Add a8 png support

1 files changed, 138 insertions, 0 deletions

diff --git a/daemon.c b/daemon.c
index 24bdca4..a4dbeeb 100644
--- a/daemon.c
+++ b/daemon.c
@@ -476,6 +476,116 @@ to_png_rgba (int w, int h, int stride, guint32 *data)
   return url;
 }
 
+char *
+to_png_a (int w, int h, int 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;
+  gint state = 0, outlen;
+  gint save = 0;
+
+  *(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));
+
+  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;
+
+  data_size = 2 + (6 + w * 2) * h + 4;
+
+  *(guint32 *)&idat_start[0] = GUINT32_TO_BE(data_size);
+
+  png_size = sizeof(header) + sizeof(ihdr) + 12 + data_size + sizeof(iend);
+  png = g_malloc (png_size);
+
+  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 += stride;
+    for (x = 0; x < w; x++) {
+      pixel = *row++;
+      *p++ = 0xff; /* white */
+#if 0
+      *p++ = 0xff; /* white */
+      *p++ = 0xff; /* white */
+#endif
+      *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);
+
+  g_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;
+
+  g_free (png);
+
+  return url;
+}
+
 static void
 send_image_rgb (GOutputStream *out,  int x, int y,
 		int w, int h, int stride, guint32 *data)
@@ -527,6 +637,32 @@ send_image_rgba (GOutputStream *out,  int x, int y,
 }
 
 static void
+send_image_a (GOutputStream *out,  int x, int y,
+	      int w, int h, int stride, guint8 *data)
+{
+  char buf[13];
+  gsize len;
+  char *url;
+
+  buf[0] = 'i';
+  base64_uint16(x, &buf[1]);
+  base64_uint16(y, &buf[4]);
+
+  url = to_png_a (w, h, stride, data);
+  len = strlen (url);
+  base64_uint32(len, &buf[7]);
+
+  g_output_stream_write_all (out, buf, 13,
+			     NULL, NULL, NULL);
+
+  g_output_stream_write_all (out, url, len,
+			     NULL, NULL, NULL);
+
+  g_free (url);
+}
+
+
+static void
 send_boundary (GOutputStream *out)
 {
   char *boundary =
@@ -555,6 +691,7 @@ send_draw_ops (GOutputStream *out)
   int i;
   guint32 pixel[4] = {0xffffff, 0xff0000, 0xff00ff, 0x00ff00};
   guint32 pixela[4] = {0xffffffff, 0x80ffffff, 0x40ffffff, 0x20ffffff};
+  guint8 pixelaa[4] = {0xff, 0x80, 0x40, 0x20};
 
   header =
     "HTTP/1.1 200 OK\r\n"
@@ -578,6 +715,7 @@ send_draw_ops (GOutputStream *out)
   send_rect (cout, 0, 0, 25, 25);
   send_image_rgba (cout, 0, 0,
 		   2, 2, 2, pixela);
+  send_image_a (cout, 2, 0, 2, 2, 2, pixelaa);
   send_select_surface(cout, 0);
 
   while (1)