits in the source's readme.txt: Martin Piecyk's platform engine, ChevyRay's view scaling scripts and tsg1zzn's Super Sound System.

oCeilingTrap's step event, 21 lines of GML.

if (status == IDLE){    // nothing}else if (status == DROP){    if (counter > 0) counter -= 1;    else    {        counter = 3;        y += 1;    }    yVel = 0;    if (collision_point(x+8, y+17, oSolid, 0, 0)) status = WAIT;    if (sprite_index = sBlock) sprite_index = sCeilingTrapS;}else if (status == WAIT){    yVel = 0;    if (isCollisionBottom(1)) y -= 1;}