LCD core move buf ptr and address look up function viewport struct

I'm currently running up against the limitations of the lcd_draw functions
I want these functions to be able to be used on any size buffer not
just buffers with a stride matching the underlying device

[DONE] allow the framebuffer to be decoupled from the device framebuffer
[DONE need examples] allow for some simple blit like transformations
[DONE] remove the device framebuffer from the plugin api
[DONE}ditto remote framebuffer
[DONE] remove _viewport_get_framebuffer you can call struct *vp = lcd_set_viewport(NULL) and vp->buffer->fb_ptr

while remote lcds may compile (and work in the sim) its not been tested on targets

[FIXED] backdrops need work to be screen agnostic

[FIXED] screen statusbar is not being combined into the main viewport correctly yet

[FIXED] screen elements are displayed incorrectly  after switch to void*

[FIXED] core didn't restore proper viewport on splash etc.

[NEEDS TESTING] remote lcd garbled data

[FIXED] osd lib garbled screen on bmp_part

[FIXED] grey_set_vp needs to return old viewport like lcd_set_viewport

[FIXED] Viewport update now handles viewports with differing buffers/strides by copying to the main buffer

[FIXED] splash on top of WPS leaves old framebuffer data (doesn't redraw)
[UPDATE] refined this a bit more to have clear_viewport set the clean bit and have skin_render do its own screen clear
scrolling viewports no longer trigger wps refresh
also fixed a bug where guisyncyesno was displaying and then disappearing

[ADDED!] New LCD macros that allow you to create properly size frame buffers in you desired size without wasting bytes
(LCD_ and LCD_REMOTE_)
LCD_STRIDE(w, h) same as STRIDE_MAIN
LCD_FBSTRIDE(w, h) returns target specific stride for a buffer W x H
LCD_NBELEMS(w, h) returns the number of fb_data sized elemenst needed for a buffer W x H
LCD_NATIVE_STRIDE(s) conversion between rockbox native vertical and lcd native stride (2bitH)
test_viewports.c has an example of usage

[FIXED!!] 2bit targets don't respect non-native strides
[FIXED] Few define snags

Change-Id: I0d04c3834e464eca84a5a715743a297a0cefd0af

1 files changed, 3 insertions, 2 deletions

diff --git a/apps/gui/usb_screen.c b/apps/gui/usb_screen.c
index 3169831322..31321ec005 100644
--- a/apps/gui/usb_screen.c
+++ b/apps/gui/usb_screen.c
@@ -179,6 +179,7 @@ static void usb_screen_fix_viewports(struct screen *screen,
 
 static void usb_screens_draw(struct usb_screen_vps_t *usb_screen_vps_ar)
 {
+    struct viewport *last_vp;
     static const struct bitmap* logos[NB_SCREENS] = {
         &bm_usblogo,
 #ifdef HAVE_REMOTE_LCD
@@ -194,7 +195,7 @@ static void usb_screens_draw(struct usb_screen_vps_t *usb_screen_vps_ar)
         struct viewport *parent = &usb_screen_vps->parent;
         struct viewport *logo = &usb_screen_vps->logo;
 
-        screen->set_viewport(parent);
+        last_vp = screen->set_viewport(parent);
         screen->clear_viewport();
         screen->backlight_on();
 
@@ -217,7 +218,7 @@ static void usb_screens_draw(struct usb_screen_vps_t *usb_screen_vps_ar)
         }
         screen->set_viewport(parent);
 
-        screen->set_viewport(NULL);
+        screen->set_viewport(last_vp);
         screen->update_viewport();
     }
 }