adicionado libphysics

1 files changed, 138 insertions, 0 deletions

diff --git a/libphysics/tick.c b/libphysics/tick.c
new file mode 100644
index 0000000..c6399ab
--- /dev/null
+++ b/libphysics/tick.c
@@ -0,0 +1,138 @@
+#include <vecmath.h>
+#include <physics.h>
+#include <stdlib.h>
+
+#include "dat.h"
+
+#define PHX_TICK_TIME (1.0 / 480.0)
+
+static void tick(void);
+static void mapcollision(Body *);
+static void bodycollision(Body *);
+
+#define TILE_SIZE 16
+
+void
+phxtick(float delta)
+{
+	static float time;
+
+	time += delta;
+	if(time >= PHX_TICK_TIME > 0) {
+		while(time >= PHX_TICK_TIME) {
+			tick();
+			time -= PHX_TICK_TIME;
+		}
+		for(int i = 0; i < phxbodypoolsize; i++) {
+			Body *b = phxbodypool + i;
+			if(!b->active)
+				continue;
+
+			b->accel[0] = 0.0;
+			b->accel[1] = 0.0;
+		}
+	}
+}
+
+void
+tick(void)
+{
+	for(int i = 0; i < phxbodypoolsize; i++) {
+		Body *b = phxbodypool + i;
+		if(!b->active)
+			continue;
+
+		vec2_add_scaled(b->vel, b->vel, b->accel, PHX_TICK_TIME);
+	}
+
+	for(int i = 0; i < phxbodypoolsize; i++) {
+		Body *b = phxbodypool + i;
+		if(!b->active)
+			continue;
+
+		mapcollision(b);
+		bodycollision(b);
+	}
+
+	for(int i = 0; i < phxbodypoolsize; i++) {
+		Body *b = phxbodypool + i;
+		if(!b->active)
+			continue;
+
+		vec2_add_scaled(b->pos, b->pos, b->vel, PHX_TICK_TIME);
+	}
+}
+
+void
+mapcollision(Body *a)
+{
+	int minx, miny, maxx, maxy;
+
+	minx = ((int)(a->pos[0] - a->size[0]) / TILE_SIZE) * TILE_SIZE;
+	maxx = ((int)(a->pos[0] + a->size[0]) / TILE_SIZE) * TILE_SIZE;
+	miny = ((int)(a->pos[1] - a->size[1]) / TILE_SIZE) * TILE_SIZE;
+	maxy = ((int)(a->pos[1] + a->size[1]) / TILE_SIZE) * TILE_SIZE;
+
+	for(int y = miny; y <= maxy + TILE_SIZE; y += TILE_SIZE)
+		for(int x = minx; x <= maxx + TILE_SIZE; x += TILE_SIZE) {
+			int tilex = x / (2 * TILE_SIZE);
+			int tiley = y / (2 * TILE_SIZE);
+
+			if(tilex < 0 || tilex >= phxmapwidth)
+				continue;
+			if(tiley < 0 || tiley >= phxmapheight)
+				continue;
+
+			if(!phxmapbuffer[tilex + tiley * phxmapwidth])
+				continue;
+
+			Body b = {
+				.pos = {
+					tilex * TILE_SIZE * 2.0,
+					tiley * TILE_SIZE * 2.0,
+				},
+				.size = { TILE_SIZE, TILE_SIZE },
+			};
+
+			if(phxaabbcheck(a, &b)) {
+				float p[2], n[2];
+				phxaabbresolv(a, &b, p, n);
+
+				vec2_sub(a->pos, a->pos, p);
+
+				if(p[0] != 0.0) {
+					a->vel[0] = 0;
+				} else {
+					a->vel[1] = 0;
+				}
+			}
+		}
+}
+
+void
+bodycollision(Body *a)
+{
+	CollisionEvent event;
+	for(Body *b = a + 1; b < (a + phxbodypoolsize); b++) {
+		if(!b->active)
+			continue;
+
+		if(phxaabbcheck(a, b)) {
+			float p[2], n[2], rvel[2], j;
+			phxaabbresolv(a, b, p, n);
+
+			vec2_sub(rvel, a->vel, b->vel);
+			j = vec2_dot(rvel, n);
+
+			vec2_sub_scaled(a->vel, a->vel, n,  0.5);
+			vec2_sub_scaled(b->vel, b->vel, n, -0.5);
+
+			vec2_sub_scaled(a->pos, a->pos, p,  0.5);
+			vec2_sub_scaled(b->pos, b->pos, p, -0.5);
+
+			event.body1 = a;
+			event.body2 = b;
+			phxenqevent(&event);
+		}
+	}
+}