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, 314 insertions, 205 deletions

diff --git a/apps/plugins/lib/gray.h b/apps/plugins/lib/gray.h
index 18be88a2f2..b7b0affd73 100644
--- a/apps/plugins/lib/gray.h
+++ b/apps/plugins/lib/gray.h
@@ -30,308 +30,417 @@
 
 #ifdef HAVE_LCD_BITMAP /* and also not for the Player */
 
-/* Initialize the framework
- *
- * every framework needs such a function, and it has to be called as
- * the very first one 
+/*===========================================================================
+ Public functions and definitions, to be used within plugins
+ ============================================================================
+ */
+
+/*---------------------------------------------------------------------------
+ Initialize the framework
+ ----------------------------------------------------------------------------
+ every framework needs such a function, and it has to be called as the very
+ first one
  */
 void gray_init(struct plugin_api* newrb);
 
-/**** general functions ****/
-
-/* Prepare the grayscale display buffer
- *
- * arguments:
- *   gbuf      = pointer to the memory area to use (e.g. plugin buffer)
- *   gbuf_size = max usable size of the buffer
- *   width     = width in pixels  (1..112)
- *   bheight   = height in 8-pixel units  (1..8)
- *   depth     = desired number of shades - 1  (1..32)
- *
- * result:
- *   = depth  if there was enough memory
- *   < depth  if there wasn't enough memory. The number of displayable
- *            shades is smaller than desired, but it still works
- *   = 0      if there wasn't even enough memory for 1 bitplane (black & white)
- *
- * You can request any depth from 1 to 32, not just powers of 2. The routine
- * performs "graceful degradation" if the memory is not sufficient for the
- * desired depth. As long as there is at least enough memory for 1 bitplane,
- * it creates as many bitplanes as fit into memory, although 1 bitplane will
- * only deliver black & white display.
- *
- * If you need info about the memory taken by the grayscale buffer, supply an
- * int* as the last parameter. This int will then contain the number of bytes
- * used. The total memory needed can be calculated as follows:
- *   total_mem =
- *     sizeof(tGraybuf)      (= 64 bytes currently)
- *   + sizeof(long)          (=  4 bytes)
- *   + (width * bheight + sizeof(long)) * depth
- *   + 0..3                  (longword alignment of grayscale display buffer)
+/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ General functions 
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ */
+
+/*---------------------------------------------------------------------------
+ Prepare the grayscale display buffer
+ ----------------------------------------------------------------------------
+ arguments:
+   gbuf      = pointer to the memory area to use (e.g. plugin buffer)
+   gbuf_size = max usable size of the buffer
+   width     = width in pixels  (1..112)
+   bheight   = height in 8-pixel units  (1..8)
+   depth     = desired number of shades - 1  (1..32)
+ 
+ result:
+   = depth  if there was enough memory
+   < depth  if there wasn't enough memory. The number of displayable
+            shades is smaller than desired, but it still works
+   = 0      if there wasn't even enough memory for 1 bitplane (black & white)
+ 
+ You can request any depth from 1 to 32, not just powers of 2. The routine
+ performs "graceful degradation" if the memory is not sufficient for the
+ desired depth. As long as there is at least enough memory for 1 bitplane,
+ it creates as many bitplanes as fit into memory, although 1 bitplane will
+ only deliver black & white display.
+
+ If you need info about the memory taken by the grayscale buffer, supply an
+ int* as the last parameter. This int will then contain the number of bytes
+ used. The total memory needed can be calculated as follows:
+   total_mem =
+     sizeof(_tGraybuf)      (= 64 bytes currently)
+   + sizeof(long)          (=  4 bytes)
+   + (width * bheight + sizeof(long)) * depth
+   + 0..3                  (longword alignment of grayscale display buffer)
  */
 int gray_init_buffer(unsigned char *gbuf, int gbuf_size, int width,
                      int bheight, int depth, int *buf_taken);
                      
-/* Release the grayscale display buffer
- *
- * Switches the grayscale overlay off at first if it is still running,
- * then sets the pointer to NULL.
- * DO CALL either this function or at least gray_show_display(false)
- * before you exit, otherwise nasty things may happen.
+/*---------------------------------------------------------------------------
+ Release the grayscale display buffer
+ ----------------------------------------------------------------------------
+ Switches the grayscale overlay off at first if it is still running,
+ then sets the pointer to NULL.
+ DO CALL either this function or at least gray_show_display(false)
+ before you exit, otherwise nasty things may happen.
  */
 void gray_release_buffer(void);
 
-/* Set position of the top left corner of the grayscale overlay
- *
- *   x  = left margin in pixels
- *   by = top margin in 8-pixel units
- *
- * You may set this in a way that the overlay spills across the right or
- * bottom display border. In this case it will simply be clipped by the 
- * LCD controller. You can even set negative values, this will clip at the
- * left or top border. I did not test it, but the limits may be +127 / -128
- *
- * If you use this while the grayscale overlay is running, the now-freed area
- * will be restored.
+/*---------------------------------------------------------------------------
+ Switch the grayscale overlay on or off
+ ----------------------------------------------------------------------------
+   enable = true:  the grayscale overlay is switched on if initialized
+          = false: the grayscale overlay is switched off and the regular lcd
+                   content is restored
+
+ DO NOT call lcd_update() or any other api function that directly accesses
+ the lcd while the grayscale overlay is running! If you need to do
+ lcd_update() to update something outside the grayscale overlay area, use
+ gray_deferred_update() instead.
+
+ Other functions to avoid are:
+   lcd_blit() (obviously), lcd_update_rect(), lcd_set_contrast(),
+   lcd_set_invert_display(), lcd_set_flip(), lcd_roll()
+
+ The grayscale display consumes ~50 % CPU power (for a full screen overlay,
+ less if the overlay is smaller) when switched on. You can switch the overlay
+ on and off as many times as you want.
  */
-void gray_position_display(int x, int by);
+void gray_show_display(bool enable);
 
-/* Switch the grayscale overlay on or off
- *
- *   enable = true:  the grayscale overlay is switched on if initialized
- *          = false: the grayscale overlay is switched off and the regular lcd
- *                   content is restored
- *
- * DO NOT call lcd_update() or any other api function that directly accesses
- * the lcd while the grayscale overlay is running! If you need to do
- * lcd_update() to update something outside the grayscale overlay area, use 
- * gray_deferred_update() instead.
- *
- * Other functions to avoid are:
- *   lcd_blit() (obviously), lcd_update_rect(), lcd_set_contrast(),
- *   lcd_set_invert_display(), lcd_set_flip(), lcd_roll()
- *
- * The grayscale display consumes ~50 % CPU power (for a full screen overlay,
- * less if the overlay is smaller) when switched on. You can switch the overlay
- * on and off as many times as you want.
+/*---------------------------------------------------------------------------
+ Set position of the top left corner of the grayscale overlay
+ ----------------------------------------------------------------------------
+   x  = left margin in pixels
+   by = top margin in 8-pixel units
+ 
+ You may set this in a way that the overlay spills across the right or
+ bottom display border. In this case it will simply be clipped by the
+ LCD controller. You can even set negative values, this will clip at the
+ left or top border. I did not test it, but the limits may be +127 / -128
+
+ If you use this while the grayscale overlay is running, the now-freed area
+ will be restored.
  */
-void gray_show_display(bool enable);
+void gray_position_display(int x, int by);
 
-/* Set the draw mode for subsequent drawing operations
- *
- *   drawmode =
- *     GRAY_DRAW_INVERSE: Foreground pixels are inverted, background pixels are
- *                        left untouched
- *     GRAY_DRAW_FG:      Only foreground pixels are drawn
- *     GRAY_DRAW_BG:      Only background pixels are drawn
- *     GRAY_DRAW_SOLID:   Foreground and background pixels are drawn
+/*---------------------------------------------------------------------------
+ Set the draw mode for subsequent drawing operations
+ ----------------------------------------------------------------------------
+   drawmode =
+     GRAY_DRAW_INVERSE: Foreground pixels are inverted, background pixels are
+                        left untouched
+     GRAY_DRAW_FG:      Only foreground pixels are drawn
+     GRAY_DRAW_BG:      Only background pixels are drawn
+     GRAY_DRAW_SOLID:   Foreground and background pixels are drawn
  */
 void gray_set_drawmode(int drawmode);
 
-/* Draw modes */
+/*---------------------------------------------------------------------------
+ Draw modes, see above
+ ----------------------------------------------------------------------------
+ */
 #define GRAY_DRAW_INVERSE 0
 #define GRAY_DRAW_FG      1
 #define GRAY_DRAW_BG      2
 #define GRAY_DRAW_SOLID   3
 
-/* Set the foreground shade for subsequent drawing operations
- *
- * brightness = 0 (black) .. 255 (white)
+/*---------------------------------------------------------------------------
+ Set the foreground shade for subsequent drawing operations
+ ----------------------------------------------------------------------------
+ brightness = 0 (black) .. 255 (white)
  */
 void gray_set_foreground(int brightness);
 
-/* Set the background shade for subsequent drawing operations
- *
- * brightness = 0 (black) .. 255 (white)
+/*---------------------------------------------------------------------------
+ Set the background shade for subsequent drawing operations
+ ----------------------------------------------------------------------------
+ brightness = 0 (black) .. 255 (white)
  */
 void gray_set_background(int brightness);
 
-/* Set draw mode, foreground and background shades at once
- * 
- * If you hand it -1 (or in fact any other out-of-bounds value) for a
- * parameter, that particular setting won't be changed
+/*---------------------------------------------------------------------------
+ Set draw mode, foreground and background shades at once
+ ----------------------------------------------------------------------------
+ If you hand it -1 (or in fact any other out-of-bounds value) for a
+ parameter, that particular setting won't be changed
  */
 void gray_set_drawinfo(int drawmode, int fg_brightness, int bg_brightness);
 
-/**** functions affecting the whole display ****/
+/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Functions affecting the whole display
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ */
 
-/* Clear the grayscale display (sets all pixels to white) */
+/*---------------------------------------------------------------------------
+ Clear the grayscale display (sets all pixels to white)
+ ----------------------------------------------------------------------------
+ */
 void gray_clear_display(void);
 
-/* Set the grayscale display to all black */
+/*---------------------------------------------------------------------------
+ Set the grayscale display to all black 
+ ----------------------------------------------------------------------------
+ */
 void gray_black_display(void);
 
-/* Do an lcd_update() to show changes done by rb->lcd_xxx() functions (in areas
- * of the screen not covered by the grayscale overlay).
- *
- * If the grayscale overlay is running, the update will be done in the next
- * call of the interrupt routine, otherwise it will be performed right away.
- * See also comment for the gray_show_display() function.
+/*---------------------------------------------------------------------------
+ Do an lcd_update() to show changes done by rb->lcd_xxx() functions (in areas
+ of the screen not covered by the grayscale overlay).
+ ----------------------------------------------------------------------------
+ If the grayscale overlay is running, the update will be done in the next
+ call of the interrupt routine, otherwise it will be performed right away.
+ See also comment for the gray_show_display() function.
  */
 void gray_deferred_update(void);
 
-/**** Scrolling functions ****/
+/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Scrolling functions
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ */
+
+/*---------------------------------------------------------------------------
+ Scroll the whole grayscale buffer left by <count> pixels
+ ----------------------------------------------------------------------------
+ black_border determines if the pixels scrolled in at the right are black
+ or white
 
-/* Scroll the whole grayscale buffer left by <count> pixels
- *
- * black_border determines if the pixels scrolled in at the right are black
- * or white
- *
- * Scrolling left/right by an even pixel count is almost twice as fast as
- * scrolling by an odd pixel count.
+ Scrolling left/right by an even pixel count is almost twice as fast as
+ scrolling by an odd pixel count.
  */
 void gray_scroll_left(int count, bool black_border);
 
-/* 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.
+/*---------------------------------------------------------------------------
+ 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);
 
-/* Scroll the whole grayscale buffer up by 8 pixels
- *
- * black_border determines if the pixels scrolled in at the bottom are black
- * or white
- *
- * Scrolling up/down by 8 pixels is very fast.
+/*---------------------------------------------------------------------------
+ Scroll the whole grayscale buffer up by 8 pixels
+ ----------------------------------------------------------------------------
+ black_border determines if the pixels scrolled in at the bottom are black
+ or white
+
+ Scrolling up/down by 8 pixels is very fast.
  */
 void gray_scroll_up8(bool black_border);
 
-/* Scroll the whole grayscale buffer down by 8 pixels
- *
- * black_border determines if the pixels scrolled in at the top are black
- * or white
- *
- * Scrolling up/down by 8 pixels is very fast.
+/*---------------------------------------------------------------------------
+ Scroll the whole grayscale buffer down by 8 pixels
+ ----------------------------------------------------------------------------
+ black_border determines if the pixels scrolled in at the top are black
+ or white
+
+ Scrolling up/down by 8 pixels is very fast.
  */
 void gray_scroll_down8(bool black_border);
 
-/* Scroll the whole grayscale buffer up by <count> pixels (<= 7)
- *
- * black_border determines if the pixels scrolled in at the bottom are black
- * or white
- *
- * Scrolling up/down pixel-wise is significantly slower than scrolling
- * left/right or scrolling up/down byte-wise because it involves bit
- * shifting. That's why it is asm optimized.
+/*---------------------------------------------------------------------------
+ Scroll the whole grayscale buffer up by <count> pixels (<= 7)
+ ----------------------------------------------------------------------------
+ black_border determines if the pixels scrolled in at the bottom are black
+ or white
+
+ Scrolling up/down pixel-wise is significantly slower than scrolling
+ left/right or scrolling up/down byte-wise because it involves bit
+ shifting. That's why it is asm optimized.
  */
 void gray_scroll_up(int count, bool black_border);
 
-/* Scroll the whole grayscale buffer down by <count> pixels (<= 7)
- *
- * black_border determines if the pixels scrolled in at the top are black
- * or white
- *
- * Scrolling up/down pixel-wise is significantly slower than scrolling
- * left/right or scrolling up/down byte-wise because it involves bit
- * shifting. That's why it is asm optimized.
+/*---------------------------------------------------------------------------
+ Scroll the whole grayscale buffer down by <count> pixels (<= 7)
+ ----------------------------------------------------------------------------
+ black_border determines if the pixels scrolled in at the top are black
+ or white
+
+ Scrolling up/down pixel-wise is significantly slower than scrolling
+ left/right or scrolling up/down byte-wise because it involves bit
+ shifting. That's why it is asm optimized.
  */
 void gray_scroll_down(int count, bool black_border);
 
-/**** Pixel and line functions ****/
+/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Pixel and line functions
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ */
 
-/* Set a pixel with the current drawinfo
- * 
- * If the drawmode is GRAY_DRAW_INVERSE, the pixel is inverted
- * GRAY_DRAW_FG and GRAY_DRAW_SOLID draw the pixel in the foreground shade
- * GRAY_DRAW_BG draws the pixel in the background shade
+/*---------------------------------------------------------------------------
+ Set a pixel with the current drawinfo
+ ----------------------------------------------------------------------------
+ If the drawmode is GRAY_DRAW_INVERSE, the pixel is inverted
+ GRAY_DRAW_FG and GRAY_DRAW_SOLID draw the pixel in the foreground shade
+ GRAY_DRAW_BG draws the pixel in the background shade
  */
 void gray_drawpixel(int x, int y);
 
-/* Draw a line from (x1, y1) to (x2, y2) with the current drawinfo,
- * See gray_drawpixel() for details
+/*---------------------------------------------------------------------------
+ Draw a line from (x1, y1) to (x2, y2) with the current drawinfo
+ ----------------------------------------------------------------------------
+ See gray_drawpixel() for details
  */
 void gray_drawline(int x1, int y1, int x2, int y2);
 
-/* Draw a horizontal line from (x1, y) to (x2, y) with the current drawinfo,
- * See gray_drawpixel() for details
+/*---------------------------------------------------------------------------
+ Draw a horizontal line from (x1, y) to (x2, y) with the current drawinfo
+ ----------------------------------------------------------------------------
+ See gray_drawpixel() for details
  */
 void gray_horline(int x1, int x2, int y);
 
-/* Draw a vertical line from (x, y1) to (x, y2) with the current drawinfo,
- * See gray_drawpixel() for details
- *
- * This one uses the block drawing optimization, so it is rather fast.
+/*---------------------------------------------------------------------------
+ Draw a vertical line from (x, y1) to (x, y2) with the current drawinfo
+ ----------------------------------------------------------------------------
+ See gray_drawpixel() for details
+ This one uses the block drawing optimization, so it is rather fast.
  */
 void gray_verline(int x, int y1, int y2);
 
-/**** Rectangle functions ****/
+/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Rectangle functions
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ */
 
-/* Draw a (hollow) rectangle with the current drawinfo,
- * See gray_drawpixel() for details
+/*---------------------------------------------------------------------------
+ Draw a (hollow) rectangle with the current drawinfo
+ ----------------------------------------------------------------------------
+ See gray_drawpixel() for details
  */
 void gray_drawrect(int x, int y, int nx, int ny);
 
-/* Draw a filled rectangle with the current drawinfo,
- * See gray_drawpixel() for details
- *
- * This one uses the block drawing optimization, so it is rather fast.
+/*---------------------------------------------------------------------------
+ Draw a filled rectangle with the current drawinfo
+ ----------------------------------------------------------------------------
+ See gray_drawpixel() for details
+ This one uses the block drawing optimization, so it is rather fast.
  */
 void gray_fillrect(int x, int y, int nx, int ny);
 
-/**** Bitmap functions ****/
+/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Bitmap functions
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ */
 
-/* Copy a grayscale bitmap into the display
- * 
- * A grayscale bitmap contains one byte for every pixel that defines the
- * brightness of the pixel (0..255). Bytes are read in row-major order.
- * The <stride> parameter is useful if you want to show only a part of a
- * bitmap. It should always be set to the "row length" of the bitmap, so
- * for displaying the whole bitmap, nx == stride.
- *
- * This is the only drawing function NOT using the drawinfo.
+/*---------------------------------------------------------------------------
+ Copy a grayscale bitmap into the display
+ ----------------------------------------------------------------------------
+ A grayscale bitmap contains one byte for every pixel that defines the
+ brightness of the pixel (0..255). Bytes are read in row-major order.
+ The <stride> parameter is useful if you want to show only a part of a
+ bitmap. It should always be set to the "row length" of the bitmap, so
+ for displaying the whole bitmap, nx == stride.
+ 
+ This is the only drawing function NOT using the drawinfo.
  */
 void gray_drawgraymap(unsigned char *src, int x, int y, int nx, int ny,
                       int stride);
 
-/* Display a bitmap with the current drawinfo
- *
- * The drawmode is used as described for gray_set_drawmode()
- *
- * This (now) uses the same bitmap format as the core b&w graphics routines,
- * so you can use bmp2rb to generate bitmaps for use with this function as
- * well.
- *
- * A bitmap contains one bit for every pixel that defines if that pixel is
- * foreground (1) or background (0). Bits within a byte are arranged
- * vertically, LSB at top.
- * The bytes are stored in row-major order, with byte 0 being top left,
- * byte 1 2nd from left etc. The first row of bytes defines pixel rows
- * 0..7, the second row defines pixel row 8..15 etc.
- *
- * The <stride> parameter is useful if you want to show only a part of a
- * bitmap. It should always be set to the "row length" of the bitmap.
+/*---------------------------------------------------------------------------
+ Display a bitmap with the current drawinfo
+ ----------------------------------------------------------------------------
+ The drawmode is used as described for gray_set_drawmode()
+
+ This (now) uses the same bitmap format as the core b&w graphics routines,
+ so you can use bmp2rb to generate bitmaps for use with this function as
+ well.
+
+ A bitmap contains one bit for every pixel that defines if that pixel is
+ foreground (1) or background (0). Bits within a byte are arranged
+ vertically, LSB at top.
+ The bytes are stored in row-major order, with byte 0 being top left,
+ byte 1 2nd from left etc. The first row of bytes defines pixel rows
+ 0..7, the second row defines pixel row 8..15 etc.
+
+ The <stride> parameter is useful if you want to show only a part of a
+ bitmap. It should always be set to the "row length" of the bitmap.
  */
 void gray_drawbitmap(unsigned char *src, int x, int y, int nx, int ny,
                      int stride);
 
-/**** Font support ****/
+/*+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Font support
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ */
 
-/* Set font for the font routines
- * 
- * newfont can be FONT_SYSFIXED or FONT_UI the same way as with the Rockbox
- * core routines
+/*---------------------------------------------------------------------------
+ Set font for the font routines
+ ----------------------------------------------------------------------------
+ newfont can be FONT_SYSFIXED or FONT_UI the same way as with the Rockbox
+ core routines
  */
 void gray_setfont(int newfont);
 
-/* Calculate width and height of the given text in pixels when rendered with
- * the currently selected font.
- *
- * This works exactly the same way as the core lcd_getstringsize(), only that
- * it uses the selected font for grayscale.
+/*---------------------------------------------------------------------------
+ Calculate width and height of the given text in pixels when rendered with
+ the currently selected font.
+ ----------------------------------------------------------------------------
+ This works exactly the same way as the core lcd_getstringsize(), only that
+ it uses the selected font for grayscale.
  */
 int gray_getstringsize(unsigned char *str, int *w, int *h);
 
-/* Display text starting at (x, y) with the current font and drawinfo
- *
- * The drawmode is used as described for gray_set_drawmode()
+/*---------------------------------------------------------------------------
+ Display text starting at (x, y) with the current font and drawinfo
+ ----------------------------------------------------------------------------
+ The drawmode is used as described for gray_set_drawmode()
  */
 void gray_putsxy(int x, int y, unsigned char *str);
 
+/*===========================================================================
+ Private functions and definitions, for use within the grayscale core only
+ ============================================================================
+ */
+
+/* flag definitions */
+#define _GRAY_RUNNING          0x0001  /* grayscale overlay is running */
+#define _GRAY_DEFERRED_UPDATE  0x0002  /* lcd_update() requested */
+
+/* unsigned 16 bit multiplication (a single instruction on the SH) */
+#define MULU16(a, b) ((unsigned long) \
+                     (((unsigned short) (a)) * ((unsigned short) (b))))
+
+/* The grayscale buffer management structure */
+typedef struct
+{
+    int x;
+    int by;         /* 8-pixel units */
+    int width;
+    int height;
+    int bheight;    /* 8-pixel units */
+    int plane_size;
+    int depth;      /* number_of_bitplanes  = (number_of_grayscales - 1) */
+    int cur_plane;  /* for the timer isr */
+    unsigned long randmask;    /* mask for random value in _writepixel() */
+    unsigned long flags;       /* various flags, see #defines */
+    unsigned long *bitpattern; /* pointer to start of pattern table */
+    unsigned char *data;       /* pointer to start of bitplane data */
+    unsigned long fg_pattern;  /* current foreground pattern */
+    unsigned long bg_pattern;  /* current background pattern */
+    int drawmode;              /* current draw mode */
+    struct font *curfont;      /* current selected font */
+} _tGraybuf;
+
+/* Global variables */
+extern struct plugin_api *_gray_rb;
+extern _tGraybuf *_graybuf;
+extern short _gray_random_buffer;
+
+/* Global function pointers */
+extern void (*_gray_pixelfuncs[4])(int x, int y, unsigned long pattern);
+extern void (*_gray_blockfuncs[4])(unsigned char *address, unsigned mask,
+                                   unsigned bits);
+
 #endif /* HAVE_LCD_BITMAP */
 #endif /* SIMULATOR */
 #endif /* __GRAY_H__ */