/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2005 by Dave Chapman
 * Copyright (C) 2009 by Karl Kurbjun
 *
 * Rockbox driver for 16-bit colour LCDs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

#include "config.h"

#include "cpu.h"
#include "lcd.h"
#include "kernel.h"
#include "thread.h"
#include <stdlib.h>
#include "string-extra.h" /* mem*() */
#include "file.h"
#include "debug.h"
#include "system.h"
#include "font.h"
#include "rbunicode.h"
#include "bidi.h"
#include "scroll_engine.h"

#define ROW_INC LCD_WIDTH
#define COL_INC 1

#define LCDADDR(x, y) (&lcd_framebuffer[(y)][(x)])

#include "lcd-16bit-common.c"

#include "lcd-bitmap-common.c"

/*** drawing functions ***/

/* Clear the current viewport */
void lcd_clear_viewport(void)
{
    fb_data *dst, *dst_end;

    dst = LCDADDR(current_vp->x, current_vp->y);
    dst_end = dst + current_vp->height * LCD_WIDTH;

    if (current_vp->drawmode & DRMODE_INVERSEVID)
    {
        do
        {
            memset16(dst, current_vp->fg_pattern, current_vp->width);
            dst += LCD_WIDTH;
        }
        while (dst < dst_end);
    }
    else
    {
        if (!lcd_backdrop)
        {
            do
            {
                memset16(dst, current_vp->bg_pattern, current_vp->width);
                dst += LCD_WIDTH;
            }
            while (dst < dst_end);
        }
        else
        {
            do
            {
                memcpy(dst, (void *)((long)dst + lcd_backdrop_offset),
                       current_vp->width * sizeof(fb_data));
                dst += LCD_WIDTH;
            }
            while (dst < dst_end);
        }
    }

    if (current_vp == &default_vp)
    {
        lcd_scroll_info.lines = 0;
    }
    else
    {
        lcd_scroll_stop(current_vp);
    }
}

/* Draw a horizontal line (optimised) */
void lcd_hline(int x1, int x2, int y)
{
    int x, width;
    unsigned bits = 0;
    enum fill_opt fillopt = OPT_NONE;
    fb_data *dst, *dst_end;

    /* direction flip */
    if (x2 < x1)
    {
        x = x1;
        x1 = x2;
        x2 = x;
    }

    /******************** In viewport clipping **********************/
    /* nothing to draw? */
    if (((unsigned)y >= (unsigned)current_vp->height) || 
        (x1 >= current_vp->width) ||
        (x2 < 0))
        return;
        
    if (x1 < 0)
        x1 = 0;
    if (x2 >= current_vp->width)
        x2 = current_vp->width-1;

    /* Adjust x1 and y to viewport */
    x1 += current_vp->x;
    x2 += current_vp->x;
    y += current_vp->y;
    
#if defined(HAVE_VIEWPORT_CLIP)
    /********************* Viewport on screen clipping ********************/
    /* nothing to draw? */
    if (((unsigned)y >= (unsigned) LCD_HEIGHT) || (x1 >= LCD_WIDTH)
        || (x2 < 0))
        return;  
    
    /* clipping */
    if (x1 < 0)
        x1 = 0;
    if (x2 >= LCD_WIDTH)
        x2 = LCD_WIDTH-1;
#endif

    width = x2 - x1 + 1;

    /* drawmode and optimisation */
    if (current_vp->drawmode & DRMODE_INVERSEVID)
    {
        if (current_vp->drawmode & DRMODE_BG)
        {
            if (!lcd_backdrop)
            {
                fillopt = OPT_SET;
                bits = current_vp->bg_pattern;
            }
            else
                fillopt = OPT_COPY;
        }
    }
    else
    {
        if (current_vp->drawmode & DRMODE_FG)
        {
            fillopt = OPT_SET;
            bits = current_vp->fg_pattern;
        }
    }
    if (fillopt == OPT_NONE && current_vp->drawmode != DRMODE_COMPLEMENT)
        return;

    dst = LCDADDR(x1, y);

    switch (fillopt)
    {
      case OPT_SET:
        memset16(dst, bits, width);
        break;

      case OPT_COPY:
        memcpy(dst, (void *)((long)dst + lcd_backdrop_offset),
               width * sizeof(fb_data));
        break;

      case OPT_NONE:  /* DRMODE_COMPLEMENT */
        dst_end = dst + width;
        do
            *dst = ~(*dst);
        while (++dst < dst_end);
        break;
    }
}

/* Draw a vertical line (optimised) */
void lcd_vline(int x, int y1, int y2)
{
    int y;
    fb_data *dst, *dst_end;
    lcd_fastpixelfunc_type *pfunc = lcd_fastpixelfuncs[current_vp->drawmode];

    /* direction flip */
    if (y2 < y1)
    {
        y = y1;
        y1 = y2;
        y2 = y;
    }

    /******************** In viewport clipping **********************/
    /* nothing to draw? */
    if (((unsigned)x >= (unsigned)current_vp->width) ||
        (y1 >= current_vp->height) ||
        (y2 < 0))
        return;

    if (y1 < 0)
        y1 = 0;
    if (y2 >= current_vp->height)
        y2 = current_vp->height-1;
        
    /* adjust for viewport */
    x += current_vp->x;
    y1 += current_vp->y;
    y2 += current_vp->y;
    
#if defined(HAVE_VIEWPORT_CLIP)
    /********************* Viewport on screen clipping ********************/
    /* nothing to draw? */
    if (( (unsigned) x >= (unsigned)LCD_WIDTH) || (y1 >= LCD_HEIGHT) 
        || (y2 < 0))
        return;
    
    /* clipping */
    if (y1 < 0)
        y1 = 0;
    if (y2 >= LCD_HEIGHT)
        y2 = LCD_HEIGHT-1;
#endif

    dst = LCDADDR(x , y1);
    dst_end = dst + (y2 - y1) * LCD_WIDTH;

    do
    {
        pfunc(dst);
        dst += LCD_WIDTH;
    }
    while (dst <= dst_end);
}

/* Fill a rectangular area */
void lcd_fillrect(int x, int y, int width, int height)
{
    unsigned bits = 0;
    enum fill_opt fillopt = OPT_NONE;
    fb_data *dst, *dst_end;

    /******************** In viewport clipping **********************/
    /* nothing to draw? */
    if ((width <= 0) || (height <= 0) || (x >= current_vp->width) || 
        (y >= current_vp->height) || (x + width <= 0) || (y + height <= 0))
        return;

    if (x < 0)
    {
        width += x;
        x = 0;
    }
    if (y < 0)
    {
        height += y;
        y = 0;
    }
    if (x + width > current_vp->width)
        width = current_vp->width - x;
    if (y + height > current_vp->height)
        height = current_vp->height - y;
        
    /* adjust for viewport */
    x += current_vp->x;
    y += current_vp->y;

#if defined(HAVE_VIEWPORT_CLIP)
    /********************* Viewport on screen clipping ********************/
    /* nothing to draw? */
    if ((x >= LCD_WIDTH) || (y >= LCD_HEIGHT) 
        || (x + width <= 0) || (y + height <= 0))
        return;
    
    /* clip image in viewport in screen */
    if (x < 0)
    {
        width += x;
        x = 0;
    }
    if (y < 0)
    {
        height += y;
        y = 0;
    }
    if (x + width > LCD_WIDTH)
        width = LCD_WIDTH - x;
    if (y + height > LCD_HEIGHT)
        height = LCD_HEIGHT - y;
#endif

    /* drawmode and optimisation */
    if (current_vp->drawmode & DRMODE_INVERSEVID)
    {
        if (current_vp->drawmode & DRMODE_BG)
        {
            if (!lcd_backdrop)
            {
                fillopt = OPT_SET;
                bits = current_vp->bg_pattern;
            }
            else
                fillopt = OPT_COPY;
        }
    }
    else
    {
        if (current_vp->drawmode & DRMODE_FG)
        {
            fillopt = OPT_SET;
            bits = current_vp->fg_pattern;
        }
    }
    if (fillopt == OPT_NONE && current_vp->drawmode != DRMODE_COMPLEMENT)
        return;

    dst = LCDADDR(x, y);
    dst_end = dst + height * LCD_WIDTH;

    do
    {
        fb_data *dst_row, *row_end;

        switch (fillopt)
        {
          case OPT_SET:
            memset16(dst, bits, width);
            break;

          case OPT_COPY:
            memcpy(dst, (void *)((long)dst + lcd_backdrop_offset),
                   width * sizeof(fb_data));
            break;

          case OPT_NONE:  /* DRMODE_COMPLEMENT */
            dst_row = dst;
            row_end = dst_row + width;
            do
                *dst_row = ~(*dst_row);
            while (++dst_row < row_end);
            break;
        }
        dst += LCD_WIDTH;
    }
    while (dst < dst_end);
}

/* Draw a partial native bitmap */
void ICODE_ATTR lcd_bitmap_part(const fb_data *src, int src_x, int src_y,
                                int stride, int x, int y, int width,
                                int height)
{
    fb_data *dst;

    /******************** Image in viewport clipping **********************/
    /* nothing to draw? */
    if ((width <= 0) || (height <= 0) || (x >= current_vp->width) ||
        (y >= current_vp->height) || (x + width <= 0) || (y + height <= 0))
        return;
        
    if (x < 0)
    {
        width += x;
        src_x -= x;
        x = 0;
    }
    if (y < 0)
    {
        height += y;
        src_y -= y;
        y = 0;
    }
    
    if (x + width > current_vp->width)
        width = current_vp->width - x;
    if (y + height > current_vp->height)
        height = current_vp->height - y;    
    
    /* adjust for viewport */
    x += current_vp->x;
    y += current_vp->y;
    
#if defined(HAVE_VIEWPORT_CLIP)
    /********************* Viewport on screen clipping ********************/
    /* nothing to draw? */
    if ((x >= LCD_WIDTH) || (y >= LCD_HEIGHT) 
        || (x + width <= 0) || (y + height <= 0))
        return;
    
    /* clip image in viewport in screen */
    if (x < 0)
    {
        width += x;
        src_x -= x;
        x = 0;
    }
    if (y < 0)
    {
        height += y;
        src_y -= y;
        y = 0;
    }
    if (x + width > LCD_WIDTH)
        width = LCD_WIDTH - x;
    if (y + height > LCD_HEIGHT)
        height = LCD_HEIGHT - y;
#endif
    
    src += stride * src_y + src_x; /* move starting point */
    dst = LCDADDR(x, y);

    do
    {
        memcpy(dst, src, width * sizeof(fb_data));
        src += stride;
        dst += LCD_WIDTH;
    }
    while (--height > 0);
}

/* Draw a partial native bitmap with transparency and foreground colors */
void ICODE_ATTR lcd_bitmap_transparent_part(const fb_data *src, int src_x,
                                            int src_y, int stride, int x,
                                            int y, int width, int height)
{
    fb_data *dst;
    unsigned fg = current_vp->fg_pattern;

    /******************** Image in viewport clipping **********************/
    /* nothing to draw? */
    if ((width <= 0) || (height <= 0) || (x >= current_vp->width) ||
        (y >= current_vp->height) || (x + width <= 0) || (y + height <= 0))
        return;
        
    if (x < 0)
    {
        width += x;
        src_x -= x;
        x = 0;
    }
    if (y < 0)
    {
        height += y;
        src_y -= y;
        y = 0;
    }
    
    if (x + width > current_vp->width)
        width = current_vp->width - x;
    if (y + height > current_vp->height)
        height = current_vp->height - y;    
    
    /* adjust for viewport */
    x += current_vp->x;
    y += current_vp->y;
    
#if defined(HAVE_VIEWPORT_CLIP)
    /********************* Viewport on screen clipping ********************/
    /* nothing to draw? */
    if ((x >= LCD_WIDTH) || (y >= LCD_HEIGHT) 
        || (x + width <= 0) || (y + height <= 0))
        return;
    
    /* clip image in viewport in screen */
    if (x < 0)
    {
        width += x;
        src_x -= x;
        x = 0;
    }
    if (y < 0)
    {
        height += y;
        src_y -= y;
        y = 0;
    }
    if (x + width > LCD_WIDTH)
        width = LCD_WIDTH - x;
    if (y + height > LCD_HEIGHT)
        height = LCD_HEIGHT - y;
#endif

    src += stride * src_y + src_x; /* move starting point */
    dst = LCDADDR(x, y);

#ifdef CPU_ARM
    {
        int w, px;
        asm volatile (
        ".rowstart:                              \n"
            "mov     %[w], %[width]              \n" /* Load width for inner loop */
        ".nextpixel:                             \n"
            "ldrh    %[px], [%[s]], #2           \n" /* Load src pixel */
            "add     %[d], %[d], #2              \n" /* Uncoditionally increment dst */
                                                 /* done here for better pipelining */
            "cmp     %[px], %[fgcolor]           \n" /* Compare to foreground color */
            "streqh  %[fgpat], [%[d], #-2]       \n" /* Store foregroud if match */
            "cmpne   %[px], %[transcolor]        \n" /* Compare to transparent color */
            "strneh  %[px], [%[d], #-2]          \n" /* Store dst if not transparent */
            "subs    %[w], %[w], #1              \n" /* Width counter has run down? */
            "bgt     .nextpixel                  \n" /* More in this row? */
            "add     %[s], %[s], %[sstp], lsl #1 \n" /* Skip over to start of next line */
            "add     %[d], %[d], %[dstp], lsl #1 \n"
            "subs    %[h], %[h], #1              \n" /* Height counter has run down? */
            "bgt     .rowstart                   \n" /* More rows? */
            : [w]"=&r"(w), [h]"+&r"(height), [px]"=&r"(px),
              [s]"+&r"(src), [d]"+&r"(dst)
            : [width]"r"(width),
              [sstp]"r"(stride - width),
              [dstp]"r"(LCD_WIDTH - width),
              [transcolor]"r"(TRANSPARENT_COLOR),
              [fgcolor]"r"(REPLACEWITHFG_COLOR),
              [fgpat]"r"(fg)
        );
    }
#else  /* optimized C version */
    do
    {
        const fb_data *src_row = src;
        fb_data *dst_row = dst;
        fb_data *row_end = dst_row + width;
        do
        {
            unsigned data = *src_row++;
            if (data != TRANSPARENT_COLOR)
            {
                if (data == REPLACEWITHFG_COLOR)
                    data = fg;
                *dst_row = data;
            }
        }
        while (++dst_row < row_end);
        src += stride;
        dst += LCD_WIDTH;
    }
    while (--height > 0);
#endif
}