From 0a927854a10e1e6b9770a81e2e1d9f3093631757 Mon Sep 17 00:00:00 2001 From: Tor Andersson Date: Wed, 19 Jun 2013 15:29:44 +0200 Subject: Rearrange source files. --- source/fitz/halftone.c | 202 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 source/fitz/halftone.c (limited to 'source/fitz/halftone.c') diff --git a/source/fitz/halftone.c b/source/fitz/halftone.c new file mode 100644 index 00000000..15aebead --- /dev/null +++ b/source/fitz/halftone.c @@ -0,0 +1,202 @@ +#include "mupdf/fitz.h" + +fz_halftone * +fz_new_halftone(fz_context *ctx, int comps) +{ + fz_halftone *ht; + int i; + + ht = fz_malloc(ctx, sizeof(fz_halftone) + (comps-1)*sizeof(fz_pixmap *)); + ht->refs = 1; + ht->n = comps; + for (i = 0; i < comps; i++) + ht->comp[i] = NULL; + + return ht; +} + +fz_halftone * +fz_keep_halftone(fz_context *ctx, fz_halftone *ht) +{ + if (ht) + ht->refs++; + return ht; +} + +void +fz_drop_halftone(fz_context *ctx, fz_halftone *ht) +{ + int i; + + if (!ht || --ht->refs != 0) + return; + for (i = 0; i < ht->n; i++) + fz_drop_pixmap(ctx, ht->comp[i]); + fz_free(ctx, ht); +} + +/* Default mono halftone, lifted from Ghostscript. */ +/* The 0x00 entry has been changed to 0x01 to avoid problems with white + * pixels appearing in the output; as we use < 0 should not appear in the + * array. I think that gs scales this slighly and hence never actually uses + * the raw values here. */ +static unsigned char mono_ht[] = +{ + 0x0E, 0x8E, 0x2E, 0xAE, 0x06, 0x86, 0x26, 0xA6, 0x0C, 0x8C, 0x2C, 0xAC, 0x04, 0x84, 0x24, 0xA4, + 0xCE, 0x4E, 0xEE, 0x6E, 0xC6, 0x46, 0xE6, 0x66, 0xCC, 0x4C, 0xEC, 0x6C, 0xC4, 0x44, 0xE4, 0x64, + 0x3E, 0xBE, 0x1E, 0x9E, 0x36, 0xB6, 0x16, 0x96, 0x3C, 0xBC, 0x1C, 0x9C, 0x34, 0xB4, 0x14, 0x94, + 0xFE, 0x7E, 0xDE, 0x5E, 0xF6, 0x76, 0xD6, 0x56, 0xFC, 0x7C, 0xDC, 0x5C, 0xF4, 0x74, 0xD4, 0x54, + 0x01, 0x81, 0x21, 0xA1, 0x09, 0x89, 0x29, 0xA9, 0x03, 0x83, 0x23, 0xA3, 0x0B, 0x8B, 0x2B, 0xAB, + 0xC1, 0x41, 0xE1, 0x61, 0xC9, 0x49, 0xE9, 0x69, 0xC3, 0x43, 0xE3, 0x63, 0xCB, 0x4B, 0xEB, 0x6B, + 0x31, 0xB1, 0x11, 0x91, 0x39, 0xB9, 0x19, 0x99, 0x33, 0xB3, 0x13, 0x93, 0x3B, 0xBB, 0x1B, 0x9B, + 0xF1, 0x71, 0xD1, 0x51, 0xF9, 0x79, 0xD9, 0x59, 0xF3, 0x73, 0xD3, 0x53, 0xFB, 0x7B, 0xDB, 0x5B, + 0x0D, 0x8D, 0x2D, 0xAD, 0x05, 0x85, 0x25, 0xA5, 0x0F, 0x8F, 0x2F, 0xAF, 0x07, 0x87, 0x27, 0xA7, + 0xCD, 0x4D, 0xED, 0x6D, 0xC5, 0x45, 0xE5, 0x65, 0xCF, 0x4F, 0xEF, 0x6F, 0xC7, 0x47, 0xE7, 0x67, + 0x3D, 0xBD, 0x1D, 0x9D, 0x35, 0xB5, 0x15, 0x95, 0x3F, 0xBF, 0x1F, 0x9F, 0x37, 0xB7, 0x17, 0x97, + 0xFD, 0x7D, 0xDD, 0x5D, 0xF5, 0x75, 0xD5, 0x55, 0xFF, 0x7F, 0xDF, 0x5F, 0xF7, 0x77, 0xD7, 0x57, + 0x02, 0x82, 0x22, 0xA2, 0x0A, 0x8A, 0x2A, 0xAA, 0x01 /*0x00*/, 0x80, 0x20, 0xA0, 0x08, 0x88, 0x28, 0xA8, + 0xC2, 0x42, 0xE2, 0x62, 0xCA, 0x4A, 0xEA, 0x6A, 0xC0, 0x40, 0xE0, 0x60, 0xC8, 0x48, 0xE8, 0x68, + 0x32, 0xB2, 0x12, 0x92, 0x3A, 0xBA, 0x1A, 0x9A, 0x30, 0xB0, 0x10, 0x90, 0x38, 0xB8, 0x18, 0x98, + 0xF2, 0x72, 0xD2, 0x52, 0xFA, 0x7A, 0xDA, 0x5A, 0xF0, 0x70, 0xD0, 0x50, 0xF8, 0x78, 0xD8, 0x58 +}; + +fz_halftone *fz_default_halftone(fz_context *ctx, int num_comps) +{ + fz_halftone *ht = fz_new_halftone(ctx, num_comps); + assert(num_comps == 1); /* Only support 1 component for now */ + ht->comp[0] = fz_new_pixmap_with_data(ctx, NULL, 16, 16, mono_ht); + return ht; +} + +/* Finally, code to actually perform halftoning. */ +static void make_ht_line(unsigned char *buf, fz_halftone *ht, int x, int y, int w) +{ + /* FIXME: There is a potential optimisation here; in the case where + * the LCM of the halftone tile widths is smaller than w, we could + * form just one 'LCM' run, then copy it repeatedly. + */ + int k, n; + n = ht->n; + for (k = 0; k < n; k++) + { + fz_pixmap *tile = ht->comp[k]; + unsigned char *b = buf++; + unsigned char *t; + unsigned char *tbase; + int px = x + tile->x; + int py = y + tile->y; + int tw = tile->w; + int th = tile->h; + int w2 = w; + int len; + px = px % tw; + if (px < 0) + px += tw; + py = py % th; + if (py < 0) + py += th; + + assert(tile->n == 1); + + /* Left hand section; from x to tile width */ + tbase = tile->samples + (unsigned int)(py * tw); + t = tbase + px; + len = tw - px; + if (len > w2) + len = w2; + w2 -= len; + while (len--) + { + *b = *t++; + b += n; + } + + /* Centre section - complete copies */ + w2 -= tw; + while (w2 >= 0) + { + len = tw; + t = tbase; + while (len--) + { + *b = *t++; + b += n; + } + w2 -= tw; + } + w2 += tw; + + /* Right hand section - stragglers */ + t = tbase; + while (w2--) + { + *b = *t++; + b += n; + } + } +} + +/* Inner mono thresholding code */ +static void do_threshold_1(unsigned char *ht_line, unsigned char *pixmap, unsigned char *out, int w) +{ + int bit = 0x80; + int h = 0; + + do + { + if (*pixmap < *ht_line++) + h |= bit; + pixmap += 2; /* Skip the alpha */ + bit >>= 1; + if (bit == 0) + { + *out++ = h; + h = 0; + bit = 0x80; + } + + } + while (--w); + if (bit != 0x80) + *out++ = h; +} + +fz_bitmap *fz_halftone_pixmap(fz_context *ctx, fz_pixmap *pix, fz_halftone *ht) +{ + fz_bitmap *out; + unsigned char *ht_line, *o, *p; + int w, h, x, y, n, pstride, ostride; + fz_halftone *ht_orig = ht; + + if (!pix) + return NULL; + + assert(pix->n == 2); /* Mono + Alpha */ + + n = pix->n-1; /* Remove alpha */ + if (ht == NULL) + { + ht = fz_default_halftone(ctx, n); + } + ht_line = fz_malloc(ctx, pix->w * n); + out = fz_new_bitmap(ctx, pix->w, pix->h, n, pix->xres, pix->yres); + o = out->samples; + p = pix->samples; + + h = pix->h; + x = pix->x; + y = pix->y; + w = pix->w; + ostride = out->stride; + pstride = pix->w * pix->n; + while (h--) + { + make_ht_line(ht_line, ht, x, y++, w); + do_threshold_1(ht_line, p, o, w); + o += ostride; + p += pstride; + } + if (!ht_orig) + fz_drop_halftone(ctx, ht); + return out; +} -- cgit v1.2.3