[gimp] plug-ins: in file-csource, add RLE support for RGB565

[N/A <ell src gnome org>]

commit 98f7fc85ac5eddbfb82a84b1c22bc42a3391d4db
Author: Ell <ell_se yahoo com>
Date:   Fri Jul 7 04:07:24 2017 -0400

    plug-ins: in file-csource, add RLE support for RGB565
    
    Currently, toggling RGB565 makes the RLE toggle insensitive, but
    if RLE is checked beforehand RLE is used anyway, with incorrect
    results.
    
    Fix this by adding RLE support for RGB565 data.

 plug-ins/common/file-csource.c |   74 ++++++++++++++++++++++++---------------
 1 files changed, 45 insertions(+), 29 deletions(-)
---
diff --git a/plug-ins/common/file-csource.c b/plug-ins/common/file-csource.c
index 9e31a99..80eb50d 100644
--- a/plug-ins/common/file-csource.c
+++ b/plug-ins/common/file-csource.c
@@ -232,6 +232,12 @@ run (const gchar      *name,
 }
 
 static gboolean
+diff2_rgb565 (guint8 *ip)
+{
+  return ip[0] != ip[2] || ip[1] != ip[3];
+}
+
+static gboolean
 diff2_rgb (guint8 *ip)
 {
   return ip[0] != ip[3] || ip[1] != ip[4] || ip[2] != ip[5];
@@ -247,10 +253,18 @@ static guint8 *
 rl_encode_rgbx (guint8 *bp,
                 guint8 *ip,
                 guint8 *limit,
-                guint   n_ch)
+                guint   bpp)
 {
-  gboolean (*diff2_pix) (guint8 *) = n_ch > 3 ? diff2_rgba : diff2_rgb;
-  guint8 *ilimit = limit - n_ch;
+  gboolean (*diff2_pix) (guint8 *);
+  guint8 *ilimit = limit - bpp;
+
+  switch (bpp)
+    {
+    case 2: diff2_pix = diff2_rgb565; break;
+    case 3: diff2_pix = diff2_rgb; break;
+    case 4: diff2_pix = diff2_rgba; break;
+    default: g_assert_not_reached ();
+    }
 
   while (ip < limit)
     {
@@ -261,33 +275,33 @@ rl_encode_rgbx (guint8 *bp,
           guint8 *s_ip = ip;
           guint l = 1;
 
-          ip += n_ch;
+          ip += bpp;
           while (l < 127 && ip < ilimit && diff2_pix (ip))
-            { ip += n_ch; l += 1; }
+            { ip += bpp; l += 1; }
           if (ip == ilimit && l < 127)
-            { ip += n_ch; l += 1; }
+            { ip += bpp; l += 1; }
           *(bp++) = l;
-          memcpy (bp, s_ip, l * n_ch);
-          bp += l * n_ch;
+          memcpy (bp, s_ip, l * bpp);
+          bp += l * bpp;
         }
       else
         {
           guint l = 2;
 
-          ip += n_ch;
+          ip += bpp;
           while (l < 127 && ip < ilimit && !diff2_pix (ip))
-            { ip += n_ch; l += 1; }
+            { ip += bpp; l += 1; }
           *(bp++) = l | 128;
-          memcpy (bp, ip, n_ch);
-          ip += n_ch;
-          bp += n_ch;
+          memcpy (bp, ip, bpp);
+          ip += bpp;
+          bp += bpp;
         }
       if (ip == ilimit)
         {
           *(bp++) = 1;
-          memcpy (bp, ip, n_ch);
-          ip += n_ch;
-          bp += n_ch;
+          memcpy (bp, ip, bpp);
+          ip += bpp;
+          bp += bpp;
         }
     }
 
@@ -321,7 +335,7 @@ save_rle_decoder (GOutputStream  *output,
                   const gchar    *macro_name,
                   const gchar    *s_uint,
                   const gchar    *s_uint_8,
-                  guint           n_ch,
+                  guint           bpp,
                   GError        **error)
 {
   return
@@ -341,7 +355,7 @@ save_rle_decoder (GOutputStream  *output,
            "        do { memcpy (__ip, __rd, 4); __ip += 4; } while (--__l); __rd += 4; \\\n"
            "      } else { __l *= 4; memcpy (__ip, __rd, __l); \\\n"
            "               __ip += __l; __rd += __l; } } \\\n"
-           "  } else { /* RGB */ \\\n"
+           "  } else if (__bpp == 3) { /* RGB */ \\\n"
            "    while (__ip < __il) { %s __l = *(__rd++); \\\n",
            s_uint) &&
     print (output, error,
@@ -349,6 +363,14 @@ save_rle_decoder (GOutputStream  *output,
            "        do { memcpy (__ip, __rd, 3); __ip += 3; } while (--__l); __rd += 3; \\\n"
            "      } else { __l *= 3; memcpy (__ip, __rd, __l); \\\n"
            "               __ip += __l; __rd += __l; } } \\\n"
+           "  } else { /* RGB16 */ \\\n"
+           "    while (__ip < __il) { %s __l = *(__rd++); \\\n",
+           s_uint) &&
+    print (output, error,
+           "      if (__l & 128) { __l = __l - 128; \\\n"
+           "        do { memcpy (__ip, __rd, 2); __ip += 2; } while (--__l); __rd += 2; \\\n"
+           "      } else { __l *= 2; memcpy (__ip, __rd, __l); \\\n"
+           "               __ip += __l; __rd += __l; } } \\\n"
            "  } } while (0)\n");
 }
 
@@ -594,7 +616,7 @@ save_image (GFile   *file,
                               macro_name,
                               config->glib_types ? "guint" : "unsigned int",
                               config->glib_types ? "guint8" : "unsigned char",
-                              config->alpha ? 4 : 3,
+                              bpp,
                               error))
         goto fail;
     }
@@ -748,7 +770,7 @@ save_image (GFile   *file,
                                   macro_name,
                                   s_uint,
                                   s_uint_8,
-                                  config->alpha ? 4 : 3,
+                                  bpp,
                                   error))
             goto fail;
         }
@@ -846,10 +868,6 @@ rgb565_toggle_button_update (GtkWidget *toggle,
   widget = g_object_get_data (G_OBJECT (toggle), "set-insensitive-1");
   if (widget)
     gtk_widget_set_sensitive (widget, ! active);
-
-  widget = g_object_get_data (G_OBJECT (toggle), "set-insensitive-2");
-  if (widget)
-    gtk_widget_set_sensitive (widget, ! active);
 }
 
 static gboolean
@@ -861,7 +879,6 @@ run_save_dialog (Config *config)
   GtkWidget *prefixed_name;
   GtkWidget *centry;
   GtkWidget *toggle;
-  GtkWidget *rle_toggle;
   GtkWidget *alpha_toggle;
   GtkObject *adj;
   gboolean   run;
@@ -937,7 +954,7 @@ run_save_dialog (Config *config)
 
   /* Use RLE
    */
-  rle_toggle = toggle =
+  toggle =
     gtk_check_button_new_with_mnemonic (_("Use _1 byte Run-Length-Encoding"));
   gtk_box_pack_start (GTK_BOX (vbox), toggle, FALSE, FALSE, 0);
   gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (toggle),
@@ -966,9 +983,8 @@ run_save_dialog (Config *config)
   toggle = gtk_check_button_new_with_mnemonic (_("Save as _RGB565 (16-bit)"));
   gtk_box_pack_start (GTK_BOX (vbox), toggle, FALSE, FALSE, 0);
 
-  /* RLE and alpha settings are not used with RGB-565 */
-  g_object_set_data (G_OBJECT (toggle), "set-insensitive-1", rle_toggle);
-  g_object_set_data (G_OBJECT (toggle), "set-insensitive-2", alpha_toggle);
+  /* Alpha setting is not used with RGB-565 */
+  g_object_set_data (G_OBJECT (toggle), "set-insensitive-1", alpha_toggle);
 
   g_signal_connect (toggle, "toggled",
                     G_CALLBACK (rgb565_toggle_button_update),