std.txt for ZC Versions 2.53.0 and higher.
1st April, 2019

=================
--- Constants ---
=================

const float STD_VERSION; 
 * The current header version. 

const float PI, PI2, E
 * The mathematical constants pi, 2*pi and e.
 
const float RADIAN, DEGREE, SQRT_MAX
const int SQRT_ERROR 
 * Some additional constants for maths.

const int NULL
 * Refers to an invalid array pointer, returned by ALLOCATEMEM when memory cannot be allocated

const float MAX_CONSTANT, float MIN_CONSTANT, float MAX_VARIABLE, float MIN_VARIABLE, int MAX_INT, MIN_INT, 
const float MAX_FLOAT, float MIN_FLOAT, int MIN_INT, float MIN_FLOAT, float MIN_
const int MAX_COUNTER, int MIN_COUNTER
const int MIN_LWEAPON, int MIN_EWEAPON, int MIN_NPC, int MIN_IEM, int MAX_LWEAPON, int MAX_EWEAPON, int MAX_NPC, 
const int MAX_ITEM, MAX_OBJECT_POINTERS< MAX_WEAPON_POINTERS, MAX_TOTAL_OBJECT_POINTERS
const int MAX_SPRITES
const int MAX_DRAWING
const int MINBITMAP_X, int MAX_BITMAP_X, int MIN_BITMAP_Y, int MAX_BITMAP_Y
const int MAX_GLOBAL_VARIABLES, int MAX_VARIABLES, int MAX_BITSPERVARIABLE
const int MAX_ARRAY_POINTERS, int MAX_TILES, int MAX_COMBOS, int MAX_STRINGS
const int HP_PER_BLOCK, int MP_PER_BLOCK
const int MAX_SCRIPTDRAWINGCOMMANDS
const int MAX_MESSAGES, int MAX_MESSAGELENGTH
const int MAX_MAPS, MAX_DMAPS
const int MAX_DMAPNAMELENGTH, MAX_DMAPTITLELENGTH, MAX_DMAPINTROLENGTH
const int MAX_FFC_*
 * Information about some system constraints
 
const int SCREEN_W, int SCREEN_H, int SUBSCREEN_BOTTOM, int SUBSCREEN_TOP
const int SCREEN_RIGHT, int SCREEN_LEFT, int SCREEN_TOP, int SCREEN_BOTTOM
 * Screen dimensions. 

const float GRAVITY
const float TERMINAL_VELOCITY
const float JUMPING_LAYER_THRESHOLD
 * Some defaults from Init. Data

const int CSET*
 * Offsets for the initial swatch of each CSet

const int SFX_*
 * Sound effects, can be used with Game->PlaySound.
 
const int SP_*
 * Default Sprite IDs

const int IC_*
 * Itemclass IDs, can be compared against itemdata->Family

const int I_*
 * Item IDs, can be used with Link->Item, Link->Equipment, item->ID, Link->HeldItem, GetEquipmentA,
 * GetEquipmentB, Screen->CreateItem, CreateItemAt, NumItemsOf

const int LA_*
 * Link's actions, can be used to set or compare against Link->Action

const int NPCT_*
 * NPC Types, can be used to compare against npc->Type

const int NPC_*
 * NPC IDs, can be used with npc->ID, Screen->CreateNPC, NumNPCsOf

const int HP_SILENT
 * NPC HP value, can be used to set npc->HP

const int LW_*
 * LWeapon IDs, can be used with lweapon->ID, Screen->CreateLWeapon, CreateLWeaponAt, NumLWeaponsOf

const int EW_*
 * EWeapon IDs, can be used with eweapon->ID, Screen->CreateEWeapon, CreateEWeaponAt, NumEWeaponsOf

const int WDS_*
 * Weapon DeadState Values, can be used to set or compare against *weapon->DeadState

const int FFCF_*
 * FFC Flags, can be used to set or compare against ffc->Flags[]

const int DIR_*
 * Directions, can be used with Link->Dir, npc->Dir, *weapon->Dir
 
const int DEG_DIR_*
 * Constants for the equivalent to a given direction, in degrees.
 
const int RAD_DIR_*
 * Constants for the equivalent to a given direction, in radians.
 
const int FLIP_*, int ROT_*
 * Flip and rotation used by sprites and tiles. 
 
const int EXT_*
 * Extend types.

const int CF_*
 * Combo Flags, can be used with Screen->ComboF[], Screen->ComboI[], Game->GetComboFlag, Game->SetComboFlag,
 * Game->GetComboInherentFlag, Game->SetComboInherentFlag

const int CT_*
 * Combo Types, can be used with Screen->ComboT[], Game->GetComboType, Game->SetComboFlag
 
const int CB_*
 * Controller buttons.

const int IP_*
 * Item Pickup Flags, can be used with item->Pickup, GetItemPickup, SetItemPickup

const int SF_*
 * Screen Flag Categories, can be used with Screen->Flags, GetScreenFlags
 
const int SFR_*
 * Room types.

const int SFV_*
 * Screen View Flags

const int SFS_* 
 * Screen Secret Flags
 
const int SFW_*
 * Screen Warp Flags
 
const int SFI_*
 * Screen Item Flags
 
const int SFC_*
 * Sreen Combo Flags
 
const int SFSV_*
 * Screen save flags
 
const int SFF_*
 * Screen FFC Flags
 
const int SFW_*
 * Screen Whistle Flags
 
const int SFM_* 
 * Screen Misc. Flags
 
const int SEF_*
 * Screen Enemy Flag Categories, can be used with Screen->EFlags, GetScreenEFlags

const int DMF_*
 * DMap Flags, can be used with Game->DMapFlags[], GetDMapFlag, SetDMapFlag

const int NPCA*_*
 * NPC Attributes, can be used to compare against npc->Attributes[]

const int NPCD_*
 * NPC Defenses, can be used to compare against npc->Defense[]

const int NPCDT_*
 * NPC Defense types, can be used to compare against npc->Defense[]
 
cons int NPCA_*
 * NPC Attribute Indices, and Values for each type of Attribute, segregated by NPC type.

const int DS_*
 * Draw Styles, can be used with item->DrawStyle

const int WT_*
 * Warp Types, can be used with Screen->SetSideWarp, Screen->SetTileWarp
 
const int TILEWARP_*, int SIDEWARP_*
 * IDs of tile warps and side warps. 

const int FONT_*
 * Font Types, can be used with Screen->DrawCharacter, Screen->DrawString, Screen->DrawInteger

const int TF_*
 * Text Formats, can be used with Screen->DrawString

const int PT_*
 * Texture Mapping Rendering Modes, can be used with Screen->*3D

const int OP_*
 * Opacity options, can be used with all shape and tile drawing commands.

const int RT_*
 * Render targets, can be used with Screen->SetRenderTarget and Screen->DrawBitmap.

const int EXT_*
 * Sprite Extend Types, can be used with Link->Extend, npc->Extend, *weapon->Extend, item->Extend

const int CR_*
 * Counter types, can be used with itemclass->Counter, Game->Counter[], Game->MCounter[], Game->DCounter[]

const int GEN_*
 * Generic Data Types, can be used to set or compare against Game->Generic[]

const int LI_*
 * Level Item Flags, can be used with Game->LItems[], GetLevelItems, SetLevelItems

cosnt int ST_*
 * Screen States, can be used with Screen->State[], Game->GetScreenState, Game->SetScreenState

const int D_*
 * Door types, can be used with Screen->Door[]

const int WPN_*
 * Enemy Weapon Types, can be used with npc->Weapon
 
const int AT_*
 * Weapon aim types, to be used with AimEWeapon

const int IS_*
 * Item Drop Sets, can be used to set or compare against npc->ItemSet

const int BPAL_*
 * Boss Palletes, can be used to set or compare against npc->BossPal

const int SL_*
 * Sprite Lists, can be used with Screen->ClearSprites

const int MB_*
 * Mouse Buttons, can be used with Link->InputMouseB
 
const int CB_*
 * Controller input buttons
 
const int NPCSF_*
* NPC Spawn Flags

const int NPCM_*
* NPC Misc. Flags
 
 const int SFM__*
* Misc. Screen Flags

const int CSET_*
 * Values for the first colour in each CSet

const int SPRITE_*
  * Values for all default sprites
 
const int AT_*
 * Aim types for use with AimEWeapon()

const int TEX_BITMAP
 * Drawing texture Mode (2.50.3 experimental, and later)

//Constants for AdjacentCombo()

const int CMB_UPLEFT    = 0;
const int CMB_UP        = 1;
const int CMB_UPRIGHT   = 2;
const int CMB_RIGHT     = 3;
const int CMB_DOWNRIGHT = 4;
const int CMB_DOWN      = 5;
const int CMB_DOWNLEFT  = 6;
const int CMB_LEFT      = 7;
const int CMB_LEFTUP    = 0;
 
 
=================
--- Functions ---
=================

-- Mathematical Functions --
============================

float LogToBase(float x, float base)
 * Returns the logarithm of x to the given base

int Floor(float x)
 * Truncates x to an integer

int Ceiling(float x)
 * Raises x to the nearest integer

int Round(float x)
 * Rounds x to the nearest integer

int VBound(int x, int high, int low)
 * Bounds x between two values

int Div(float x, float y)
 * Modulo's complement; returns the quotient only of x divided by y

int Rand(int min, int max)
 * Overload to rand, returning a random integer in the bounds of min and max

float Randf(float n)
 * Returns a random floating point number up to n

float Randf(float n1, float n2)
 * Overloaded to take two boundaries as arguments

float DegtoRad(float d)
 * Converts 'd' in degrees to radians

float RadtoDeg(float r)
 * Converts 'r' in radians to degrees

int Sign(int n)
 * Returns the sign of n

float Distance(int x1, int y1, int x2, int y2)
 * Returns the distance between two sets of coordinates using Pythagoras' Theorem
 
float LargeDistance(int x1, int y1, int x2, int y2, int divisor);
 * Calculates the distance over a scale 'divisor' that would otherwise 
   overflow Distance(). 
   
float Angle(int x1, int y1, int x2, int y2)
 * Returns the direction of the vector from point 1 to point 2, in degrees from -180 to 180. (0 = right)

float RadianAngle(int x1, int y1, int x2, int y2)
 * The above, but in radians.

float VectorX(int len, float angle)
 * Returns the X component of a vector with a degree angle.
 * A length of 3 and angle of 0 returns 3.
 * A length of 3 and angle of 45 returns approx. 1.57.
 * A length of 3 and angle of 90 returns 0.

float VectorY(int len, float angle)
 * Returns the Y component of a vector with a degree angle.
 * A length of 3 and angle of 0 returns 0.
 * A length of 3 and angle of 45 returns approx. 1.57.
 * A length of 3 and angle of 90 returns 3.

float Lerp(float p1, float p2, float t)
 * Interpolates between p1 and p2 given 't' clamped within range 0,1.

float DotProduct( float x1, float y1, float x2, float y2 )
 * Returns the dot product of two vectors.

float CrossProduct( float x1, float y1, float x2, float y2 )
 * Returns the cross product of two vectors.

float DistanceSquared( float x, float y )
 * Returns the squared distance of a vector.

float Midpoint(float p1, float p2)
 * Finds the center of p1 and p2.

float SmoothStep(float p1, float p2, float t)
 * Performs a "Smooth" Interpolation given 't' clamped within range 0,1.

float WrapAngle( float radians )
 * Wraps radian value towards the range of -PI,PI.

float WrapDegrees( float degrees )
 * Wraps degree value towards the range of -180,180.

float TurnTowards( int X, int Y, int targetX, int targetY, float radian_angle, float t )
 * Returns an angle pointing (t)percentage more accurate to the target than the specified radian_angle.

int DirAngle(int dir);
 * Returns angle of the given direction.

int Dir4Angle(int dir);
 * Returns angle of the given direction.

int DirRad(int dir);
 * Same as DirAngle, but return value is measured in radians.

int Dir4Rad(int dir);
 * Same as Dir4Angle, but return value is measured in radians.
 
-- Direction Functions --
=========================
 * Make sure your angles are in the range -PI to PI (with WrapAngle) before using these functions


int AngleDir8(float angle)
 * Converts a counterclockwise degree angle (from -180 to 180) into one of the eight
 * standard directions (DIR_UP etc.) used by ZC.

int RadianAngleDir8(float angle)
 * The above, but for radian angles.

int AngleDir4(float angle)
 * Converts a counterclockwise degree angle (from -180 to 180) into one of the four
 * standard directions (DIR_UP, DIR_DOWN, DIR_LEFT, DIR_RIGHT) used by ZC.

int RadianAngleDir4(float angle)
 * The above, but for radian angles.

int OppositeDir(int dir)
 * Returns the opposite direction to 'dir'

int SpinDir(int dir)
 * Converts directions to go round in a circle rather than U, D, L, R
   
bool Facing(ffc f);
 * Returns true if Link is facing the ffc.

bool Above(T);
 * Returns true if Link is above the object T.
 
bool Below(T);
 * Returns true if Link is below the object T.

bool LeftOf(T);
 * Returns true if Link is to the left of the object T.
 
bool RightOf(T);
 * Returns true if Link is to the right of the object T.
 
bool DistXY(ffc a, int dist);
 * Returns true if Link is within 'dist' pixels distance 
   of the ffc on both axis. 


-- Drawing Functions --
=======================

void DrawString(int layer, int x, int y, int font, int color, int background_color, int format, int opacity,
				int string, int start)
 * Overload to Screen->DrawString which includes a position to start drawing from in the string
 * Does not check for overflow

void DrawString(int layer, int x, int y, int font, int color, int background_color, int format, int opacity,
				int string, int start, int end)
 * Overload to Screen->DrawString which includes a start and end position to draw the string
 * Does not check for overflow

void DrawTileSimple(int x, int y, int tile, int color)
 *  A very simple layer 0 tile drawing routine.

void DrawToLayer(T ptr, int layer, int opacity)
 * Draws a pointer to given layer. Overloaded to take all pointers as arguments


-- Conditional Functions --
===========================

T Cond(bool cond, T a, T b)
 * Returns a if cond is true, else b. Overloaded to take all types as arguments

float Choose(float a, float b)
float Choose(float a, float b, float c)
float Choose(float a, float b, float c, float d)
float Choose(float a, float b, float c, float d, float e)
float Choose(float a, float b, float c, float d, float e, float f)
 * Chooses one of the options randomly and fairly.


-- Collision Detection Functions --
===================================

bool RectCollision(int box1_x1, int box1_y1, int box1_x2, int box1_y2, int box2_x1, int box2_y1, int box2_x2, int box2_y2)
 * Generalized and optimized rectangle collision checking function.
 * Returns true if the bounding box of box1 and box2 overlap.

bool SquareCollision(int c1x, int c1y, int side1, int c2x, int c2y, int side2)
 * Check for collisions of two squares given upper-left coordinates and a side length for each.

bool SquareCollision2(int c1x, int c1y, int radius1, int c2x, int c2y, int radius2)
 * Check for collisions of two squares given center coordinates and a halved side length for each.

bool CircleCollision(int c1x, int c1y, int radius1, int c2x, int c2y, int radius2)
 * Returns true if the two circles c1 and c2 overlap.

bool Collision(T a, S b)
 * Returns true if there is a collision between the hitboxes of any two pointers

bool LinkCollision(T ptr)
 * Returns true if there is a collision between Link's hitbox and any pointer's

int HitboxLeft(T ptr)
 * Returns the X coordinate of the left edge of the hitbox for any pointer

int HitboxTop(T ptr)
 * Returns the Y coordinate of the top edge of the hitbox for any pointer

int HitboxRight(T ptr)
 * Returns the X coordinate of the right edge of the hitbox for any pointer

int HitboxBottom(T ptr)
 * Returns the Y coordinate of the bottom edge of the hitbox.

bool CanWalk(int x, int y, int dir, int step, bool full_tile)
 * This should allow any scripted object to easily mimic Link styled LOZ solidity collision
 * checking, be it Link, FFCs, or enemies.
 * Note - You should use full_tile=true if you don't want the upper eight pixels to overlap
 * solid combos as per LOZ1 behavior.

bool OnSidePlatform(int x, int y)
bool OnSidePlatform(int x, int y, int xOff, int yOff, int h)
 * Returns true if the sprite at (x,y) is standing on a sideview platform on a sideview screen, as worked out
 * by ZC's internal code.



-- Functions for accessing data stored in binary format --
==========================================================

bool IsSideview()
 * Returns true if Link is on a sideview screen
 
bool IsDungeonFlag();
 * Returns true if Link is on a Dungeon (flagged) screen

bool IsInteriorFlag();
 * Returns true if Link is on an Interior (flagged) screen

int HasTriforce(int level);
 * Returns if Link has the Triforce piece for a given level.

int HasCompass(int level);
 * Returns if Link has the compass for a given level.

int HasMap(int level);
 * Returns if Link has the map for a given level.

int HasBossKey(int level);
 * Returns if Link has the map for a given level.

int DefeatedLevelBoss(int level);
 * Returns if Link has defeated the dungeon boss for a given level.

void SetScreenDBit(int dmap, int screen, int d, int bit, bool state)
void SetScreenDBit(int screen, int d, int bit, bool state)
void SetScreenDBit(int d, int bit, bool state)
 * Sets bit 'bit' of Screen->D[] register 'd' to 'state', overloaded to set on other screens

bool GetScreenDBit(int dmap, int screen, int d, int bit)
bool GetScreenDBit(int screen, int d, int bit)
bool GetScreenDBit(int d, int bit)
 * Returns the state of bit 'bit' of Screen->D[] register 'd'
 * Overloaded to get from other screens

bool InputLeftClick()
 * Returns true if the left mouse button is pressed

bool InputRightClick()
 * Returns true if the right mouse button is pressed

bool InputMiddleClick()
 * Returns true if the middle mouse button is pressed. 
 * Note that not all mice have a middle button. 
 
int GetEquipmentA()
 * Returns the item ID of the item equipped to Link's A button

int GetEquipmentB()
 * Returns the item ID of the item equipped to Link's B button

bool UsingItem(int id)
 * Returns true if Link is using item 'id'

int ScreenFlag(int category, int flag)
 * Returns 1 if Screen Flag 'flag' is set from category 'category', 0 if it's not and -1 if an invalid flag is passed
 * Flags are numbered starting from 0

int ScreenEFlag(int category, int flag)
 * Returns 1 if Screen Enemy Flag 'flag' is set from category 'category', 0 if it's not and -1 if an invalid flag is passed
 * Flags are numbered starting from 0

bool GetDMapFlag(int dmap, int flag)
 * Returns true if DMap Flag 'flag' is set on dmap 'dmap'

void SetDMapFlag(int dmap, int flag, bool state)
 * Sets a certain DMap flag to 'state'

bool GetItemPickup(item i, int pickup)
 * Returns true if an item's Pickup state is set
 * Use the IP_ constants for the 'pickup' argument of this function

void SetItemPickup(item i, int pickup, bool state)
 * Sets an item's Pickup state to 'state'

bool GetNPCMiscFlag(npc e, int flag)
 * Returns true if an npc's Misc. flag is set.

bool GetLevelItem(int level, int itm)
bool GetLevelItem(int itm)
 * Returns true if Link has the level item 'itm' from level 'level'
 * Overloaded to use the current level if no 'level' arg is entered
 * Use the LI_ constants for the 'itm' argument

void SetLevelItem(int level, int itm, bool state)
void SetLevelItem(int itm, bool state)
 * Gives or removes a level item from Link's inventory


-- Functions to help handling in-built pointers --
==================================================

lweapon NextToLink(int id, int distx, int disty)
lweapon NextToLink(int id, int dist)
 * Creates an lweapon at 'distx, disty' away from where Link is facing

eweapon NextToNPC(npc n, int id, int distx, int disty)
eweapon NextToNPC(npc n, int id, int dist)
 * Creates an eweapon at 'distx, disty' away from where npc 'n' is facing

void AimEWeapon(eweapon e, int aimtype)
 * Aims eweapon e according to the AT_* constant passed to aimtype

void AimLWeapon(lweapon l, npc n, int aimtype)
void AimLWeapon(lweapon l, int aimtype)
 * Aims lweapon l according to the AT_* constant passed to aimtype, overloaded to shoot
 * at an npc or at random

int WeaponTypeToID(int weapontype)
 * Turns a WPN_* constant to an EW_* constant

*weapon Duplicate(*weapon a)
 * Creates and returns an exact copy of the passed weapon. Assumes that the passed pointer is valid.

npc CreateNPCAt(int id, int x, int y)
 * Create an NPC and set its X and Y position in one command

item CreateItemAt(int id, int x, int y)
 * Create an Item and set its X and Y position in one command

lweapon CreateLWeaponAt(int id, int x, int y)
 * Create an LWeapon and set its X and Y position in one command

eweapon CreateEWeaponAt(int id, int x, int y)
 * Create an EWeapon and set its X and Y position in one command

void Remove(T n)
 * Removes sprite 'n' from the screen. Overloaded.

int NumLWeaponsOf(int type)
 * Returns the number of lweapons of type 'type' currently on the screen

int NumEWeaponsOf(int type)
 * Returns the number of weapons of type 'type' currently on the screen

int NumNPCsOf(int type)
 * Returns the number of npcs of type 'type' currently on the screen

int NumberEnemies();
 * Returns the number of enemy NPCs on the current screen, ignoring 
   guys, faeries, projectile shooters, unbeatable enemies, and similar.
   
bool EnemiesAlive();
 * Returns true if there are any enemies on the screen that are beatable, 
   excluding projectile statues, guys, and faeries. 

int NumItemsOf(int type)
 * Returns the number of items of type 'type' currently on the screen

lweapon LoadLWeaponOf(int type)
 * Returns the first LWeapon of the given type. Use the LW_ constants.
 * If none exist, it returns an uninitialised pointer.

eweapon LoadEWeaponOf(int type)
 * Returns the first EWeapon of the given type. Use the EW_ constants.
 * If none exist, it returns an uninitialised pointer.

npc LoadNPCOfType(int type)
 * Returns the first NPC of the given type. Use the NPCT_ constants.
 * If none exist, it returns an uninitialised pointer.

npc LoadNPCOf(int type)
 * Returns the first NPC of the given ID. Use the NPC_ constants.
 * If none exist, it returns an uninitialised pointer.

item CreateTimeoutItem(int id, int x, int y)
 * Creates a timeout item (such as a rupee or heart) with ID 'id' at '(x, y)'

-- Position Functions --
========================

int GridX(int x)
 * Snaps 'x' to the combo grid
 * Equivalent to calling ComboX(ComboAt(x, foo));

int GridY(int y)
 * Snaps 'y' to the combo grid
 * Equivalent to calling ComboY(ComboAt(foo, y));

int AtFrontX(int dir)
int AtFrontY(int dir)
 * Returns the correct offset to be at the front of a sprite facing in
 * the direction 'dir'

int InFrontX(int dir, int dist)
int InFrontY(int dir, int dist)
 * Returns the correct offset to be 'dist' pixels away from the front of
 * a sprite facing in the direction 'dir'

int CenterX(ffc anFFC)
int CenterY(ffc anFFC)
int CenterX(npc anNPC)
int CenterY(npc anNPC)
int CenterX(eweapon anEWeapon)
int CenterY(eweapon anEWeapon)
int CenterX(lweapon anLWeapon)
int CenterY(lweapon anLWeapon)
int CenterLinkX()
int CenterLinkY()
 * Returns the X or Y coordinate at the center of the given sprite.


-- Combo Functions --
=====================

int ComboAt(int x, int y)
 * Finds the location of a combo, given its (x,y) coordinates on the screen

int ComboX(int loc)
int ComboY(int y)
 * Return the coordinates of a combo on the screen

bool ComboFI(int x, int y, int flag)
bool ComboFI(int loc, int flag)
 * Returns true if the combo at '(x, y)' or 'loc' has either an
 * inherent or placed flag of type 'flag'

int GetLayerComboD(int layer, int pos)
 * A shorthand way to get a combo on the specified layer.
 * Layer 0 is the screen itself.

void SetLayerComboD(int layer, int pos, int combo)
 * A shorthand way to set a combo on the specified layer.
 * Layer 0 is the screen itself.

int GetLayerComboF(int layer, int pos)
 * A shorthand way to get a combo flag on the specified layer.
 * Layer 0 is the screen itself.

void SetLayerComboF(int layer, int pos, int flag)
 * A shorthand way to set a combo flag on the specified layer.
 * Layer 0 is the screen itself.

int GetLayerComboT(int layer, int pos)
 * A shorthand way to get a combo type on the specified layer.
 * Layer 0 is the screen itself.

void SetLayerComboT(int layer, int pos, int type)
 * A shorthand way to set a combo type on the specified layer.
 * Layer 0 is the screen itself.

int GetLayerComboS(int layer, int pos)
 * A shorthand way to get a combo's solidity on the specified layer.
 * Layer 0 is the screen itself.

void SetLayerComboS(int layer, int pos, int solidity)
 * A shorthand way to set a combo's solidity on the specified layer.
 * Layer 0 is the screen itself.
 
int GetLayerComboI(int layer, int pos)
 * A shorthand way to get a combo inherent flag on the specified layer.
 * Layer 0 is the screen itself.

void SetLayerComboI(int layer, int pos, int flag)
 * A shorthand way to set a combo inherent flag on the specified layer.
 * Layer 0 is the screen itself.

int GetLayerComboC(int layer, int pos)
 * A shorthand way to get a combo's CSet on the specified layer.
 * Layer 0 is the screen itself.

void SetLayerComboC(int layer, int pos, int cset)
 * A shorthand way to set a combo's CSet on the specified layer.
 * Layer 0 is the screen itself.

int FirstComboOf(int t, int layer)
 * Returns the position of the first instance of the given combo, or -1.

int LastComboOf(int t, int layer)
 * Returns the position of the last instance of the given combo, or -1.

int FirstComboTypeOf(int t, int layer)
 * Returns the position of the first instance of the given combo, or -1.

int LastComboTypeOf(int t, int layer)
 * Returns the position of the last instance of the given combo, or -1.

int FirstComboFlagOf(int t, int layer)
 * Returns the position of the first instance of the given combo flag, or -1.
 * Checks inherent flags too!

int LastComboFlagOf(int t, int layer)
 * Returns the position of the last instance of the given combo flag, or -1.
 * Checks inherent flags too!

bool IsWater(int position)
 * Returns true if the combo at the given position is water or a swim or dive warp. Shallow water doesn't count.

bool IsPit(int position)
 * Returns true if the combo at the given position is a pit.


-- Tile Functions --
====================

void SwapTileRow(int first, int second, int length)
 * Swaps a row of tiles of length 'length' between positions 'first' and 'second'

void CopyTileRow(int source, int dest, int length)
 * Copies a row of tiles of length 'length' from 'source' onto 'dest'

void ClearTileRow(int ref, int length)
 * Clears a row of tiles of length 'length' starting from tile 'ref'

void SwapTileBlock(int first, int last, int second)
 * Swaps a block of tiles defined by diagonal corners 'first' and 'last'
 * with the block starting with top left tile 'second'

void CopyTileBlock(int sourcefirst, int sourcelast, int destfirst)
 * Copies a block of tiles defined by diagonal corners 'sourcefirst' and 'sourcelast'
 * onto the block starting with top left tile 'destfirst'

void ClearTileBlock(int reffirst, int reflast)
 * Clears a block of tiles defined by diagonal corners 'reffirst' and 'reflast'


-- Miscellaneous Functions --
=============================

void Waitframes(int n)
 * Wait for 'n' frames

void NoAction()
 * Kills all of Link's inputs, including those from the analogue stick.
 
void NoAction(bool analogue_stick)
* As NoAction() but the analoge stick is not killed by default. 

void WaitNoAction()
void WaitNoAction(int frames)
 * NoAction, then Waitframe or (equivalent of) Waitframes

void ScreenCopy(int destmap, int destscr, int srcmap, int srcscr)
 * Copies the combos and csets from one screen to another.
 * Only copies layer 0!

int FFCNum(ffc f)
 * Returns the number of an FFC, and -1 for a non-valid FFC (which should never happen)

int NumTriforcePieces()
 * Returns the number of Triforce Pieces Link currently has in his inventory.
 
int NumTriforcePieces(int maxlevel);
 * Returns the number of Triforce Pieces Link currently has in his inventory.
 * Specify the highest level in your game with arg 'maxlevel'.

void GetNPCName(int ID, int string[])
 * Puts the name of an npc into a string

void GetMessage(int ID, int string[])
 * Puts string 'ID' into 'string', removing the trailing spaces.

itemdata GetItemData(item i)
 * Returns an itemdata pointer from an item pointer

int GetHighestLevelItem(int itemclass)
int GetHighestLevelItem(item i)
 * Returns the highest level item of a given itemclass, or of the class 'i' belongs to

void CounterAdd(int counter, int amount);
 * Add to a counter without rollover.

void CounterReduce(int counter, int amount);
 * Reduce a counter without rollvoer. 

void MCounterAdd(int counter, int amount);
 * Add to a counter max without rollover.

void MCounterReduce(int counter, int amount);
 * Reduce a counter max without rollvoer. 

void DCounterAdd(int counter, int amount);
 * Add to a drain counter without rollover.

void DCounterReduce(int counter, int amount);
 * Reduce a drain counter without rollover. 

int DMapToMap(int screen, int dmap)
int MapToDMap(int screen, int dmap)
 * Convert between map and DMap screen coordinates
 
int ScreenItem();
 * Returns the item ID for the current screen, if there is one. 

bool HasKey(int level);
 * Returns true if Link has keys that he can use in the specified level.
 
bool HasKey();
 * Returns true if Link has keys that he can use in the current level.
 
int NumKeys(int level);
 * Returns the total number of keys (normal, and level-specific) that Link
 * has, that work in the specified level.
 
int NumKeys();
 * Returns the total number of keys (normal, and level-specific) that Link
 * has, that work in the current level.

bool ConsumeKey(int level);
 * Uses a key for the current level. 
 * If Link has a level key for this level, it uses this first.
 * If Link does not have a level key for this level, it the tries to
 * use a normal key.
 * Returns true on success.
 * Returns false if Link has no valid keys to use.
 
bool ConsumeKey();
 * As ConsumeKey(int level), except that it is for only the
 * current level.


 ============================
 --  Bug Fixes ( 2.53.0 )  --
 ============================
 
SquareCollision now properly uses 'side2' arg for its calculation. (Bugfix)


 
 =============================
 -- New Includes ( 2.53.0 ) --
 =============================
 std.zh now includes some new files, that you will want to review. The outline, scope, and purpose of 
 the new expansions is outlined below.
 
/******************
* std.zh Settings *
*******************/

std.zh now includes a SETTINGS FILE ( std.cfg ) that has a few options
that you may enable, if you wish to change the behaviour of std.zh at compilation
for your quests. These settings are disbaled by default, and affect only a handful of
minimal mechanical differences as follows:

MAX_HIGHEST_LEVEL_ITEM_CHECK
 * The highest item ID to check, with GetHighestLevelItem. 
   The default value is now 255.

SETLAYERCOMBO_ALWAYS_USE_SETCOMBO
 * If enabled, SetLayerCombo* functions will always use Screen->Combo*[]
   for layer 0. Otherwise, they will use Game-> combo data. 
   
REVISED_ROTATEPOINT_X_FUNCTION
REVISED_ROTATEPOINT_Y_FUNCTION
 * If enabled. the new functions for RotatePoint*() will be used.
 * If disabled, the old 2.50.x functions will run, instead.

STD_FORCE_OLD_DISTANCE
 * If enabled, Distance2() will use Sqrt() instead of SafeSqrt().

STD_DISTANCE_USE_SAFESQRT
 * If enabled, Distance2() will use SafeSqrt(); otherwise, it will
 * use a hardcoded factor and return specific values on overflows/underflows.

STD_NEVER_USE_SAFESQRT
 * If enabled, SafeSqrt() calls run Sqrt() instead.

STD_EMULATE_ENGINE_COLLISION
 * Not implemented in this version of std.zh.
STD_CENTERXY_USES_HITBOXES
 * Not implemented in this version of std.zh.


/*********************/
*   STRING HANDLING   * 
/*********************/

string.zh is embedded by default. This will *not* interfere with EXISTING calls to: import "string.zh".
Furthermore, string.zh has been expanded, now consisting of string_constants.zh and string_functions.zh, with
new functions, and a complete map of ASCII values (as constants).

/*********************/
*    LOCALISATION    * 
/*********************/


std.zh now includes some basic local support. These files are in */locale/std_std_'language'.zh, 
and contain constants, and functions in other laguages. The base included locale file at this time
is 'UK/International English', with more to follow. 


/*************************/
*    GENERAL-USE ARRAY   * 
/*************************/

float std_zh___GlobalRAM[4096]
 * A base, general-purpose array with a size of 4096, and a float type. 
 
std.zh now includes ONE BASE ARRAY with a float type. This is to allow users who are not versed in ZScript 
from avoiding a pitfall of either running out of global vars, by allowing you easy use of one global array
and getter/setter functions to modify it.

Furthermore, it prevents being unable to modify a quest, after releasing it, by ensuring that there is a general
use array for expansion. The array is in std_vars.zh, and if you wish to, you may comment out this import directive
instruction in std.zh to prevent loading the general use array, and the functions associated with it.

The following functions are in the std_vars.zh file, for use with the general-use array:

float __stdzh_GetV(int index);
* Returns the value of the Nth 'index' of the general use array std_zh___GlobalRAM[];

void __stdzh_SetV(int index, int value);
* Sets the value of std_zh___GlobalRAM['index'] to 'value'.

void __stdzh_IncV(int index);
* Increases an index value: Equivalent to doing std_zh___GlobalRAM['index']++  

void __stdzh_IncV(int index, int value);
* Increases the value of std_zh___GlobalRAM['index'] by 'value'.

void __stdzh_DecV(int index);
* Decreases an index value: Equivalent to doing std_zh___GlobalRAM['index']--  

void __stdzh_DecV(int index, int value);
* Decreases the value of std_zh___GlobalRAM['index'] by 'value'.

void __stdzh_StoreArrayPointer(int ptr, int index);
 * Stores the pointer to an array 'ptr' min an index of std_zh___GlobalRAM.

float __stdzh_getVersion(); 
 * Returns the version of std.zh that was used during compilation. 
