六边形算法：
我把六边形铺满的分布图进行了切分，切分为矩形，每个矩形中有一个六边形、4个三角形、两个小长方形，依次计算。边界判断上，采用主流的MP>MN的方式（M为上边界对称点，N为与六边形的交点，p为要判断的点，如下图）。
实际效果（双色对比）：
拾取效果：
代码：
1 /// <summary> 2 /// 根据参数获得六边形索引 3 /// </summary> 4 /// <param name="width">页面宽度</param> 5 /// <param name="height">页面长度</param> 6 /// <param name="r">六边形边长</param> 7 /// <param name="thickness">六边形上下拓扑半间距</param> 8 /// <param name="flat">扁平化程度（由于计算过程中，thickness在侧向拓扑中作用减小，故增加了这个系数）</param> 9 /// <param name="x">横坐标</param> 10 /// <param name="y">纵坐标</param> 11 /// <param name="transparent">透明度设置，一般位置为正常值；如果是六边形边界位置的过渡色，减半</param> 12 /// <returns></returns> 13 public static int[] GetHexGridIndex(int width, int height, int r, int thickness, int flat, int x, int y, ref byte transparent) 14 { 15 //中心点索引（长方形中的六边形的索引） 16 int indexX = (x / 3) / r * 2; 17 int indexY = (int)((int)(y / Math.Sqrt(3)) / r + indexX / 2); 18 19 //中心点坐标 20 int centerX = r + (int)(1.5 * r * indexX); 21 int centerY = (int)(Math.Sqrt(3) * 0.5 * r * (1 + 2 * indexY - indexX)); 22 23 //位于六边外框之外 24 if (x > (centerX + r)) 25 { 26 if (y > centerY + thickness)//右下 27 { 28 indexX++; 29 indexY++; 30 } 31 else if (y < centerY - thickness)//右上 32 { 33 indexX++; 34 } 35 else//中间部分以及外延部分 36 { 37 indexX = -1; 38 indexY = -1; 39 } 40 } 41 else//六边外框之内 42 { 43 if (x > centerX + r / 2)//右半区 44 { 45 if (y > centerY)//右下 46 { 47 var M = Math.Sqrt(3) / 2 * r + centerY;//上边界点 48 var N = (centerX + r - x) * Math.Sqrt(3) + centerY;//六边形边界点 49 var MP = (int)(M - y); 50 var MN = (int)(M - N); 51 if (MP > (MN + thickness * flat))//六边形内部 52 { 53 //索引不变 54 } 55 else if (MP < (MN - thickness * flat))//六边形外部 56 { 57 indexX++; 58 indexY++; 59 } 60 else//交界区 61 { 62 if (MP == MN + thickness * flat)//紧靠内部 63 { 64 transparent = (byte)(transparent / 2); 65 ////去除右侧尖尖 66 if (x == centerX + r - thickness) 67 { 68 indexX = -1; 69 indexY = -1; 70 } 71 } 72 else if (MP == MN - thickness * flat)//紧靠外部 73 { 74 indexX++; 75 indexY++; 76 transparent = (byte)(transparent / 2); 77 } 78 else//中间区 79 { 80 indexX = -1; 81 indexY = -1; 82 } 83 } 84 } 85 else//右上 86 { 87 var M = centerY - Math.Sqrt(3) / 2 * r; 88 var N = centerY - (centerX + r - x) * Math.Sqrt(3); 89 var MP = (int)(y - M); 90 var MN = (int)(N - M); 91 if (MP > (MN + thickness * flat))//内部 92 { 93 ////索引不变，但是要去除右侧尖尖 94 if (x == centerX + r - thickness) 95 { 96 indexX = -1; 97 indexY = -1; 98 } 99 } 100 else if (MP < (MN - thickness * flat))//外部,索引单变 101 { 102 indexX++; 103 } 104 else 105 { 106 if (MP == MN + thickness * flat)//里侧 107 { 108 transparent = (byte)(transparent / 2); 109 if (x == centerX + r - thickness - 1)////去除右侧尖尖 110 { 111 indexX = -1; 112 indexY = -1; 113 } 114 } 115 else if (MP == MN - thickness * flat)//外侧 116 { 117 indexX++; 118 transparent = (byte)(transparent / 2); 119 } 120 else 121 { 122 indexX = -1; 123 indexY = -1; 124 } 125 } 126 } 127 } 128 else if (x < centerX - r / 2)//左半区 129 { 130 if (y < centerY)//左上 131 { 132 var M = centerY - Math.Sqrt(3) / 2 * r; 133 var N = centerY + (centerX - r - x) * Math.Sqrt(3); 134 var MP = (int)(y - M); 135 var MN = (int)(N - M); 136 if (MP > (MN + thickness * flat)) 137 { 138 //索引不变 139 } 140 else if (MP < (MN - thickness * flat))//索引单变 141 { 142 indexX--; 143 indexY--; 144 } 145 else 146 { 147 if (MP == MN + thickness * flat)//里侧 148 { 149 transparent = (byte)(transparent / 2); 150 if (x == centerX - r + thickness + 1) 151 { 152 indexX = -1; 153 indexY = -1; 154 } 155 } 156 else if (MP == MN - thickness * flat)//外侧 157 { 158 indexX--; 159 indexY--; 160 transparent = (byte)(transparent / 2); 161 } 162 else 163 { 164 indexX = -1; 165 indexY = -1; 166 } 167 } 168 } 169 else//左下 170 { 171 var M = centerY + Math.Sqrt(3) / 2 * r; 172 var N = centerY - (centerX - r - x) * Math.Sqrt(3); 173 var MP = (int)(M - y); 174 var MN = (int)(M - N); 175 if (MP > (MN + thickness * flat))//内部 176 { 177 if (x == centerX - r + thickness + 1)//索引不变，但是要清除突兀部分 178 { 179 indexX = -1; 180 indexY = -1; 181 } 182 } 183 else if (MP < (MN - thickness * flat))//索引单变 184 { 185 indexX--; 186 } 187 else//隔离带 188 { 189 if (MP == MN + thickness * flat)//里侧 190 { 191 transparent = (byte)(transparent / 2); 192 if (x < centerX - r + thickness * flat - 1) 193 { 194 indexX = -1; 195 indexY = -1; 196 } 197 } 198 else if (MP == MN - thickness * flat)//外侧 199 { 200 indexX--; 201 transparent = (byte)(transparent / 2); 202 } 203 else 204 { 205 indexX = -1; 206 indexY = -1; 207 } 208 } 209 } 210 } 211 else//六边形竖条内部 212 { 213 var step = (int)Math.Round(Math.Sqrt(3) * r); 214 var remainder = y % step; 215 216 if (remainder <= thickness)//上缓冲 217 { 218 indexX = -1; 219 indexY = -1; 220 } 221 else if (step - remainder - 1 <= thickness)//下缓冲 222 { 223 indexX = -1; 224 indexY = -1; 225 } 226 227 if ((remainder - 1 == thickness) || (step - remainder - 2 == thickness))//六边形上下四圆角控制（分为上下半身） 228 { 229 //去除四点 230 var first = (int)(centerX - r / 2); 231 var second = (int)Math.Ceiling((double)centerX - r / 2); 232 var third = (int)(centerX + r / 2); 233 var fourth = (int)Math.Ceiling((double)centerX + r / 2); 234 235 if (x == first || x == second || x == third || x == fourth) 236 { 237 indexX = -1; 238 indexY = -1; 239 } 240 } 241 } 242 } 243 244 //right超出界面的设置 245 var rightIndex = Math.Floor(Convert.ToDouble(width - r - r) / (3 * Convert.ToDouble(r) / 2)); 246 bool xx = indexX > rightIndex; 247 if (indexX > rightIndex) 248 { 249 indexX = -1; 250 indexY = -1; 251 } 252 253 //bottom超出界面的设置 254 var bottomIndex = Math.Floor(height / (r * Math.Sqrt(3))) - 1; 255 //基础位置为（0，bottomIndex+1） 256 if (indexY > bottomIndex)//&&((indexX-0)%(indexY-(bottomIndex+1))==0)) 257 { 258 //下分三种情况，第一种是首索引 259 var isOrNotFirstIndex = indexX == 0 && (indexY == bottomIndex + 1); 260 //与首索引同行位置的索引 261 var isOrNotFirstLineIndex = indexX == (indexY - (bottomIndex + 1)) * 2; 262 //侧移索引 263 var isOrNotSideSwayIndex = (indexX + 1) == (indexY - (bottomIndex + 1)) * 2; 264 265 if (isOrNotFirstIndex || isOrNotFirstLineIndex || isOrNotSideSwayIndex) 266 { 267 indexX = -1; 268 indexY = -1; 269 } 270 } 271 272 return new int[] { indexX, indexY }; 273 }