1 files changed, 62 insertions, 13 deletions

diff --git a/firmware/drivers/lcd-16bit.c b/firmware/drivers/lcd-16bit.c
index bf5cdbcdd0..aaf7bde1aa 100644
--- a/firmware/drivers/lcd-16bit.c
+++ b/firmware/drivers/lcd-16bit.c
@@ -38,6 +38,9 @@
 /*** globals ***/
 fb_data lcd_framebuffer[LCD_HEIGHT][LCD_WIDTH] __attribute__ ((aligned (16)));
 
+fb_data* lcd_backdrop IDATA_ATTR = NULL;
+int lcd_backdrop_offset = NULL;
+
 static unsigned fg_pattern IDATA_ATTR = LCD_DEFAULT_FG;
 static unsigned bg_pattern IDATA_ATTR = LCD_DEFAULT_BG;
 static int drawmode = DRMODE_SOLID;
@@ -105,6 +108,17 @@ void lcd_set_background(unsigned color)
     bg_pattern = color;
 }
 
+void lcd_set_backdrop(fb_data* backdrop)
+{
+    lcd_backdrop = backdrop;
+    if (backdrop)
+        lcd_backdrop_offset = (int)backdrop - (int)&lcd_framebuffer[0][0];
+}
+
+fb_data* lcd_get_backdrop(void)
+{
+    return lcd_backdrop;
+}
 
 unsigned lcd_get_background(void)
 {
@@ -160,6 +174,12 @@ static void clearpixel(fb_data *address)
     *address = bg_pattern;
 }
 
+static void clearimgpixel(fb_data *address) ICODE_ATTR;
+static void clearimgpixel(fb_data *address)
+{
+    *address = *(fb_data *)((int)address + lcd_backdrop_offset);
+}
+
 static void flippixel(fb_data *address) ICODE_ATTR;
 static void flippixel(fb_data *address)
 {
@@ -177,26 +197,41 @@ lcd_fastpixelfunc_type* const lcd_fastpixelfuncs[8] = {
     nopixel, clearpixel, nopixel, clearpixel
 };
 
+lcd_fastpixelfunc_type* const lcd_fastimgpixelfuncs[8] = {
+    flippixel, nopixel, setpixel, setpixel,
+    nopixel, clearimgpixel, nopixel, clearimgpixel
+};
+
 /*** drawing functions ***/
 
 /* Clear the whole display */
 void lcd_clear_display(void)
 {
-    fb_data bits = (drawmode & DRMODE_INVERSEVID) ? fg_pattern : bg_pattern;
     fb_data *dst = LCDADDR(0, 0);
     fb_data *dst_end = dst + LCD_HEIGHT*LCD_WIDTH;
-    
-    do
-        *dst++ = bits;
-    while (dst < dst_end);
+
+    if (lcd_backdrop) {    
+        do
+            clearimgpixel(dst++);
+        while (dst < dst_end);
+    } else {
+        do
+            clearpixel(dst++);
+        while (dst < dst_end);
+    }
     scrolling_lines = 0;
 }
 
 /* Set a single pixel */
 void lcd_drawpixel(int x, int y)
 {
-    if (((unsigned)x < LCD_WIDTH) && ((unsigned)y < LCD_HEIGHT))
-        lcd_fastpixelfuncs[drawmode](LCDADDR(x, y));
+    if (((unsigned)x < LCD_WIDTH) && ((unsigned)y < LCD_HEIGHT)) {
+        if (lcd_backdrop) {
+            lcd_fastimgpixelfuncs[drawmode](LCDADDR(x, y));
+        } else {
+            lcd_fastpixelfuncs[drawmode](LCDADDR(x, y));
+        }
+    }
 }
 
 /* Draw a line */
@@ -208,7 +243,10 @@ void lcd_drawline(int x1, int y1, int x2, int y2)
     int d, dinc1, dinc2;
     int x, xinc1, xinc2;
     int y, yinc1, yinc2;
-    lcd_fastpixelfunc_type *pfunc = lcd_fastpixelfuncs[drawmode];
+    lcd_fastpixelfunc_type *pfunc = (lcd_backdrop ? 
+                                     lcd_fastimgpixelfuncs[drawmode] :
+                                     lcd_fastpixelfuncs[drawmode]);
+
 
     deltax = abs(x2 - x1);
     deltay = abs(y2 - y1);
@@ -275,7 +313,9 @@ void lcd_hline(int x1, int x2, int y)
 {
     int x;
     fb_data *dst, *dst_end;
-    lcd_fastpixelfunc_type *pfunc = lcd_fastpixelfuncs[drawmode];
+    lcd_fastpixelfunc_type *pfunc = (lcd_backdrop ? 
+                                     lcd_fastimgpixelfuncs[drawmode] :
+                                     lcd_fastpixelfuncs[drawmode]);
 
     /* direction flip */
     if (x2 < x1)
@@ -308,7 +348,9 @@ void lcd_vline(int x, int y1, int y2)
 {
     int y;
     fb_data *dst, *dst_end;
-    lcd_fastpixelfunc_type *pfunc = lcd_fastpixelfuncs[drawmode];
+    lcd_fastpixelfunc_type *pfunc = (lcd_backdrop ? 
+                                     lcd_fastimgpixelfuncs[drawmode] :
+                                     lcd_fastpixelfuncs[drawmode]);
 
     /* direction flip */
     if (y2 < y1)
@@ -358,7 +400,9 @@ void lcd_drawrect(int x, int y, int width, int height)
 void lcd_fillrect(int x, int y, int width, int height)
 {
     fb_data *dst, *dst_end;
-    lcd_fastpixelfunc_type *pfunc = lcd_fastpixelfuncs[drawmode];
+    lcd_fastpixelfunc_type *pfunc = (lcd_backdrop ? 
+                                     lcd_fastimgpixelfuncs[drawmode] :
+                                     lcd_fastpixelfuncs[drawmode]);
 
     /* nothing to draw? */
     if ((width <= 0) || (height <= 0) || (x >= LCD_WIDTH) || (y >= LCD_HEIGHT)
@@ -450,8 +494,13 @@ void lcd_mono_bitmap_part(const unsigned char *src, int src_x, int src_y,
     src_end = src + width;
 
     dst = LCDADDR(x, y);
-    fgfunc = lcd_fastpixelfuncs[drawmode];
-    bgfunc = lcd_fastpixelfuncs[drawmode ^ DRMODE_INVERSEVID];
+    if (lcd_backdrop) {
+        fgfunc = lcd_fastimgpixelfuncs[drawmode];
+        bgfunc = lcd_fastimgpixelfuncs[drawmode ^ DRMODE_INVERSEVID];
+    } else {
+        fgfunc = lcd_fastpixelfuncs[drawmode];
+        bgfunc = lcd_fastpixelfuncs[drawmode ^ DRMODE_INVERSEVID];
+    }
 
     do
     {