X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=hexagon.c;h=264734c6c95ee17493d39f0cad5ce411821377da;hb=5011228dceecadb0c1ed94c2635d6c0342e2af48;hp=123e5cfa2539928b357a178f3bef9402c685df0f;hpb=b23bb67f8c88ba23499d1c6e7b444b6561aeb49a;p=hexagon

diff --git a/hexagon.c b/hexagon.c
index 123e5cf..264734c 100644
--- a/hexagon.c
+++ b/hexagon.c
@@ -31,6 +31,17 @@ double HL_fand[16] = {
 	.577350269189625764509148780502, 0.0
 };
 
+double HL_hfand[16] = {
+	0.0, 0.0,
+	0.0, .577350269189625764509148780502,
+	0.5, .288675134594812882254574390251,
+	0.5, -.288675134594812882254574390251,
+	0.0, -.577350269189625764509148780502,
+	-0.5, -.288675134594812882254574390251,
+	-0.5, .288675134594812882254574390251,
+	0.0, .577350269189625764509148780502
+};
+
 float HL_fanf[16] = {
 	0.0f, 0.0f,
 	.577350269189625764509148780502f, 0.0f,
@@ -42,6 +53,21 @@ float HL_fanf[16] = {
 	.577350269189625764509148780502f, 0.0f
 };
 
+float HL_hfanf[16] = {
+	0.0f, 0.0f,
+	0.0f, .577350269189625764509148780502f,
+	0.5f, .288675134594812882254574390251f,
+	0.5f, -.288675134594812882254574390251f,
+	0.0f, -.577350269189625764509148780502f,
+	-0.5f, -.288675134594812882254574390251f,
+	-0.5f, .288675134594812882254574390251f,
+	0.0f, .577350269189625764509148780502f
+};
+
+/* size of a square that will exactly fit in a hexagon */
+/* 2.0/(1+sqrt(3.0)) */
+double HL_square = .73205080756887729352;
+
 /* these all are for a hex one unit across */
 static double          hexptvd[6][2] = {
 	{.577350269189625764509148780502, 0.0},	/* 1.0/sqrt3 */
@@ -459,14 +485,16 @@ static int hex_iso(struct hex *h) {
 
 #endif
 
+#define COS30 (.866025403784438646763723170752)
+
 int HL_hexbin(double width, double x, double y, int *i, int *j) {
 	double z, rx, ry, rz;
 	double abs_dx, abs_dy, abs_dz;
 	int ix, iy, iz, s;
 	struct hex h;
 
-	/* TODO just hard-code this cosine */
-	x = x / cos(30 * M_PI / 180.0); /* rotated X coord */
+	/*x = x / cos(30 * M_PI / 180.0); */ /* rotated X coord */
+	x = x / COS30;
 	y = y - x / 2.0; /* adjustment for rotated X */
 
 	/* adjust for actual hexwidth */