I know this question has been asked several times before, but I can't track where the issue is coming from. For some context, I am updating an 8 year old iPad Powder Toy port to make it compatible on my iPad, but when I run the same project as the iPad port, I get the error ld: 6032 duplicate symbols. These errors are always happening in combination with a file air.o. I've checked the file and traced the symbols to a header file defines.h. In this file, I found the symbols. All of the duplicate symbols are variables, such as int GSPEED, int ISWIRE and int CGOL. I'm still kind of a beginner in C, and these variables are defined only once in the file defines.h, and not twice (duplicate). I'm attaching relevant files. Thanks for any help, and sorry if this is an obvious mistake.
defines.h
#pragma once
#ifndef PATH_SEP
#define PATH_SEP "/"
#endif
//VersionInfoStart
#ifndef SAVE_VERSION
#define SAVE_VERSION 83
#endif
#ifndef MINOR_VERSION
#define MINOR_VERSION 0
#endif
#ifndef BUILD_NUM
#define BUILD_NUM 205
#endif
//VersionInfoEnd
#ifndef IDENT_VERSION
#define IDENT_VERSION "G" //Change this if you're not Simon! It should be a single letter
#endif
#ifndef MTOS_EXPAND
#define MTOS_EXPAND(str) #str
#endif
#ifndef MTOS
#define MTOS(str) MTOS_EXPAND(str)
#endif
#ifndef LOCAL_SAVE_DIR
#define LOCAL_SAVE_DIR "Saves"
#endif
#ifndef APPDATA_SUBDIR
#define APPDATA_SUBDIR "\\HardWIRED"
#endif
#ifndef THUMB_CACHE_SIZE
#define THUMB_CACHE_SIZE 256
#endif
#ifndef M_PI
#define M_PI 3.14159265f
#endif
#ifndef M_GRAV
#define M_GRAV 6.67300e-1
#endif
#ifndef IMGCONNS
#define IMGCONNS 3
#endif
#ifndef TIMEOUT
#define TIMEOUT 100
#endif
#ifdef RENDERER
#define MENUSIZE 0
#define BARSIZE 0
#else
#define MENUSIZE 25
#define BARSIZE 17
#endif
#ifndef XRES
#define XRES 463
#endif
#ifndef YRES
#define YRES 335
#endif
//#define XRES 230
//#define YRES 168
#ifndef NPART
#define NPART XRES*YRES
#endif
#ifndef MAX_DISTANCE
#define MAX_DISTANCE sqrt(pow(XRES, 2)+pow(YRES, 2))
#endif
#ifndef GRAV_DIFF
#define GRAV_DIFF
#endif
#ifndef MAXSIGNS
#define MAXSIGNS 16
#endif
#ifndef TAG_MAX
#define TAG_MAX 256
#endif
#ifndef ZSIZE_D
#define ZSIZE_D 16
#endif
#ifndef ZFACTOR_D
#define ZFACTOR_D 8
#endif
extern unsigned char ZFACTOR;
extern unsigned char ZSIZE;
#ifndef CELL
#define CELL 4
#endif
#ifndef ISTP
#define ISTP (CELL/2)
#endif
#ifndef CFDS
#define CFDS (4.0f/CELL)
#endif
#define AIR_TSTEPP 0.3f
#define AIR_TSTEPV 0.4f
#define AIR_VADV 0.3f
#define AIR_VLOSS 0.999f
#define AIR_PLOSS 0.9999f
#define GRID_X 5
#define GRID_Y 4
#define GRID_P 3
#define GRID_S 6
#define GRID_Z 3
#define CATALOGUE_X 4
#define CATALOGUE_Y 3
#define CATALOGUE_S 6
#define CATALOGUE_Z 3
#define STAMP_MAX 240
#define SAVE_OPS
//#define REALISTIC
#define NGOL 25
#define NGOLALT 24 //NGOL should be 24, but use this var until I find out why
#define CIRCLE_BRUSH 0
#define SQUARE_BRUSH 1
#define TRI_BRUSH 2
#define BRUSH_NUM 3
#ifdef PIX16
typedef unsigned short pixel;
#else
typedef unsigned int pixel;
#endif
#define SURF_RANGE 10
#define NORMAL_MIN_EST 3
#define NORMAL_INTERP 20
#define NORMAL_FRAC 16
#define REFRACT 0x80000000
/* heavy flint glass, for awesome refraction/dispersion
this way you can make roof prisms easily */
#define GLASS_IOR 1.9
#define GLASS_DISP 0.07
#define SDEUT
//#define REALHEAT
#define DEBUG_PARTS 0x0001
#define DEBUG_PARTCOUNT 0x0002
#define DEBUG_DRAWTOOL 0x0004
#define DEBUG_PERFORMANCE_CALC 0x0008
#define DEBUG_PERFORMANCE_FRAME 0x0010
typedef unsigned char uint8;
extern int saveURIOpen;
extern char * saveDataOpen;
extern int saveDataOpenSize;
extern int amd;
extern int FPSB;
int NUM_PARTS;
int GRAV;
int GRAV_R;
int GRAV_G;
int GRAV_B;
int GRAV_R2;
int GRAV_G2;
int GRAV_B2;
extern int legacy_enable;
extern int kiosk_enable;
extern int aheat_enable;
extern int decorations_enable;
extern int active_menu;
extern int hud_enable;
extern int pretty_powder;
extern int drawgrav_enable;
extern int ngrav_enable;
extern char bframe;
int limitFPS;
int water_equal_test;
//extern int quickoptions_tooltip_fade;
extern int loop_time;
extern int debug_flags;
#define DEBUG_PERF_FRAMECOUNT 256
extern int debug_perf_istart;
extern int debug_perf_iend;
extern long debug_perf_frametime[DEBUG_PERF_FRAMECOUNT];
extern long debug_perf_partitime[DEBUG_PERF_FRAMECOUNT];
extern long debug_perf_time;
extern int active_menu;
extern int sys_pause;
extern int framerender;
extern int mousex, mousey;
struct sign
{
int x,y,ju;
char text[256];
};
typedef struct sign sign;
struct stamp
{
char name[11];
pixel *thumb;
int thumb_w, thumb_h, dodelete;
};
typedef struct stamp stamp;
int frameidx;
int MSIGN;
int CGOL;
int ISGOL;
int ISLOVE;
int ISLOLZ;
int ISGRAV;
int ISWIRE;
int GSPEED;
int love[XRES/9][YRES/9];
int lolz[XRES/9][YRES/9];
unsigned char gol[YRES][XRES];
unsigned char gol2[YRES][XRES][NGOL+1];
int SEC;
int SEC2;
int console_mode;
int REPLACE_MODE;
int CURRENT_BRUSH;
int GRID_MODE;
int VINE_MODE;
int DEBUG_MODE;
int GENERATION;
int ISSPAWN1;
int ISSPAWN2;
extern sign signs[MAXSIGNS];
extern stamp stamps[STAMP_MAX];
extern int stamp_count;
extern int itc;
extern char itc_msg[64];
extern int do_open;
extern int sys_pause;
extern int sys_shortcuts;
extern int legacy_enable; //Used to disable new features such as heat, will be set by commandline or save.
extern int framerender;
extern pixel *vid_buf;
extern unsigned char last_major, last_minor, last_build;
//Functions in main.c
void thumb_cache_inval(char *id);
void thumb_cache_add(char *id, void *thumb, int size);
int thumb_cache_find(char *id, void **thumb, int *size);
void clear_sim(void);
void del_stamp(int d);
int set_scale(int scale, int kiosk);
The duplicate variables are at the bottom.
air.c
#include <math.h>
#include "air.h"
#include "powder.h"
#include "defines.h"
#include "gravity.h"
float kernel[9];
float vx[YRES/CELL][XRES/CELL], ovx[YRES/CELL][XRES/CELL];
float vy[YRES/CELL][XRES/CELL], ovy[YRES/CELL][XRES/CELL];
float pv[YRES/CELL][XRES/CELL], opv[YRES/CELL][XRES/CELL];
unsigned char bmap_blockair[YRES/CELL][XRES/CELL];
unsigned char bmap_blockairh[YRES/CELL][XRES/CELL];
float cb_vx[YRES/CELL][XRES/CELL];
float cb_vy[YRES/CELL][XRES/CELL];
float cb_pv[YRES/CELL][XRES/CELL];
float cb_hv[YRES/CELL][XRES/CELL];
float fvx[YRES/CELL][XRES/CELL], fvy[YRES/CELL][XRES/CELL];
float hv[YRES/CELL][XRES/CELL], ohv[YRES/CELL][XRES/CELL]; // For Ambient Heat
void make_kernel(void) //used for velocity
{
int i, j;
float s = 0.0f;
for (j=-1; j<2; j++)
for (i=-1; i<2; i++)
{
kernel[(i+1)+3*(j+1)] = expf(-2.0f*(i*i+j*j));
s += kernel[(i+1)+3*(j+1)];
}
s = 1.0f / s;
for (j=-1; j<2; j++)
for (i=-1; i<2; i++)
kernel[(i+1)+3*(j+1)] *= s;
}
void update_airh(void)
{
int x, y, i, j;
float odh, dh, dx, dy, f, tx, ty;
for (i=0; i<YRES/CELL; i++) //reduces pressure/velocity on the edges every frame
{
hv[i][0] = 295.15f;
hv[i][1] = 295.15f;
hv[i][XRES/CELL-3] = 295.15f;
hv[i][XRES/CELL-2] = 295.15f;
hv[i][XRES/CELL-1] = 295.15f;
}
for (i=0; i<XRES/CELL; i++) //reduces pressure/velocity on the edges every frame
{
hv[0][i] = 295.15f;
hv[1][i] = 295.15f;
hv[YRES/CELL-3][i] = 295.15f;
hv[YRES/CELL-2][i] = 295.15f;
hv[YRES/CELL-1][i] = 295.15f;
}
for (y=0; y<YRES/CELL; y++) //update velocity and pressure
{
for (x=0; x<XRES/CELL; x++)
{
dh = 0.0f;
dx = 0.0f;
dy = 0.0f;
for (j=-1; j<2; j++)
{
for (i=-1; i<2; i++)
{
if (y+j>0 && y+j<YRES/CELL-2 &&
x+i>0 && x+i<XRES/CELL-2 &&
!bmap_blockairh[y+j][x+i])
{
f = kernel[i+1+(j+1)*3];
dh += hv[y+j][x+i]*f;
dx += vx[y+j][x+i]*f;
dy += vy[y+j][x+i]*f;
}
else
{
f = kernel[i+1+(j+1)*3];
dh += hv[y][x]*f;
dx += vx[y][x]*f;
dy += vy[y][x]*f;
}
}
}
tx = x - dx*0.7f;
ty = y - dy*0.7f;
i = (int)tx;
j = (int)ty;
tx -= i;
ty -= j;
if (i>=2 && i<XRES/CELL-3 && j>=2 && j<YRES/CELL-3)
{
odh = dh;
dh *= 1.0f - AIR_VADV;
dh += AIR_VADV*(1.0f-tx)*(1.0f-ty)*(bmap_blockairh[j][i] ? odh : hv[j][i]);
dh += AIR_VADV*tx*(1.0f-ty)*(bmap_blockairh[j][i+1] ? odh : hv[j][i+1]);
dh += AIR_VADV*(1.0f-tx)*ty*(bmap_blockairh[j+1][i] ? odh : hv[j+1][i]);
dh += AIR_VADV*tx*ty*(bmap_blockairh[j+1][i+1] ? odh : hv[j+1][i+1]);
}
pv[y][x] += (dh-hv[y][x])/5000.0f;
if(!gravityMode){ //Vertical gravity only for the time being
float airdiff = hv[y-1][x]-hv[y][x];
if(airdiff>0 && !bmap_blockairh[y-1][x])
vy[y][x] -= airdiff/5000.0f;
}
ohv[y][x] = dh;
}
}
memcpy(hv, ohv, sizeof(hv));
}
void update_air(void)
{
int x, y, i, j;
float dp, dx, dy, f, tx, ty;
if (airMode != 4) { //airMode 4 is no air/pressure update
for (i=0; i<YRES/CELL; i++) //reduces pressure/velocity on the edges every frame
{
pv[i][0] = pv[i][0]*0.8f;
pv[i][1] = pv[i][1]*0.8f;
pv[i][2] = pv[i][2]*0.8f;
pv[i][XRES/CELL-2] = pv[i][XRES/CELL-2]*0.8f;
pv[i][XRES/CELL-1] = pv[i][XRES/CELL-1]*0.8f;
vx[i][0] = vx[i][1]*0.9f;
vx[i][1] = vx[i][2]*0.9f;
vx[i][XRES/CELL-2] = vx[i][XRES/CELL-3]*0.9f;
vx[i][XRES/CELL-1] = vx[i][XRES/CELL-2]*0.9f;
vy[i][0] = vy[i][1]*0.9f;
vy[i][1] = vy[i][2]*0.9f;
vy[i][XRES/CELL-2] = vy[i][XRES/CELL-3]*0.9f;
vy[i][XRES/CELL-1] = vy[i][XRES/CELL-2]*0.9f;
}
for (i=0; i<XRES/CELL; i++) //reduces pressure/velocity on the edges every frame
{
pv[0][i] = pv[0][i]*0.8f;
pv[1][i] = pv[1][i]*0.8f;
pv[2][i] = pv[2][i]*0.8f;
pv[YRES/CELL-2][i] = pv[YRES/CELL-2][i]*0.8f;
pv[YRES/CELL-1][i] = pv[YRES/CELL-1][i]*0.8f;
vx[0][i] = vx[1][i]*0.9f;
vx[1][i] = vx[2][i]*0.9f;
vx[YRES/CELL-2][i] = vx[YRES/CELL-3][i]*0.9f;
vx[YRES/CELL-1][i] = vx[YRES/CELL-2][i]*0.9f;
vy[0][i] = vy[1][i]*0.9f;
vy[1][i] = vy[2][i]*0.9f;
vy[YRES/CELL-2][i] = vy[YRES/CELL-3][i]*0.9f;
vy[YRES/CELL-1][i] = vy[YRES/CELL-2][i]*0.9f;
}
for (j=1; j<YRES/CELL; j++) //clear some velocities near walls
{
for (i=1; i<XRES/CELL; i++)
{
if (bmap_blockair[j][i])
{
vx[j][i] = 0.0f;
vx[j][i-1] = 0.0f;
vy[j][i] = 0.0f;
vy[j-1][i] = 0.0f;
}
}
}
for (y=1; y<YRES/CELL; y++) //pressure adjustments from velocity
for (x=1; x<XRES/CELL; x++)
{
dp = 0.0f;
dp += vx[y][x-1] - vx[y][x];
dp += vy[y-1][x] - vy[y][x];
pv[y][x] *= AIR_PLOSS;
pv[y][x] += dp*AIR_TSTEPP;
}
for (y=0; y<YRES/CELL-1; y++) //velocity adjustments from pressure
for (x=0; x<XRES/CELL-1; x++)
{
dx = dy = 0.0f;
dx += pv[y][x] - pv[y][x+1];
dy += pv[y][x] - pv[y+1][x];
vx[y][x] *= AIR_VLOSS;
vy[y][x] *= AIR_VLOSS;
vx[y][x] += dx*AIR_TSTEPV;
vy[y][x] += dy*AIR_TSTEPV;
if (bmap_blockair[y][x] || bmap_blockair[y][x+1])
vx[y][x] = 0;
if (bmap_blockair[y][x] || bmap_blockair[y+1][x])
vy[y][x] = 0;
}
for (y=0; y<YRES/CELL; y++) //update velocity and pressure
for (x=0; x<XRES/CELL; x++)
{
dx = 0.0f;
dy = 0.0f;
dp = 0.0f;
for (j=-1; j<2; j++)
for (i=-1; i<2; i++)
if (y+j>0 && y+j<YRES/CELL-1 &&
x+i>0 && x+i<XRES/CELL-1 &&
!bmap_blockair[y+j][x+i])
{
f = kernel[i+1+(j+1)*3];
dx += vx[y+j][x+i]*f;
dy += vy[y+j][x+i]*f;
dp += pv[y+j][x+i]*f;
}
else
{
f = kernel[i+1+(j+1)*3];
dx += vx[y][x]*f;
dy += vy[y][x]*f;
dp += pv[y][x]*f;
}
tx = x - dx*0.7f;
ty = y - dy*0.7f;
i = (int)tx;
j = (int)ty;
tx -= i;
ty -= j;
if (i>=2 && i<XRES/CELL-3 &&
j>=2 && j<YRES/CELL-3)
{
dx *= 1.0f - AIR_VADV;
dy *= 1.0f - AIR_VADV;
dx += AIR_VADV*(1.0f-tx)*(1.0f-ty)*vx[j][i];
dy += AIR_VADV*(1.0f-tx)*(1.0f-ty)*vy[j][i];
dx += AIR_VADV*tx*(1.0f-ty)*vx[j][i+1];
dy += AIR_VADV*tx*(1.0f-ty)*vy[j][i+1];
dx += AIR_VADV*(1.0f-tx)*ty*vx[j+1][i];
dy += AIR_VADV*(1.0f-tx)*ty*vy[j+1][i];
dx += AIR_VADV*tx*ty*vx[j+1][i+1];
dy += AIR_VADV*tx*ty*vy[j+1][i+1];
}
if (bmap[y][x] == WL_FAN)
{
dx += fvx[y][x];
dy += fvy[y][x];
}
// pressure/velocity caps
if (dp > 256.0f) dp = 256.0f;
if (dp < -256.0f) dp = -256.0f;
if (dx > 256.0f) dx = 256.0f;
if (dx < -256.0f) dx = -256.0f;
if (dy > 256.0f) dy = 256.0f;
if (dy < -256.0f) dy = -256.0f;
switch (airMode)
{
default:
case 0: //Default
break;
case 1: //0 Pressure
dp = 0.0f;
break;
case 2: //0 Velocity
dx = 0.0f;
dy = 0.0f;
break;
case 3: //0 Air
dx = 0.0f;
dy = 0.0f;
dp = 0.0f;
break;
case 4: //No Update
break;
}
ovx[y][x] = dx;
ovy[y][x] = dy;
opv[y][x] = dp;
}
memcpy(vx, ovx, sizeof(vx));
memcpy(vy, ovy, sizeof(vy));
memcpy(pv, opv, sizeof(pv));
}
}
This file is present in every duplicate symbol error.
air.h
#ifndef AIR_H
#define AIR_H
#include "defines.h"
extern float vx[YRES/CELL][XRES/CELL], ovx[YRES/CELL][XRES/CELL];
extern float vy[YRES/CELL][XRES/CELL], ovy[YRES/CELL][XRES/CELL];
extern float pv[YRES/CELL][XRES/CELL], opv[YRES/CELL][XRES/CELL];
extern unsigned char bmap_blockair[YRES/CELL][XRES/CELL];
extern unsigned char bmap_blockairh[YRES/CELL][XRES/CELL];
extern float cb_vx[YRES/CELL][XRES/CELL];
extern float cb_vy[YRES/CELL][XRES/CELL];
extern float cb_pv[YRES/CELL][XRES/CELL];
extern float cb_hv[YRES/CELL][XRES/CELL];
extern float fvx[YRES/CELL][XRES/CELL], fvy[YRES/CELL][XRES/CELL];
extern float hv[YRES/CELL][XRES/CELL], ohv[YRES/CELL][XRES/CELL]; // Ambient Heat
extern float kernel[9];
void make_kernel(void);
void update_airh(void);
void update_air(void);
#endif
