/*
	EPOCH Super Cassette Vision Emulator 'eSCV'

	Author : Takeda.Toshiya
	Date   : 2006.08.21 -

	[ EPOCH TV-1 ]
*/

#include "vdp.h"
#include "../upd7801.h"

namespace SCV {

static const scrntype_t palette_pc[16] = {
#if 1
	RGB_COLOR(  0, 90,156), RGB_COLOR(  0,  0,  0), RGB_COLOR( 58,148,255), RGB_COLOR(  0,  0,255),
	RGB_COLOR( 16,214,  0), RGB_COLOR( 66,255, 16), RGB_COLOR(123,230,197), RGB_COLOR(  0,173,  0),
	RGB_COLOR(255, 41,148), RGB_COLOR(255, 49, 16), RGB_COLOR(255, 58,255), RGB_COLOR(239,156,255),
	RGB_COLOR(255,206, 33), RGB_COLOR( 74,123, 16), RGB_COLOR(165,148,165), RGB_COLOR(255,255,255)
#else
	RGB_COLOR(  0, 90,156), RGB_COLOR(  0,  0,  0), RGB_COLOR(  0, 58,255), RGB_COLOR(  0,  0,255),
	RGB_COLOR(  0,255,  0), RGB_COLOR( 58,255, 90), RGB_COLOR(  0,255,255), RGB_COLOR(  0,255,  0),
	RGB_COLOR(255, 58,156), RGB_COLOR(255,156,156), RGB_COLOR(255, 58,255), RGB_COLOR(255,156,255),
	RGB_COLOR(255,255, 90), RGB_COLOR(123,156,  0), RGB_COLOR(189,189,189), RGB_COLOR(255,255,255)
#endif
};

#if 1
// table analyzed by Enri
static const uint8_t color_pair0[16] = {0x0, 0xf, 0xc, 0xd, 0xa, 0xb, 0x8, 0x9, 0x6, 0x7, 0x4, 0x5, 0x2, 0x3, 0x1, 0x1};
static const uint8_t color_pair1[16] = {0x0, 0x1, 0x8, 0xb, 0x2, 0x3, 0xa, 0x9, 0x4, 0x5, 0xc, 0xd, 0x6, 0x7, 0xe, 0xf};
#else
static const uint8_t color_pair0[16] = {0xe, 0xf, 0xc, 0xd, 0xa, 0xb, 0x8, 0x9, 0x6, 0x7, 0x4, 0x5, 0x2, 0x3, 0x0, 0x1};
static const uint8_t color_pair1[16] = {0x0, 0x1, 0x8, 0x9, 0x2, 0x3, 0xa, 0xb, 0x4, 0x5, 0xc, 0xd, 0x6, 0x7, 0xe, 0xf};
#endif

static const uint8_t symbol[32][8] = {
	{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},{0x00,0x02,0x7a,0x84,0x84,0x7a,0x00,0x00},
	{0x00,0x3c,0x42,0x7c,0x42,0x7c,0x40,0x40},{0x00,0x62,0x94,0x08,0x08,0x08,0x00,0x00},
	{0x00,0xfc,0x50,0x50,0x52,0x8c,0x00,0x00},{0xfe,0x82,0x60,0x10,0x60,0x82,0xfe,0x00},
	{0x38,0x44,0x82,0x82,0x82,0x44,0xc6,0x00},{0x10,0x7c,0xfe,0xfe,0xfe,0x10,0x38,0x00},
	{0x6c,0xfe,0xfe,0xfe,0xfe,0x7c,0x10,0x00},{0x10,0x10,0x38,0xfe,0x38,0x10,0x10,0x00},
	{0x10,0x7c,0x92,0xfe,0x92,0x10,0x38,0x00},{0x38,0x44,0xba,0xa2,0xba,0x44,0x38,0x00},
	{0x80,0x80,0x88,0x44,0x3e,0x04,0x08,0x00},{0x02,0x02,0x22,0x44,0xf8,0x40,0x20,0x00},
	{0x10,0x00,0x00,0xfe,0x00,0x00,0x10,0x00},{0x00,0x80,0x40,0x20,0x10,0x08,0x04,0x00},
	{0x7c,0x82,0x82,0x82,0x82,0x82,0x7c,0x00},{0x7c,0xfe,0xfe,0xfe,0xfe,0xfe,0x7c,0x00},
	{0x7c,0x82,0xba,0xba,0xba,0x82,0x7c,0x00},{0xfe,0x82,0x82,0x82,0x82,0x82,0xfe,0x00},
	{0xaa,0x55,0xaa,0x55,0xaa,0x55,0xaa,0x55},{0xff,0x80,0x80,0x80,0x80,0x80,0x80,0x80},
	{0xff,0x01,0x01,0x01,0x01,0x01,0x01,0x01},{0x80,0x80,0x80,0x80,0x80,0x80,0x80,0xff},
	{0x01,0x01,0x01,0x01,0x01,0x01,0x01,0xff},{0xfe,0x00,0xfe,0x10,0x10,0x10,0x10,0x00},
	{0x18,0x14,0x12,0x12,0x72,0xf0,0x60,0x00},{0x18,0x14,0x12,0x12,0x72,0x90,0x60,0x00},
	{0x10,0x08,0x04,0xfe,0x04,0x08,0x10,0x00},{0x10,0x20,0x40,0xfe,0x40,0x20,0x10,0x00},
	{0x10,0x38,0x54,0x92,0x10,0x10,0x10,0x00},{0x10,0x10,0x10,0x92,0x54,0x38,0x10,0x00}
};

void VDP::initialize()
{
	// copy font in bios
	for(int i = 0, c = 0x20, p = 0; i < 3; i++, c += 32) {
		for(int j = 0; j < 16; j++) {
			for(int k = 0; k < 8; k += 2) {
				uint8_t d0 = font_ptr[p++];
				uint8_t d1 = font_ptr[p++];
				uint8_t d2 = font_ptr[p++];
				uint8_t d3 = font_ptr[p++];
				
				font[c + j     ][k    ] = (d0 & 0xf0) | (d1 >> 4);
				font[c + j + 16][k    ] = (d2 & 0xf0) | (d3 >> 4);
				font[c + j     ][k + 1] = (d0 << 4) | (d1 & 0x0f);
				font[c + j + 16][k + 1] = (d2 << 4) | (d3 & 0x0f);
			}
		}
	}
	memcpy(font, symbol, sizeof(symbol));
	memcpy(font[0xb], font[0x60], 8);	// copyright mark
	
	// register event to interrupt
	register_vline_event(this);
}

void VDP::event_vline(int v, int clock)
{
	if(v == 239) {
		d_cpu->write_signal(SIG_UPD7801_INTF2, 1, 1);
	} else if(v == 261) {
		d_cpu->write_signal(SIG_UPD7801_INTF2, 0, 1);
	}
}

void VDP::draw_screen()
{
	// get vdc control params
	vdc0 = vram1[0x400];
	vdc1 = vram1[0x401];
	vdc2 = vram1[0x402];
	vdc3 = vram1[0x403];
	
	// draw text screen
	memset(text, vdc1 & 0xf, sizeof(text));
	draw_text_screen();
	
	// draw sprite screen
	memset(sprite, 0, sizeof(sprite));
	if(vdc0 & 0x10) {
		draw_sprite_screen();
	}
	
	// mix screens
	int ty = ((vdc0 & 0xf7) == 0x17 && (vdc2 & 0xef) == 0x4f) ? 32 : 0;
	uint16_t back = palette_pc[vdc1 & 0xf];
	
	for(int y = 0; y < ty; y++) {
		// patch for nekketsu kung-fu road
		scrntype_t* d = emu->get_screen_buffer(y);
		uint8_t* t = &text[y + 23][24];
		
		for(int x = 0; x < SCREEN_WIDTH; x++) {
			d[x] = palette_pc[t[x]];
		}
	}
	for(int y = ty; y < SCREEN_HEIGHT; y++) {
		scrntype_t* d = emu->get_screen_buffer(y);
		uint8_t* s = &sprite[y + 21][28];
		uint8_t* t = &text[y + 23][24];
		
		for(int x = 0; x < SCREEN_WIDTH; x++) {
			d[x] = palette_pc[s[x] ? s[x] : t[x]];
		}
	}
}

void VDP::draw_text_screen()
{
	int xmax = (vdc2 & 0xf) * 2;
	//xmax = xmax ? xmax : 32;
	int ymax = vdc2 >> 4;
	int xs = (vdc0 & 0x40) ? xmax : 0;
	int xe = (vdc0 & 0x40) ? 32 : xmax;
	int ys = (vdc0 & 0x80) ? ymax : 0;
	int ye = (vdc0 & 0x80) ? 16 : ymax;
	
	uint8_t ct = vdc3 >> 4;
	uint8_t cb = vdc3 & 0xf;
	uint8_t cg = vdc1 >> 4;
	
	for(int y = 1; y < 16; y++) {
		bool t = (ys <= y && y < ye);
		int y32 = y << 5;
		
		for(int x = 2; x < 29; x++) {
			if(t && (xs <= x && x < xe)) {
				// draw text
				uint8_t data = (x < 26) ? (vram1[y32 + x] & 0x7f) : 0;
				draw_text(x, y, data, ct, cb);
			} else if((vdc0 & 3) == 1) {
				// semi graph
				uint8_t data = vram1[y32 + x];
				draw_graph(x, y, data, cg);
			} else if((vdc0 & 3) == 3) {
				// block
				uint8_t data = vram1[y32 + x];
				draw_block(x, y, data);
			}
		}
	}
}

void VDP::draw_text(int dx, int dy, uint8_t data, uint8_t tcol, uint8_t bcol)
{
	int dx8 = dx << 3, dy16 = dy << 4;
	
	for(int l = 0; l < 8 && data; l++) {
		uint8_t* dest = &text[dy16 + l][dx8];
		uint8_t pat = font[data][l];
		
		dest[0] = (pat & 0x80) ? tcol : bcol;
		dest[1] = (pat & 0x40) ? tcol : bcol;
		dest[2] = (pat & 0x20) ? tcol : bcol;
		dest[3] = (pat & 0x10) ? tcol : bcol;
		dest[4] = (pat & 0x08) ? tcol : bcol;
		dest[5] = (pat & 0x04) ? tcol : bcol;
		dest[6] = (pat & 0x02) ? tcol : bcol;
		dest[7] = (pat & 0x01) ? tcol : bcol;
	}
	for(int l = (data ? 8 : 0); l < 16; l++) {
		memset(&text[dy16 + l][dx8], bcol, 8);
	}
}

void VDP::draw_block(int dx, int dy, uint8_t data)
{
	int dx8 = dx << 3, dy16 = dy << 4;
	uint8_t cu = data >> 4, cl = data & 0xf;
	
	if(cu) {
		for(int l = 0; l < 8; l++) {
			memset(&text[dy16 + l][dx8], cu, 8);
		}
	}
	if(cl) {
		for(int l = 8; l < 16; l++) {
			memset(&text[dy16 + l][dx8], cl, 8);
		}
	}
}

void VDP::draw_graph(int dx, int dy, uint8_t data, uint8_t col)
{
	int dx8l = dx << 3, dx8r = (dx << 3) + 4, dy16 = dy << 4;
	
	if(data & 0x80) {
		for(int l = 0; l < 4; l++) {
			memset(&text[dy16 + l][dx8l], col, 4);
		}
	}
	if(data & 0x40) {
		for(int l = 0; l < 4; l++) {
			memset(&text[dy16 + l][dx8r], col, 4);
		}
	}
	if(data & 0x20) {
		for(int l = 4; l < 8; l++) {
			memset(&text[dy16 + l][dx8l], col, 4);
		}
	}
	if(data & 0x10) {
		for(int l = 4; l < 8; l++) {
			memset(&text[dy16 + l][dx8r], col, 4);
		}
	}
	if(data & 0x08) {
		for(int l = 8; l < 12; l++) {
			memset(&text[dy16 + l][dx8l], col, 4);
		}
	}
	if(data & 0x04) {
		for(int l = 8; l < 12; l++) {
			memset(&text[dy16 + l][dx8r], col, 4);
		}
	}
	if(data & 0x02) {
		for(int l = 12; l < 16; l++) {
			memset(&text[dy16 + l][dx8l], col, 4);
		}
	}
	if(data & 0x01) {
		for(int l = 12; l < 16; l++) {
			memset(&text[dy16 + l][dx8r], col, 4);
		}
	}
}

void VDP::draw_sprite_screen()
{
	for(int index = 0; index < 128; index++) {
		uint8_t atb0 = vram1[0x200 + (index << 2)];
		uint8_t atb1 = vram1[0x201 + (index << 2)];
		uint8_t atb2 = vram1[0x202 + (index << 2)];
		uint8_t atb3 = vram1[0x203 + (index << 2)];
		
		int dx = atb2 & 0xfe;
		int dy = atb0 & 0xfe;
		bool conx = ((atb2 & 1) != 0);
		bool cony = ((atb0 & 1) != 0);
		uint8_t col0 = atb1 & 0xf;
		
		int sx = 0, ex = 4;
		int sy = atb1 >> 4, ey = 8;
		if(atb3 & 0x80) {
			// half/quarter sprite
			if(atb3 & 0x40) {
				sy = !cony ? 0 : 4;
				ey = !cony ? 4 : 8;
				dy = !cony ? dy : dy - 8;
				cony = false;
			}
			sx = !conx ? 0 : 2;
			ex = !conx ? 2 : 4;
			dx = !conx ? dx : dx - 8;
			conx = false;
			
			atb3 &= 0x7f;
		}
		
		if((index & 0x20) && (vdc0 & 0x20)) {
			// 2 colors sprite
			uint8_t col1 = (index & 0x40) ? color_pair1[col0] : color_pair0[col0];
			int no1 = atb3, no2 = atb3 ^ ((conx ? 8 : 0) | (cony ? 1 : 0));
			
			draw_sprite(dx, dy, sx, ex, sy, ey, no1, col0);
			if(conx || cony) {
				draw_sprite(dx, dy, sx, ex, sy, ey, no2, col1);
			}
		} else {
			// mono color sprite
			int no1 = atb3, no2 = atb3 | 1, no3 = atb3 | 8, no4 = atb3 | 9;
			
			draw_sprite(dx, dy, sx, ex, sy, ey, no1, col0);
			if(cony) {
				draw_sprite(dx, dy + 16, sx, ex, sy - 8, 8, no2, col0);
			}
			if(conx) {
				draw_sprite(dx + 16, dy, 0, 4, sy, ey, no3, col0);
			}
			if(conx && cony) {
				draw_sprite(dx + 16, dy + 16, 0, 4, sy - 8, 8, no4, col0);
			}
		}
	}
}

void VDP::draw_sprite(int dx, int dy, int sx, int ex, int sy, int ey, int no, uint8_t col)
{
	// color #0 is transparent
	if(!col) {
		return;
	}
	for(int y = (sy < 0 ? 0 : sy), no32 = no << 5; y < ey; y++) {
		int y2u = (y << 1) + dy, y2l = (y << 1) + dy + 1, y4 = (y << 2) + no32;
		
		for(int x = sx; x < ex; x++) {
			int x4 = dx + (x << 2);
			uint8_t* du = &sprite[y2u][x4];
			uint8_t* dl = &sprite[y2l][x4];
			uint8_t p = vram0[y4 + x];
			
			if(p & 0x80) du[0] = col;
			if(p & 0x40) du[1] = col;
			if(p & 0x20) du[2] = col;
			if(p & 0x10) du[3] = col;
			if(p & 0x08) dl[0] = col;
			if(p & 0x04) dl[1] = col;
			if(p & 0x02) dl[2] = col;
			if(p & 0x01) dl[3] = col;
		}
	}
}

#define STATE_VERSION	1


bool VDP::process_state(FILEIO* state_fio, bool loading)
{
	if(!state_fio->StateCheckUint32(STATE_VERSION)) {
		return false;
	}
	if(!state_fio->StateCheckInt32(this_device_id)) {
		return false;
	}
	state_fio->StateValue(vdc0);
	state_fio->StateValue(vdc1);
	state_fio->StateValue(vdc2);
	state_fio->StateValue(vdc3);
	return true;
}

}
