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#include "k053250.h"
const device_type K053250 = &device_creator<k053250_t>;
k053250_t::k053250_t(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
: device_t(mconfig, K053250, "K053250", tag, owner, clock)
{
}
void k053250_t::static_set_screen_tag(device_t &device, const char *screen_tag)
{
k053250_t &dev = downcast<k053250_t &>(device);
dev.screen_tag = screen_tag;
}
void k053250_t::static_set_offsets(device_t &device, int offx, int offy)
{
k053250_t &dev = downcast<k053250_t &>(device);
dev.offx = offx;
dev.offy = offy;
}
void k053250_t::unpack_nibbles()
{
if(!m_region)
throw emu_fatalerror("k053250 %s: no associated region found\n", tag());
const UINT8 *base = m_region->base();
int size = m_region->bytes();
unpacked = auto_alloc_array(machine(), UINT8, size*2);
for(int i=0; i<size; i++) {
unpacked[2*i] = base[i] >> 4;
unpacked[2*i+1] = base[i] & 15;
}
unpacked_size = 2*size;
}
void k053250_t::device_start()
{
screen = machine().device<screen_device>(screen_tag);
ram = auto_alloc_array_clear(machine(), UINT16, 0x6000/2);
buffer[0] = ram + 0x2000;
buffer[1] = ram + 0x2800;
unpack_nibbles();
save_pointer(NAME(ram), 0x6000/2);
save_item(NAME(regs));
save_item(NAME(page));
save_item(NAME(frame));
}
void k053250_t::device_reset()
{
page = 0;
frame = -1;
memset(regs, 0, sizeof(regs));
}
// utility function to render a clipped scanline vertically or horizontally
inline void k053250_t::pdraw_scanline32(bitmap_t *bitmap, const pen_t *palette, UINT8 *source,
const rectangle *cliprect, int linepos, int scroll, int zoom,
UINT32 clipmask, UINT32 wrapmask, UINT32 orientation, bitmap_t *priority, UINT8 pri)
{
// a sixteen-bit fixed point resolution should be adequate to our application
#define FIXPOINT_PRECISION 16
#define FIXPOINT_PRECISION_HALF (1<<(FIXPOINT_PRECISION-1))
int end_pixel, flip, dst_min, dst_max, dst_start, dst_length;
UINT32 src_wrapmask;
UINT8 *src_base;
int src_fx, src_fdx;
int pix_data, dst_offset;
const pen_t *pal_base;
UINT8 *pri_base;
UINT32 *dst_base;
int dst_adv;
// flip X and flip Y also switch role when the X Y coordinates are swapped
if (!(orientation & ORIENTATION_SWAP_XY))
{
flip = orientation & ORIENTATION_FLIP_X;
dst_min = cliprect->min_x;
dst_max = cliprect->max_x;
}
else
{
flip = orientation & ORIENTATION_FLIP_Y;
dst_min = cliprect->min_y;
dst_max = cliprect->max_y;
}
if (clipmask)
{
// reject scanlines that are outside of the target bitmap's right(bottom) clip boundary
dst_start = -scroll;
if (dst_start > dst_max) return;
// calculate target length
dst_length = clipmask + 1;
if (zoom) dst_length = (dst_length << 6) / zoom;
// reject scanlines that are outside of the target bitmap's left(top) clip boundary
end_pixel = dst_start + dst_length - 1;
if (end_pixel < dst_min) return;
// clip scanline tail
if ((end_pixel -= dst_max) > 0) dst_length -= end_pixel;
// reject zero-length scanlines
if (dst_length <= 0) return;
// calculate zoom factor
src_fdx = zoom << (FIXPOINT_PRECISION-6);
// clip scanline head
end_pixel = dst_min;
if ((end_pixel -= dst_start) > 0)
{
// chop scanline to the correct length and move target start location to the left(top) clip boundary
dst_length -= end_pixel;
dst_start = dst_min;
// and skip the source for the left(top) clip region
src_fx = end_pixel * src_fdx + FIXPOINT_PRECISION_HALF;
}
else
// the point five bias is to ensure even distribution of stretched or shrinked pixels
src_fx = FIXPOINT_PRECISION_HALF;
// adjust flipped source
if (flip)
{
// start from the target's clipped end if the scanline is flipped
dst_start = dst_max + dst_min - dst_start - (dst_length-1);
// and move source start location to the opposite end
src_fx += (dst_length-1) * src_fdx - 1;
src_fdx = -src_fdx;
}
}
else
{
// draw wrapped scanline at virtual bitmap boundary when source clipping is off
dst_start = dst_min;
dst_length = dst_max - dst_min + 1; // target scanline spans the entire visible area
src_fdx = zoom << (FIXPOINT_PRECISION-6);
// pre-advance source for the clipped region
if (!flip)
src_fx = (scroll + dst_min) * src_fdx + FIXPOINT_PRECISION_HALF;
else
{
src_fx = (scroll + dst_max) * src_fdx + FIXPOINT_PRECISION_HALF-1;
src_fdx = -src_fdx;
}
}
if (!(orientation & ORIENTATION_SWAP_XY))
{
// calculate target increment for horizontal scanlines which is exactly one
dst_adv = 1;
dst_offset = dst_length;
pri_base = BITMAP_ADDR8(priority, linepos, dst_start + dst_offset);
dst_base = BITMAP_ADDR32(bitmap, linepos, dst_start + dst_length);
}
else
{
// calculate target increment for vertical scanlines which is the bitmap's pitch value
dst_adv = bitmap->rowpixels;
dst_offset= dst_length * dst_adv;
pri_base = BITMAP_ADDR8(priority, dst_start, linepos + dst_offset);
dst_base = BITMAP_ADDR32(bitmap, dst_start, linepos + dst_offset);
}
// generalized
src_base = source;
// there is no need to wrap source offsets along with source clipping
// so we set all bits of the wrapmask to one
src_wrapmask = (clipmask) ? ~0 : wrapmask;
pal_base = palette;
dst_offset = -dst_offset; // negate target offset in order to terminated draw loop at zero condition
if (pri)
{
// draw scanline and update priority bitmap
do
{
pix_data = src_base[(src_fx>>FIXPOINT_PRECISION) & src_wrapmask];
src_fx += src_fdx;
if (pix_data)
{
pix_data = pal_base[pix_data];
pri_base[dst_offset] = pri;
dst_base[dst_offset] = pix_data;
}
}
while (dst_offset += dst_adv);
}
else
{
// draw scanline but do not update priority bitmap
do
{
pix_data = src_base[(src_fx>>FIXPOINT_PRECISION) & src_wrapmask];
src_fx += src_fdx;
if (pix_data)
{
dst_base[dst_offset] = pal_base[pix_data];
}
}
while (dst_offset += dst_adv);
}
#undef FIXPOINT_PRECISION
#undef FIXPOINT_PRECISION_HALF
}
void k053250_t::draw( bitmap_t *bitmap, const rectangle *cliprect, int colorbase, int flags, int priority )
{
UINT8 *pix_ptr;
const pen_t *pal_base, *pal_ptr;
UINT32 src_clipmask, src_wrapmask, dst_wrapmask;
int linedata_offs, line_pos, line_start, line_end, scroll_corr;
int color, offset, zoom, scroll, passes, i;
bool wrap500 = false;
UINT16 *line_ram = buffer[page]; // pointer to physical line RAM
int map_scrollx = short(regs[0] << 8 | regs[1]) - offx; // signed horizontal scroll value
int map_scrolly = short(regs[2] << 8 | regs[3]) - offy; // signed vertical scroll value
UINT8 ctrl = regs[4]; // register four is the main control register
// copy visible boundary values to more accessible locations
int dst_minx = cliprect->min_x;
int dst_maxx = cliprect->max_x;
int dst_miny = cliprect->min_y;
int dst_maxy = cliprect->max_y;
int orientation = 0; // orientation defaults to no swapping and no flipping
int dst_height = 512; // virtual bitmap height defaults to five hundred and twelve pixels
int linedata_adv = 4; // line info packets are four words(eight bytes) apart
// switch X and Y parameters when the first bit of the control register is cleared
if (!(ctrl & 0x01)) orientation |= ORIENTATION_SWAP_XY;
// invert X parameters when the forth bit of the control register is set
if (ctrl & 0x08) orientation |= ORIENTATION_FLIP_X;
// invert Y parameters when the fifth bit of the control register is set
if (ctrl & 0x10) orientation |= ORIENTATION_FLIP_Y;
switch (ctrl >> 5) // the upper four bits of the control register select source and target dimensions
{
case 0 :
// Xexex: L6 galaxies
// Metam: L4 forest, L5 arena, L6 tower interior, final boss
// crop source offset between zero and two hundred and fifty-five inclusive,
// and set virtual bitmap height to two hundred and fifty-six pixels
src_wrapmask = src_clipmask = 0xff;
dst_height = 0x100;
break;
case 1 :
// Xexex: prologue, L7 nebulae
// the source offset is cropped to zero and five hundred and eleven inclusive
src_wrapmask = src_clipmask = 0x1ff;
break;
case 4 :
// Xexex: L1 sky and boss, L3 planet, L5 poly-face, L7 battle ship patches
// Metam: L1 summoning circle, L3 caves, L6 gargoyle towers
// crop source offset between zero and two hundred and fifty-five inclusive,
// and allow source offset to wrap back at 500 hexadecimal to minus 300 hexadecimal
src_wrapmask = src_clipmask = 0xff;
wrap500 = true;
break;
// case 2 : // Xexex: title
// case 7 : // Xexex: L4 organic stage
default:
// crop source offset between zero and one thousand and eleven inclusive,
// keep other dimensions to their defaults
src_wrapmask = src_clipmask = 0x3ff;
break;
}
// disable source clipping when the third bit of the control register is set
if (ctrl & 0x04) src_clipmask = 0;
if (!(orientation & ORIENTATION_SWAP_XY)) // normal orientaion with no X Y switching
{
line_start = dst_miny; // the first scanline starts at the minimum Y clip location
line_end = dst_maxy; // the last scanline ends at the maximum Y clip location
scroll_corr = map_scrollx; // concentrate global X scroll
linedata_offs = map_scrolly; // determine where to get info for the first line
if (orientation & ORIENTATION_FLIP_X)
{
scroll_corr = -scroll_corr; // X scroll adjustment should be negated in X flipped scenarioes
}
if (orientation & ORIENTATION_FLIP_Y)
{
linedata_adv = -linedata_adv; // traverse line RAM backward in Y flipped scenarioes
linedata_offs += bitmap->height - 1; // and get info for the first line from the bottom
}
dst_wrapmask = ~0; // scanlines don't seem to wrap horizontally in normal orientation
passes = 1; // draw scanline in a single pass
}
else // orientaion with X and Y parameters switched
{
line_start = dst_minx; // the first scanline starts at the minimum X clip location
line_end = dst_maxx; // the last scanline ends at the maximum X clip location
scroll_corr = map_scrolly; // concentrate global Y scroll
linedata_offs = map_scrollx; // determine where to get info for the first line
if (orientation & ORIENTATION_FLIP_Y)
{
scroll_corr = 0x100 - scroll_corr; // apply common vertical correction
// Y correction (ref: 1st and 5th boss)
scroll_corr -= 2; // apply unique vertical correction
// X correction (ref: 1st boss, seems to undo non-rotated global X offset)
linedata_offs -= 5; // apply unique horizontal correction
}
if (orientation & ORIENTATION_FLIP_X)
{
linedata_adv = -linedata_adv; // traverse line RAM backward in X flipped scenarioes
linedata_offs += bitmap->width - 1; // and get info for the first line from the bottom
}
if (src_clipmask)
{
// determine target wrap boundary and draw scanline in two passes if the source is clipped
dst_wrapmask = dst_height - 1;
passes = 2;
}
else
{
// otherwise disable target wraparound and draw scanline in a single pass
dst_wrapmask = ~0;
passes = 1;
}
}
linedata_offs *= 4; // each line info packet has four words(eight bytes)
linedata_offs &= 0x7ff; // and it should wrap at the four-kilobyte boundary
linedata_offs += line_start * linedata_adv; // pre-advance line info offset for the clipped region
// load physical palette base
pal_base = machine().pens + (colorbase << 4) % machine().total_colors();
// walk the target bitmap within the visible area vertically or horizontally, one line at a time
for (line_pos=line_start; line_pos <= line_end; linedata_offs += linedata_adv, line_pos++)
{
linedata_offs &= 0x7ff; // line info data wraps at the four-kilobyte boundary
color = line_ram[linedata_offs]; // get scanline color code
if (color == 0xffff) continue; // reject scanline if color code equals minus one
offset = line_ram[linedata_offs + 1]; // get first pixel offset in ROM
if (!(color & 0xff) && !offset) continue; // reject scanline if both color and pixel offset are zero
// calculate physical palette location
// there can be thirty-two color codes and each code represents sixteen pens
pal_ptr = pal_base + ((color & 0x1f) << 4);
// calculate physical pixel location
// each offset unit represents two hundred and fifty six pixels and should wrap at ROM boundary for safty
pix_ptr = unpacked + ((offset << 8) % unpacked_size);
// get scanline zoom factor
// For example, 0x20 doubles the length, 0x40 maintains a one-to-one length,
// and 0x80 halves the length. The zoom center is at the beginning of the
// scanline therefore it is not necessary to adjust render start position
zoom = line_ram[linedata_offs + 2];
scroll = (short)line_ram[linedata_offs + 3]; // get signed local scroll value for the current scanline
// scavenged from old code; improves Xexex' first level sky
if (wrap500 && scroll >= 0x500) scroll -= 0x800;
scroll += scroll_corr; // apply final scroll correction
scroll &= dst_wrapmask; // wraparound scroll value if necessary
// draw scanlines wrapped at virtual bitmap boundary in two passes
// this should not impose too much overhead due to clipping performed by the render code
i = passes;
do
{
/*
Parameter descriptions:
bitmap : pointer to a MAME bitmap as the render target
pal_ptr : pointer to the palette's physical location relative to the scanline
pix_ptr : pointer to the physical start location of source pixels in ROM
cliprect : pointer to a rectangle structue which describes the visible area of the target bitmap
line_pos : scanline render position relative to the target bitmap
should be a Y offset to the target bitmap in normal orientaion,
or an X offset to the target bitmap if X,Y are swapped
scroll : source scroll value of the scanline
zoom : source zoom factor of the scanline
src_clipmask : source offset clip mask; source pixels with offsets beyond the scope of this mask will not be drawn
src_wrapmask : source offset wrap mask; wraps source offset around, no effect when src_clipmask is set
orientation : flags indicating whether scanlines should be drawn horizontally, vertically, forward or backward
priority : value to be written to the priority bitmap, no effect when equals zero
*/
pdraw_scanline32(bitmap, pal_ptr, pix_ptr, cliprect,
line_pos, scroll, zoom, src_clipmask, src_wrapmask, orientation, machine().priority_bitmap, (UINT8)priority);
// shift scanline position one virtual screen upward to render the wrapped end if necessary
scroll -= dst_height;
}
while (--i);
}
}
void k053250_t::dma(int limiter)
{
int current_frame = screen->frame_number();
if (limiter && current_frame == frame)
return; // make sure we only do DMA transfer once per frame
frame = current_frame;
memcpy(buffer[page], ram, 0x1000);
page ^= 1;
}
READ16_MEMBER(k053250_t::reg_r)
{
return regs[offset];
}
WRITE16_MEMBER(k053250_t::reg_w)
{
if (ACCESSING_BITS_0_7)
{
// start LVC DMA transfer at the falling edge of control register's bit1
if (offset == 4 && !(data & 2) && (regs[4] & 2))
dma(1);
regs[offset] = data;
}
}
READ16_MEMBER(k053250_t::ram_r)
{
return ram[offset];
}
WRITE16_MEMBER(k053250_t::ram_w)
{
COMBINE_DATA(ram+offset);
}
READ16_MEMBER(k053250_t::rom_r)
{
return m_region->base()[0x80000 * regs[6] + 0x800 * regs[7] + offset/2];
}
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