--- deliantra/Deliantra-Client/texcache.c	2006/07/04 23:23:32	1.1
+++ deliantra/Deliantra-Client/texcache.c	2018/11/18 00:52:22	1.9
@@ -1,4 +1,5 @@
 // all these must be powers of two
+// width and height better be <=256 as we use bytes in the rendercache
 #define TC_WIDTH  256
 #define TC_HEIGHT 256
 #define TC_ROUND  4
@@ -8,18 +9,28 @@
   int x, y, w, h;
 } tc_area;
 
-void tc_get (tc_area *area, int width, int height);
-void tc_put (tc_area *area);
-void tc_clear ();
+extern int tc_generation;
+
+static void tc_get (tc_area *area, int width, int height);
+static void tc_put (tc_area *area);
+static void tc_clear (void);
+static void tc_backup (void);
+static void tc_restore (void);
 
 /////////////////////////////////////////////////////////////////////////////
 
+// required as bug-workaround for apple/ati/...
+static unsigned char tc_temptile [TC_WIDTH * TC_HEIGHT];
+
 #include <glib.h>
 
+int tc_generation;
+
 typedef struct tc_texture {
   struct tc_texture *next;
   GLuint name;
   int avail;
+  char *saved; /* stores saved texture data */
 } tc_texture;
 
 typedef struct tc_slice {
@@ -31,7 +42,7 @@
 static tc_texture *first_texture;
 
 void
-tc_clear ()
+tc_clear (void)
 {
   int i;
 
@@ -41,10 +52,51 @@
   while (first_texture)
     {
       tc_texture *next = first_texture->next;
-      glDeleteTextures (1, &first_texture->name);
+      del_texture (first_texture->name);
       g_slice_free (tc_texture, first_texture);
       first_texture = next;
     }
+
+  ++tc_generation;
+}
+
+void
+tex_backup (tc_texture *tex)
+{
+  tex->saved = (char *)g_slice_alloc (TC_WIDTH * TC_HEIGHT);
+
+  glBindTexture (GL_TEXTURE_2D, tex->name);
+  glGetTexImage (GL_TEXTURE_2D, 0, GL_ALPHA, GL_UNSIGNED_BYTE, tex->saved);
+}
+
+void
+tex_restore (tc_texture *tex)
+{
+  glBindTexture (GL_TEXTURE_2D, tex->name);
+  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+  glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+  glTexImage2D (GL_TEXTURE_2D, 0, GL_ALPHA, TC_WIDTH, TC_HEIGHT, 0, GL_ALPHA, GL_UNSIGNED_BYTE, tex->saved);
+
+  g_slice_free1 (TC_WIDTH * TC_HEIGHT, tex->saved);
+  tex->saved = 0;
+}
+
+void
+tc_backup (void)
+{
+  tc_texture *tex;
+  
+  for (tex = first_texture; tex; tex = tex->next)
+    tex_backup (tex);
+}
+
+void
+tc_restore (void)
+{
+  tc_texture *tex;
+  
+  for (tex = first_texture; tex; tex = tex->next)
+    tex_restore (tex);
 }
 
 void
@@ -71,15 +123,23 @@
       if (!match)
         {
           match = g_slice_new (tc_texture);
-          match->next = first_texture;
+          match->next   = first_texture;
           first_texture = match;
-          glGenTextures (1, &match->name);
-          match->avail = TC_HEIGHT;
+          match->name   = gen_texture ();
+          match->avail  = TC_HEIGHT;
+          match->saved  = 0;
 
           glBindTexture (GL_TEXTURE_2D, match->name);
           glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
           glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-          glTexImage2D (GL_TEXTURE_2D, 0, GL_ALPHA, TC_WIDTH, TC_HEIGHT, 0, GL_ALPHA, GL_UNSIGNED_BYTE, 0);
+
+          // the last parameter should be NULL, but way too amny drivers (ATI, Mesa) crash,
+          // so we better provide some random garbage data for them.
+          glTexImage2D (GL_TEXTURE_2D,
+                        0, GL_ALPHA,
+                        TC_WIDTH, TC_HEIGHT,
+                        0, GL_ALPHA,
+                        GL_UNSIGNED_BYTE, tc_temptile);
         }
 
       match->avail -= slice_height;