fixed lcd_bitmap code.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@373 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 32 insertions, 41 deletions

diff --git a/firmware/drivers/lcd.c b/firmware/drivers/lcd.c
index 8a6207bc87..80e46adbdf 100644
--- a/firmware/drivers/lcd.c
+++ b/firmware/drivers/lcd.c
@@ -488,55 +488,46 @@ void lcd_bitmap (unsigned char *src, int x, int y, int nx, int ny,
                  bool clear)
 {
     unsigned char *dst;
-    unsigned char *dst2 = &display[x][y/8];
+    unsigned char *dst2;
     unsigned int data, mask, mask2, mask3, mask4;
-    int shift = y & 7;
+    int shift;
+    int nny, _nnx = x, _nny = y;
 
-    ny += shift;
-
-    /* Calculate bit masks */
-    mask4 = ~(0xfe << ((ny-1) & 7));
-    if (clear)
+    for (nny = ny; nny > 0; nny -= 8, _nny += 8)
     {
-        mask = ~(0xff << shift);
-        mask2 = 0;
-        mask3 = ~mask4;
-        if (ny <= 8)
-            mask3 |= mask;
-    }
-    else
-        mask = mask2 = mask3 = 0xff;
+        x = _nnx; y = _nny; ny = 8;
 
-    /* Loop for each column */
-    for (x = 0; x < nx; x++)
-    {
-        dst = dst2;
-        dst2 += LCD_HEIGHT/8;
-        data = 0;
-        y = 0;
+        dst2 = &display[x][y/8];
+        shift = y & 7;
+
+        ny += shift;
 
-        if (ny > 8)
+        /* Calculate bit masks */
+        mask4 = ~(0xfe << ((ny-1) & 7));
+        if (clear)
         {
-            /* First partial row */
-            data = *src++ << shift;
-            *dst = (*dst & mask) ^ data;
-            data >>= 8;
-            dst++;
-
-            /* Intermediate rows */
-            for (y = 8; y < ny-8; y += 8)
-            {
-                data |= *src++ << shift;
-                *dst = (*dst & mask2) ^ data;
-                data >>= 8;
-                dst++;
-            }
+            mask = ~(0xff << shift);
+            mask2 = 0;
+            mask3 = ~mask4;
+            if (ny <= 8)
+                mask3 |= mask;
         }
+        else
+            mask = mask2 = mask3 = 0xff;
+
+        /* Loop for each column */
+        for (x = 0; x < nx; x++)
+        {
+            dst = dst2;
+            dst2 += LCD_HEIGHT/8;
+            data = 0;
+            y = 0;
 
-        /* Last partial row */
-        if (y + shift < ny)
-            data |= *src++ << shift;
-        *dst = (*dst & mask3) ^ (data & mask4);
+            /* Last partial row */
+            if (y + shift < ny)
+                data |= *src++ << shift;
+            *dst = (*dst & mask3) ^ (data & mask4);
+        }
     }
 }