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

2 files changed, 19 insertions, 6 deletions

diff --git a/apps/plugins/rockboy/lcd.c b/apps/plugins/rockboy/lcd.c
index 387a88c3df..92db851ee8 100644
--- a/apps/plugins/rockboy/lcd.c
+++ b/apps/plugins/rockboy/lcd.c
@@ -64,6 +64,12 @@ unsigned char *vdest;
 fb_data *vdest;
 #endif
 
+static fb_data* get_framebuffer(void)
+{
+    struct viewport *vp_main = *(rb->screens[SCREEN_MAIN]->current_viewport);
+    return vp_main->buffer->fb_ptr;
+}
+
 #ifndef ASM_UPDATEPATPIX
 static void updatepatpix(void) ICODE_ATTR;
 static void updatepatpix(void)
@@ -741,10 +747,11 @@ static void spr_scan(void)
 
 void lcd_begin(void)
 {
+    fb_data *lcd_fb = get_framebuffer();
 #if defined(HAVE_LCD_MODES) && (HAVE_LCD_MODES & LCD_MODE_PAL256)
-    vdest=(unsigned char*)*rb->lcd_framebuffer;
+    vdest=(unsigned char*)lcd_fb;
 #else
-    vdest=*rb->lcd_framebuffer;
+    vdest=lcd_fb;
 #endif
 
 #ifdef HAVE_LCD_COLOR
@@ -975,9 +982,9 @@ void lcd_refreshline(void)
 
 #if defined(HAVE_LCD_MODES) && (HAVE_LCD_MODES & LCD_MODE_PAL256)
         if(options.scaling==3) {
-            rb->lcd_blit_pal256((unsigned char*)*rb->lcd_framebuffer,(LCD_WIDTH-160)/2, (LCD_HEIGHT-144)/2, (LCD_WIDTH-160)/2, (LCD_HEIGHT-144)/2, 160, 144);
+            rb->lcd_blit_pal256((unsigned char*)lcd_fb,(LCD_WIDTH-160)/2, (LCD_HEIGHT-144)/2, (LCD_WIDTH-160)/2, (LCD_HEIGHT-144)/2, 160, 144);
         } else {
-            rb->lcd_blit_pal256((unsigned char*)*rb->lcd_framebuffer,0,0,0,0,LCD_WIDTH,LCD_HEIGHT);
+            rb->lcd_blit_pal256((unsigned char*)lcd_fb,0,0,0,0,LCD_WIDTH,LCD_HEIGHT);
         }
 #else
         if(options.scaling==3) {
diff --git a/apps/plugins/rockboy/sys_rockbox.c b/apps/plugins/rockboy/sys_rockbox.c
index 364176ce2d..64acd37563 100644
--- a/apps/plugins/rockboy/sys_rockbox.c
+++ b/apps/plugins/rockboy/sys_rockbox.c
@@ -282,6 +282,12 @@ fb_data *frameb;
 void vid_update(int scanline) 
 { 
    register int cnt=0;
+    static fb_data *lcd_fb = NULL;
+    if (!lcd_fb)
+    {
+        struct viewport *vp_main = *(rb->screens[SCREEN_MAIN]->current_viewport);
+        lcd_fb = vp_main->buffer->fb_ptr;
+    }
     int scanline_remapped;
 #if (LCD_HEIGHT == 64) && (LCD_DEPTH == 1) /* Archos, Clip, m200v4 */
     int balance = 0;
@@ -290,7 +296,7 @@ void vid_update(int scanline)
     else if (fb.mode==2)
         scanline-=8;
     scanline_remapped = scanline / 16;
-    frameb = *rb->lcd_framebuffer + scanline_remapped * LCD_WIDTH;
+    frameb = lcd_fb + scanline_remapped * LCD_WIDTH;
     while (cnt < 160) {
         balance += LCD_WIDTH;
         if (balance > 0)
@@ -316,7 +322,7 @@ void vid_update(int scanline)
     else if (fb.mode==2)
         scanline-=8;
     scanline_remapped = scanline / 4;
-    frameb = *rb->lcd_framebuffer + scanline_remapped * LCD_WIDTH;
+    frameb = lcd_fb + scanline_remapped * LCD_WIDTH;
     while (cnt < 160) {
         *(frameb++) = (scan.buf[0][cnt]&0x3) |
                       ((scan.buf[1][cnt]&0x3)<<2) |