objects/oAlien/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.

oAlien's step event, 78 lines of GML.

// ==== action 0: lib 1 id 604: action_inherited() ====// ==== action 1: lib 1 id 603: code ====if ((x > view_xview[0]-20 and x < view_xview[0] + view_wview[0]+4 and        y > view_yview[0]-20 and y < view_yview[0] + view_hview[0]+4)){moveTo(xVel,yVel);if (collision_point(x+8, y+8, oSolid, 0, 0)){    hp = 0;}if (hp < 1){    scrCreateBlood(x+8, y+8, 3);    if (countsAsKill)    {        if (isRealLevel()) global.enemyKills[15] += 1;        global.aliens += 1;        global.kills += 1;    }    instance_destroy();}yVel += 0.6;if (isCollisionBottom(1) and status != STUNNED)    yVel = 0;if (status == IDLE){    if (counter > 0) counter -= 1;        if (counter == 0)    {        facing = rand(0,1);        status = WALK;    }}else if (status == WALK){    if (isCollisionRight(1))    {        facing = LEFT;    }    if (isCollisionLeft(1))    {        facing = RIGHT;    }    if (facing == LEFT and not collision_point(x-1, y, oSolid, -1, -1) and        not collision_point(x-1, y+16, oSolid, -1, -1))    {        facing = RIGHT;    }    else if (facing == RIGHT and not collision_point(x+16, y, oSolid, -1, -1) and             not collision_point(x+16, y+16, oSolid, -1, -1))    {        facing = LEFT;    }    if ((not collision_point(x-1, y+16, oSolid, -1, -1) or collision_point(x-1, y, oSolid, -1, -1)) and        (not collision_point(x+16, y+16, oSolid, -1, -1) or collision_point(x+16, y, oSolid, -1, -1)))    {        if (collision_point(x-1, y, oSolid, -1, -1)) facing = RIGHT        else facing = LEFT;        xVel = 0;    }    else if (facing == LEFT) xVel = -1;    else xVel = 1;        if (rand(1,100) == 1)    {        status = IDLE;        counter = rand(20,50);        xVel = 0;    }}}//if (isCollisionSolid())//    y -= 2;