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, 22 insertions, 4 deletions

diff --git a/apps/gui/viewport.c b/apps/gui/viewport.c
index db58b5d72d..9fdf88e8f0 100644
--- a/apps/gui/viewport.c
+++ b/apps/gui/viewport.c
@@ -31,6 +31,7 @@
 #include "settings.h"
 #include "misc.h"
 #include "list.h"
+
 /*some short cuts for fg/bg/line selector handling */
 #ifdef HAVE_LCD_COLOR
 #define FG_FALLBACK global_settings.fg_color
@@ -44,7 +45,6 @@
 #define REMOTE_BG_FALLBACK LCD_REMOTE_DEFAULT_BG
 #endif
 
-
 /* all below isn't needed for pc tools (i.e. checkwps/wps editor)
  * only viewport_parse_viewport() is */
 #ifndef __PCTOOL__
@@ -101,6 +101,7 @@ static void toggle_theme(enum screen_type screen, bool force)
     bool enable_event = false;
     static bool was_enabled[NB_SCREENS] = {false};
     static bool after_boot[NB_SCREENS] = {false};
+    struct viewport *last_vp;
 
     FOR_NB_SCREENS(i)
     {
@@ -111,6 +112,7 @@ static void toggle_theme(enum screen_type screen, bool force)
 
     if (is_theme_enabled(screen))
     {
+        last_vp = screens[screen].set_viewport(NULL);
         bool first_boot = theme_stack_top[screen] == 0;
         /* remove the left overs from the previous screen.
          * could cause a tiny flicker. Redo your screen code if that happens */
@@ -162,7 +164,7 @@ static void toggle_theme(enum screen_type screen, bool force)
                 screens[screen].clear_viewport();
                 screens[screen].update_viewport();
             }
-            screens[screen].set_viewport(NULL);
+            screens[screen].set_viewport(last_vp);
         }
         intptr_t force = first_boot?0:1;
 
@@ -282,11 +284,11 @@ static void set_default_align_flags(struct viewport *vp)
 void viewport_set_fullscreen(struct viewport *vp,
                               const enum screen_type screen)
 {
+    screens[screen].init_viewport(vp);
     vp->x = 0;
     vp->y = 0;
     vp->width = screens[screen].lcdwidth;
     vp->height = screens[screen].lcdheight;
-
 #ifndef __PCTOOL__
     set_default_align_flags(vp);
 #endif
@@ -312,9 +314,25 @@ void viewport_set_fullscreen(struct viewport *vp,
 #endif
 }
 
+void viewport_set_buffer(struct viewport *vp, struct frame_buffer_t *buffer,
+                                                const enum screen_type screen)
+{
+    if (!vp) /* NULL vp grabs current framebuffer */
+        vp = *(screens[screen].current_viewport);
+
+    /* NULL sets default buffer */
+    if (buffer && buffer->elems == 0)
+        vp->buffer = NULL;
+    else
+        vp->buffer = buffer;
+    screens[screen].init_viewport(vp);
+}
+
 void viewport_set_defaults(struct viewport *vp,
                             const enum screen_type screen)
 {
+    vp->buffer = NULL; /* use default frame_buffer */
+
 #if !defined(__PCTOOL__)
     struct viewport *sbs_area = NULL;
     if (!is_theme_enabled(screen))
@@ -323,7 +341,7 @@ void viewport_set_defaults(struct viewport *vp,
         return;
     }
     sbs_area = sb_skin_get_info_vp(screen);
-    
+
     if (sbs_area)
         *vp = *sbs_area;
     else