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, 5 insertions, 2 deletions

diff --git a/apps/screen_access.h b/apps/screen_access.h
index 79ad79c153..81c7cb2a85 100644
--- a/apps/screen_access.h
+++ b/apps/screen_access.h
@@ -58,7 +58,11 @@ struct screen
     bool has_disk_led;
 #endif
     void (*set_drawmode)(int mode);
-    void (*set_viewport)(struct viewport* vp);
+    struct viewport* (*init_viewport)(struct viewport* vp);
+    struct viewport* (*set_viewport)(struct viewport* vp);
+    struct viewport* (*set_viewport_ex)(struct viewport* vp, int flags);
+    void (*viewport_set_buffer)(struct viewport *vp, struct frame_buffer_t *buffer);
+    struct viewport** current_viewport;
     int (*getwidth)(void);
     int (*getheight)(void);
     int (*getstringsize)(const unsigned char *str, int *w, int *h);
@@ -126,7 +130,6 @@ struct screen
     bool (*backdrop_load)(const char *filename, char* backdrop_buffer);
     void (*backdrop_show)(char* backdrop_buffer);
 #endif
-    void (*set_framebuffer)(void *framebuffer);
 #if defined(HAVE_LCD_COLOR)    
     void (*gradient_fillrect)(int x, int y, int width, int height,
             unsigned start, unsigned end);