(20111215) 12:00

Util.h

@@ -0,0 +1,44 @@
+#ifndef _UTIL_H_
+#define _UTIL_H_
+
+
+/////////////////////////////
+// SolveQuadratic
+//
+// Solves a Quadratic equation using a, b and c coeficients.
+int SolveQuadratic(float a,float b,float c,float *Rmin,float *Rmax);
+
+
+////////////////////////////////////////////////
+// vec2 //
+//////////
+// A 2D vector.
+typedef float vec2[2];
+#define vec2_set(v,x,y) (v)[0]=(x);(v)[1]=(y);
+#define vec2_copy(v1,v2) (v1)[0]=(v2)[0];(v1)[1]=(v2)[1];
+#define vec2_plus(v,v1,v2) (v)[0]=(v1)[0]+(v2)[0];(v)[1]=(v1)[1]+(v2)[1];
+#define vec2_minus(v,v1,v2) (v)[0]=(v1)[0]-(v2)[0];(v)[1]=(v1)[1]-(v2)[1];
+#define vec2_scale(v,v1,s) (v)[0]=(v1)[0]*(s);(v)[1]=(v1)[1]*(s);
+#define vec2_dot(v1,v2) ((v1)[0]*(v2)[0]+(v1)[1]*(v2)[1])
+
+
+/////////////////////////////
+// Intersec_RayUnitCircle
+//
+// Intersection between a ray and a Unit Circle.
+int Intersec_RayUnitCircle(vec2 orig,vec2 vel,vec2 center,float *t);
+
+
+
+
+/////////////////////////////
+// Intersect_CircleCircle
+//
+// Colision point of a circle against another circle.
+int Colision_CircleCircle(
+	vec2 ca[2],float ra,
+	vec2 cb,float rb,
+	float *t,vec2 n);
+
+
+#endif