C++ and Headers/includes.
Author
I'm having trouble understanding this, I have a header global.h which has all my global variables and constants, I want these to be available to some of my classes and functions (stored in their own cpp) but if I include the header in the .cpp containing said functions or constants my compiler says I've declared the variables/constants from the header file have been defined as many times as I've included them, even with #ifndef. [/run on]
I'm sure I'm just doing something wrong here, any tips would be great.
Author
Quote:Original post by Oluseyi
Read Organizing Code Files in C and C++
Thank you but even reading that didn't help me. I'm already using #ifndef HEADER_H_, #DEFINE HEADER_H_ ..code.. #endif
EDIT: I'm using Dev-C++ if that matters at all.
Hmm, I'm not sure if you read that entire article thoroughly. Here's a tested example(code::blocks with mingw)
globals.h
globals.cpp
main.cpp
globals.h
#ifndef GLOBALS_H_#define GLOBALS_H_extern int alpha;extern int beta;#endifglobals.cpp
#include "globals.h"int alpha = 0;int beta = 1;main.cpp
#include <iostream>#include "globals.h"int main(){ std::cout << alpha << " " << beta << std::endl; return 0;}
Author
Yea, that is precisely what I have.. let me post my code.
global.h
Draw.h
Draw.cpp
Main.cpp
global.h
#ifndef GLOBAL_H_#define GLOBAL_H_#include <allegro.h>#include <alpng.h>#include <stdlib.h>//#define MODE GFX_AUTODETECT_WINDOWED#define MODE GFX_AUTODETECT_FULLSCREEN#define SCREENW 640#define SCREENH 480#define BALLSPEED 3#define PADDLESPEED 2//Colors#define RED makecol(235, 0 ,0)#define BLUE makecol(0, 0, 225)#define WHITE makecol(255, 255 ,255)//Paddlesize#define PADDLEW 29#define PADDLEH 5//Ballsize#define BALLW 3#define BALLH 3/* Gameload = 0 Gamepause = 1 Gameon = 10 Gamequit = 100*/ extern int gamestate;extern int random;BITMAP *buffer; extern struct paddleTag { int x, y; int dir; int color, score;} paddles[2];extern struct ballTag { int x, y; int xspeed, yspeed; int color; int status; // 0 = dead, 1 = alive} balls;extern struct moveTag { int x, y;} move;#endifDraw.h
#ifndef DRAW_H_#define DRAW_H_#include "global.h"class eraseClass;class drawClass { private: void draw(int, int, int); int x, y; int objtype; public: void ball(); void paddle(int); void screens(); friend class eraseClass;} draw;#endifDraw.cpp
//Draw some fun stuff on the screen#include "draw.h"/* Main draw function.This function will determine if it should draw a ball, or a paddle and then do so. */void drawClass::draw(int num, int objtype, int color) { if(objtype == 1) { x = paddles[num].x; y = paddles[num].y; rectfill(buffer, x - PADDLEW, y - PADDLEH, x + PADDLEW, y + PADDLEH, color); } else if (objtype == 2) { if (balls.status == 1) { x = balls.x; y = balls.y; rectfill(buffer, x - BALLW, y + BALLH, x + BALLW, y - BALLH, color); } }}/* Passes the required variables to draw.draw() to draw a paddle. */void drawClass::paddle(int num) { draw(num, 1, paddles[num].color);}/* Passes the required variables to draw.draw() to draw a ball. */void drawClass::ball() { draw(1, 2, balls.color); }//Blits all the new drawings to the buffer.void drawClass::screens() { blit(buffer, screen, 0, 0, 0, 0, 640, 480);}Main.cpp
/* Ba-BOUNCE! */////////////////#include "global.h"#include "ai.h"#include "draw.h"#include "erase.h"#include "init.h"#include "move.h"#include "titlescreen.h"#include "getinput.h"#include "shutdown.h"using namespace std;int main(void) { init.startup(); titlescreen(); init.game(); while (gamestate == 10) { erase.paddle(0); erase.paddle(1); erase.ball(); motion.paddle(0); motion.paddle(1); motion.ball(); draw.paddle(0); draw.paddle(1); draw.ball(); getinput(); ai(); if(balls.status == 0) { init.nextround(); } draw.screens(); rest(10); } shutdown(); return 1; }END_OF_MAIN();Quote:Original post by Lempface
global.h
BITMAP *buffer;
Also needs to be extern'd. Post the actual compile errors that you get.
-me
Author
init.o(.bss+0x0):init.cpp: multiple definition of `init'
main.o(.bss+0xd):main.cpp: first defined here
init.o(.bss+0x4):init.cpp: multiple definition of `draw'
main.o(.bss+0x0):main.cpp: first defined here
init.o(.bss+0x10):init.cpp: multiple definition of `erase'
main.o(.bss+0xc):main.cpp: first defined here
draw.o(.bss+0x0):draw.cpp: multiple definition of `draw'
main.o(.bss+0x0):main.cpp: first defined here
erase.o(.bss+0x0):erase.cpp: multiple definition of `erase'
main.o(.bss+0xc):main.cpp: first defined here
erase.o(.bss+0x4):erase.cpp: multiple definition of `draw'
main.o(.bss+0x0):main.cpp: first defined here
move.o(.bss+0x0):move.cpp: multiple definition of `motion'
main.o(.bss+0x10):main.cpp: first defined here
main.o(.text+0x25):main.cpp: undefined reference to `gamestate'
main.o(.text+0xd8):main.cpp: undefined reference to `balls'
init.o(.text+0x8e):init.cpp: undefined reference to `buffer'
init.o(.text+0x94):init.cpp: undefined reference to `gamestate'
init.o(.text+0x123):init.cpp: undefined reference to `paddles'
init.o(.text+0x129):init.cpp: undefined reference to `paddles'
init.o(.text+0x133):init.cpp: undefined reference to `paddles'
init.o(.text+0x13d):init.cpp: undefined reference to `paddles'
init.o(.text+0x147):init.cpp: undefined reference to `paddles'
init.o(.text+0x16c):init.cpp: more undefined references to `paddles' follow
init.o(.text+0x1b5):init.cpp: undefined reference to `balls'
init.o(.text+0x1bb):init.cpp: undefined reference to `balls'
init.o(.text+0x1c5):init.cpp: undefined reference to `balls'
init.o(.text+0x1cf):init.cpp: undefined reference to `balls'
init.o(.text+0x1d9):init.cpp: undefined reference to `balls'
init.o(.text+0x1e3):init.cpp: more undefined references to `balls' follow
init.o(.text+0x200):init.cpp: undefined reference to `random'
init.o(.text+0x205):init.cpp: undefined reference to `random'
init.o(.text+0x210):init.cpp: undefined reference to `random'
init.o(.text+0x216):init.cpp: undefined reference to `random'
init.o(.text+0x21f):init.cpp: undefined reference to `move'
init.o(.text+0x22b):init.cpp: undefined reference to `move'
init.o(.text+0x251):init.cpp: undefined reference to `random'
init.o(.text+0x256):init.cpp: undefined reference to `random'
init.o(.text+0x261):init.cpp: undefined reference to `random'
init.o(.text+0x267):init.cpp: undefined reference to `random'
init.o(.text+0x270):init.cpp: undefined reference to `move'
init.o(.text+0x27a):init.cpp: undefined reference to `move'
init.o(.text+0x286):init.cpp: undefined reference to `move'
init.o(.text+0x290):init.cpp: undefined reference to `move'
init.o(.text+0x2ca):init.cpp: undefined reference to `balls'
init.o(.text+0x2d4):init.cpp: undefined reference to `balls'
init.o(.text+0x2de):init.cpp: undefined reference to `balls'
init.o(.text+0x2e8):init.cpp: undefined reference to `paddles'
init.o(.text+0x2f2):init.cpp: undefined reference to `paddles'
init.o(.text+0x2fc):init.cpp: undefined reference to `paddles'
init.o(.text+0x306):init.cpp: undefined reference to `paddles'
init.o(.text+0x352):init.cpp: undefined reference to `buffer'
init.o(.text+0x37d):init.cpp: undefined reference to `paddles'
init.o(.text+0x386):init.cpp: undefined reference to `paddles'
init.o(.text+0x3b6):init.cpp: undefined reference to `buffer'
init.o(.text+0x412):init.cpp: undefined reference to `buffer'
draw.o(.text+0x1e):draw.cpp: undefined reference to `paddles'
draw.o(.text+0x36):draw.cpp: undefined reference to `paddles'
draw.o(.text+0x77):draw.cpp: undefined reference to `buffer'
draw.o(.text+0x8d):draw.cpp: undefined reference to `balls'
draw.o(.text+0x98):draw.cpp: undefined reference to `balls'
draw.o(.text+0xa2):draw.cpp: undefined reference to `balls'
draw.o(.text+0xe3):draw.cpp: undefined reference to `buffer'
draw.o(.text+0x143):draw.cpp: undefined reference to `paddles'
draw.o(.text+0x16f):draw.cpp: undefined reference to `balls'
draw.o(.text+0x1d6):draw.cpp: undefined reference to `buffer'
getinput.o(.text+0x12):getinput.cpp: undefined reference to `gamestate'
getinput.o(.text+0x2b):getinput.cpp: undefined reference to `paddles'
getinput.o(.text+0x44):getinput.cpp: undefined reference to `paddles'
getinput.o(.text+0x50):getinput.cpp: undefined reference to `paddles'
ai.o(.text+0x4):ai.cpp: undefined reference to `balls'
ai.o(.text+0xa):ai.cpp: undefined reference to `paddles'
ai.o(.text+0x12):ai.cpp: undefined reference to `paddles'
ai.o(.text+0x1d):ai.cpp: undefined reference to `balls'
ai.o(.text+0x23):ai.cpp: undefined reference to `paddles'
ai.o(.text+0x2b):ai.cpp: undefined reference to `paddles'
ai.o(.text+0x37):ai.cpp: undefined reference to `paddles'
move.o(.text+0x56):move.cpp: undefined reference to `move'
move.o(.text+0x5c):move.cpp: undefined reference to `move'
move.o(.text+0x68):move.cpp: undefined reference to `move'
move.o(.text+0x95):move.cpp: undefined reference to `move'
move.o(.text+0xb6):move.cpp: undefined reference to `paddles'
move.o(.text+0xdd):move.cpp: undefined reference to `paddles'
move.o(.text+0xe6):move.cpp: undefined reference to `paddles'
move.o(.text+0xff):move.cpp: undefined reference to `paddles'
move.o(.text+0x126):move.cpp: undefined reference to `paddles'
move.o(.text+0x12f):move.cpp: more undefined references to `paddles' follow
move.o(.text+0x1ba):move.cpp: undefined reference to `balls'
move.o(.text+0x1c6):move.cpp: undefined reference to `balls'
move.o(.text+0x1d1):move.cpp: undefined reference to `balls'
move.o(.text+0x1db):move.cpp: undefined reference to `balls'
move.o(.text+0x1e7):move.cpp: undefined reference to `paddles'
move.o(.text+0x1ed):move.cpp: undefined reference to `balls'
move.o(.text+0x1fa):move.cpp: undefined reference to `paddles'
move.o(.text+0x204):move.cpp: undefined reference to `paddles'
move.o(.text+0x20d):move.cpp: undefined reference to `balls'
move.o(.text+0x214):move.cpp: undefined reference to `paddles'
move.o(.text+0x21d):move.cpp: undefined reference to `balls'
move.o(.text+0x224):move.cpp: undefined reference to `paddles'
move.o(.text+0x22d):move.cpp: undefined reference to `balls'
move.o(.text+0x24e):move.cpp: undefined reference to `move'
move.o(.text+0x25c):move.cpp: undefined reference to `paddles'
move.o(.text+0x265):move.cpp: undefined reference to `balls'
move.o(.text+0x26c):move.cpp: undefined reference to `paddles'
move.o(.text+0x275):move.cpp: undefined reference to `balls'
move.o(.text+0x27c):move.cpp: undefined reference to `paddles'
move.o(.text+0x285):move.cpp: undefined reference to `balls'
move.o(.text+0x2a6):move.cpp: undefined reference to `move'
move.o(.text+0x2b3):move.cpp: undefined reference to `balls'
move.o(.text+0x2bf):move.cpp: undefined reference to `balls'
move.o(.text+0x2d8):move.cpp: undefined reference to `move'
move.o(.text+0x2e4):move.cpp: undefined reference to `move'
move.o(.text+0x2ea):move.cpp: undefined reference to `balls'
move.o(.text+0x2ef):move.cpp: undefined reference to `move'
move.o(.text+0x2f5):move.cpp: undefined reference to `balls'
titlescreen.o(.text+0x4e):titlescreen.cpp: undefined reference to `buffer'
titlescreen.o(.text+0x9d):titlescreen.cpp: undefined reference to `buffer'
titlescreen.o(.text+0xb0):titlescreen.cpp: undefined reference to `gamestate'
titlescreen.o(.text+0x10b):titlescreen.cpp: undefined reference to `buffer'
shutdown.o(.text+0x7):shutdown.cpp: undefined reference to `buffer'
main.o(.bss+0xd):main.cpp: first defined here
init.o(.bss+0x4):init.cpp: multiple definition of `draw'
main.o(.bss+0x0):main.cpp: first defined here
init.o(.bss+0x10):init.cpp: multiple definition of `erase'
main.o(.bss+0xc):main.cpp: first defined here
draw.o(.bss+0x0):draw.cpp: multiple definition of `draw'
main.o(.bss+0x0):main.cpp: first defined here
erase.o(.bss+0x0):erase.cpp: multiple definition of `erase'
main.o(.bss+0xc):main.cpp: first defined here
erase.o(.bss+0x4):erase.cpp: multiple definition of `draw'
main.o(.bss+0x0):main.cpp: first defined here
move.o(.bss+0x0):move.cpp: multiple definition of `motion'
main.o(.bss+0x10):main.cpp: first defined here
main.o(.text+0x25):main.cpp: undefined reference to `gamestate'
main.o(.text+0xd8):main.cpp: undefined reference to `balls'
init.o(.text+0x8e):init.cpp: undefined reference to `buffer'
init.o(.text+0x94):init.cpp: undefined reference to `gamestate'
init.o(.text+0x123):init.cpp: undefined reference to `paddles'
init.o(.text+0x129):init.cpp: undefined reference to `paddles'
init.o(.text+0x133):init.cpp: undefined reference to `paddles'
init.o(.text+0x13d):init.cpp: undefined reference to `paddles'
init.o(.text+0x147):init.cpp: undefined reference to `paddles'
init.o(.text+0x16c):init.cpp: more undefined references to `paddles' follow
init.o(.text+0x1b5):init.cpp: undefined reference to `balls'
init.o(.text+0x1bb):init.cpp: undefined reference to `balls'
init.o(.text+0x1c5):init.cpp: undefined reference to `balls'
init.o(.text+0x1cf):init.cpp: undefined reference to `balls'
init.o(.text+0x1d9):init.cpp: undefined reference to `balls'
init.o(.text+0x1e3):init.cpp: more undefined references to `balls' follow
init.o(.text+0x200):init.cpp: undefined reference to `random'
init.o(.text+0x205):init.cpp: undefined reference to `random'
init.o(.text+0x210):init.cpp: undefined reference to `random'
init.o(.text+0x216):init.cpp: undefined reference to `random'
init.o(.text+0x21f):init.cpp: undefined reference to `move'
init.o(.text+0x22b):init.cpp: undefined reference to `move'
init.o(.text+0x251):init.cpp: undefined reference to `random'
init.o(.text+0x256):init.cpp: undefined reference to `random'
init.o(.text+0x261):init.cpp: undefined reference to `random'
init.o(.text+0x267):init.cpp: undefined reference to `random'
init.o(.text+0x270):init.cpp: undefined reference to `move'
init.o(.text+0x27a):init.cpp: undefined reference to `move'
init.o(.text+0x286):init.cpp: undefined reference to `move'
init.o(.text+0x290):init.cpp: undefined reference to `move'
init.o(.text+0x2ca):init.cpp: undefined reference to `balls'
init.o(.text+0x2d4):init.cpp: undefined reference to `balls'
init.o(.text+0x2de):init.cpp: undefined reference to `balls'
init.o(.text+0x2e8):init.cpp: undefined reference to `paddles'
init.o(.text+0x2f2):init.cpp: undefined reference to `paddles'
init.o(.text+0x2fc):init.cpp: undefined reference to `paddles'
init.o(.text+0x306):init.cpp: undefined reference to `paddles'
init.o(.text+0x352):init.cpp: undefined reference to `buffer'
init.o(.text+0x37d):init.cpp: undefined reference to `paddles'
init.o(.text+0x386):init.cpp: undefined reference to `paddles'
init.o(.text+0x3b6):init.cpp: undefined reference to `buffer'
init.o(.text+0x412):init.cpp: undefined reference to `buffer'
draw.o(.text+0x1e):draw.cpp: undefined reference to `paddles'
draw.o(.text+0x36):draw.cpp: undefined reference to `paddles'
draw.o(.text+0x77):draw.cpp: undefined reference to `buffer'
draw.o(.text+0x8d):draw.cpp: undefined reference to `balls'
draw.o(.text+0x98):draw.cpp: undefined reference to `balls'
draw.o(.text+0xa2):draw.cpp: undefined reference to `balls'
draw.o(.text+0xe3):draw.cpp: undefined reference to `buffer'
draw.o(.text+0x143):draw.cpp: undefined reference to `paddles'
draw.o(.text+0x16f):draw.cpp: undefined reference to `balls'
draw.o(.text+0x1d6):draw.cpp: undefined reference to `buffer'
getinput.o(.text+0x12):getinput.cpp: undefined reference to `gamestate'
getinput.o(.text+0x2b):getinput.cpp: undefined reference to `paddles'
getinput.o(.text+0x44):getinput.cpp: undefined reference to `paddles'
getinput.o(.text+0x50):getinput.cpp: undefined reference to `paddles'
ai.o(.text+0x4):ai.cpp: undefined reference to `balls'
ai.o(.text+0xa):ai.cpp: undefined reference to `paddles'
ai.o(.text+0x12):ai.cpp: undefined reference to `paddles'
ai.o(.text+0x1d):ai.cpp: undefined reference to `balls'
ai.o(.text+0x23):ai.cpp: undefined reference to `paddles'
ai.o(.text+0x2b):ai.cpp: undefined reference to `paddles'
ai.o(.text+0x37):ai.cpp: undefined reference to `paddles'
move.o(.text+0x56):move.cpp: undefined reference to `move'
move.o(.text+0x5c):move.cpp: undefined reference to `move'
move.o(.text+0x68):move.cpp: undefined reference to `move'
move.o(.text+0x95):move.cpp: undefined reference to `move'
move.o(.text+0xb6):move.cpp: undefined reference to `paddles'
move.o(.text+0xdd):move.cpp: undefined reference to `paddles'
move.o(.text+0xe6):move.cpp: undefined reference to `paddles'
move.o(.text+0xff):move.cpp: undefined reference to `paddles'
move.o(.text+0x126):move.cpp: undefined reference to `paddles'
move.o(.text+0x12f):move.cpp: more undefined references to `paddles' follow
move.o(.text+0x1ba):move.cpp: undefined reference to `balls'
move.o(.text+0x1c6):move.cpp: undefined reference to `balls'
move.o(.text+0x1d1):move.cpp: undefined reference to `balls'
move.o(.text+0x1db):move.cpp: undefined reference to `balls'
move.o(.text+0x1e7):move.cpp: undefined reference to `paddles'
move.o(.text+0x1ed):move.cpp: undefined reference to `balls'
move.o(.text+0x1fa):move.cpp: undefined reference to `paddles'
move.o(.text+0x204):move.cpp: undefined reference to `paddles'
move.o(.text+0x20d):move.cpp: undefined reference to `balls'
move.o(.text+0x214):move.cpp: undefined reference to `paddles'
move.o(.text+0x21d):move.cpp: undefined reference to `balls'
move.o(.text+0x224):move.cpp: undefined reference to `paddles'
move.o(.text+0x22d):move.cpp: undefined reference to `balls'
move.o(.text+0x24e):move.cpp: undefined reference to `move'
move.o(.text+0x25c):move.cpp: undefined reference to `paddles'
move.o(.text+0x265):move.cpp: undefined reference to `balls'
move.o(.text+0x26c):move.cpp: undefined reference to `paddles'
move.o(.text+0x275):move.cpp: undefined reference to `balls'
move.o(.text+0x27c):move.cpp: undefined reference to `paddles'
move.o(.text+0x285):move.cpp: undefined reference to `balls'
move.o(.text+0x2a6):move.cpp: undefined reference to `move'
move.o(.text+0x2b3):move.cpp: undefined reference to `balls'
move.o(.text+0x2bf):move.cpp: undefined reference to `balls'
move.o(.text+0x2d8):move.cpp: undefined reference to `move'
move.o(.text+0x2e4):move.cpp: undefined reference to `move'
move.o(.text+0x2ea):move.cpp: undefined reference to `balls'
move.o(.text+0x2ef):move.cpp: undefined reference to `move'
move.o(.text+0x2f5):move.cpp: undefined reference to `balls'
titlescreen.o(.text+0x4e):titlescreen.cpp: undefined reference to `buffer'
titlescreen.o(.text+0x9d):titlescreen.cpp: undefined reference to `buffer'
titlescreen.o(.text+0xb0):titlescreen.cpp: undefined reference to `gamestate'
titlescreen.o(.text+0x10b):titlescreen.cpp: undefined reference to `buffer'
shutdown.o(.text+0x7):shutdown.cpp: undefined reference to `buffer'
Quote:Original post by Lempface
Yea, that is precisely what I have.. let me post my code.
global.h
*** Source Snippet Removed ***
Draw.h
*** Source Snippet Removed ***
Draw.cpp
*** Source Snippet Removed ***
Main.cpp
*** Source Snippet Removed ***
from the looks of it, you have all your globals externed in global.h, but they arent defined anywhere to begin with. you need a global.cpp or some such implementation file in which you actually declair your globals.
Author
They are defined in the functions that call them. For instance
extern struct paddleTag{
...
...
...
} paddles[2];
is defined in init.cpp
Full Source
[Edited by - Lempface on June 5, 2006 6:51:29 PM]
extern struct paddleTag{
...
...
...
} paddles[2];
is defined in init.cpp
void initClass::game() { //setup paddle0 paddles[0].color = RED; paddles[0].x = SCREENW / 2; paddles[0].y = SCREENH - 30; paddles[0].score = 0; paddles[0].dir = 0; //setup paddle1 paddles[1].color = BLUE; paddles[1].x = SCREENW / 2; paddles[1].y = 30; paddles[1].score = 0; paddles[1].dir = 0; //setup ball balls.color = WHITE; balls.status = 1; balls.x = SCREENW / 2; balls.y = SCREENH / 2; balls.xspeed = 0; balls.yspeed = 0; /* This starts the ball moving at the start of the game. Positive BALLSPEED will send the ball down where -BALLSPEED will send the ball up */ random = rand() % 2; if (random == 1) { move.y = BALLSPEED; } else { move.y = -BALLSPEED; }}Full Source
[Edited by - Lempface on June 5, 2006 6:51:29 PM]
Quote:Original post by Lempface
They are defined in the functions that call them. For instance
..snip
that's not defining it, that's using it. You actually need to define it:
globals.h
extern struct paddleTag{.........} paddles[2];globals.cpp
struct paddleTag paddles[2];-me
This topic is closed to new replies.
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