[broadway] Use cairo to generate png uris

This commit is contained in:
Alexander Larsson 2011-04-18 20:23:19 +02:00
parent 0abd5e2767
commit cfd8150759

View File

@ -3,7 +3,7 @@
#include <stdio.h>
#include <assert.h>
#include <errno.h>
#include <zlib.h>
#include <cairo.h>
#include "broadway.h"
@ -53,391 +53,117 @@ base64_uint32 (guint32 v, char *c)
c[5] = base64_alphabet[(v >> 30) & 0x2];
}
/************************************************************************
* conversion of raw image data to uncompressed png data: uris *
************************************************************************/
/***********************************************************
* conversion of raw image data to png data: uris *
***********************************************************/
/* Table of CRCs of all 8-bit messages. */
static unsigned long crc_table[256];
struct PngTarget {
GString *url;
int state;
int save;
};
/* Flag: has the table been computed? Initially false. */
static int crc_table_computed = 0;
/* Make the table for a fast CRC. */
static void
make_crc_table(void)
static cairo_status_t
write_png_url (void *closure,
const unsigned char *data,
unsigned int data_len)
{
unsigned long c;
int n, k;
struct PngTarget *target = closure;
gsize res, old_len;
for (n = 0; n < 256; n++) {
c = (unsigned long) n;
for (k = 0; k < 8; k++) {
if (c & 1)
c = 0xedb88320L ^ (c >> 1);
else
c = c >> 1;
}
crc_table[n] = c;
}
crc_table_computed = 1;
}
old_len = target->url->len;
g_string_set_size (target->url,
old_len + (data_len / 3 + 1) * 4 + 4);
static unsigned long
update_crc(unsigned long crc, unsigned char *buf, int len)
{
unsigned long c = crc;
int n;
res = g_base64_encode_step (data, data_len, FALSE,
target->url->str + old_len,
&target->state, &target->save);
if (!crc_table_computed)
make_crc_table();
for (n = 0; n < len; n++) {
c = crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
}
return c;
}
g_string_set_size (target->url, old_len + res);
static unsigned long
crc(unsigned char *buf, int len)
{
return update_crc(0xffffffffL, buf, len) ^ 0xffffffffL;
}
#define BASE 65521 /* largest prime smaller than 65536 */
static unsigned long
update_adler32(unsigned long adler, unsigned char *buf, int len)
{
unsigned long s1 = adler & 0xffff;
unsigned long s2 = (adler >> 16) & 0xffff;
int n;
for (n = 0; n < len; n++) {
s1 = (s1 + buf[n]) % BASE;
s2 = (s2 + s1) % BASE;
}
return (s2 << 16) + s1;
return CAIRO_STATUS_SUCCESS;
}
static char *
to_png_rgb (int w, int h, int byte_stride, guint32 *data)
{
guchar header[] = {137, 80, 78, 71, 13, 10, 26, 10};
guchar ihdr[13+12] = {0, 0, 0, 13, 'I', 'H', 'D', 'R',
/* w: */ 0, 0, 0, 0, /* h: */ 0,0,0,0,
/* bpp: */ 8, /* color type: */ 2,
0, 0, 0};
guchar idat_start[8] = { /* len: */0, 0, 0, 0, 'I', 'D', 'A', 'T' };
guchar iend[12] = {0, 0, 0, 0, 'I', 'E', 'N', 'D', 0xae, 0x42, 0x60, 0x82};
gsize data_size, row_size;
char row_header[6];
guint8 *png, *p, *p_row, *p_idat;
guint32 *row;
unsigned long adler;
guint32 pixel;
gsize png_size;
int x, y;
char *url, *url_base64;
int state = 0, outlen;
int save = 0;
cairo_surface_t *surface;
struct PngTarget target;
gsize res, old_len;
*(guint32 *)&ihdr[8] = GUINT32_TO_BE(w);
*(guint32 *)&ihdr[12] = GUINT32_TO_BE(h);
*(guint32 *)&ihdr[21] = GUINT32_TO_BE(crc(&ihdr[4], 13 + 4));
target.url = g_string_new ("data:image/png;base64,");
target.state = 0;
target.save = 0;
row_size = 1 + w * 3;
row_header[0] = 0;
row_header[1] = row_size & 0xff;
row_header[2] = (row_size >> 8) & 0xff;
row_header[3] = ~row_header[1];
row_header[4] = ~row_header[2];
row_header[5] = 0;
surface = cairo_image_surface_create_for_data ((guchar *)data,
CAIRO_FORMAT_RGB24, w, h, byte_stride);
data_size = 2 + (6 + w * 3) * h + 4;
cairo_surface_write_to_png_stream (surface, write_png_url, &target);
*(guint32 *)&idat_start[0] = GUINT32_TO_BE(data_size);
old_len = target.url->len;
png_size = sizeof(header) + sizeof(ihdr) + 12 + data_size + sizeof(iend);
png = g_malloc (png_size);
g_string_set_size (target.url, old_len + 4);
res = g_base64_encode_close (FALSE,
target.url->str + old_len,
&target.state, &target.save);
g_string_set_size (target.url, old_len + res);
p = png;
memcpy (p, header, sizeof(header));
p += sizeof(header);
memcpy (p, ihdr, sizeof(ihdr));
p += sizeof(ihdr);
memcpy (p, idat_start, sizeof(idat_start));
p += sizeof(idat_start);
/* IDAT data:
zlib header: 0x78, 0x01 ,
h * scanline: row_header[] + width * r,g,b
checksum: adler32
*/
p_idat = p - 4;
/* zlib header */
*p++ = 0x78;
*p++ = 0x01;
adler = 1;
/* scanline data */
for (y = 0; y < h; y++) {
if (y == h - 1)
row_header[0] = 1; /* final block */
memcpy (p, row_header, sizeof(row_header));
p += sizeof(row_header);
p_row = p - 1;
row = data;
data += byte_stride / 4;
for (x = 0; x < w; x++) {
pixel = *row++;
*p++ = (pixel >> 16) & 0xff; /* red */
*p++ = (pixel >> 8) & 0xff; /* green */
*p++ = (pixel >> 0) & 0xff; /* blue */
}
adler = update_adler32(adler, p_row, p - p_row);
}
/* adler32 */
*(guint32 *)p = GUINT32_TO_BE(adler);
p += 4;
*(guint32 *)p = GUINT32_TO_BE(crc(p_idat, p - p_idat));
p += 4;
memcpy (p, iend, sizeof(iend));
p += sizeof(iend);
assert(p - png == png_size);
url = g_malloc (strlen("data:image/png;base64,") +
((png_size / 3 + 1) * 4 + 4) + 1);
strcpy (url, "data:image/png;base64,");
url_base64 = url + strlen("data:image/png;base64,");
outlen = g_base64_encode_step (png, png_size, FALSE, url_base64, &state, &save);
outlen += g_base64_encode_close (FALSE, url_base64 + outlen, &state, &save);
url_base64[outlen] = 0;
free (png);
return url;
return g_string_free (target.url, FALSE);
}
static char *
to_png_rgba (int w, int h, int byte_stride, guint32 *data)
{
guchar header[] = {137, 80, 78, 71, 13, 10, 26, 10};
guchar ihdr[13+12] = {0, 0, 0, 13, 'I', 'H', 'D', 'R',
/* w: */ 0, 0, 0, 0, /* h: */ 0,0,0,0,
/* bpp: */ 8, /* color type: */ 6,
0, 0, 0};
guchar idat_start[8] = { /* len: */0, 0, 0, 0, 'I', 'D', 'A', 'T' };
guchar iend[12] = {0, 0, 0, 0, 'I', 'E', 'N', 'D', 0xae, 0x42, 0x60, 0x82};
gsize data_size, row_size;
char row_header[6];
guint8 *png, *p, *p_row, *p_idat;
guint32 *row;
unsigned long adler;
guint32 pixel;
gsize png_size;
int x, y;
char *url, *url_base64;
int state = 0, outlen;
int save = 0;
cairo_surface_t *surface;
struct PngTarget target;
gsize res, old_len;
*(guint32 *)&ihdr[8] = GUINT32_TO_BE(w);
*(guint32 *)&ihdr[12] = GUINT32_TO_BE(h);
*(guint32 *)&ihdr[21] = GUINT32_TO_BE(crc(&ihdr[4], 13 + 4));
target.url = g_string_new ("data:image/png;base64,");
target.state = 0;
target.save = 0;
row_size = 1 + w * 4;
row_header[0] = 0;
row_header[1] = row_size & 0xff;
row_header[2] = (row_size >> 8) & 0xff;
row_header[3] = ~row_header[1];
row_header[4] = ~row_header[2];
row_header[5] = 0;
surface = cairo_image_surface_create_for_data ((guchar *)data,
CAIRO_FORMAT_ARGB32, w, h, byte_stride);
data_size = 2 + (6 + w * 4) * h + 4;
cairo_surface_write_to_png_stream (surface, write_png_url, &target);
*(guint32 *)&idat_start[0] = GUINT32_TO_BE(data_size);
old_len = target.url->len;
png_size = sizeof(header) + sizeof(ihdr) + 12 + data_size + sizeof(iend);
png = g_malloc (png_size);
g_string_set_size (target.url, old_len + 4);
res = g_base64_encode_close (FALSE,
target.url->str + old_len,
&target.state, &target.save);
g_string_set_size (target.url, old_len + res);
p = png;
memcpy (p, header, sizeof(header));
p += sizeof(header);
memcpy (p, ihdr, sizeof(ihdr));
p += sizeof(ihdr);
memcpy (p, idat_start, sizeof(idat_start));
p += sizeof(idat_start);
/* IDAT data:
zlib header: 0x78, 0x01 ,
h * scanline: row_header[] + width * r,g,b,a
checksum: adler32
*/
p_idat = p - 4;
/* zlib header */
*p++ = 0x78;
*p++ = 0x01;
adler = 1;
/* scanline data */
for (y = 0; y < h; y++) {
if (y == h - 1)
row_header[0] = 1; /* final block */
memcpy (p, row_header, sizeof(row_header));
p += sizeof(row_header);
p_row = p - 1;
row = data;
data += byte_stride / 4;
for (x = 0; x < w; x++) {
pixel = *row++;
*p++ = (pixel >> 16) & 0xff; /* red */
*p++ = (pixel >> 8) & 0xff; /* green */
*p++ = (pixel >> 0) & 0xff; /* blue */
*p++ = (pixel >> 24) & 0xff; /* alpha */
}
adler = update_adler32(adler, p_row, p - p_row);
}
/* adler32 */
*(guint32 *)p = GUINT32_TO_BE(adler);
p += 4;
*(guint32 *)p = GUINT32_TO_BE(crc(p_idat, p - p_idat));
p += 4;
memcpy (p, iend, sizeof(iend));
p += sizeof(iend);
assert(p - png == png_size);
url = g_malloc (strlen("data:image/png;base64,") +
((png_size / 3 + 1) * 4 + 4) + 1);
strcpy (url, "data:image/png;base64,");
url_base64 = url + strlen("data:image/png;base64,");
outlen = g_base64_encode_step (png, png_size, FALSE, url_base64, &state, &save);
outlen += g_base64_encode_close (FALSE, url_base64 + outlen, &state, &save);
url_base64[outlen] = 0;
free (png);
return url;
return g_string_free (target.url, FALSE);
}
#if 0
static char *
to_png_a (int w, int h, int byte_stride, guint8 *data)
{
guchar header[] = {137, 80, 78, 71, 13, 10, 26, 10};
guchar ihdr[13+12] = {0, 0, 0, 13, 'I', 'H', 'D', 'R',
/* w: */ 0, 0, 0, 0, /* h: */ 0,0,0,0,
/* bpp: */ 8, /* color type: */ 4,
0, 0, 0};
guchar idat_start[8] = { /* len: */0, 0, 0, 0, 'I', 'D', 'A', 'T' };
guchar iend[12] = {0, 0, 0, 0, 'I', 'E', 'N', 'D', 0xae, 0x42, 0x60, 0x82};
gsize data_size, row_size;
char row_header[6];
guint8 *png, *p, *p_row, *p_idat;
guint8 *row;
unsigned long adler;
guint32 pixel;
gsize png_size;
int x, y;
char *url, *url_base64;
int state = 0, outlen;
int save = 0;
cairo_surface_t *surface;
struct PngTarget target;
gsize res, old_len;
*(guint32 *)&ihdr[8] = GUINT32_TO_BE(w);
*(guint32 *)&ihdr[12] = GUINT32_TO_BE(h);
*(guint32 *)&ihdr[21] = GUINT32_TO_BE(crc(&ihdr[4], 13 + 4));
target.url = g_string_new ("data:image/png;base64,");
target.state = 0;
target.save = 0;
row_size = 1 + w * 2;
row_header[0] = 0;
row_header[1] = row_size & 0xff;
row_header[2] = (row_size >> 8) & 0xff;
row_header[3] = ~row_header[1];
row_header[4] = ~row_header[2];
row_header[5] = 0;
surface = cairo_image_surface_create_for_data (data,
CAIRO_FORMAT_A8, w, h, byte_stride);
data_size = 2 + (6 + w * 2) * h + 4;
cairo_surface_write_to_png_stream (surface, write_png_url, &target);
*(guint32 *)&idat_start[0] = GUINT32_TO_BE(data_size);
old_len = target.url->len;
png_size = sizeof(header) + sizeof(ihdr) + 12 + data_size + sizeof(iend);
png = g_malloc (png_size);
g_string_set_size (target.url, old_len + 4);
res = g_base64_encode_close (FALSE,
target.url->str + old_len,
&target.state, &target.save);
g_string_set_size (target.url, old_len + res);
p = png;
memcpy (p, header, sizeof(header));
p += sizeof(header);
memcpy (p, ihdr, sizeof(ihdr));
p += sizeof(ihdr);
memcpy (p, idat_start, sizeof(idat_start));
p += sizeof(idat_start);
/* IDAT data:
zlib header: 0x78, 0x01 ,
h * scanline: row_header[] + width * r,g,b,a
checksum: adler32
*/
p_idat = p - 4;
/* zlib header */
*p++ = 0x78;
*p++ = 0x01;
adler = 1;
/* scanline data */
for (y = 0; y < h; y++) {
if (y == h - 1)
row_header[0] = 1; /* final block */
memcpy (p, row_header, sizeof(row_header));
p += sizeof(row_header);
p_row = p - 1;
row = data;
data += byte_stride / 4;
for (x = 0; x < w; x++) {
pixel = *row++;
*p++ = 0x00; /* gray */
*p++ = pixel; /* alpha */
}
adler = update_adler32(adler, p_row, p - p_row);
}
/* adler32 */
*(guint32 *)p = GUINT32_TO_BE(adler);
p += 4;
*(guint32 *)p = GUINT32_TO_BE(crc(p_idat, p - p_idat));
p += 4;
memcpy (p, iend, sizeof(iend));
p += sizeof(iend);
assert(p - png == png_size);
url = g_malloc (strlen("data:image/png;base64,") +
((png_size / 3 + 1) * 4 + 4) + 1);
strcpy (url, "data:image/png;base64,");
url_base64 = url + strlen("data:image/png;base64,");
outlen = g_base64_encode_step (png, png_size, FALSE, url_base64, &state, &save);
outlen += g_base64_encode_close (FALSE, url_base64 + outlen, &state, &save);
url_base64[outlen] = 0;
free (png);
return url;
return g_string_free (target.url, FALSE);
}
#endif