Pygame: Snap-to-grid/board in chess - python

Is there a way in pygame for sprites, when dragged, to snap to an invisible (or visible) grid? Kinda like drag 'n drop? If so, how? I've been trying to do some sprite overlap, but it's too tedious to make an if-statement for each of the grid-lines. So how can I make a snap-to-grid drag-n-drop sprite? This is for a chess program. I'll appreciate your help.

Make an array of corners of the chess board using for loops.
corners = []
for x in range(edgeRight, edgeLeft, interval):
for y in range(edgeTop, edgeBottom, interval):
corners.append((x,y))
Then, make an event listener. When the piece is being dragged around, insert this code into whatever while statement you have:
px, py = Piece.Rect.topleft //using tuples to assign multiple vars
for cx, cy in corners:
if math.hypot(cx-px, cy-py) < distToSnap:
Piece.setPos((cx,cy))
break
I have no idea what your actual code is, but this should give you an idea. Again, pygame has no snap-to-grid functionality.

So this can be done quite simply by using the round function in python.
sprite.rect.x = ((round(sprite.rect.x/gridSquareSize))*gridSquareSize)
sprite.rect.y = ((round(sprite.rect.y/gridSquareSize))*gridSquareSize)
This manipulates the round function, by rounding your sprite's coordinates to the nearest grid square.

Related

I need assistance regarding my function and game

def death_en():
death = pygame.Surface.blit(pygame.image.load('tombstone.png'))
if x + (WarriorSize_x * .8) == x_en:
screenDisplay.blit(death, (x_en, y_en))
I'm new to Python and over all programing. I have started learning about pygame and I'm trying to create a game. What I want this function to do is to put another image on top of the enemy that was killed, though nothing happens when I get close enough to it with the main character. I now I haven't assigned a y-axis, but want to make sure this works first. I could send the whole code if it's necessary.
Thanks in advance.
To check for collisions use the PyGame Rect Class. Keep a rectangle for your player, and a rectangle for each enemy, updating the position of the rect whenever the item it tracks changes position. Also, when an enemy or the player moves, use the function Rect.colliderect() to determine if the two items have intersected on-screen.
This might be something like:
tombstone_image = pygame.image.load('tombstone.png')
...
# Inside main loop
# Have there been any collisions?
for e_rect in all_enemy_rects:
if ( e_rect.colliderect( player_rect ) ):
screenDisplay.blit( tombstone_image, e_rect )
# TODO: remove enemy from game

How do I change the Hitbox size of a turtle in python turtle graphics?

I dont know how to change the size of a turtle hitbox in python turtle graphics
I haven't tried anything yet because I'm new, and know very little about this. I've tried googling it, though, but nothing popped up.
from turtle import *
import turtle
from random import randint
import time
screen = turtle.Screen()
screen.setup(1920, 1080)
player = turtle.Turtle()
I want to add a button that you have to click to start right here
The game starts right here :
wn = turtle.Screen()
last_pressed = 'up'
def setup(col, x, y, w, s, shape):
player.penup()
player.up()
player.goto(x,y)
player.width(w)
player.turtlesize(s)
player.color(col)
player.lt(90)
player.down()
wn.onkey(up, "s")
wn.onkey(left, "d")
wn.onkey(right, "a")
wn.onkey(back, "w")
wn.onkey(quitTurtles, "Escape")
wn.listen()
wn.mainloop()
This may not be exactly what you are looking for, but this might work in your situation.
Detecting collision in Python turtle game
This is a thread on collision detection between objects and with some tweaking of numbers you could increase the hitbox of the turtle using the abs() function
I dont know how to change the size of a turtle hitbox in python turtle graphics
What do you mean by "hitbox"? I'm not sure what you mean by that (and neither does Google, apparently).
Do you mean that you want a rectangular button to click on? If that's the case, you could use the tkinter module together with the turtle module to create a button to click. (But be aware that it's not always easy to get the tkinter and turtle modules to work together to do what you want.)
If you want a button to click on, but don't need a Tkinter button, you could just try creating a new turtle in the shape of a rectangle that intercepts mouse clicks with onclick(). You can see an example of this if you run:
python3 -m turtledemo
and select Examples >> colormixer from the main menubar.
Or, if by "hitbox" you mean how to detect when one turtle has intercepted another turtle (as in, one has come close enough to the other to be considered a "hit"), I suggest querying each turtle's location, then using the Pythagorean Theorem to calculate the distance from each other. If this distance is within a predetermined threshold, consider the hitbox as being "hit."
You can see an example of this by typing:
python3 -m turtle
(Pay attention to the yellow turtle as he tries to catch up to the other turtle.)
I apologize if this answer isn't quite what you're looking for, but I'm just not sure what you mean by "hitbox." Maybe you could clarify?
I just saw this question today (2 years too late i know), and was having a similar problem / question.
What I ended up doing was running 3 distance checks (as i had increased my object size by 3) which differed along the x-axis (width). So it would check the distance between the ball(turtle) and the paddle (any 3 points and if it was shorter than X it would trigger the collision mechanic.
so it was something like :
check the ball class' ball object, and see how far away it is from the paddle,
and if its either in the center, or 30 pixels to the left or right of the center then hit.
if
ball.ball.distance(pad.paddle(), pad.paddle.ycor()) < 30 or
ball.ball.distance(pad.paddle.xcor() - 30, pad.paddle.ycor()) < 30 or
ball.ball.distance(pad.paddle.xcor() + 30, pad.paddle.ycor()) < 30

How do I make a rectangular sprite stop when it collides with another rectangular sprite using pygame?

I'm trying to create some obstacles for the player in my program. I can't figure out how to make the sprite stop when it comes in contact with it from all sides.
I tried to use pygame.sprite.collide_rect and pygame.sprite.spritecollide, but couldn't figure out how to do it.
If you could just try to explain the concept, I'd rather try to figure the rest out myself. Thanks in advance!
def move_rect():
new_pos = player_rect.pos
new_pos = new_pos[0]+dx,new_pos[1]+dy
new_rect = rect(new_pos,player_rect.size)
for enemy in enemy_rects:
if new_rect.colliderect(enemy):
dx,dy=dx*-1,dy*-1 #reverse direction to "bounce"
#alternatively you could just return here probably
player_rect.move(dx,dy) #do the move, no collisions
something like that at least ... (I doubt it will work, its more to give you the concept)

python pygame physics rectange - circle collision

Again this question is on PyParticles4.
Link to last question for reference
Comment if unclear...
I am working on a Shooter game, much like this, but on a flat land with a wall that varies it's height on every turn(something for fun in the game) and with 2 players,each with a cannon that can move some distance (there's a limit, and they can't move beyond a certain amount from their start position) on each turn(the player decides if he wishes to move).
My code so far(for the Bullet and Shooter)
class Bullet(PyParticles.Particle):
def hit(self,shooterlist):
for shoot in shooterlist:
#confusion
dist = math.hypot(dx,dy)
# other funcs to added
class Shooter:
def __init__(self,pos,size):
self.rect = pygame.Rect(pos,size)
# other funcs to added
My Problems
Collision of the bullet with the Shooter. Any Ideas on how to know when the bullet collides with the rect?
I have been advised by someone to look at all the points on the edge of the rect, and see if it is within the circle but it seems to be very slow.
I think something faster would be better..
..
..
Update:
The circle can have a rect around it, which if collides with the rect, I now know when the rect is close to the circle, maybe even touching it.. How do i move forward??(Thx to PygameNerd)
I am not sure what you mean by your question, but I thingk that you need the colliderect function.
rect.colliderect(rect): Return bool
Put this in the code somewhere, and if it returns true, have the ball explode.
You can run another test every time colliderect returns true. There are a few options for what that test can be. One is similar to the advice you already received but with the wall and circle switched. Check the points on the circumference of the circle to see if one of them collides with the wall using Rect.collidepoint. In pygame, you can get a list of circumference points by creating a Mask from the circle surface and running Mask.outline. You probably won't need every point, so you could get just every Nth point. In fact, you may only need the midpoints of the edges of the circle's rect, which you can get from the Rect object itself.
You're asking for precise collision, and that would give you pixel perfect collision detection between a circle and a rectangle. You may not need it in your game, though, so I suggest trying with just colliderect first. If you're interested in collision detection in pygame in general, there are a lot of options that are directly implemented in or based on functions described in the Mask and Sprite documentation.
You can use Rect.collidepoint with the center of the circle but make rect bigger
collide_rect = Rect(x - p.radius,y - p.radius,w + 2 * p.radius,h + 2 * p.radius)
if collide_rect.collide_point(p.pos):
# Collision Resolution

How do I use gluLookAt properly?

I don't want to get into complex trigonometry to calculate rotations and things like that for my 3D world so gluLookAt seems like a nice alternative. According to the documentation all I need to do is place 3 coordinates for the cameras position, three for what I should be looking at and an "up" position. The last made no sense until I assumed it had to be at right angles with the line of sight in the direction the top of the screen should be.
It doesn't work like that at all. I have some python code. This is the code which initialises some data and some mode code for when I enter this part of the game:
def init(self):
self.game_over = False
self.z = -30
self.x = 0
def transfer(self):
#Make OpenGL use 3D
game.engage_3d(45,0.1,100)
gluLookAt(0,0,-30,0,0,0,0,1,0)
"game.engage_3d(45,0.1,100)" basically sets up the projection matrix to have a 45 degree angle of view and near and far coordinates of 0.1 and 100.
The first gluLookAt puts the camera in the correct position, nicely.
I have a cube drawn with the centre of (0,0,0) and it works fine without gluLookAt. Before I draw it I have this code:
gluLookAt(self.x,0,self.z,0,0,0,0,1,0)
if game.key(KEY_UP):
self.z += 2.0/game.get_fps()
if game.key(KEY_DOWN):
self.z -= 2.0/game.get_fps()
if game.key(KEY_LEFT):
self.x += 2.0/game.get_fps()
if game.key(KEY_RIGHT):
self.x -= 2.0/game.get_fps()
Now from that, the up position should always be the same as it's always at right angles. What I'd have thought it would do is move forward and back the z-axis with the up and down keys and left and right through the x-axis with the left and right keys. What actually happens, is when I use the left and right keys, the cube will rotate around the "eye" being accelerated by the keys. The up key causes another cube from nowhere to slice through the screen and hit the first cube. THe down key brings the mysterious cloned cube back. This can be combined with the rotation to give a completely different outcome as the documentation said would arise.
What on earth is wrong?
Thank you.
(The intuition behind the "up" vector in gluLookAt is simple: Look at anything. Now tilt your head 90 degrees. Where you are hasn't changed, the direction you're looking at hasn't changed, but the image in your retina clearly has. What's the difference? Where the top of your head is pointing to. That's the up vector.)
But to answer your question: gluLookAt calls should not be concatenated. In other words, the only pattern in which it's OK to use gluLookAt if you don't know exactly how it works is the following:
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(...);
# do not touch the modelview matrix anymore!
It seems from your code that you're doing something like this:
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(...);
# some stuff..
gluLookAt(...);
This will generate weird results, because gluLookAt multiplies the current matrix by the viewing matrix it computes. If you want to concatenate transformations you're really better off figuring out how to make glTranslate, glScale and glRotatef work for you. Even better, you should learn how the coordinate transformations work and stick to glMultMatrix.

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