From 0978da8f14d855eecae9882b559d6e8b0533e78e Mon Sep 17 00:00:00 2001
From: Joshua Grams <josh@qualdan.com>
Date: Fri, 24 Mar 2006 00:46:58 +0000
Subject: [PATCH] sprites now have a flag field (MOVE/DRAW/COLLIDE). rocks
 which have been blasted do not collide.

---
 main.c   |    9 +++++----
 rocks.c  |    4 +++-
 sprite.c |   19 +++++++++----------
 sprite.h |   17 ++++++++++++++---
 4 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/main.c b/main.c
index a068033..96c3968 100644
--- a/main.c
+++ b/main.c
@@ -66,7 +66,7 @@ struct bangdots bdot[MAXBANGDOTS], *bdotptr = bdot;
 char topline[1024];
 char *initerror = "";
 
-struct ship ship = { SHIP, NULL, XSIZE/2, YSIZE/2, SCREENDXMIN, 0.0 };
+struct ship ship = { SHIP, ALL_FLAGS, NULL, XSIZE/2, YSIZE/2, SCREENDXMIN, 0.0 };
 	  
 float screendx = SCREENDXMIN, screendy = 0.0;
 float xscroll, yscroll;
@@ -531,9 +531,9 @@ void
 do_collision(Sprite *a, Sprite *b)
 {
 	if(a->type == SHIP) {
-		a->type = -SHIP; bang = true;
+		a->flags = MOVE_FLAG; bang = true;
 	} else if (b->type == SHIP) {
-		b->type = -SHIP; bang = true;
+		b->flags = MOVE_FLAG; bang = true;
 	} else {
 		bounce(a, b);
 	}
@@ -553,7 +553,7 @@ gameloop() {
 				switch(state) {
 					case DEAD_PAUSE:
 						// Create a new ship and start all over again
-						ship.sprite_type = SHIP;
+						ship.flags = ALL_FLAGS;
 						state = GAMEPLAY;
 						play_tune(TUNE_GAMEPLAY);
 						break;
@@ -668,6 +668,7 @@ gameloop() {
 				ship.x = XSIZE/2.2; ship.y = YSIZE/2;
 				ship.dx = screendx; ship.dy = screendy;
 				ship.lives = 4;
+				ship.flags = ALL_FLAGS;
 				add_sprite(SPRITE(&ship));
 
 				score = 0;
diff --git a/rocks.c b/rocks.c
index 2ab0fa1..7285d3b 100644
--- a/rocks.c
+++ b/rocks.c
@@ -46,6 +46,7 @@ load_rocks(void)
 		snprintf(a, ROCK_LEN, "sprites/rock%02d.png", i);
 		load_sprite(SPRITE(&prototypes[i]), a);
 		prototypes[i].sprite_type = ROCK;
+		prototypes[i].flags = ALL_FLAGS;
 	}
 
 	memset(rocks, 0, MAXROCKS*sizeof(struct rock));
@@ -206,7 +207,7 @@ blast_rocks(float x, float y, float radius)
 	float dx, dy, n;
 
 	for(i=0; i<MAXROCKS; i++) {
-		if(rocks[i].sprite_type == NONE) continue;
+		if(!rocks[i].flags) continue;
 		r = SPRITE(&rocks[i]);
 		if(r->x <= 0) continue;
 
@@ -218,6 +219,7 @@ blast_rocks(float x, float y, float radius)
 			n *= 15;
 			r->dx += 54.0*dx/n;
 			r->dy += 54.0*dy/n;
+			r->flags &= ~COLLIDE_FLAG;
 		}
 	}
 }
diff --git a/sprite.c b/sprite.c
index 1609368..db5ac8d 100644
--- a/sprite.c
+++ b/sprite.c
@@ -111,7 +111,6 @@ square(int x, int y, int set)
 void
 add_sprite(Sprite *s)
 {
-	if(s->type < 0) s->type = -s->type;
 	insert_sprite(square(s->x, s->y, set), s);
 }
 
@@ -123,18 +122,19 @@ reset_sprites(void)
 	for(i=0; i<gw*gh; i++)
 		while(sprites[set][i]) {
 			Sprite *s = remove_sprite(&sprites[set][i]);
-			if(s->type < 0) s->type = -s->type;
 			insert_sprite(&free_sprites[s->type], s);
-			if(s->type > 0) s->type = -s->type;
+			s->flags = 0;
 		}
 }
 
 void
 move_sprite(Sprite *s)
 {
-	// move it.
-	s->x += (s->dx - screendx)*t_frame;
-	s->y += (s->dy - screendy)*t_frame;
+	if(s->flags & DRAW_FLAG) {
+		// move it.
+		s->x += (s->dx - screendx)*t_frame;
+		s->y += (s->dy - screendy)*t_frame;
+	}
 }
 
 void
@@ -143,9 +143,8 @@ sort_sprite(Sprite *s)
 	// clip it, or sort it into the other set of sprites.
 	if(s->x + s->w < 0 || s->x >= XSIZE
 	   || s->y + s->h < 0 || s->y >= YSIZE) {
-		if(s->type < 0) s->type = -s->type;
 		insert_sprite(&free_sprites[s->type], s);
-		if(s->type > 0) s->type = -s->type;
+		s->flags = 0;
 	} else insert_sprite(square(s->x, s->y, 1-set), s);
 }
 
@@ -214,7 +213,7 @@ collide(Sprite *a, Sprite *b)
 {
 	int dx, dy, xov, yov;
 
-	if(a->type < 0 || b->type < 0) return false;
+	if(!COLLIDES(a) || !COLLIDES(b)) return false;
 
 	if(b->x < a->x) { Sprite *tmp = a; a = b; b = tmp; }
 
@@ -306,7 +305,7 @@ int
 pixel_hit_in_square(Sprite *r, float x, float y)
 {
 	for(; r; r=r->next) {
-		if(r->type >= 0 && pixel_collide(r, x, y)) return 1;
+		if(COLLIDES(r) && pixel_collide(r, x, y)) return 1;
 	}
 	return 0;
 }
diff --git a/sprite.h b/sprite.h
index f9070b4..2e7ad3b 100644
--- a/sprite.h
+++ b/sprite.h
@@ -15,6 +15,7 @@ typedef struct sprite Sprite;
 
 struct sprite {
 	int8_t type;
+	int8_t flags;
 	Sprite *next;
 	float x, y;
 	float dx, dy;
@@ -25,6 +26,13 @@ struct sprite {
 	uint32_t area;
 };
 
+#define MOVE_FLAG 1
+#define DRAW_FLAG 2
+#define COLLIDE_FLAG 4
+#define ALL_FLAGS (~0)
+
+#define COLLIDES(sprite) ((sprite)->flags & COLLIDE_FLAG)
+
 Sprite *free_sprites[N_TYPES];  // lists of free sprites, by type.
 
 void do_collision(Sprite *a, Sprite *b);
@@ -48,6 +56,7 @@ void bounce(Sprite *a, Sprite *b);
 struct ship {
 	// core sprite fields
 	int8_t sprite_type;
+	int8_t flags;
 	struct ship *next;
 	float x, y;
 	float dx, dy;
@@ -64,6 +73,7 @@ struct ship {
 struct rock {
 	// core sprite fields
 	int8_t sprite_type;
+	int8_t flags;
 	struct rock *next;
 	float x, y;
 	float dx, dy;
@@ -99,9 +109,10 @@ static inline void
 draw_sprite(Sprite *s)
 {
 	SDL_Rect dest;
-	if(s->type < 0) return;
-	dest.x = s->x; dest.y = s->y;
-	SDL_BlitSurface(s->image, NULL, surf_screen, &dest);
+	if(s->flags & DRAW_FLAG) {
+		dest.x = s->x; dest.y = s->y;
+		SDL_BlitSurface(s->image, NULL, surf_screen, &dest);
+	}
 }
 
 #endif // VOR_SPRITE_H
-- 
1.7.10.4