pommyman
DIV Junior
Posts: 10
Registered: 19-1-2017
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Help! End Expected
Hi. I'm trying to do a simple shooter type game, but have come across a very basic stumbling block. After doing my first bits of code and then trying
to run it, I get an error "end expected". I thought all the begin/end pairs were correct. Can someone please check to see where I'm going wrong?
/*
* test1.PRG by Peter
* (c) 2017 Home
*/
PROGRAM test1;
BEGIN
load_fpg("test1.fpg");
spacecraft();
process spacecraft()
Begin
graph=1;
x=160;
y=100;
loop
if (key(_right))
x=x+1;
end
if (key(_left))
x-=1;
end
if (key(_down))
y+=1;
end
if(key(_up))
y-=1;
end
frame;
end
END
process shot(x,y)
begin
graph=3;
loop
y-=16;
frame;
end
end
END
Thanks,
Pommyman
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CicTec
DIV Pro
Posts: 471
Registered: 6-8-2016
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Hi pommyman,
You have missing END statement after "spacecraft();" to close the Begin of program:
| Code: |
PROGRAM test1;
BEGIN
load_fpg("test1.fpg");
spacecraft();
END
...
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Now should compile. 
[Edited on 21-1-2017 by CicTec]
[Edited on 21-1-2017 by CicTec]
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pommyman
DIV Junior
Posts: 10
Registered: 19-1-2017
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Hi.
Thanks, but I tried that and get an expecting process error when I do that.
Any more suggestions?
Cheers.
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CicTec
DIV Pro
Posts: 471
Registered: 6-8-2016
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Yes, you have also to delete the last END (process shot).
I suggest the use of indentation of the code, so it is easier to identify errors like this.
[Edited on 21-1-2017 by CicTec]
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pommyman
DIV Junior
Posts: 10
Registered: 19-1-2017
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You legend! That did it. Thanks for the quick replies.
On I go!
Cheers,
Pommyman
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MikeDX
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Just came to reply and see cictec has helped you out.
Looking forward to seeing what you make pommyman!
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pommyman
DIV Junior
Posts: 10
Registered: 19-1-2017
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It all worked, and I've now got a ship that moves across the screen, enemies that approach from above, and I can fire bullets that destroys the
enemies.
Next, to add scores, sound, collision if an enemy hits the ship and maybe an increasing difficulty as the game progresses.
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MikeDX
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You might want to add something that "kills" the bullets as thry go off screen
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pommyman
DIV Junior
Posts: 10
Registered: 19-1-2017
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Hi Mike. Yeah, I added a bit of code that kills the process once they get to the top. It works OK too.
I also added a collision from the enemy to the player, but it happens almost instantly.
Is there a way I can add a pause at the start to get the player ready?
Cheers,
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CicTec
DIV Pro
Posts: 471
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I'm happy to help.
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CicTec
DIV Pro
Posts: 471
Registered: 6-8-2016
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There are many ways to add a "pause", you could provide more details on what you mean by "pause", please?
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pommyman
DIV Junior
Posts: 10
Registered: 19-1-2017
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Something along the lines of "press a key to start", so that it give the player time to be ready before the enemy comes. Also a way to delay the enemy
spawning for a few seconds once that key has been pressed.
Just something to add a little more "player friendly" touch.
Cheers,
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CicTec
DIV Pro
Posts: 471
Registered: 6-8-2016
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Well, there are many forms, one could be inserted before the game loop (the process that controls the game) another loop waiting for you to press a
button, example:
| Code: |
// main loop
loop
// freezes all processes in the lot / level, this blocks the physical execution of the process code, but allows the rendering to screen.
signal(TYPE enemy, s_freeze_tree);
signal(TYPE player, s_freeze_tree);
text_id = write(......, "Press a key to start");
// waiting loop
while(scan_code == 0) frame; end
// delete "key message"
delete_text(text_id);
// awakens all game processes to start the game / level
signal(TYPE enemies, s_wakeup_tree);
signal(TYPE playe, s_wakeup_tree);
// level loop
while(level_done == false || player_lives > 0)
...
frame;
end
end
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the code "while(scan_code == 0) frame; end". just check the pressure of a button, when this happens scan_code (global variable, see its use with F1),
it contains the scan code of the last key pressed in the last frame:
the SIGNAL function sends a signal to a determined process, in this case "s_freeze_tree" indicates the function to freeze all processes of type "ENEMY
/ PLAYER" and each one of these processes in turn once freeze all those created (even of different types).
The "s_wakeup_tree" command performs the opposite operation, ie awaken or thaw processes.
The sentence FRAME is fundamental within the loop in order to finish properly and resume the execution of the current process and all others in the
run queue, without it you would cause a runtime error.
[Edited on 22-1-2017 by CicTec]
[Edited on 22-1-2017 by CicTec]
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