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, 6 insertions, 5 deletions

diff --git a/apps/onplay.c b/apps/onplay.c
index f2ebd47630..ded2994c97 100644
--- a/apps/onplay.c
+++ b/apps/onplay.c
@@ -795,33 +795,34 @@ static int cat_playlist_callback(int action,
 
 static void draw_slider(void)
 {
+    struct viewport *last_vp;
     FOR_NB_SCREENS(i)
     {
         struct viewport vp;
         int slider_height = 2*screens[i].getcharheight();
         viewport_set_defaults(&vp, i);
-        screens[i].set_viewport(&vp);
+        last_vp = screens[i].set_viewport(&vp);
         show_busy_slider(&screens[i], 1, vp.height - slider_height,
                          vp.width-2, slider_height-1);
         screens[i].update_viewport();
-        screens[i].set_viewport(NULL);
+        screens[i].set_viewport(last_vp);
     }
 }
 
 static void clear_display(bool update)
 {
     struct viewport vp;
-
+    struct viewport *last_vp;
     FOR_NB_SCREENS(i)
     {
         struct screen * screen = &screens[i];
         viewport_set_defaults(&vp, screen->screen_type);
-        screen->set_viewport(&vp);
+        last_vp = screen->set_viewport(&vp);
         screen->clear_viewport();
         if (update) {
             screen->update_viewport();
         }
-        screen->set_viewport(NULL);
+        screen->set_viewport(last_vp);
     }
 }