shithub: fnt

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simpler area equation for straight lines

--- a/rast.c

+++ b/rast.c

@@ -354,9 +354,14 @@

 	s₀ = 0;

 	for(i = 0; i < ns; i++){

 #define det(a,b) (a.x*b.y - a.y*b.x)

-#define cQ(s) (det(s.p0, s.p1) + det(s.p1, s.p2) + det(s.p0, s.p2)/2.0)/3.0

-		s₀ -= cQ(seg[i]);

+#define cL(s) det(s.p0, s.p2)/2.0

+#define cQ(s) (2*det(s.p0, s.p1) + 2*det(s.p1, s.p2) + det(s.p0, s.p2))/6.0

+		if(seg[i].p1.x == seg[i].p2.x && seg[i].p1.y == seg[i].p2.y)

+			s₀ -= cL(seg[i]);

+		else

+			s₀ -= cQ(seg[i]);

 #undef det

+#undef cL

 #undef cQ

 	}

 	s₀ *= QBZR_PIX_SCALE;