/*

  Malzak

  Video functions

  SAA 5050 -- Character display
  S2636 (x2) -- Sprites, Sprite->Sprite collisions
  Playfield graphics generator
      (TODO: probably best to switch this to tilemaps one day, figure out banking)

*/


#include "emu.h"
#include "video/s2636.h"
#include "video/saa5050.h"
#include "includes/malzak.h"


SCREEN_UPDATE( malzak )
{
	malzak_state *state = screen->machine().driver_data<malzak_state>();
	int sx, sy;
	int x,y;
	bitmap_t *s2636_0_bitmap;
	bitmap_t *s2636_1_bitmap;

	bitmap_fill(bitmap, 0, 0);

	saa5050_update(state->m_saa5050, bitmap, cliprect);
	saa5050_frame_advance(state->m_saa5050);

	// playfield - not sure exactly how this works...
	for (x = 0; x < 16; x++)
		for (y = 0; y < 16; y++)
		{
			sx = ((x * 16 - 48) - state->m_malzak_x) * 2;
			sy = ((y * 16) - state->m_malzak_y) * 2;

			if (sx < -271*2)
				sx += 512*2;
			if (sx < -15*2)
				sx += 256*2;

			drawgfxzoom_transpen(bitmap,cliprect, screen->machine().gfx[0], state->m_playfield_code[x * 16 + y], 7*2, 0, 0, sx, sy, 0x20000, 0x20000, 0);
		}

	/* update the S2636 chips */
	s2636_0_bitmap = s2636_update(state->m_s2636_0, cliprect);
	s2636_1_bitmap = s2636_update(state->m_s2636_1, cliprect);

	/* copy the S2636 images into the main bitmap */
	{
		int y;

		for (y = cliprect->min_y; y <= cliprect->max_y / 2; y++)
		{
			int x;

			for (x = cliprect->min_x; x <= cliprect->max_x / 2; x++)
			{
				int pixel0 = *BITMAP_ADDR16(s2636_0_bitmap, y, x);
				int pixel1 = *BITMAP_ADDR16(s2636_1_bitmap, y, x);

				if (S2636_IS_PIXEL_DRAWN(pixel0)) {
					*BITMAP_ADDR16(bitmap, y*2, x*2) = S2636_PIXEL_COLOR(pixel0);
					*BITMAP_ADDR16(bitmap, y*2+1, x*2) = S2636_PIXEL_COLOR(pixel0);
					*BITMAP_ADDR16(bitmap, y*2, x*2+1) = S2636_PIXEL_COLOR(pixel0);
					*BITMAP_ADDR16(bitmap, y*2+1, x*2+1) = S2636_PIXEL_COLOR(pixel0);
				}

				if (S2636_IS_PIXEL_DRAWN(pixel1)) {
					*BITMAP_ADDR16(bitmap, y*2, x*2) = S2636_PIXEL_COLOR(pixel1);
					*BITMAP_ADDR16(bitmap, y*2+1, x*2) = S2636_PIXEL_COLOR(pixel1);
					*BITMAP_ADDR16(bitmap, y*2, x*2+1) = S2636_PIXEL_COLOR(pixel1);
					*BITMAP_ADDR16(bitmap, y*2+1, x*2+1) = S2636_PIXEL_COLOR(pixel1);
				}
			}
		}
	}

	return 0;
}

WRITE8_HANDLER( malzak_playfield_w )
{
	malzak_state *state = space->machine().driver_data<malzak_state>();
	int tile = ((state->m_malzak_x / 16) * 16) + (offset / 16);

//  state->m_playfield_x[tile] = state->m_malzak_x / 16;
//  state->m_playfield_y[tile] = state->m_malzak_y;
	state->m_playfield_code[tile] = (data & 0x1f);
	logerror("GFX: 0x16%02x write 0x%02x\n", offset, data);
}
