How do I change the hitbox of one of my sprites?

Question

So when the game starts there will be boxes for the user to dodge, but currently, the hitbox of the objects is a bit off.. for example when you move the ship across a box it registers as a hit, ending in a game over.

This is for a Software Design and Development HSC Assessment task I'm not quite sure what to do to fix this problem

Here's the code!

#This program was created by Tadiwa Mooyo
#more of the car game has been worked on, now there are boxes for the user to "dodge" and it will display the crash message when the boxes are hit
#This program was started on the 22/02/2019
import pygame
import time
import random

pygame.init()

display_width = 1200
display_height = 700
black = (0,0,0)
white = (255,255,255)
red = (255,0,0)

car_width = 100

gameDisplay = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption('The Great Space Escape!')
clock = pygame.time.Clock()
carImg = pygame.image.load('Ships_directory\\Green_black_ship.png')

def things_dodged(count):
    font = pygame.font.SysFont(None, 25)
    text = font.render("Score: "+str(count), True, white)
    gameDisplay.blit(text,(0,0))


def things(thingx, thingy, thingw, thingh, color):
    pygame.draw.rect(gameDisplay, color, [thingx, thingy, thingw, thingh])

def car(x,y):
    gameDisplay.blit(carImg,(x,y))

def text_objects(text, font):
    textSurface = font.render(text, True, white)
    return textSurface, textSurface.get_rect()

def message_display(text):
    largeText = pygame.font.Font('freesansbold.ttf',115)
    TextSurf, TextRect = text_objects(text, largeText)
    TextRect.center = ((display_width/2),(display_height/2))
    gameDisplay.blit(TextSurf, TextRect)

    pygame.display.update()

    time.sleep(2)

    game_loop()



def crash():
    message_display("You Crashed")

def game_intro():

    intro = True

    while intro:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()

        gameDisplay.fill(black)
        largeText = pygame.font.Font('freesansbold.ttf',115)
        TextSurf, TextRect = text_objects("A bit Racey", largeText)
        TextRect.center = ((display_width/2),(display_height/2))
        gameDisplay.blit(TextSurf, TextRect)
        pygame.display.update()
        clock.tick(15)




def game_loop():
    x = (display_width * 0.45)
    y = (display_height * 0.5)

    x_change = 0

    thing_startx = random.randrange(0, display_width)
    thing_starty = -600
    thing_speed = 4
    thing_width = 200
    thing_height = 200

    dodged = 0

    gameExit = False

    while not gameExit:

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()

            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_LEFT:
                    x_change = -10
                if event.key ==pygame.K_RIGHT:
                    x_change = 10

            if event.type == pygame.KEYUP:
                if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT:
                    x_change = 0

        x += x_change

        gameDisplay.fill(black)


        #things(thingx, thingy, thingw, thingh, color)
        things(thing_startx, thing_starty, thing_width, thing_height, white)
        thing_starty += thing_speed
        car(x,y)
        things_dodged(dodged)

        if x > display_width - car_width or x < 0:
            crash()

        if thing_starty > display_height:
            thing_starty = 0 - thing_height
            thing_startx = random.randrange(0,display_width)
            dodged += 1
            thing_speed += 0.5
            thing_width += (dodged * 1.4)        

        if y < thing_starty+thing_height:
            print('y crossover')

            if x > thing_startx and x < thing_startx + thing_width or x+car_width > thing_startx and x + car_width < thing_startx+thing_width:
                print('x crossover')
                crash()


        pygame.display.update()
        clock.tick(60)

game_loop()
pygame.quit()
quit()

Answer 1

Use pygame.Rect to simplify your code and implement the collision test by .colliderect() :

eg

things_rect = pygame.Rect(thing_startx, thing_starty, thing_width, thing_height)
car_rect    = pygame.Rect(x, y, *carImg.get_size())

if car_rect.colliderect(things_rect):
    crash()

---

If you want to implement your "own" test, which checks if 2 rectangles are intersecting, the you've to check if the rectangles are "overlapping" in both dimensions.

2 ranges [ x1 , x1+w1 ] and [ x2 , x2+w2 ] are overlapping if x1 < x2+w2 and x2 < x1+w1 .

So a intersection test for rectangles can be implmented as follows:

car_w, car_h = carImg.get_size()
if (thing_startx < x+car_w and x < thing_startx+thing_width and 
    thing_starty < y+car_h and y < thing_starty+thing_height):
    crash()