RPG Basics

Question 1

Adjusting Camera and Viewport

Answer 1

Within room properties:

• enable viewports
• set viewport[#] to visible
• set camera properties:
• • 288 x 216 is 4:3 ratio (ex. Undertale), 1920 x 1080 is 16:9 (modern; ex. Hollow Knight)
• set viewport properties:
• • multiply camera ratio by some whole number
• -input object for Object Following
• –set horizontal and vertical borders to half the camera ratio to have the camera stay centered on the followed object when it moves

Question 2

Setting Player Speed

Answer 2

(create event)

xspd = 0;
yspd = 0;

mv_spd = #;

Question 3

What is a create event

Answer 3

Used for initializing variables

Runs once when an object is loaded

Question 4

What is a step event

Answer 4

Runs every single frame of the game

Question 5

Binding Arrow Keys

Answer 5

(step event)

//set movement keys
right_key = keyboard_check(vk_right);
left_key = keyboard_check(vk_left);
up_key = keyboard_check(vk_up);
down_key = keyboard_check(vk_down);

Question 6

Binding WASD Keys

Answer 6

(step event)

//set movement keys
d_key = keyboard_check(ord("D"));
w_key = keyboard_check(ord("W"));
a_key = keyboard_check(ord("A"));
s_key = keyboard_check(ord("S"));

Question 7

Get X & Y Speed

Answer 7

(step event)

//get xspd and yspd
xspd = (right_key - left_key) * mv_spd;
yspd = (down_key - up_key) * mv_spd;

OR

//get xspd and yspd
xspd = (a_key - d_key) * mv_spd;
yspd = (s_key - w_key) * mv_spd;

Question 8

Moving the Player

Answer 8

(step event)

BELOW COLLISIONS

//move the player
x += xspd;
y += yspd;

Question 9

Setting Collisions

Answer 9

(step event)

BELOW SETTING SPRITE

//collisions
if place_meeting( x + xspd, y, obj_wall ) == true
	{
	xspd = 0;
	}
if place_meeting( x, y + yspd, obj_wall ) == true
	{
	yspd = 0;
	}

Question 10

Setting Sprite

Answer 10

(step event)

ABOVE COLLISIONS (else xspd & yspd gets set to 0 and it interferes with changing directional faces properly)

//set sprite
mask_index = sprite[DOWN];

if yspd == 0
	{
	if xspd > 0 {face = RIGHT};
	if xspd < 0 {face = LEFT};
	}
if xspd > 0 && face == LEFT {face = RIGHT};
if xspd < 0 && face == RIGHT {face = LEFT};
if xspd == 0
	{
	if yspd > 0 {face = DOWN};
	if yspd < 0 {face = UP};
	}
if yspd > 0 && face == UP {face = DOWN};
if yspd < 0 && face == DOWN {face = UP};

sprite_index = sprite[face];

• Lines such as “if xspd > 0 && face == LEFT {face = RIGHT};” fix the issue of sprite faces not adjusting properly if the object goes from not moving to moving at a diagonal
• “mask_index = sprite[DOWN];” sets all sprite collision masks to the same as the indicated sprite

Question 11

Setting Animations

Answer 11

(step event)

BELOW COLLISIONS

//animate
if xspd == 0 && yspd == 0
	{
	image_index = 0;
	}

(SET ALL FACE SPRITES TO THE SAME ORIGIN POINT)

Makes an unmoving object stay at indicated image index frame instead of animating

Question 12

Setting up Macros (constants)

Answer 12

(script)

#macro RIGHT 0
#macro UP 1
#macro LEFT 2
#macro DOWN 3

Question 13

Assigning Directional Sprites

Answer 13

(create event)

REQUIRES MACRO (else use 0-3)

sprite[RIGHT] = spr_player_right;
sprite[UP] = spr_player_up;
sprite[LEFT] = spr_player_left;
sprite[DOWN] = spr_player_down;

face = DOWN;

Question 14

Wall Layer

Answer 14

• Place obj_wall in a separate layer from Instances
• When finished placing walls, turn layer visibility off
• Adjust obj_wall opacity to not visually obscure parts of rooms

Question 15

Parent and Child Objects (& Expanding Collision)

Answer 15

• When setting a parent object for any object, this means anytime the game references/checks the parent object, the game will also reference/check any object that is a child of it
• Making obj_wall a parent object will then reference the collision coding, allowing collision with child objects without writing them all into the code

Question 16

Depth Sorting

Answer 16

(step event for PLAYER)
(create event for OTHER OBJECTS)

//depth
depth=-bbox_bottom;

bbox is the collision box. this makes the bottom of the collision box a negative number. THE LOWER THE NUMBER, THE HIGHER THE OBJECT DEPTH PRIORITY
Ex. an object at -10 will have their sprite show up on top of an object at -5

Question 17

Objects with the Same Collision Masks (Reducing Clutter)

Answer 17

• If you know multiple objects will have the same collision mask, you can make multiple sprites in the frames of a single sprite and set the fps to 0
• you can then place the object and change the frame to achieve the sprite you want

Question 18

Room Order

Answer 18

Room at the top of the list is where the game will start

Question 19

obj_warp_block (general)

Answer 19

(create event)

target_x = 0;
target_y = 0;
target_rm = 0;
target_face = 0;

(step event)

//warp blocks
if place_meeting( x, y, obj_player) && !instance_exists(obj_warp)
	{
	var inst = instance_create_depth( 0, 0, 
        -9999, obj_warp );
	inst.target_x = target_x;
	inst.target_y = target_y;
	inst.target_rm = target_rm;
	inst.target_face = target_face;
	}

Ensure the warp block object is actually touchable by the player when placing it

“var inst” is a local variable (a variable only needed in the one event it’s put into; it won’t be referenced by code outside this event)

“&& !instance_exists(obj_warp)” is to ensure an obj_warp is not created every frame the player is touching the warp block [ “!” means “not” ]. it will only run the code if the warp object does not currently exist.

Question 20

obj_warp_block (placed)

Answer 20

Set obj_player to “persistent” by checking box in object options

After placing obj_warp_block, click on it and select “Creation Code”

Add and change the 0s in the following code to desired coordinates, room, and face after warping:

target_x = 0;
target_y = 0;
target_rm = 0;
target_face = 0;

remember to uncheck “visible” when done editing the warp block

Question 21

Creation Code

Answer 21

Adds code to every individual instance of the selected object and will run immediately after the create event

Question 22

Warping Between Rooms (obj_warp)

Answer 22

Create obj_warp using your room transition animation as the sprite and set it as “persistent”

(create event)

target_x = 0;
target_y = 0;
target_rm = 0;

(step_event)

if room == target_rm && image_index < 1
{
instance_destroy();
}

(draw event)

var _camx = camera_get_view_x(view_camera[0]);
var _camy = camera_get_view_y(view_camera[0]);

draw_sprite_tiled(sprite_index, image_index, _camx, _camy);

(animation end event)

room_goto(target_rm);
obj_player.x = target_x;
obj_player.y = target_y;
obj_player.face = target_face;

image_speed = -1;

setting image_speed to -1 will make the animation play in reverse once the animation has ended

draw_sprite_tiled (rather than draw_sprite) will tile the sprite across the entire room

don’t use if image_index = 0 in the step event because the image index usually has a decimal point to ensure the animation is running at the correct speed

Question 23

obj_pauser (pausing the player during room transitions)

Answer 23

in obj_player

(step event)
(between “//get xspd and yspd” and “//set sprite”)

//pause
if instance_exists(obj_pauser)
	{
	xspd = 0;
	yspd = 0;
	}

make obj_pauser the parent object of obj_warp

forces the player’s speed to 0 while obj_pauser exists

Question 24

Parallax Backgrounds

Answer 24

Visually disable the “Background” layer

Make a background that is the same size as the camera

Make obj_parallax_background

(create event)

depth = 10000;

(draw event)

var _camx = camera_get_view_x(view_camera[0]);
var _camy = camera_get_view_y(view_camera[0]);

var _p = 1;

draw_sprite_tiled(bg_name, 0, _camx_p, _camy_p);

IF YOU WANT A SUB-IMAGE: draw_sprite_tiled(bg_name, 1, _camx.25, _camy.25);

the lower the number value of var _p, the closer the background will appear

.25 is an example number for the sub image code, it just needs to be >_p

the second variable in draw_sprite_tiled is the sprite frame

Question 25

Parallax Tips & Tricks

Answer 25

-Make parts of the background in seperate layers so you can visually enable/disable parts of it as needed per room
–in the draw event code, give each layer it’s own code line and assign each layer it’s own parallax value
(var _p0 =, var _p1 =, etc.)

-To help alleviate tiling issues when the start and end y-axis pixels don’t allign:

• > cut (ctrl+x) left half of the background
• > perfectly move the right half over to the left side
• > paste and place the cut left half on the right side
• you can now see in the center of the background if there would be any visual tiling issues*
• > do your best to smoothly connect the halves at the center
• you can also do this for the top and bottom halves if vertical tiling is the issue*

Question 26

Begin Step & End Step

Answer 26

Begin Step will occur before any other object’s step events

End Step will occur after every other object’s step events