/*
winnie - an experimental window system

Copyright (C) 2013 Eleni Maria Stea

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 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Author: Eleni Maria Stea <elene.mst@gmail.com>
*/

#ifdef WINNIE_SDL
#include <SDL/SDL.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

#include "sdl/gfx.h"
#include "winnie.h"

static SDL_Surface *fbsurf;

struct Graphics {
  Rect screen_rect;
  Rect clipping_rect;
  int color_depth; // bits per pixel
  Pixmap *pixmap;
};

static Graphics *gfx;

bool
init_gfx()
{
  if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER) == -1) {
    fprintf(stderr, "failed to initialize SDL\n");
    return false;
  }

  if (!(gfx = (Graphics *) malloc(sizeof *gfx))) {
    return false;
  }

  get_subsys()->graphics_offset = (intptr_t) (gfx);

  Rect scr_rect(0, 0, 1280, 853);
  gfx->screen_rect = scr_rect;
  gfx->color_depth = 32;

  if (!(fbsurf = SDL_SetVideoMode(gfx->screen_rect.width,
                                  gfx->screen_rect.height,
                                  gfx->color_depth,
                                  0))) {
    fprintf(stderr, "Failed to set video mode\n");
    return false;
  }
  SDL_ShowCursor(0);

  if (!(gfx->pixmap = (Pixmap *) malloc(sizeof(Pixmap)))) {
    fprintf(stderr, "Failed to allocate pixmap.\n");
    return false;
  }

  gfx->pixmap->width = gfx->screen_rect.width;
  gfx->pixmap->height = gfx->screen_rect.height;

  int fbsize = gfx->pixmap->width * gfx->pixmap->height * gfx->color_depth / 8;
  if (!(gfx->pixmap->pixels = (unsigned char *) malloc(fbsize))) {
    fprintf(stderr, "failed to allocate the pixmap framebuffer.\n");
    return false;
  }

  set_clipping_rect(gfx->screen_rect);

  return true;
}

void
destroy_gfx()
{
  free(gfx->pixmap->pixels);
  gfx->pixmap->pixels = 0;
  free(gfx->pixmap);
  free(gfx);
  SDL_Quit();
}

unsigned char *
get_framebuffer()
{
  return gfx->pixmap->pixels;
}

Pixmap *
get_framebuffer_pixmap()
{
  return gfx->pixmap;
}

Rect
get_screen_size()
{
  return gfx->screen_rect;
}

int
get_color_depth()
{
  return gfx->color_depth;
}

void
set_clipping_rect(const Rect &rect)
{
  gfx->clipping_rect = rect_intersection(rect, get_screen_size());
}

const Rect &
get_clipping_rect()
{
  return gfx->clipping_rect;
}

void
set_cursor_visibility(bool visible)
{
}

void
gfx_update(const Rect &upd_rect)
{
  if (SDL_MUSTLOCK(fbsurf)) {
    SDL_LockSurface(fbsurf);
  }

  Rect rect = rect_intersection(upd_rect, gfx->screen_rect);

  unsigned char *sptr
      = gfx->pixmap->pixels + (rect.y * gfx->screen_rect.width + rect.x) * 4;
  unsigned char *dptr = (unsigned char *) fbsurf->pixels
                        + (rect.y * gfx->screen_rect.width + rect.x) * 4;

  for (int i = 0; i < rect.height; i++) {
    memcpy(dptr, sptr, rect.width * 4);
    sptr += gfx->screen_rect.width * 4;
    dptr += gfx->screen_rect.width * 4;
  }

  if (SDL_MUSTLOCK(fbsurf)) {
    SDL_UnlockSurface(fbsurf);
  }
  SDL_UpdateRect(fbsurf, rect.x, rect.y, rect.width, rect.height);
}

void
wait_vsync()
{
}

void
get_rgb_order(int *r, int *g, int *b)
{
  *r = fbsurf->format->Rshift / 8;
  *g = fbsurf->format->Gshift / 8;
  *b = fbsurf->format->Bshift / 8;
}

#endif // WINNIE_SDL