X-Git-Url: https://jasonwoof.com/gitweb/?p=vor.git;a=blobdiff_plain;f=sprite.c;h=1a35a6a16266a6c3fb4b0db34c86d31063c30988;hp=760af111e0ac65253a7b9dd8dfbc4c9f721462d3;hb=37b3a2e06abc694205e843a573c4bb2eaaabb730;hpb=3f9238432d3b902a7744ad5a61f61995d67267a5

diff --git a/sprite.c b/sprite.c
index 760af11..1a35a6a 100644
--- a/sprite.c
+++ b/sprite.c
@@ -1,29 +1,48 @@
+#include <math.h>
 #include <stdlib.h>
+#include <string.h>
+#include "config.h"
 #include "common.h"
+#include "globals.h"
 #include "sprite.h"
+#include "rocks.h"
 
-void
-load_sprite(Sprite *s, char *filename)
-{
-	s->image = load_image(filename);
-	if(s->image) get_shape(s);
-}
+SDL_Surface *load_image(char *filename);
+void load_ship(void);
 
-void
+// 2 sets of sprites, sorted by position
+static Sprite **sprites[2] = { NULL, NULL };
+
+// which set are we using?
+static int set = 0;
+
+// size of squares into which sprites are sorted.
+static int grid_size = 0;
+
+// screen size in grid squares.
+static int gw = 0, gh = 0;
+
+// lists of free sprites, by type.
+Sprite *free_sprites[N_TYPES];
+
+
+static void
 get_shape(Sprite *s)
 {
 	int x, y;
 	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);
 	}
 
 	s->w = s->image->w; s->h = s->image->h;
-	s->mask_w = ((s->image->w+31)>>5);
-	s->mask = malloc(4*s->mask_w*s->h);
+	grid_size = max(grid_size, max(s->w, s->h));
+	s->mask_w = ((s->w+31)>>5);
+	s->mask = malloc(s->mask_w*s->h*sizeof(uint32_t));
 	if(!s->mask) {
 		fprintf(stderr, "get_shape(): can't allocate bitmask.\n");
 		exit(1);
@@ -37,7 +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; }
 		}
@@ -46,6 +65,106 @@ get_shape(Sprite *s)
 	SDL_UnlockSurface(s->image);
 }
 
+
+void
+load_sprite(Sprite *s, char *filename)
+{
+	s->image = load_image(filename);
+	if(s->image) get_shape(s);
+}
+
+
+static void
+load_sprites(void)
+{
+	load_ship();
+	load_rocks();
+}
+
+
+void
+init_sprites(void)
+{
+	load_sprites();
+
+	grid_size = grid_size * 3 / 2;
+	gw = (XSIZE-1 + 2*grid_size) / grid_size;
+	gh = (YSIZE-1 + 2*grid_size) / grid_size;
+
+	sprites[0] = malloc(2 * gw * gh * sizeof(Sprite *));
+	sprites[1] = (void *)sprites[0] + gw * gh * sizeof(Sprite *);
+	if(!sprites[0]) {
+		fprintf(stderr, "init_sprites(): can't allocate grid squares.\n");
+		exit(1);
+	}
+	memset(sprites[0], 0, 2 * gw * gh * sizeof(Sprite *));
+	set = 0;
+}
+
+static inline Sprite **
+square(int x, int y, int set)
+{
+	int b = (x+grid_size)/grid_size + gw*((y+grid_size)/grid_size);
+	return &sprites[set][b];
+}
+
+void
+add_sprite(Sprite *s)
+{
+	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]);
+			insert_sprite(&free_sprites[s->type], s);
+			s->flags = 0;
+		}
+}
+
+void
+move_sprite(Sprite *s)
+{
+	if(s->flags & MOVE) {
+		s->x += (s->dx - screendx)*t_frame;
+		s->y += (s->dy - screendy)*t_frame;
+	}
+}
+
+void
+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) {
+		insert_sprite(&free_sprites[s->type], s);
+		s->flags = 0;
+	} else insert_sprite(square(s->x, s->y, 1-set), s);
+}
+
+void
+move_sprites(void)
+{
+	int sq;
+	Sprite **head;
+
+	// Move all the sprites
+	for(sq=0; sq<gw*gh; sq++) {
+		head=&sprites[set][sq];
+		while(*head) {
+			Sprite *s = remove_sprite(head);
+			move_sprite(s); sort_sprite(s);
+		}
+	}
+	set = 1-set;  // switch to other set of sprites.
+}
+
+
 static int
 line_collide(int xov, unsigned bit, uint32_t *amask, uint32_t *bmask)
 {
@@ -93,6 +212,8 @@ collide(Sprite *a, Sprite *b)
 {
 	int dx, dy, xov, yov;
 
+	if(!COLLIDES(a) || !COLLIDES(b)) return false;
+
 	if(b->x < a->x) { Sprite *tmp = a; a = b; b = tmp; }
 
 	dx = b->x - a->x;
@@ -101,16 +222,78 @@ collide(Sprite *a, Sprite *b)
 	xov = max(min(a->w - dx, b->w), 0);
 
 	if(dy >= 0) yov = max(min(a->h - dy, b->h), 0);
-	else yov = -max(min(a->h - -dy, b->h), 0);
+	else yov = -max(min(b->h - -dy, a->h), 0);
 
 	if(xov == 0 || yov == 0) return false;
 	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)
+{
+	for(; r; r=r->next)
+		if(collide(r, s)) break;
+	return r;
+}
+
+Sprite *
+collides(Sprite *s)
+{
+	int l, r, t, b;
+	Sprite **sq;
+	Sprite *c;
+
+	l = (s->x + grid_size) / grid_size;
+	r = (s->x + s->w + grid_size) / grid_size;
+	t = (s->y + grid_size) / grid_size;
+	b = (s->y + s->h + grid_size) / grid_size;
+	sq = &sprites[set][l + t*gw];
+
+	if((c = hit_in_square(*sq, s))) return c;
+	if(l > 0 && (c = hit_in_square(*(sq-1), s))) return c;
+	if(t > 0 && (c = hit_in_square(*(sq-gw), s))) return c;
+	if(l > 0 && t > 0 && (c = hit_in_square(*(sq-1-gw), s))) return c;
+
+	if(r > l) {
+		if((c = hit_in_square(*(sq+1), s))) return c;
+		if(t > 0 && hit_in_square(*(sq+1-gw), s)) return c;
+	}
+	if(b > t) {
+		if((c = hit_in_square(*(sq+gw), s))) return c;
+		if(l > 0 && (c = hit_in_square(*(sq-1+gw), s))) return c;
+	}
+	if(r > l && b > t && (c = hit_in_square(*(sq+1+gw), s))) return c;
+	return NULL;
+}
+
 int
 pixel_collide(Sprite *s, int x, int y)
 {
 	uint32_t pmask;
+
+	if(!COLLIDES(s)) return false;
 	
 	if(x < s->x || y < s->y || x >= s->x + s->w || y >= s->y + s->h) return 0;
 
@@ -118,3 +301,61 @@ pixel_collide(Sprite *s, int x, int y)
 	pmask = 0x80000000 >> (x&0x1f);
 	return s->mask[(y*s->mask_w) + (x>>5)] & pmask;
 }
+
+Sprite *
+pixel_hit_in_square(Sprite *r, float x, float y)
+{
+	for(; r; r=r->next) {
+		if(COLLIDES(r) && pixel_collide(r, x, y)) return r;
+	}
+	return 0;
+}
+
+Sprite *
+pixel_collides(float x, float y)
+{
+	int l, t;
+	Sprite **sq;
+	Sprite *ret;
+
+	l = (x + grid_size) / grid_size; t = (y + grid_size) / grid_size;
+	sq = &sprites[set][l + t*gw];
+	if((ret = pixel_hit_in_square(*sq, x, y))) return ret;
+	if(l > 0 && (ret = pixel_hit_in_square(*(sq-1), x, y))) return ret;
+	if(t > 0 && (ret = pixel_hit_in_square(*(sq-gw), x, y))) return ret;
+	if(l > 0 && t > 0 && (ret = pixel_hit_in_square(*(sq-1-gw), x, y))) return ret;
+	return 0;
+}
+
+
+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 va, vb, vc;
+	float ma, mb;
+
+	// (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;
+
+	// velocities along (x, y), or 0 if already moving away.
+	va = x*a->dx + y*a->dy;
+	vb = x*b->dx + y*b->dy;
+	if(vb-va > 0) return;
+
+	ma = sprite_mass(a); mb = sprite_mass(b);
+	vc = (va*ma + vb*mb) / (ma+mb);
+
+	a->dx += 2*x*(vc-va); a->dy += 2*y*(vc-va);
+	b->dx += 2*x*(vc-vb); b->dy += 2*y*(vc-vb);
+}