scripts/moveTo.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.

The script moveTo, 110 lines of GML.

/*Any object that has the collision bounds set can use this script. (To set the collision bounds, call the script "setCollisionBounds.")If the object collides into a solid when moving the specified distance,the object will stop precisely at the solid.If the object collides into a "moveable solid," it will stop and push themoveable solid.This function also pushes moveable solids and allows the character to land on platforms.Note: First the script moves the object in the x direction, then inthe y direction.Once the functin is finished, one can use the xVelInteger and yVelInteger variables formore precise calculations inside of the engine.0: x distance to move1: y distance to move*/mtXPrev=xmtYPrev=y//change the decimal arguments to integer variables with relation to timexVelFrac=frac(abs(argument0))yVelFrac=frac(abs(argument1))xVelInteger=0yVelInteger=0if xVelFrac!=0    if round(1/xVelFrac)!=0         xVelInteger=(oGame.time mod round(1/xVelFrac)=0)if yVelFrac!=0    if round(1/yVelFrac)!=0         yVelInteger=(oGame.time mod round(1/yVelFrac)=0)xVelInteger+=floor(abs(argument0))yVelInteger+=floor(abs(argument1))if argument0<0    xVelInteger*=-1if argument1<0    yVelInteger*=-1xVelInteger=round(xVelInteger)yVelInteger=round(yVelInteger)//object is moving to the rightif xVelInteger>0  for(x=x;x<mtXPrev+xVelInteger;x+=1)  {    solidId=getIdCollisionRight(1)    //if there is a collision with a solid    if solidId>0    {      if object_get_parent(solidId.object_index)=oMoveableSolid and canPushMoveableSolids()      {        //we must move the moveable solid, unless there is another solid (moveable or non-moveable) in it's way        with solidId        {          if place_meeting(x+1,y,oSolid)      //there will be a collision!          {            break          }          else          {            x += 1;             //we're free to move the moveable solid            if (not SS_IsSoundPlaying(global.sndPush)) playSound(global.sndPush);          }        }      }      else        break    }      }//object is moving to the leftif xVelInteger<0  for(x=x;x>mtXPrev+xVelInteger;x-=1)  {    solidId=getIdCollisionLeft(1)    //if there is a collision with a solid    if solidId>0    {      if object_get_parent(solidId.object_index)=oMoveableSolid and canPushMoveableSolids()      {        //we must move the moveable solid, unless there is another solid (moveable or non-moveable) in it's way        with solidId        {          if place_meeting(x-1,y,oSolid)      //there will be a collision!          {            break          }          else          {            x-=1             //we're free to move the moveable solid            if (not SS_IsSoundPlaying(global.sndPush)) playSound(global.sndPush);          }        }      }      else        break    }   }  //object is moving downif yVelInteger>0  for(y=y;y<mtYPrev+yVelInteger;y+=1)  {    if isCollisionBottom(1)      break    if canLandOnPlatforms()      if isCollisionPlatform()=0 and isCollisionPlatformBottom(1) and kDown=0        break  }//object is moving upif yVelInteger<0  for(y=y;y>mtYPrev+yVelInteger;y-=1)  {    if isCollisionTop(1)      break  }