blind-hexagon-tessellation.c (3144B)
1 /* See LICENSE file for copyright and license details. */ 2 #include "common.h" 3 4 USAGE("[-F pixel-format] block-diameter") 5 6 #define SET_XYZA(TYPE)\ 7 (colours = alloca(4 * stream.pixel_size),\ 8 ((TYPE *)colours)[ 0] = (TYPE)0.412457445582367600,\ 9 ((TYPE *)colours)[ 1] = (TYPE)0.212673370378408280,\ 10 ((TYPE *)colours)[ 2] = (TYPE)0.019333942761673460,\ 11 ((TYPE *)colours)[ 3] = (TYPE)1,\ 12 ((TYPE *)colours)[ 4] = (TYPE)0.770033310827883400,\ 13 ((TYPE *)colours)[ 5] = (TYPE)0.927825100869440000,\ 14 ((TYPE *)colours)[ 6] = (TYPE)0.138525897843512050,\ 15 ((TYPE *)colours)[ 7] = (TYPE)1,\ 16 ((TYPE *)colours)[ 8] = (TYPE)0.357575865245515900,\ 17 ((TYPE *)colours)[ 9] = (TYPE)0.715151730491031800,\ 18 ((TYPE *)colours)[10] = (TYPE)0.119191955081838600,\ 19 ((TYPE *)colours)[11] = (TYPE)1,\ 20 ((TYPE *)colours)[12] = (TYPE)D65_XYZ_X,\ 21 ((TYPE *)colours)[13] = (TYPE)1.0000,\ 22 ((TYPE *)colours)[14] = (TYPE)D65_XYZ_Z,\ 23 ((TYPE *)colours)[15] = (TYPE)1) 24 25 static struct stream stream = { .width = 0, .height = 0, .frames = 1 }; 26 27 int 28 main(int argc, char *argv[]) 29 { 30 size_t diameter; 31 const char *pixfmt = "xyza"; 32 char *colours; 33 size_t x, y, y2; 34 int k; 35 36 ARGBEGIN { 37 case 'F': 38 pixfmt = UARGF(); 39 break; 40 default: 41 usage(); 42 } ARGEND; 43 44 if (argc != 1) 45 usage(); 46 47 diameter = etozu_arg("block-diameter", argv[0], 1, SIZE_MAX); 48 49 eset_pixel_format(&stream, pixfmt); 50 CHECK_N_CHAN(&stream, 4, 4); 51 if (stream.encoding == DOUBLE) 52 SET_XYZA(double); 53 else if (stream.encoding == FLOAT) 54 SET_XYZA(float); 55 else 56 eprintf("pixel format %s is not supported, try xyza\n", stream.pixfmt); 57 58 stream.width = (size_t)((double)diameter * sqrt(3.)); 59 stream.height = diameter * 3 / 2; 60 fprint_stream_head(stdout, &stream); 61 efflush(stdout, "<stdout>"); 62 63 for (y = 0; y < stream.height; y++) { 64 for (x = 0; x < stream.width; x++) { 65 if (y * 4 < diameter) { 66 switch (x * 4 / stream.width) { 67 case 0: 68 k = 2 * (4 * x * diameter < stream.width * diameter - 4 * y * stream.width); 69 break; 70 case 1: 71 k = 3 * (4 * x * diameter - stream.width * diameter > 4 * y * stream.width); 72 break; 73 case 2: 74 k = 1 + 2 * (3 * diameter * stream.width - 4 * x * diameter > 4 * y * stream.width); 75 break; 76 default: 77 k = 1 + (4 * x * diameter - 3 * stream.width * diameter > 4 * y * stream.width); 78 break; 79 } 80 } else if (y * 4 < diameter * 3) { 81 k = (x * 2 >= stream.width); 82 } else if (y < diameter) { 83 y2 = diameter - y; 84 switch (x * 4 / stream.width) { 85 case 0: 86 k = 2 * (4 * x * diameter < stream.width * diameter - 4 * y2 * stream.width); 87 break; 88 case 1: 89 k = 3 * (4 * x * diameter - stream.width * diameter > 4 * y2 * stream.width); 90 break; 91 case 2: 92 k = 1 + 2 * (3 * diameter * stream.width - 4 * x * diameter > 4 * y2 * stream.width); 93 break; 94 default: 95 k = 1 + (4 * x * diameter - 3 * stream.width * diameter > 4 * y2 * stream.width); 96 break; 97 } 98 } else { 99 k = (stream.width <= x * 4 && x * 4 < stream.width * 3) + 2; 100 } 101 ewriteall(STDOUT_FILENO, colours + (size_t)k * stream.pixel_size, stream.pixel_size, "<stdout>"); 102 } 103 } 104 105 return 0; 106 }