objects/oBat/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.

oBat's step event, 96 lines of GML.

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 = -999;if (hp < 1){    scrCreateBlood(x+8, y+8, 3);    if (countsAsKill)    {        if (isRealLevel()) global.enemyKills[0] += 1;        global.bats += 1;        global.kills += 1;    }    instance_destroy();}dir = 0dist = point_distance(x+8, y+8, oPlayer1.x, oPlayer1.y)if (status == HANG){  if (not oPlayer1.swimming and not oPlayer1.dead and      ((dist < 90 and oPlayer1.y > y + 16) or not collision_point(x+8, y-1, oSolid, 0, 0)))  {    status = ATTACK;    playSound(global.sndBat);  }    sprite_index = sBatHang}else if (instance_exists(oPlayer1) and not oPlayer1.swimming and not oPlayer1.dead){    if (dist < 160)    {        dir = point_direction(x+8, y+8, oPlayer1.x, oPlayer1.y)        if (isCollisionRight(1) and oPlayer1.x > x+8)        {            if (oPlayer1.y < y+8) dir = 90;            else dir = 270;        }        if (isCollisionLeft(1) and oPlayer1.x < x+8)        {            if (oPlayer1.y < y+8) dir = 90;            else dir = 270;        }        if (isCollisionTop(1) and oPlayer1.y < y+8 and abs(oPlayer1.x - x) > 8)        {            if (oPlayer1.x < x+8) dir = 180;            else dir = 0;        }        if (isCollisionBottom(1) and oPlayer1.y > y+8 and abs(oPlayer1.x - x) > 8)        {            if (oPlayer1.x < x+8) dir = 180;            else dir = 0;        }                if (collision_point(x+8, y+16, oWater, 0, 0) and dir > 180 and dir < 360)        {            dir = 90;        }                if (not collision_point(x, y+12, oWater, 0, 0) or oPlayer1.y < y)        {            xVel = 1 * cos(degtorad(dir));            yVel = -1 * sin(degtorad(dir));        }    }    else    {        if (collision_point(x+8, y-1, oSolid, 0, 0)) status = HANG;        else        {            dir = 90;            xVel = 1 * cos(degtorad(dir));            yVel = -1 * sin(degtorad(dir));          }    }      if (oPlayer1.x < x+8)        sprite_index = sBatLeft    else        sprite_index = sBatRight}else{    if (collision_point(x+8, y-1, oSolid, 0, 0)) status = HANG;    else    {        dir = 90;        xVel = 1 * cos(degtorad(dir));        yVel = -1 * sin(degtorad(dir));      }}}