Why is this happening?

[Prithak]

Here is a code:

Code: QB64: [Select]

1. _TITLE "A Promising Game!"
2. SCREEN _NEWIMAGE(800, 600, 32)
3. COLOR , _RGB32(211, 211, 211)
4. CLS
5. DIM SHARED x AS INTEGER
6. DIM SHARED y AS INTEGER
7. DIM SHARED gravity AS SINGLE
8. DIM SHARED y_change AS SINGLE
9. restart:
10. x = 200
11. y = 200
12. gravity = 9.8
13. CLS
14. DO
15.     CLS
16.     makechar
17.     k$ = UCASE$(INKEY$)
18.     IF _KEYDOWN(18432) AND NOT y_change > 50 THEN
19.         y = y - 25
20.         y_change = y_change + 1
21.         y = y + gravity
22.     ELSEIF _KEYDOWN(20480) AND NOT y_change > 50 THEN
23.         y = y + 25
24.         y_change = y_change + 1
25.         y = y + gravity
26.     ELSEIF _KEYDOWN(19200) THEN
27.         x = x - 10
28.     ELSEIF _KEYDOWN(19712) THEN
29.         x = x + 10
30.     END IF
31.     y = y + gravity
32.     'Blocks
33.     'LINE (100, 400)-STEP(200, 50), _RGB32(255, 83, 33), BF
34.     'IF collision%(x, y, 20, 20, 100, 400, 200, 50) THEN
35.     '    y = oldy
36.     '    y_change = 0
37.     '    gravity = 0
38.     'ELSE
39.     '    gravity = 9.8
40.     '    oldy = y
41.     'END IF
42.     makeobs 100, 400
43.     LINE (500, 400)-STEP(200, 50), _RGB32(127, 255, 127), BF
44.     IF collision%(x, y, 20, 20, 500, 400, 200, 50) THEN
45.         CLS
46.         _PRINTSTRING (300, 300), "LEVEL 1 COMPLETE!"
47.         END
48.     END IF
49.     IF y > 700 THEN GOTO restart
50.  
51.     _DISPLAY
52.     _LIMIT 60
53. LOOP
54.  
55. SUB makechar
56.     CIRCLE (x, y), 20, _RGB32(100, 150, 255)
57.     PAINT (x, y), _RGB32(100, 150, 255), _RGB32(100, 150, 255)
58. END SUB
59.  
60. FUNCTION collision% (b1x, b1y, b1w, b1h, b2x, b2y, b2w, b2h)
61.     IF (b1y + b1h < b2y) OR (b1y > b2y + b2h) OR (b1x > b2x + b2w) OR (b1x + b1w < b2x) THEN
62.         collision% = 0
63.     ELSE
64.         collision% = 1
65.     END IF
66. END FUNCTION
67.  
68. SUB makeobs (bx, by)
69.     LINE (bx, by)-STEP(200, 50), _RGB32(255, 150, 100), BF
70.     IF collision%(x, y, 20, 20, bx, by, 200, 50) THEN
71.         y = oldy
72.         gravity = 0
73.         y_change = 0
74.     ELSE
75.         oldy = y
76.         gravity = 9.8
77.     END IF
78. END SUB
79.  

What is the bug that brings the player to it's initial position?

[Prithak]

Here is a code:

Code: QB64: [Select]

1. _TITLE "A Promising Game!"
2. SCREEN _NEWIMAGE(800, 600, 32)
3. COLOR , _RGB32(211, 211, 211)
4. CLS
5. DIM SHARED x AS INTEGER
6. DIM SHARED y AS INTEGER
7. DIM SHARED gravity AS SINGLE
8. DIM SHARED y_change AS SINGLE
9. restart:
10. x = 200
11. y = 200
12. gravity = 9.8
13. CLS
14. DO
15.     CLS
16.     makechar
17.     k$ = UCASE$(INKEY$)
18.     IF _KEYDOWN(18432) AND NOT y_change > 50 THEN
19.         y = y - 25
20.         y_change = y_change + 1
21.         y = y + gravity
22.     ELSEIF _KEYDOWN(20480) AND NOT y_change > 50 THEN
23.         y = y + 25
24.         y_change = y_change + 1
25.         y = y + gravity
26.     ELSEIF _KEYDOWN(19200) THEN
27.         x = x - 10
28.     ELSEIF _KEYDOWN(19712) THEN
29.         x = x + 10
30.     END IF
31.     y = y + gravity
32.     'Blocks
33.     'LINE (100, 400)-STEP(200, 50), _RGB32(255, 83, 33), BF
34.     'IF collision%(x, y, 20, 20, 100, 400, 200, 50) THEN
35.     '    y = oldy
36.     '    y_change = 0
37.     '    gravity = 0
38.     'ELSE
39.     '    gravity = 9.8
40.     '    oldy = y
41.     'END IF
42.     makeobs 100, 400
43.     LINE (500, 400)-STEP(200, 50), _RGB32(127, 255, 127), BF
44.     IF collision%(x, y, 20, 20, 500, 400, 200, 50) THEN
45.         CLS
46.         _PRINTSTRING (300, 300), "LEVEL 1 COMPLETE!"
47.         END
48.     END IF
49.     IF y > 700 THEN GOTO restart
50.  
51.     _DISPLAY
52.     _LIMIT 60
53. LOOP
54.  
55. SUB makechar
56.     CIRCLE (x, y), 20, _RGB32(100, 150, 255)
57.     PAINT (x, y), _RGB32(100, 150, 255), _RGB32(100, 150, 255)
58. END SUB
59.  
60. FUNCTION collision% (b1x, b1y, b1w, b1h, b2x, b2y, b2w, b2h)
61.     IF (b1y + b1h < b2y) OR (b1y > b2y + b2h) OR (b1x > b2x + b2w) OR (b1x + b1w < b2x) THEN
62.         collision% = 0
63.     ELSE
64.         collision% = 1
65.     END IF
66. END FUNCTION
67.  
68. SUB makeobs (bx, by)
69.     LINE (bx, by)-STEP(200, 50), _RGB32(255, 150, 100), BF
70.     IF collision%(x, y, 20, 20, bx, by, 200, 50) THEN
71.         y = oldy
72.         gravity = 0
73.         y_change = 0
74.     ELSE
75.         oldy = y
76.         gravity = 9.8
77.     END IF
78. END SUB
79.  

What is the bug that brings the player to it's initial position?

Nevermind, Just realizedthat the value of oldy wasn't global xD

[Prithak]

Alright, another question!

When I press the upper arrow key and the left arrow key at the same time, only the upper arrow key works but not the left arrow key. What is causing it and How do I solve it? HELP!

-Prithak

[SMcNeill]

Alright, another question!

When I press the upper arrow key and the left arrow key at the same time, only the upper arrow key works but not the left arrow key. What is causing it and How do I solve it? HELP!

-Prithak

It’s because the _KEYDOWN check is in an ELSEIF statement.  Make all those become independent IF checks instead.

[Prithak]

It’s because the _KEYDOWN check is in an ELSEIF statement.  Make all those become independent IF checks instead.

Thanks man, wouldh've never figured out that on my own!

[AmandaC]

Here is a code:

Code: QB64: [Select]

1. _TITLE "A Promising Game!"
2. SCREEN _NEWIMAGE(800, 600, 32)
3. COLOR , _RGB32(211, 211, 211)
4. CLS
5. DIM SHARED x AS INTEGER
6. DIM SHARED y AS INTEGER
7. DIM SHARED gravity AS SINGLE
8. DIM SHARED y_change AS SINGLE
9. restart:
10. x = 200
11. y = 200
12. gravity = 9.8
13. CLS
14. DO
15.     CLS
16.     makechar
17.     k$ = UCASE$(INKEY$)
18.     IF _KEYDOWN(18432) AND NOT y_change > 50 THEN
19.         y = y - 25
20.         y_change = y_change + 1
21.         y = y + gravity
22.     ELSEIF _KEYDOWN(20480) AND NOT y_change > 50 THEN
23.         y = y + 25
24.         y_change = y_change + 1
25.         y = y + gravity
26.     ELSEIF _KEYDOWN(19200) THEN
27.         x = x - 10
28.     ELSEIF _KEYDOWN(19712) THEN
29.         x = x + 10
30.     END IF
31.     y = y + gravity
32.     'Blocks
33.     'LINE (100, 400)-STEP(200, 50), _RGB32(255, 83, 33), BF
34.     'IF collision%(x, y, 20, 20, 100, 400, 200, 50) THEN
35.     '    y = oldy
36.     '    y_change = 0
37.     '    gravity = 0
38.     'ELSE
39.     '    gravity = 9.8
40.     '    oldy = y
41.     'END IF
42.     makeobs 100, 400
43.     LINE (500, 400)-STEP(200, 50), _RGB32(127, 255, 127), BF
44.     IF collision%(x, y, 20, 20, 500, 400, 200, 50) THEN
45.         CLS
46.         _PRINTSTRING (300, 300), "LEVEL 1 COMPLETE!"
47.         END
48.     END IF
49.     IF y > 700 THEN GOTO restart
50.  
51.     _DISPLAY
52.     _LIMIT 60
53. LOOP
54.  
55. SUB makechar
56.     CIRCLE (x, y), 20, _RGB32(100, 150, 255)
57.     PAINT (x, y), _RGB32(100, 150, 255), _RGB32(100, 150, 255)
58. END SUB
59.  
60. FUNCTION collision% (b1x, b1y, b1w, b1h, b2x, b2y, b2w, b2h)
61.     IF (b1y + b1h < b2y) OR (b1y > b2y + b2h) OR (b1x > b2x + b2w) OR (b1x + b1w < b2x) THEN
62.         collision% = 0
63.     ELSE
64.         collision% = 1
65.     END IF
66. END FUNCTION
67.  
68. SUB makeobs (bx, by)
69.     LINE (bx, by)-STEP(200, 50), _RGB32(255, 150, 100), BF
70.     IF collision%(x, y, 20, 20, bx, by, 200, 50) THEN
71.         y = oldy
72.         gravity = 0
73.         y_change = 0
74.     ELSE
75.         oldy = y
76.         gravity = 9.8
77.     END IF
78. END SUB
79.  

What is the bug that brings the player to it's initial position?

It’s because the _KEYDOWN check gimp freejobalert notepad++  is in an ELSEIF statement.  Make all those become independent IF checks instead.

Thanks Both of you for this. I was also facing the same and happened to find this has already been answered.

Regards,
Amanda