static void draw_one_sprite(sprite_params_data data, uint[] dest, int xclip, int scanline)
{
int xstep = data.xscale;
int xoffs = data.xoffs;
int xcurr, offset;
UIntSubArray src;
/* xoffs of -1 means don't draw */
if (xoffs == -1) return;
/* clip to the road */
xcurr = 0;
if (xoffs < xclip)
{
/* the pixel clock starts on xoffs regardless of clipping; take this into account */
xcurr = ((xclip - xoffs) * xstep) & 0xffff;
xoffs = xclip;
}
/* compute the current data offset */
scanline = ((scanline - data.miny) * data.yscale) >> 16;
offset = data.offset + (scanline + 1) * data.rowbytes;
/* determine the bitmap location */
src = new UIntSubArray(data._base, (int)(offset & 0x7fff));
/* loop over columns */
while (xoffs < VIEW_WIDTH)
{
uint srcval = src[xcurr >> 16];
/* stop on the end-of-row signal */
if (srcval == 0x12345678) break;
dest[xoffs++] |= srcval;
xcurr += xstep;
}
}
public override int vh_start()
{
uint[] sprite_expand = new uint[16];
_BytePtr src;
/* allocate the expanded sprite data */
int sprite_length = Mame.memory_region_length(Mame.REGION_GFX1);
int sprite_bank_size = sprite_length / 8;
sprite_expanded_data = new uint[sprite_length*2];
/* allocate the expanded background data */
int back_length = Mame.memory_region_length(Mame.REGION_GFX3);
back_expanded_data = new ushort[back_length/2];
/* allocate the expanded road palette */
road_expanded_palette = new ushort[0x40];
/* determine ROM/PROM addresses */
sprite_gfxdata = Mame.memory_region(Mame.REGION_GFX1);
sprite_priority = new _BytePtr(Mame.memory_region(Mame.REGION_PROMS), 0x0200);
road_gfxdata = Mame.memory_region(Mame.REGION_GFX2);
road_palette = new _BytePtr(Mame.memory_region(Mame.REGION_PROMS), 0x0b00);
road_enable_collide = new _BytePtr(Mame.memory_region(Mame.REGION_PROMS), 0x0b40);
back_gfxdata = Mame.memory_region(Mame.REGION_GFX3);
back_palette = new _BytePtr(Mame.memory_region(Mame.REGION_PROMS), 0x0a00);
overall_priority = new _BytePtr(Mame.memory_region(Mame.REGION_PROMS), 0x0600);
collision_map = new _BytePtr(Mame.memory_region(Mame.REGION_PROMS), 0x0b60);
/* compute the sprite expansion array */
for (int i = 0; i < 16; i++)
{
uint value = 0;
if ((i & 1) != 0) value |= 0x00000001;
if ((i & 2) != 0) value |= 0x00000100;
if ((i & 4) != 0) value |= 0x00010000;
if ((i & 8) != 0) value |= 0x01000000;
/* special value for the end-of-row */
if ((i & 0x0c) == 0x04) value = 0x12345678;
sprite_expand[i] = value;
}
/* expand the sprite ROMs */
src = new _BytePtr(sprite_gfxdata);
//dst = sprite_expanded_data;
for (int i = 0; i < 8; i++)
{
int di = 0;
/* expand this bank */
for (int j = 0; j < sprite_bank_size; j++)
{
sprite_expanded_data[di++] = sprite_expand[src[0] >> 4];
sprite_expanded_data[di++] = sprite_expand[src[0] & 15];
src.offset++;
}
/* shift for the next bank */
for (int j = 0; j < 16; j++)
if (sprite_expand[j] != 0x12345678) sprite_expand[j] <<= 1;
}
/* expand the background ROMs */
src = new _BytePtr(back_gfxdata);
//bdst = back_expanded_data;
int bdi = 0;
for (int i = 0; i < back_length / 2; i++, src.offset++)
{
int bits1 = src[0];
int bits2 = src[back_length / 2];
int newbits = 0;
for (int j = 0; j < 8; j++)
{
newbits |= ((bits1 >> (j ^ 7)) & 1) << (j * 2);
newbits |= ((bits2 >> (j ^ 7)) & 1) << (j * 2 + 1);
}
back_expanded_data[bdi++] = (ushort)newbits;
}
/* expand the road palette */
src = road_palette;
//bdst = road_expanded_palette;
bdi = 0;
for (int i = 0; i < 0x20; i++, src.offset++)
road_expanded_palette[bdi++] = (ushort)(src[0] | (src[0x20] << 8));
/* set the default drawing parameters */
startx = game_clip.min_x;
starty = game_clip.min_y;
deltax = deltay = 1;
adjusted_clip = game_clip;
/* adjust our parameters for the specified orientation */
if (Mame.Machine.orientation != 0)
{
if ((Mame.Machine.orientation & Mame.ORIENTATION_SWAP_XY) != 0)
{
int temp = startx; startx = starty; starty = temp;
temp = adjusted_clip.min_x; adjusted_clip.min_x = adjusted_clip.min_y; adjusted_clip.min_y = temp;
temp = adjusted_clip.max_x; adjusted_clip.max_x = adjusted_clip.max_y; adjusted_clip.max_y = temp;
}
if ((Mame.Machine.orientation & Mame.ORIENTATION_FLIP_X) != 0)
{
startx = adjusted_clip.max_x;
if ((Mame.Machine.orientation & Mame.ORIENTATION_SWAP_XY) == 0) deltax = -deltax;
else deltay = -deltay;
}
if ((Mame.Machine.orientation & Mame.ORIENTATION_FLIP_Y) != 0)
{
starty = adjusted_clip.max_y;
if ((Mame.Machine.orientation & Mame.ORIENTATION_SWAP_XY) == 0) deltay = -deltay;
else deltax = -deltax;
}
}
/* other stuff */
drew_frame = false;
for (int i = 0; i < 16; i++)
sprite_params[i] = new sprite_params_data();
/* return success */
return 0;
}