adicionado libphysics

1 files changed, 52 insertions, 0 deletions

diff --git a/libphysics/aabb.c b/libphysics/aabb.c
new file mode 100644
index 0000000..59648c8
--- /dev/null
+++ b/libphysics/aabb.c
@@ -0,0 +1,52 @@
+#include <vecmath.h>
+#include <physics.h>
+#include <stdlib.h>
+
+#include "dat.h"
+
+static void mink(Body *a, Body *b, vec2 min, vec2 max);
+
+int
+phxaabbcheck(Body *a, Body *b)
+{
+	vec2 min, max;
+	mink(a, b, min, max);
+	return min[0] < 0 && max[0] > 0 && min[1] < 0 && max[1] > 0;
+}
+
+void
+phxaabbresolv(Body *a, Body *b, vec2 p, vec2 n)
+{
+	vec2 min, max;
+	mink(a, b, min, max);
+
+	float hx = fabsf(min[0]) < fabsf(max[0]) ? fabsf(min[0]) : fabsf(max[0]);
+	float hy = fabsf(min[1]) < fabsf(max[1]) ? fabsf(min[1]) : fabsf(max[1]);
+
+	if(hx < hy) {
+		n[1] = 0.0;
+		n[0] = (fabsf(min[0]) < fabsf(max[0]) ? -1.0 : 1.0);
+	} else {
+		n[0] = 0;
+		n[1] = (fabsf(min[1]) < fabsf(max[1]) ? -1.0 : 1.0);
+	}
+	
+	vec2_mul(p, (vec2){ hx, hy }, n);
+}
+
+
+void 
+mink(Body *a, Body *b, vec2 min, vec2 max)
+{
+	float p[2], s[2];
+	
+	for(int i = 0; i < 2; i++) {
+		s[i] = a->size[i] + b->size[i];
+		p[i] = a->pos[i] - b->pos[i];
+	}
+	
+	for(int i = 0; i < 2; i++) {
+		min[i] = p[i] - s[i];
+		max[i] = p[i] + s[i];
+	}
+}