X-Git-Url: https://jasonwoof.com/gitweb/?p=vor.git;a=blobdiff_plain;f=sprite.c;h=1609368d324ab653070e6315e90d75b2260ed774;hp=a772668b104254a65b57153b3b52d65d136be1db;hb=e06676edd300c8a85d2e6715427e7e22e55c7670;hpb=22c206a9ad669ebf46c38ce78079a6be4238e0d9

diff --git a/sprite.c b/sprite.c
index a772668..1609368 100644
--- a/sprite.c
+++ b/sprite.c
@@ -33,6 +33,7 @@ get_shape(Sprite *s)
 	uint16_t *px, transp;
 	uint32_t bits = 0, bit, *p;
 
+	s->area = 0;
 	if(s->image->format->BytesPerPixel != 2) {
 		fprintf(stderr, "get_shape(): not a 16-bit image!\n");
 		exit(1);
@@ -55,7 +56,7 @@ get_shape(Sprite *s)
 		bit = 0;
 		for(x=0; x<s->image->w; x++) {
 			if(!bit) { bits = 0; bit = 0x80000000; }
-			if(*px++ != transp) { bits |= bit; }
+			if(*px++ != transp) { bits |= bit; s->area++; }
 			bit >>= 1;
 			if(!bit || x == s->image->w - 1) { *(p++) = bits; }
 		}
@@ -110,10 +111,25 @@ 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);
 }
 
 void
+reset_sprites(void)
+{
+	int i;
+
+	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;
+		}
+}
+
+void
 move_sprite(Sprite *s)
 {
 	// move it.
@@ -127,8 +143,9 @@ 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);
-		s->type = NONE;
+		if(s->type > 0) s->type = -s->type;
 	} else insert_sprite(square(s->x, s->y, 1-set), s);
 }
 
@@ -138,7 +155,7 @@ move_sprites(void)
 	int sq;
 	Sprite **head;
 
-	// Move all the sprites (position and set)
+	// Move all the sprites
 	for(sq=0; sq<gw*gh; sq++) {
 		head=&sprites[set][sq];
 		while(*head) {
@@ -197,6 +214,8 @@ collide(Sprite *a, Sprite *b)
 {
 	int dx, dy, xov, yov;
 
+	if(a->type < 0 || b->type < 0) return false;
+
 	if(b->x < a->x) { Sprite *tmp = a; a = b; b = tmp; }
 
 	dx = b->x - a->x;
@@ -211,6 +230,28 @@ collide(Sprite *a, Sprite *b)
 	else return mask_collide(xov, yov, a, b);
 }
 
+void
+collide_with_list(Sprite *s, Sprite *list)
+{
+	for(; list; list=list->next)
+		if(collide(s, list)) do_collision(s, list);
+}
+
+void
+collisions(void)
+{
+	int i, end = gw*gh;
+	Sprite *s;
+	for(i=0; i<end; i++) {
+		for(s=sprites[set][i]; s; s=s->next) {
+			collide_with_list(s, s->next);
+			if(i+1 < end) collide_with_list(s, sprites[set][i+1]);
+			if(i+gw < end) collide_with_list(s, sprites[set][i+gw]);
+			if(i+gw+1 < end) collide_with_list(s, sprites[set][i+gw+1]);
+		}
+	}
+}
+
 Sprite *
 hit_in_square(Sprite *r, Sprite *s)
 {
@@ -265,7 +306,7 @@ int
 pixel_hit_in_square(Sprite *r, float x, float y)
 {
 	for(; r; r=r->next) {
-		if(pixel_collide(r, x, y)) return 1;
+		if(r->type >= 0 && pixel_collide(r, x, y)) return 1;
 	}
 	return 0;
 }
@@ -285,19 +326,35 @@ pixel_collides(float x, float y)
 	return false;
 }
 
+
+static float
+sprite_mass(Sprite *s)
+{
+	if(s->type == SHIP) return s->area;
+	else if(s->type == ROCK) return 3*s->area;
+	else return 0;
+}
+
 void
 bounce(Sprite *a, Sprite *b)
 {
 	float x, y, n;
-	float na, nb;
+	float va, vb;
+	float ma, mb, mr;
 
+	// (x, y) is unit vector pointing from A's center to B's center.
 	x = (b->x + b->w / 2) - (a->x + a->w / 2);
 	y = (b->y + b->h / 2) - (a->y + a->h / 2);
 	n = sqrt(x*x + y*y); x /= n; y /= n;
 
-	na = (x*a->dx + y*a->dy); // sqrt(a->dx*a->dx + a->dy*a->dy);
-	nb = (x*b->dx + y*b->dy); // sqrt(b->dx*b->dx + b->dy*b->dy);
+	// velocities along (x, y), or 0 if already moving away.
+	va = max(x*a->dx + y*a->dy, 0);
+	vb = min(x*b->dx + y*b->dy, 0);
+
+	// mass ratio
+	ma = sprite_mass(a); mb = sprite_mass(b);
+	if(ma && mb) mr = mb/ma; else mr = 1;
 
-	a->dx += x*(nb-na); a->dy += y*(nb-na);
-	b->dx += x*(na-nb); b->dy += y*(na-nb);
+	a->dx += x*(mb*vb - ma*va)/ma; a->dy += y*(mb*vb - ma*va)/ma;
+	b->dx += x*(ma*va - mb*vb)/mb; b->dy += y*(ma*va - mb*vb)/mb;
 }