/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2006 Dan Everton
 *
 * 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 <SDL.h>
#include "lcd-sdl.h"
#include "sim-ui-defines.h"
#include "system.h" /* for MIN() and MAX() */

int display_zoom = 1;

void sdl_update_rect(SDL_Surface *surface, int x_start, int y_start, int width,
                     int height, int max_x, int max_y,
                     unsigned long (*getpixel)(int, int))
{
    SDL_Rect dest;
#if LCD_DEPTH >= 8 && (LCD_PIXELFORMAT == RGB565) \
    && !defined(LCD_STRIDEFORMAT) && !defined(HAVE_LCD_SPLIT)
    SDL_Rect src;
    (void)max_x;
    (void)max_y;
    (void)getpixel;
    /* Update complete screen via one blit operation (fast) */
    SDL_Surface *lcd = SDL_CreateRGBSurfaceFrom(lcd_framebuffer, LCD_FBWIDTH,
                                                LCD_FBHEIGHT, LCD_DEPTH,
                                                LCD_FBWIDTH * LCD_DEPTH/8,
                                                0, 0, 0, 0);
    src.x = x_start;
    src.y = y_start;
    src.w = width;
    src.h = height;

    if (display_zoom == 1) {
        dest = src;
        SDL_BlitSurface(lcd, &src, surface, &dest);
    } else {
        /* Note: SDL_SoftStretch is currently marked as DO NOT USE
           but there are no real alternatives for efficent zooming. */
        dest.x = src.x * display_zoom;
        dest.y = src.y * display_zoom;
        dest.w = src.w * display_zoom;
        dest.h = src.h * display_zoom;
        SDL_SoftStretch(lcd, &src, surface, &dest);
    }
    SDL_FreeSurface(lcd);
#else
    int x, y;
    int xmax, ymax;
    /* Very slow pixel-by-pixel drawing */
    ymax = y_start + height;
    xmax = x_start + width;

    if(xmax > max_x)
        xmax = max_x;
    if(ymax >= max_y)
        ymax = max_y;

    dest.w = display_zoom;
    dest.h = display_zoom;

    for (x = x_start; x < xmax; x++) {
        dest.x = x * display_zoom;

#ifdef HAVE_LCD_SPLIT
        for (y = y_start; y < MIN(ymax, LCD_SPLIT_POS); y++) {
            dest.y = y * display_zoom;

            SDL_FillRect(surface, &dest, (Uint32)(getpixel(x, y) | 0x80));
        }
        for (y = MAX(y_start, LCD_SPLIT_POS); y < ymax; y++) {
            dest.y = (y + LCD_SPLIT_LINES) * display_zoom ;

            SDL_FillRect(surface, &dest, (Uint32)getpixel(x, y));
        }
#else
        for (y = y_start; y < ymax; y++) {
            dest.y = y * display_zoom;

            SDL_FillRect(surface, &dest, (Uint32)getpixel(x, y));
        }
#endif
    }
#endif
}

void sdl_gui_update(SDL_Surface *surface, int x_start, int y_start, int width,
                    int height, int max_x, int max_y, int ui_x, int ui_y)
{
    if (x_start + width > max_x)
        width = max_x - x_start;
    if (y_start + height > max_y)
        height = max_y - y_start;

    SDL_Rect src = {x_start * display_zoom, y_start * display_zoom,
                    width * display_zoom, height * display_zoom};
    SDL_Rect dest= {(ui_x + x_start) * display_zoom,
                    (ui_y + y_start) * display_zoom,
                    width * display_zoom, height * display_zoom};

    if (surface->flags & SDL_SRCALPHA) /* alpha needs a black background */
        SDL_FillRect(gui_surface, &dest, 0);

    SDL_BlitSurface(surface, &src, gui_surface, &dest);

    SDL_Flip(gui_surface);
}

/* set a range of bitmap indices to a gradient from startcolour to endcolour */
void sdl_set_gradient(SDL_Surface *surface, SDL_Color *start, SDL_Color *end,
                      int first, int steps)
{
    int i;
    SDL_Color palette[steps];

    for (i = 0; i < steps; i++) {
        palette[i].r = start->r + (end->r - start->r) * i / (steps - 1);
        palette[i].g = start->g + (end->g - start->g) * i / (steps - 1);
        palette[i].b = start->b + (end->b - start->b) * i / (steps - 1);
    }

    SDL_SetPalette(surface, SDL_LOGPAL|SDL_PHYSPAL, palette, first, steps);
}

int lcd_get_dpi(void)
{
    /* TODO: find a way to query it from the OS, SDL doesn't support it
     * directly; for now assume the more or less standard 96 */
    return 96;
}
