diff options
Diffstat (limited to 'ff2ppm.c')
| -rw-r--r-- | ff2ppm.c | 88 |
1 files changed, 27 insertions, 61 deletions
@@ -9,109 +9,75 @@ #include <string.h> #include "arg.h" - -char *argv0; +#include "util.h" static void usage(void) { - fprintf(stderr, "usage: %s [-b #rrggbb]\n", argv0); + fprintf(stderr, "usage: %s [-b colour]\n", argv0); exit(1); } int main(int argc, char *argv[]) { - size_t rowlen; + size_t rowlen, rowoutlen; uint64_t a; - uint32_t hdr[4], width, height, i, j, k, l; + uint32_t width, height, i, j, k, l; uint16_t *row, mask[3] = { 0xffff, 0xffff, 0xffff }; uint8_t *rowout; - char *color, colfmt[] = "%#x%#x%#x"; - unsigned int collen, col[3], colfac; - argv0 = argv[0]; + /* arguments */ ARGBEGIN { case 'b': - color = EARGF(usage()); - if (color[0] == '#') { - color++; - } - collen = strlen(color); - if (collen != 3 && collen != 6 && collen != 12) { - usage(); - } - colfmt[1] = colfmt[4] = colfmt[7] = ((collen / 3) + '0'); - if (sscanf(color, colfmt, col, col + 1, col + 2) != 3) { + if (parse_mask(EARGF(usage()), mask)) { usage(); } - /* UINT16_MAX / 255 = 257; UINT16_MAX / 15 = 4369 */ - colfac = (collen == 3) ? 4369 : (collen == 6) ? 257 : 1; - for (i = 0; i < 3; i++) { - mask[i] = col[i] * colfac; - } break; default: usage(); } ARGEND - if (argc) + if (argc) { usage(); - - /* header */ - if (fread(hdr, sizeof(*hdr), 4, stdin) != 4) { - goto readerr; - } - if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) { - fprintf(stderr, "%s: invalid magic value\n", argv0); - return 1; } - width = ntohl(hdr[2]); - height = ntohl(hdr[3]); - if (width > SIZE_MAX / ((sizeof("RGBA") - 1) * sizeof(uint16_t))) { - fprintf(stderr, "%s: row length integer overflow\n", argv0); - return 1; - } + /* prepare */ + ff_read_header(&width, &height); + row = ereallocarray(NULL, width, (sizeof("RGBA") - 1) * sizeof(uint16_t)); + rowout = ereallocarray(NULL, width, (sizeof("RGB") - 1) * sizeof(uint8_t)); rowlen = width * (sizeof("RGBA") - 1); - if (!(row = malloc(rowlen * sizeof(uint16_t)))) { - fprintf(stderr, "%s: malloc: %s\n", argv0, strerror(errno)); - return 1; - } - if (!(rowout = malloc(width * (sizeof("RGB") - 1) * sizeof(uint8_t)))) { - fprintf(stderr, "%s: malloc: %s\n", argv0, strerror(errno)); - return 1; - } + rowoutlen = width * (sizeof("RGB") - 1); - /* PPM binary */ + /* write data */ printf("P6\n%" PRIu32 " %" PRIu32 "\n255\n", width, height); - /* write rows */ for (i = 0; i < height; ++i) { if (fread(row, sizeof(uint16_t), rowlen, stdin) != rowlen) { - goto readerr; + if (ferror(stdin)) { + fprintf(stderr, "%s: fread: %s\n", argv0, + strerror(errno)); + } else { + fprintf(stderr, "%s: unexpected end of file\n", + argv0); + } + return 1; } for (j = 0, k = 0; j < rowlen; j += 4, k += 3) { a = ntohs(row[j + 3]); for (l = 0; l < 3; l++) { + /* alpha blending and 8-bit-reduction */ rowout[k + l] = (a * ntohs(row[j + l]) + - (65535 - a) * mask[l]) / - (257 * 65535); + (UINT16_MAX - a) * mask[l]) / + (UINT16_MAX * + (UINT16_MAX / UINT8_MAX)); } } - if (fwrite(rowout, 3, width, stdout) != width) { + if (fwrite(rowout, sizeof(uint8_t), rowoutlen, stdout) != rowoutlen) { fprintf(stderr, "%s: fwrite: %s\n", argv0, strerror(errno)); return 1; } } - return 0; -readerr: - if (ferror(stdin)) { - fprintf(stderr, "%s: fread: %s\n", argv0, strerror(errno)); - } else { - fprintf(stderr, "%s: unexpected end of file\n", argv0); - } - - return 1; + return fshut(stdout, "<stdout>"); } |