last thing to ask today, i promise...

[codevsb12]

what do i need to do so that my character stops moving when it hits the corner of the screen?
i already set up some variables such as x speed, y speed, x max, y max, etc.

[FellippeHeitor]

Show the code you already have first, so people can help debug it.

[codevsb12]

Code: QB64: [Select]

1. DEFINT A-Z
2. SCREEN 12
3.  
4.  
5. DATA 00,00,00,00,00,00,00,00,14,14,14,14,14,00,00,00,00,00,00,00,00
6. DATA 00,00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,00,00,00
7. DATA 00,00,00,00,00,00,14,14,14,14,00,14,14,14,14,00,00,00,00,00,00
8. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,00,00,00,00
9. DATA 00,00,00,00,00,00,14,14,14,14,14,14,00,00,00,00,00,00,14,14,00
10. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,14,14,14,14
11. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,14,14,00,00,14,14,14,14
12. DATA 00,00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,14,14,00
13. DATA 00,00,00,00,00,00,00,00,14,14,14,14,14,00,00,00,00,00,14,14,00
14. DATA 00,00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,14,14,00
15. DATA 00,00,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,00
16. DATA 00,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,00,00
17. DATA 00,14,14,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
18. DATA 00,14,14,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
19. DATA 00,14,14,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
20. DATA 14,14,14,14,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
21. DATA 14,14,14,14,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
22. DATA 00,14,14,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
23. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
24. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
25. DATA 00,00,00,00,00,14,14,14,14,14,00,14,14,14,14,14,00,00,00,00,00
26. DATA 00,00,00,00,00,14,14,14,14,00,00,00,14,14,14,14,00,00,00,00,00
27. DATA 00,00,00,00,14,14,14,14,14,00,00,00,14,14,14,14,00,00,00,00,00
28. DATA 00,00,00,00,14,14,14,14,00,00,00,00,00,14,14,14,14,00,00,00,00
29. DATA 00,00,00,14,14,14,14,14,00,00,00,00,00,14,14,14,14,00,00,00,00
30. DATA 00,00,00,14,14,14,14,00,00,00,00,00,00,14,14,14,14,00,14,14,00
31. DATA 00,00,14,14,14,14,14,00,00,00,00,00,00,14,14,14,14,14,14,14,00
32. DATA 00,00,00,14,14,14,14,14,14,00,00,00,00,14,14,14,14,14,14,14,00
33. DATA 00,00,00,00,14,14,14,14,14,00,00,00,14,14,14,14,14,14,00,00,00
34. DATA 00,00,00,00,00,14,14,14,00,00,00,00,00,14,14,00,00,00,00,00,00
35.  
36. FOR y = 1 TO 30
37.     FOR x = 0 TO 20
38.         READ sprite%: PSET (x, y), sprite%
39.     NEXT x
40. NEXT y
41.  
42. DIM player%(500)
43.  
44. GET (0, 1)-(20, 30), player%()
45.  
46. xp = 64
47. yp = 70
48. xb = 400
49. yb = 300
50. xmax = 639
51. ymax = 349
52. xspd = 0
53. yspd = 0
54.  
55. CLS
56.  
57.  
58. tecla:
59. PUT (xp, yp), player%()
60. WAIT &H3DA, 8
61. PUT (xp, yp), player%()
62. te$ = INKEY$
63. IF te$ = "d" THEN xp = xp + 2
64. IF te$ = "a" THEN xp = xp - 2
65. IF te$ = "w" THEN yp = yp - 2
66. IF te$ = "s" THEN yp = yp + 2
67. IF te$ = "q" THEN END
68. GOTO tecla:
69.  

[FellippeHeitor]

Use IF to limit xp and yp to the screen boundaries:

Code: QB64: [Select]

1. DEFINT A-Z
2. SCREEN 12
3.  
4.  
5. DATA 00,00,00,00,00,00,00,00,14,14,14,14,14,00,00,00,00,00,00,00,00
6. DATA 00,00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,00,00,00
7. DATA 00,00,00,00,00,00,14,14,14,14,00,14,14,14,14,00,00,00,00,00,00
8. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,00,00,00,00
9. DATA 00,00,00,00,00,00,14,14,14,14,14,14,00,00,00,00,00,00,14,14,00
10. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,14,14,14,14
11. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,14,14,00,00,14,14,14,14
12. DATA 00,00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,14,14,00
13. DATA 00,00,00,00,00,00,00,00,14,14,14,14,14,00,00,00,00,00,14,14,00
14. DATA 00,00,00,00,00,00,00,14,14,14,14,14,14,14,00,00,00,00,14,14,00
15. DATA 00,00,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,00
16. DATA 00,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,14,00,00
17. DATA 00,14,14,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
18. DATA 00,14,14,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
19. DATA 00,14,14,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
20. DATA 14,14,14,14,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
21. DATA 14,14,14,14,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
22. DATA 00,14,14,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
23. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
24. DATA 00,00,00,00,00,00,14,14,14,14,14,14,14,14,14,00,00,00,00,00,00
25. DATA 00,00,00,00,00,14,14,14,14,14,00,14,14,14,14,14,00,00,00,00,00
26. DATA 00,00,00,00,00,14,14,14,14,00,00,00,14,14,14,14,00,00,00,00,00
27. DATA 00,00,00,00,14,14,14,14,14,00,00,00,14,14,14,14,00,00,00,00,00
28. DATA 00,00,00,00,14,14,14,14,00,00,00,00,00,14,14,14,14,00,00,00,00
29. DATA 00,00,00,14,14,14,14,14,00,00,00,00,00,14,14,14,14,00,00,00,00
30. DATA 00,00,00,14,14,14,14,00,00,00,00,00,00,14,14,14,14,00,14,14,00
31. DATA 00,00,14,14,14,14,14,00,00,00,00,00,00,14,14,14,14,14,14,14,00
32. DATA 00,00,00,14,14,14,14,14,14,00,00,00,00,14,14,14,14,14,14,14,00
33. DATA 00,00,00,00,14,14,14,14,14,00,00,00,14,14,14,14,14,14,00,00,00
34. DATA 00,00,00,00,00,14,14,14,00,00,00,00,00,14,14,00,00,00,00,00,00
35.  
36. FOR y = 1 TO 30
37.     FOR x = 0 TO 20
38.         READ sprite%: PSET (x, y), sprite%
39.     NEXT x
40. NEXT y
41.  
42. DIM player%(500)
43.  
44. GET (0, 1)-(20, 30), player%()
45.  
46. xp = 64
47. yp = 70
48. xb = 400
49. yb = 300
50. xmax = 639
51. ymax = 349
52. xspd = 0
53. yspd = 0
54.  
55. CLS
56.  
57.  
58. DO
59.     CLS
60.     IF xp > _WIDTH - 20 THEN xp = _WIDTH - 20
61.     IF xp < 0 THEN xp = 0
62.     IF yp > _HEIGHT - 30 THEN yp = _HEIGHT - 30
63.     IF yp < 0 THEN yp = 0
64.     PUT (xp, yp), player%(), _CLIP
65.     _DISPLAY
66.     te$ = INKEY$
67.     IF te$ = "d" THEN xp = xp + 2
68.     IF te$ = "a" THEN xp = xp - 2
69.     IF te$ = "w" THEN yp = yp - 2
70.     IF te$ = "s" THEN yp = yp + 2
71.     IF te$ = "q" THEN END
72. LOOP
73.  
74.  

_DISPLAY is used here to stop the flickering, and instead of a GOTO, I added a DO/LOOP block.

PS: When you post code in the forum, make sure to add [code=qb64] before and [/code] after your code block.

[codevsb12]

just wanna check if it runs on dos box or something before i put it in my code

edit: it doesnt

c'mon, i know someone has the solution...

edit2: i tried it by myself, and now my character dies when going straight to the right

i dont even need to put the entire code, so...

Code: QB64: [Select]

1. xp = 64
2. yp = 70
3. xb = 400
4. yb = 300
5. xmax = 639
6. ymax = 349
7.  
8. CLS
9.  
10.  
11. tecla:
12. PUT (xp, yp), player%()
13. PUT (xp, yp), player%()
14. IF xp <= 1 THEN xp = 1
15. IF xp > 639 THEN xp = xmax
16. IF yp <= 1 THEN yp = 1
17. IF yp >= ymax THEN yp = ymax
18. te$ = INKEY$
19. IF te$ = "d" THEN xp = xp + 2
20. IF te$ = "a" THEN xp = xp - 2
21. IF te$ = "w" THEN yp = yp - 2
22. IF te$ = "s" THEN yp = yp + 2
23. IF te$ = "q" THEN END
24. GOTO tecla:
25.  

[FellippeHeitor]

c'mon, i know someone has the solution...

Love your attitude.

When is your homework due?

[Richard Frost]

The bounds checking should be immediately after you change the variables.
The way you've got it, if that code is in a loop, you'll get PUTs with invalid
parameters.  It probably won't crash QB64, but why take a chance?

[STxAxTIC]

just wanna check if it runs on dos box or something before i put it in my code

Are you using QB64 or some other QB? Dosbox shouldn't matter if you're using QB64, amirite?