PictureFlow fixes and improvements:

* Reduced popping effect (FS#8303)
* Scale the empty slide to average album width
* Introduced some visual settings
* Fix FS#8298 but make the criteria a screen height of less than 100 px so that only the c200 gets 50x50 slides

The scaling code is added as a lib function with a basic test plugin that's not compiled by default.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15913 a1c6a512-1295-4272-9138-f99709370657

2 files changed, 39 insertions, 0 deletions

diff --git a/apps/plugins/lib/bmp.c b/apps/plugins/lib/bmp.c
index dc8432f..03bdc73 100644
--- a/apps/plugins/lib/bmp.c
+++ b/apps/plugins/lib/bmp.c
@@ -82,3 +82,36 @@ int save_bmp_file( char* filename, struct bitmap *bm, struct plugin_api* rb )
     rb->close( fh );
     return 1;
 }
+
+/**
+   Very simple image scale from src to dst (nearest neighbour).
+   Source and destination dimensions are read from the struct bitmap.
+*/
+void simple_resize_bitmap(struct bitmap *src, struct bitmap *dst)
+{
+    const int srcw = src->width;
+    const int srch = src->height;
+    const int dstw = dst->width;
+    const int dsth = dst->height;
+    const fb_data *srcd = (fb_data*)(src->data);
+    const fb_data *dstd = (fb_data*)(dst->data);
+
+    const long xrstep = ((srcw-1) << 8) / (dstw-1);
+    const long yrstep = ((srch-1) << 8) / (dsth-1);
+    fb_data *src_row, *dst_row;
+    long xr, yr = 0;
+    int src_x, src_y, dst_x, dst_y;
+    for (dst_y=0; dst_y < dsth; dst_y++)
+    {
+        src_y = (yr >> 8);
+        src_row = (fb_data*)&srcd[src_y * srcw];
+        dst_row = (fb_data*)&dstd[dst_y * dstw];
+        for (xr=0,dst_x=0; dst_x < dstw; dst_x++)
+        {
+            src_x = (xr >> 8);
+            dst_row[dst_x] = src_row[src_x];
+            xr += xrstep;
+        }
+        yr += yrstep;
+    }
+}
diff --git a/apps/plugins/lib/bmp.h b/apps/plugins/lib/bmp.h
index dc26e80..e35c1ec 100644
--- a/apps/plugins/lib/bmp.h
+++ b/apps/plugins/lib/bmp.h
@@ -27,4 +27,10 @@
  */
 int save_bmp_file( char* filename, struct bitmap *bm, struct plugin_api* rb  );
 
+/**
+   Very simple image scale from src to dst (nearest neighbour).
+   Source and destination dimensions are read from the struct bitmap.
+*/
+void simple_resize_bitmap(struct bitmap *src, struct bitmap *dst);
+
 #endif