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/***************************************************************************

    General sprite handling helpers

****************************************************************************

    Copyright Aaron Giles
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:

        * Redistributions of source code must retain the above copyright
          notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above copyright
          notice, this list of conditions and the following disclaimer in
          the documentation and/or other materials provided with the
          distribution.
        * Neither the name 'MAME' nor the names of its contributors may be
          used to endorse or promote products derived from this software
          without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND ANY EXPRESS OR
    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    DISCLAIMED. IN NO EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
    INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
    IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

***************************************************************************/

#include "emu.h"
#include "sprite.h"


//-------------------------------------------------
//  sparse_dirty_bitmap -- constructor
//-------------------------------------------------

sparse_dirty_bitmap::sparse_dirty_bitmap(int granularity)
	: m_width(0),
	  m_height(0),
	  m_granularity(granularity),
	  m_rect_list_bounds(0, -1, 0, -1)
{
}

sparse_dirty_bitmap::sparse_dirty_bitmap(int width, int height, int granularity)
	: m_width(0),
	  m_height(0),
	  m_granularity(granularity),
	  m_rect_list_bounds(0, -1, 0, -1)
{
	// resize to the specified width/height
	resize(width, height);
}


//-------------------------------------------------
//  dirty -- dirty a region
//-------------------------------------------------

void sparse_dirty_bitmap::dirty(INT32 left, INT32 right, INT32 top, INT32 bottom)
{
	// compute a rectangle in dirty space, and fill it with 1
	rectangle rect(left >> m_granularity, right >> m_granularity, top >> m_granularity, bottom >> m_granularity);
	m_bitmap.fill(1, rect);
	
	// invalidate existing rect list
	invalidate_rect_list();
}


//-------------------------------------------------
//  clean a region -- dirty a region
//-------------------------------------------------

void sparse_dirty_bitmap::clean(INT32 left, INT32 right, INT32 top, INT32 bottom)
{
	// if right or bottom intersect the edge of the bitmap, round up
	int round = (1 << m_granularity) - 1;
	if (right >= m_width - 1)
		right = m_width + round;
	if (bottom >= m_height - 1)
		bottom = m_height + round;

	// compute a rectangle in dirty space, and fill it with 0
	rectangle rect((left + round) >> m_granularity, (right - round) >> m_granularity, (top + round) >> m_granularity, (bottom - round) >> m_granularity);
	m_bitmap.fill(0, rect);
	
	// invalidate existing rect list
	invalidate_rect_list();
}


//-------------------------------------------------
//  resize -- resize the bitmap
//-------------------------------------------------

void sparse_dirty_bitmap::resize(int width, int height)
{
	// set new size
	m_width = width;
	m_height = height;
	
	// resize the bitmap
	int round = (1 << m_granularity) - 1;
	m_bitmap.resize((width + round) >> m_granularity, (height + round) >> m_granularity);
	
	// reset everything
	dirty_all();
}


//-------------------------------------------------
//  first_dirty_rect -- return the first dirty
//	rectangle in the list
//-------------------------------------------------

sparse_dirty_rect *sparse_dirty_bitmap::first_dirty_rect(const rectangle &cliprect)
{
	// if what we have is valid, just return it again
	if (m_rect_list_bounds == cliprect)
		return m_rect_list.first();
	
	// reclaim the dirty list and start over
	m_rect_allocator.reclaim_all(m_rect_list);
	
	// compute dirty space rectangle coordinates
	int sx = cliprect.min_x >> m_granularity;
	int ex = cliprect.max_x >> m_granularity;
	int sy = cliprect.min_y >> m_granularity;
	int ey = cliprect.max_y >> m_granularity;
	int tilesize = 1 << m_granularity;

	// loop over all grid rows that intersect our cliprect
	for (int y = sy; y <= ey; y++)
	{
		UINT8 *dirtybase = &m_bitmap.pix(y);
		sparse_dirty_rect *currect = NULL;

		// loop over all grid columns that intersect our cliprect
		for (int x = sx; x <= ex; x++)
		{
			// if this tile is not dirty, end our current run and continue
			if (!*dirtybase++)
			{
				if (currect != NULL)
					*currect &= cliprect;
				currect = NULL;
				continue;
			}
		
			// if we can't add to an existing rect, create a new one
			if (currect == NULL)
			{
				// allocate a new rect and add it to the list
				currect = &m_rect_list.append(*m_rect_allocator.alloc());

				// make a rect describing this grid square
				currect->min_x = x << m_granularity;
				currect->max_x = currect->min_x + tilesize - 1;
				currect->min_y = y << m_granularity;
				currect->max_y = currect->min_y + tilesize - 1;
			}

			// if we can add to the previous rect, just expand its width
			else
				currect->max_x += tilesize;
		}

		// clip the last rect to the cliprect
		if (currect != NULL)
			*currect &= cliprect;
	}

	// mark the list as valid
	m_rect_list_bounds = cliprect;
	return m_rect_list.first();
}