List rewrite

Makefile

@@ -1,7 +1,7 @@
 DBG = -g
 CC	= gcc
 WARNFLAGS = -Wall -Wmissing-declarations -Wdeclaration-after-statement -Wcast-align -Winline -Wsign-compare -Wnested-externs -Wpointer-arith -Wformat-security
-override CFLAGS += -D_REENTRANT -O2 $(shell sdl-config --cflags) $(DBG) $(WARNFLAGS)
+override CFLAGS += -D_REENTRANT $(shell sdl-config --cflags) $(DBG) $(WARNFLAGS)
 
 .PHONY: all clean install
 all: sdlbomber

bomber.h

@@ -59,9 +59,13 @@ typedef struct solid
 	uchar	*graphics;
 } solid;
 
-typedef struct player
-{
-	struct player *next;
+typedef struct listhead listhead;
+struct listhead {
+	listhead *prev, *next;
+};
+
+typedef struct player {
+	listhead list;
 	int xpos,ypos;
 	int flags;
 	int abilities;
@@ -95,12 +99,8 @@ typedef struct damage {
 	int xsize,ysize;
 } damage;
 
-typedef struct list {
-	void *next;
-} list;
-
 typedef struct bomb {
-	struct bomb *next;
+	listhead list;
 	int type;
 	int xpos,ypos;
 	int px,py;
@@ -119,7 +119,7 @@ typedef struct bomb {
 #define DECAYLIFE 15
 
 typedef struct flame {
-	struct flame *next;
+	listhead list;
 	int xpos,ypos;
 	int px,py;
 	int timer;
@@ -133,23 +133,21 @@ typedef struct flame {
 #define FL_RIGHT 4
 
 typedef struct brickdecay {
-	struct brickdecay *next;
+	listhead list;
 	int xpos,ypos;
 	int px,py;
 	int timer;
 } brickdecay;
 
-typedef union listitem listitem;
-union listitem {
-	listitem *next;
-	bomb b;
-	flame f;
-	brickdecay bc;
-	player p;
-};
+typedef struct bonustile {
+	listhead list;
+	int xpos,ypos;
+	int px,py;
+	int type;
+} bonustile;
 
 typedef struct generic {
-	struct generic *next;
+	listhead list;
 	int xpos,ypos;
 	int px,py;
 	int timer;
@@ -159,12 +157,16 @@ typedef struct generic {
 	int data1,data2;
 } generic;
 
-typedef struct bonustile {
-	struct bonustile *next;
-	int xpos,ypos;
-	int px,py;
-	int type;
-} bonustile;
+typedef union genericlistitem genericlistitem;
+union genericlistitem {
+	listhead h;
+	bomb b;
+	flame f;
+	brickdecay bc;
+	player p;
+	bonustile bt;
+	generic g;
+};
 
 enum tile_types {
 	TILE_NONE = -1,

game.c

@@ -11,20 +11,20 @@
 
 static int gameframe;
 
-static list activebombs;
-static list activedecays;
-static list activebonus;
-static list activegeneric;
+static listhead activebombs;
+static listhead activedecays;
+static listhead activebonus;
+static listhead activegeneric;
 
 static bomb *detonated[MAXBOMBSDETONATED];
 static int detonateput=0;
 static int detonatetake=0;
 
-static list activeflames;
-static list activeplayers;
+static listhead activeflames;
+static listhead activeplayers;
 
 figure walking[MAXSETS][NUMWALKFRAMES];
-solid background,backgroundoriginal;
+solid background, backgroundoriginal;
 
 /* The playfield array, contains FIELD_* equates */
 unsigned char field[32][32];
@@ -68,7 +68,6 @@ static void initplayer(int color,int x,int y,int controller) {
 	if(!pl)
 		nomem("Couldn't get player structure (allocentry())");
 	addtail(&activeplayers,pl);
-	memset(pl,0,sizeof(player));
 	pl->xpos=arraytoscreenx(x);
 	pl->ypos=arraytoscreeny(y);
 	pl->color=color;
@@ -239,9 +238,9 @@ static void adddetonate(bomb *bmb) {
 
 static void processbombs() {
 	bomb *bmb;
+	listhead *iter;
 
-	bmb=activebombs.next;
-	while(bmb) {
+	foreach_list_entry(&activebombs, iter, bmb) {
 		switch(bmb->type) {
 		case BOMB_NORMAL:
 			++bmb->timer;
@@ -253,7 +252,6 @@ static void processbombs() {
 			++(bmb->figcount);
 			break;
 		}
-		bmb=bmb->next;
 	}
 }
 
@@ -313,7 +311,7 @@ static void deletebonus(bonustile *bonus) {
 	py=bonus->py;
 	field[py][px]=0;
 	info[py][px]=0;
-	delink(&activebonus,bonus);
+	delink(bonus);
 }
 
 static void flameshaft(player *owner,int px,int py,int dx,int dy,int power) {
@@ -361,7 +359,7 @@ static void detonatebomb(bomb *bmb) {
 	py=bmb->py;
 	power=bmb->power;
 	owner=bmb->owner;
-	delink(&activebombs,bmb);
+	delink(bmb);
 	addflame(owner,px,py);
 	flameshaft(owner,px,py,-1,0,power);
 	flameshaft(owner,px,py,0,-1,power);
@@ -381,53 +379,43 @@ static void dodetonations(void) {
 }
 
 static void processflames(void) {
-	flame *fl,*fl2;
+	flame *fl;
+	listhead *iter;
 
-	fl=activeflames.next;
-	while(fl) {
+	foreach_list_entry(&activeflames, iter, fl) {
 		++(fl->timer);
-		fl=fl->next;
-	}
-	fl=activeflames.next;
-	while(fl) {
-		if(fl->timer==FLAMELIFE)
-		{
+
+		if(fl->timer==FLAMELIFE) {
 			field[fl->py][fl->px]=FIELD_EMPTY;
 			info[fl->py][fl->px]=0;
-			fl2=fl;
-			fl=fl->next;
-			delink(&activeflames,fl2);
-		} else
-			fl=fl->next;
+			iter = delinkhead(iter);
+		}
 	}
 }
 
 static void processdecays() {
-	brickdecay *bd,*bd2;
+	brickdecay *bd;
+	listhead *iter;
 
-	bd=activedecays.next;
-	while(bd) {
+	foreach_list_entry(&activedecays, iter, bd) {
 		++(bd->timer);
-		if(bd->timer==DECAYLIFE) {
-			field[bd->py][bd->px]=FIELD_EMPTY;
-			trybonus(bd->px,bd->py);
-			bd2=bd;
-			bd=bd->next;
-			delink(&activedecays,bd2);
-		} else
-			bd=bd->next;
+		if(bd->timer == DECAYLIFE) {
+			field[bd->py][bd->px] = FIELD_EMPTY;
+			trybonus(bd->px, bd->py);
+			iter = delinkhead(iter);
+		}
 	}
 }
 
 static void drawbombs(void) {
 	int j;
 	bomb *bmb;
+	listhead *iter;
 	struct figure *figtab;
 	int color;
 	int xpos,ypos;
 
-	bmb=activebombs.next;
-	while(bmb) {
+	foreach_list_entry(&activebombs, iter, bmb) {
 		color=bmb->owner->color;
 		figtab=(bmb->type==BOMB_NORMAL) ? bombs1[color] : bombs2[color];
 		j=bmb->figcount % (NUMBOMBFRAMES<<1);
@@ -436,18 +424,17 @@ static void drawbombs(void) {
 		ypos=tovideoy(bmb->ypos)-3;
 
 		addsprite(xpos,ypos,figtab+j);
-		bmb=bmb->next;
 	}
 }
 
 static void drawflames(void) {
 	flame *fl;
+	listhead *iter;
 	int xpos,ypos;
 	int color;
 	int fig;
 
-	fl=activeflames.next;
-	while(fl) {
+	foreach_list_entry(&activeflames, iter, fl) {
 		color=fl->owner->color;
 		xpos=tovideox(fl->xpos);
 		ypos=tovideoy(fl->ypos);
@@ -455,39 +442,35 @@ static void drawflames(void) {
 		if(fig>=5) fig=9-fig;
 		fig+=5*fl->lurd;
 		addsprite(xpos,ypos,flamefigs[0/* color */]+fig);
-		fl=fl->next;
 	}
 }
 
 static void drawdecays() {
+	listhead *iter;
 	brickdecay *bd;
 
-	bd=activedecays.next;
-	while(bd) {
+	foreach_list_entry(&activedecays, iter, bd) {
 		addsprite(tovideox(bd->xpos),tovideoy(bd->ypos),
 			blocksx+(bd->timer*9)/DECAYLIFE);
-		bd=bd->next;
 	}
 }
 
 static void drawbonus() {
 	bonustile *bonus;
+	listhead *iter;
 
-	bonus=activebonus.next;
-	while(bonus) {
+	foreach_list_entry(&activebonus, iter, bonus) {
 		addsprite(tovideox(bonus->xpos),tovideoy(bonus->ypos),
 			tiles+bonus->type);
-		bonus=bonus->next;
 	}
 }
 
 static void drawplayers() {
 	player *pl;
 	int xpos,ypos;
+	listhead *iter;
 
-	pl=activeplayers.next;
-
-	while(pl) {
+	foreach_list_entry(&activeplayers, iter, pl) {
 		if(!(pl->flags & FLG_DEAD)) {
 			if(!pl->figure)
 				pl->figure=walking[pl->color]+30;
@@ -495,24 +478,22 @@ static void drawplayers() {
 			ypos=tovideoy(pl->ypos)+pl->fixy;
 			addsprite(xpos,ypos,pl->figure);
 		}
-		pl=pl->next;
 	}
 }
 
 static void detonatecontrolled(player *pl) {
 	bomb *bmb;
+	listhead *iter;
 
-	bmb=activebombs.next;
-	while(bmb) {
+	foreach_list_entry(&activebombs, iter, bmb) {
 		if(bmb->owner==pl && bmb->type==BOMB_CONTROLLED)
 			adddetonate(bmb);
-		bmb=bmb->next;
 	}
 }
 
 static void playonce(generic *gen) {
 	if(gen->timer==gen->data1)
-		delink(&activegeneric,gen);
+		delink(gen);
 }
 
 static void drawgeneric(generic *gen) {
@@ -551,10 +532,10 @@ static void killplayer(player *pl) {
 static void processgenerics(void) {
 	generic *gen,*gen2;
 
-	gen=activegeneric.next;
-	while(gen) {
-		gen2=gen;
-		gen=gen->next;
+	gen = (generic*) activegeneric.next;
+	while ((listhead*) gen != &activegeneric) {
+		gen2 = gen;
+		gen = (generic*) gen->list.next;
 		++(gen2->timer);
 		gen2->process(gen2);
 	}
@@ -562,11 +543,10 @@ static void processgenerics(void) {
 
 static void drawgenerics(void) {
 	generic *gen;
+	listhead *iter;
 
-	gen=activegeneric.next;
-	while(gen) {
+	foreach_list_entry(&activegeneric, iter, gen) {
 		gen->draw(gen);
-		gen=gen->next;
 	}
 }
 
@@ -795,12 +775,12 @@ static void doplayer(player *pl) {
 }
 
 static void processplayers(void) {
-	player *pl,*pl2;
+	player *pl, *pl2;
 
-	pl=activeplayers.next;
-	while(pl) {
-		pl2=pl;
-		pl=pl->next;
+	pl = (player*) activeplayers.next;
+	while ((listhead*) pl != &activeplayers) {
+		pl2 = pl;
+		pl = (player*) pl->list.next;
 		doplayer(pl2);
 	}
 }
@@ -888,11 +868,14 @@ static int iterate(void) {
 	drawplayers();
 	plotsprites();
 	copyup();
-	if(!activegeneric.next) {
+	if (activegeneric.next == &activegeneric) {
 		player *pl;
+		listhead *iter;
+
 		int deadplayers = 0;
 		i = 0;
-		for (pl = activeplayers.next; pl; pl = pl->next) {
+
+		foreach_list_entry(&activeplayers, iter, pl) {
 			if(!(pl->flags & FLG_DEAD))
 				++i;
 			else

list.c

@@ -3,60 +3,64 @@
 #include "list.h"
 #include "utils.h"
 
-static listitem *things=0, *free_things;
+/* doesn't use prev link */
+static genericlistitem *things=0;
+static listhead *free_things;
 
 void allocthings(void) {
 	int i;
 	const int num = MAXTHINGS;
 
 	if (!things) {
-		things = calloc(sizeof(listitem), num);
+		things = calloc(sizeof(genericlistitem), num);
 	} else {
-		memset(things, 0, sizeof(listitem)*num);
+		memset(things, 0, sizeof(genericlistitem)*num);
 	}
 	if(!things) nomem("Trying to allocate thing memory");
 	for(i=0;i<num-1;++i) {
-		things[i].next = &things[i+1];
+		things[i].h.next = (listhead*) &things[i+1];
 	}
-	things[i].next = 0;
-	free_things = things;
+	things[i].h.next = 0;
+	free_things = (listhead*) things;
 }
 
 void *allocentry(void) {
-	listitem *entry = free_things;
+	listhead *entry = free_things;
 
 	if (free_things) {
 		free_things = free_things->next;
-		memset(entry, 0, sizeof(*entry));
+		memset(entry, 0, sizeof(genericlistitem));
 	}
 	return entry;
 }
 
-void freeentry(void *_entry) {
-	listitem *entry = _entry;
+static void freeentry(void *_entry) {
+	listhead *entry = _entry;
 
 	entry->next = free_things;
+	entry->prev = NULL;
 	free_things = entry;
 }
 
-void addtail(void *_header,void *_entry) {
-	listitem *header = _header, *entry = _entry;
-
-	while (header->next) header = header->next;
-	header->next = entry;
-	entry->next = 0;
+void _addtail(listhead *head, listhead *entry) {
+	entry->next = head;
+	entry->prev = head->prev;
+	head->prev->next = entry;
+	head->prev = entry;
 }
 
-void delink(void *_header,void *_entry) {
-	listitem *header = _header, *entry = _entry;
+listhead* delinkhead(listhead *entry) {
+	listhead *result = entry->prev;
+
+	entry->next->prev = entry->prev;
+	entry->prev->next = entry->next;
 
-	while (header->next != entry) header = header->next;
-	header->next = entry->next;
-	entry->next = 0;
 	freeentry(entry);
+	return result;
 }
 
-void initheader(void *p) {
-	memset(p,0,sizeof(list));
+void initheader(listhead *head) {
+	head->next = head;
+	head->prev = head;
 }
 

list.h

@@ -3,10 +3,22 @@
 
 void allocthings(void);
 void *allocentry(void);
-void freeentry(void *entry);
-void addtail(void *header,void *entry);
-void delink(void *header,void *entry);
 
-void initheader(void *p);
+void _addtail(listhead *header, listhead *entry);
+#define addtail(head, entry) _addtail(head, &(entry->list));
+
+/* returns previous entry, use as
+ *   iter = delinkhead(iter);
+ * in foreach_list_entry loops
+ */
+listhead* delinkhead(listhead *entry);
+#define delink(entry) delinkhead(&(entry->list));
+
+
+void initheader(listhead *head);
+
+/* listhead *head, listhead *iter, XXX *item */
+#define foreach_list_entry(head, iter, item) \
+	for (iter = (head)->next, item = (void*) iter; iter != (head); iter = iter->next, item = (void*) iter)
 
 #endif