Split grayscale library into several files to make up a real function library. Significantly decreases binary size for plugins using it.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4802 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 100 insertions, 0 deletions

diff --git a/apps/plugins/lib/gray_scroll_right.c b/apps/plugins/lib/gray_scroll_right.c
new file mode 100644
index 0000000000..2b0b85aab7
--- /dev/null
+++ b/apps/plugins/lib/gray_scroll_right.c
@@ -0,0 +1,100 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* Grayscale framework
+* gray_scroll_right() function
+*
+* This is a generic framework to use grayscale display within Rockbox
+* plugins. It obviously does not work for the player.
+*
+* Copyright (C) 2004 Jens Arnold
+*
+* All files in this archive are subject to the GNU General Public License.
+* See the file COPYING in the source tree root for full license agreement.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+
+#ifndef SIMULATOR /* not for simulator by now */
+#include "plugin.h"
+
+#ifdef HAVE_LCD_BITMAP /* and also not for the Player */
+#include "gray.h"
+
+/*---------------------------------------------------------------------------
+ Scroll the whole grayscale buffer right by <count> pixels
+ ----------------------------------------------------------------------------
+ black_border determines if the pixels scrolled in at the left are black
+ or white
+
+ Scrolling left/right by an even pixel count is almost twice as fast as
+ scrolling by an odd pixel count.
+ */
+void gray_scroll_right(int count, bool black_border)
+{
+    int by, d;
+    unsigned filler;
+    unsigned char *ptr;
+
+    if ((unsigned) count >= (unsigned) _graybuf->width)
+        return;
+
+    filler = black_border ? 0xFF : 0;
+
+    /* Scroll row by row to minimize flicker (byte rows = 8 pixels each) */
+    for (by = 0; by < _graybuf->bheight; by++)
+    {
+        ptr = _graybuf->data + MULU16(_graybuf->width, by);
+        for (d = 0; d < _graybuf->depth; d++)
+        {
+            asm volatile (
+                "mov     %0,r1            \n" /* check if both source... */
+                "or      %2,r1            \n" /* ...and offset are even */
+                "shlr    r1               \n" /* -> lsb = 0 */
+                "bf      .sr_start2       \n" /* -> copy word-wise */
+
+                "add     #-1,%2           \n" /* copy byte-wise */
+            ".sr_loop1:                   \n"
+                "mov.b   @(%2,%0),r1      \n"
+                "mov.b   r1,@-%0          \n"
+                "cmp/hi  %1,%0            \n"
+                "bt      .sr_loop1        \n"
+                
+                "bra     .sr_end          \n"
+                "nop                      \n"
+                
+            ".sr_start2:                  \n" /* copy word-wise */
+                "add     #-2,%2           \n"
+            ".sr_loop2:                   \n"
+                "mov.w   @(%2,%0),r1      \n"
+                "mov.w   r1,@-%0          \n"
+                "cmp/hi  %1,%0            \n"
+                "bt      .sr_loop2        \n"
+                
+            ".sr_end:                     \n"
+                : /* outputs */
+                : /* inputs */
+                /* %0 */ "r"(ptr + _graybuf->width),
+                /* %1 */ "r"(ptr + count),
+                /* %2 */ "z"(-count)
+                : /* clobbers */
+                "r1"
+            );
+
+            _gray_rb->memset(ptr, filler, count);
+            ptr += _graybuf->plane_size;
+        }
+    }
+}
+
+#endif // #ifdef HAVE_LCD_BITMAP
+#endif // #ifndef SIMULATOR
+