eBookReaderSwitch/mupdf/source/fitz/glyph.c

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#include "mupdf/fitz.h"
#include <string.h>
#define RLE_THRESHOLD 256
/*
Take a reference to a glyph.
pix: The glyph to increment the reference for.
Returns pix.
*/
fz_glyph *
fz_keep_glyph(fz_context *ctx, fz_glyph *glyph)
{
return fz_keep_storable(ctx, &glyph->storable);
}
/*
Drop a reference and free a glyph.
Decrement the reference count for the glyph. When no
references remain the glyph will be freed.
*/
void
fz_drop_glyph(fz_context *ctx, fz_glyph *glyph)
{
fz_drop_storable(ctx, &glyph->storable);
}
static void
fz_drop_glyph_imp(fz_context *ctx, fz_storable *glyph_)
{
fz_glyph *glyph = (fz_glyph *)glyph_;
fz_drop_pixmap(ctx, glyph->pixmap);
fz_free(ctx, glyph);
}
fz_irect
fz_glyph_bbox(fz_context *ctx, fz_glyph *glyph)
{
fz_irect bbox;
bbox.x0 = glyph->x;
bbox.y0 = glyph->y;
bbox.x1 = glyph->x + glyph->w;
bbox.y1 = glyph->y + glyph->h;
return bbox;
}
fz_irect
fz_glyph_bbox_no_ctx(fz_glyph *glyph)
{
fz_irect bbox;
bbox.x0 = glyph->x;
bbox.y0 = glyph->y;
bbox.x1 = glyph->x + glyph->w;
bbox.y1 = glyph->y + glyph->h;
return bbox;
}
/*
Return the width of the glyph in pixels.
*/
int
fz_glyph_width(fz_context *ctx, fz_glyph *glyph)
{
return glyph->w;
}
/*
Return the height of the glyph in pixels.
*/
int
fz_glyph_height(fz_context *ctx, fz_glyph *glyph)
{
return glyph->h;
}
#ifndef NDEBUG
#include <stdio.h>
void
fz_dump_glyph(fz_glyph *glyph)
{
int x, y;
if (glyph->pixmap)
{
printf("pixmap glyph\n");
return;
}
printf("glyph: %dx%d @ (%d,%d)\n", glyph->w, glyph->h, glyph->x, glyph->y);
for (y = 0; y < glyph->h; y++)
{
int offset = ((int *)(glyph->data))[y];
if (offset >= 0)
{
int extend = 0;
int eol = 0;
x = glyph->w;
do
{
int v = glyph->data[offset++];
int len;
char c;
switch(v&3)
{
case 0: /* extend */
extend = v>>2;
len = 0;
break;
case 1: /* Transparent pixels */
len = 1 + (v>>2) + (extend<<6);
extend = 0;
c = '.';
break;
case 2: /* Solid pixels */
len = 1 + (v>>3) + (extend<<5);
extend = 0;
eol = v & 4;
c = (eol ? '$' :'#');
break;
default: /* Intermediate pixels */
len = 1 + (v>>3) + (extend<<5);
extend = 0;
offset += len;
eol = v & 4;
c = (eol ? '!' : '?');
break;
}
x -= len;
while (len--)
fputc(c, stdout);
if (eol)
break;
}
while (x > 0);
}
printf("\n");
}
}
#endif
/*
Create a new glyph from a pixmap
Returns a pointer to the new glyph. Throws exception on failure to
allocate.
*/
fz_glyph *
fz_new_glyph_from_pixmap(fz_context *ctx, fz_pixmap *pix)
{
fz_glyph *glyph = NULL;
if (pix == NULL)
return NULL;
fz_var(glyph);
fz_try(ctx)
{
if (pix->n != 1 || pix->w * pix->h < RLE_THRESHOLD)
{
glyph = fz_malloc_struct(ctx, fz_glyph);
FZ_INIT_STORABLE(glyph, 1, fz_drop_glyph_imp);
glyph->x = pix->x;
glyph->y = pix->y;
glyph->w = pix->w;
glyph->h = pix->h;
glyph->size = fz_pixmap_size(ctx, pix);
glyph->pixmap = fz_keep_pixmap(ctx, pix);
}
else
glyph = fz_new_glyph_from_8bpp_data(ctx, pix->x, pix->y, pix->w, pix->h, pix->samples, pix->stride);
}
fz_always(ctx)
{
fz_drop_pixmap(ctx, pix);
}
fz_catch(ctx)
{
fz_rethrow(ctx);
}
return glyph;
}
/*
Create a new glyph from 8bpp data
x, y: X and Y position for the glyph
w, h: Width and Height for the glyph
sp: Source Pointer to data
span: Increment from line to line of data
Returns a pointer to the new glyph. Throws exception on failure to
allocate.
*/
fz_glyph *
fz_new_glyph_from_8bpp_data(fz_context *ctx, int x, int y, int w, int h, unsigned char *sp, int span)
{
fz_glyph *glyph = NULL;
fz_pixmap *pix = NULL;
int size, fill, yy;
unsigned char *orig_sp = sp;
fz_var(glyph);
fz_var(pix);
fz_try(ctx)
{
/* We start out by allocating space as large as the pixmap.
* If we need more than that give up on using RLE. We can
* never hope to beat the pixmap for really small sizes. */
if (w <= 6 || w * h < RLE_THRESHOLD)
goto try_pixmap;
size = h * w;
fill = h * sizeof(int);
glyph = Memento_label(fz_malloc(ctx, sizeof(fz_glyph) + size), "fz_glyph(8)");
FZ_INIT_STORABLE(glyph, 1, fz_drop_glyph_imp);
glyph->x = x;
glyph->y = y;
glyph->w = w;
glyph->h = h;
glyph->pixmap = NULL;
if (w == 0 || h == 0)
{
glyph->size = 0;
break;
}
for (yy=0; yy < h; yy++)
{
int nonblankfill = fill;
int nonblankfill_end = fill;
int linefill = fill;
int ww = w;
do
{
int code;
int len = ww;
int needed;
unsigned char *ep;
switch (*sp)
{
case 0:
if (len > 0x1000)
len = 0x1000;
ep = sp+len;
while (++sp != ep && *sp == 0);
code = 1;
len -= ep-sp;
ww -= len;
needed = fill + 1 + (len > 0x40);
break;
case 255:
if (len > 0x800)
len = 0x800;
ep = sp+len;
while (++sp != ep && *sp == 255);
code = 2;
len -= ep-sp;
ww -= len;
needed = fill + 1 + (len > 0x20);
break;
default:
{
unsigned char c;
if (len > 0x800)
len = 0x800;
ep = sp+len;
while (++sp != ep && (c = *sp) != 255 && c != 0);
len -= ep-sp;
ww -= len;
needed = fill + 1 + len + (len > 0x20);
code = 3;
}
}
if (needed > size)
goto try_pixmap;
if (code == 1)
{
if (len > 0x40)
glyph->data[fill++] = ((len-1)>>6)<<2;
glyph->data[fill++] = 1 | (((len-1)&63)<<2);
}
else
{
if (len > 0x20)
glyph->data[fill++] = ((len-1)>>5)<<2;
nonblankfill = fill;
glyph->data[fill++] = code | (((len-1)&31)<<3);
if (code == 3)
{
memcpy(&glyph->data[fill], sp - len, len);
fill += len;
}
nonblankfill_end = fill;
}
}
while (ww > 0);
if (nonblankfill_end == linefill)
{
((int *)(glyph->data))[yy] = -1;
fill = linefill;
}
else
{
glyph->data[nonblankfill] |= 4;
fill = nonblankfill_end;
((int *)(glyph->data))[yy] = linefill;
}
sp += span - w;
}
if (fill != size)
{
glyph = fz_realloc(ctx, glyph, sizeof(fz_glyph) + fill);
size = fill;
}
glyph->size = size;
break;
/* Nasty use of a goto here, but it saves us having to exit
* and reenter the try context, and this routine is speed
* critical. */
try_pixmap:
glyph = Memento_label(fz_realloc(ctx, glyph, sizeof(fz_glyph)), "fz_glyph(8r)");
FZ_INIT_STORABLE(glyph, 1, fz_drop_glyph_imp);
pix = fz_new_pixmap_from_8bpp_data(ctx, x, y, w, h, orig_sp, span);
glyph->x = pix->x;
glyph->y = pix->y;
glyph->w = pix->w;
glyph->h = pix->h;
glyph->size = fz_pixmap_size(ctx, pix);
glyph->pixmap = pix;
}
fz_catch(ctx)
{
fz_drop_pixmap(ctx, pix);
fz_free(ctx, glyph);
fz_rethrow(ctx);
}
return glyph;
}
/*
Create a new glyph from 1bpp data
x, y: X and Y position for the glyph
w, h: Width and Height for the glyph
sp: Source Pointer to data
span: Increment from line to line of data
Returns a pointer to the new glyph. Throws exception on failure to
allocate.
*/
fz_glyph *
fz_new_glyph_from_1bpp_data(fz_context *ctx, int x, int y, int w, int h, unsigned char *sp, int span)
{
fz_pixmap *pix = NULL;
fz_glyph *glyph = NULL;
int size, fill, yy;
unsigned char *orig_sp = sp;
fz_var(glyph);
fz_var(pix);
fz_try(ctx)
{
/* We start out by allocating space as large as the pixmap.
* If we need more than that give up on using RLE. We can
* never hope to beat the pixmap for really small sizes. */
if (w <= 6 || w * h < RLE_THRESHOLD)
goto try_pixmap;
size = h * w;
fill = h * sizeof(int);
glyph = Memento_label(fz_malloc(ctx, sizeof(fz_glyph) + size), "fz_glyph(1)");
FZ_INIT_STORABLE(glyph, 1, fz_drop_glyph_imp);
glyph->x = x;
glyph->y = y;
glyph->w = w;
glyph->h = h;
glyph->pixmap = NULL;
if (w == 0 || h == 0)
{
glyph->size = 0;
break;
}
for (yy=0; yy < h; yy++)
{
int nonblankfill = fill;
int nonblankfill_end = fill;
int linefill = fill;
int ww = w;
int bit = 0x80;
do
{
int len = 0;
int needed;
int b = *sp & bit;
bit >>= 1;
if (bit == 0)
bit = 0x80, sp++;
ww--;
if (b == 0)
{
while (ww > 0 && len < 0xfff && (*sp & bit) == 0)
{
bit >>= 1;
if (bit == 0)
bit = 0x80, sp++;
len++;
ww--;
}
needed = fill + (len >= 0x40) + 1;
if (needed > size)
goto try_pixmap;
if (len >= 0x40)
glyph->data[fill++] = (len>>6)<<2;
glyph->data[fill++] = 1 | ((len&63)<<2);
}
else
{
while (ww > 0 && len < 0x7ff && (*sp & bit) != 0)
{
bit >>= 1;
if (bit == 0)
bit = 0x80, sp++;
len++;
ww--;
}
needed = fill + (len >= 0x20) + 1;
if (needed > size)
goto try_pixmap;
if (len >= 0x20)
glyph->data[fill++] = (len>>5)<<2;
nonblankfill = fill;
glyph->data[fill++] = 2 | ((len&31)<<3);
nonblankfill_end = fill;
}
}
while (ww > 0);
if (nonblankfill_end == linefill)
{
((int *)(glyph->data))[yy] = -1;
fill = linefill;
}
else
{
glyph->data[nonblankfill] |= 4;
fill = nonblankfill_end;
((int *)(glyph->data))[yy] = linefill;
}
sp += span - (w>>3);
}
if (fill != size)
{
glyph = fz_realloc(ctx, glyph, sizeof(fz_glyph) + fill);
size = fill;
}
glyph->size = size;
break;
/* Nasty use of a goto here, but it saves us having to exit
* and reenter the try context, and this routine is speed
* critical. */
try_pixmap:
glyph = fz_realloc(ctx, glyph, sizeof(fz_glyph));
FZ_INIT_STORABLE(glyph, 1, fz_drop_glyph_imp);
pix = fz_new_pixmap_from_1bpp_data(ctx, x, y, w, h, orig_sp, span);
glyph->x = pix->x;
glyph->y = pix->y;
glyph->w = pix->w;
glyph->h = pix->h;
glyph->size = fz_pixmap_size(ctx, pix);
glyph->pixmap = pix;
}
fz_catch(ctx)
{
fz_drop_pixmap(ctx, pix);
fz_free(ctx, glyph);
fz_rethrow(ctx);
}
return glyph;
}