/* uuterm, Copyright (C) 2006 Rich Felker; licensed under GNU GPL v2 only */

#include <inttypes.h>

#include "uuterm.h"
#include "dblbuf.h"

static void blitline8(unsigned char *dest, unsigned char *src, unsigned long *colors, int w)
{
#define T(x) ~((x&8)*0xff>>3 | (x&4)*0xff<<6 | (x&2)*0xff<<15 | (x&1)*0xff<<24)
        static const uint32_t tab[16] = {
                T(0), T(1), T(2), T(3), T(4), T(5), T(6), T(7),
                T(8), T(9), T(10), T(11), T(12), T(13), T(14), T(15)
        };
#undef T
	uint32_t *dest4 = (uint32_t*)dest;
	for(; w--; dest4+=2, colors+=2) {
		int s = *src++;
		int t0 = tab[s>>4];
		int t1 = tab[s&15];
		dest4[0] = colors[0] ^ (colors[1] & t0);
		dest4[1] = colors[0] ^ (colors[1] & t1);
	}
}

static void blit_slice(struct uudisp *d, int idx, int x1, int x2)
{
	struct dblbuf *b = (void *)&d->priv;
	int cs = (d->cell_w+7)>>3;
	int y = b->slices[idx].y;
	int w = x2 - x1 + 1;
	int s = d->w * cs;
	int i;

	unsigned char *dest = b->vidmem + y*b->row_stride
		+ x1*d->cell_w*b->bytes_per_pixel;
	unsigned char *src = b->slices[idx].bitmap + x1*cs;
	unsigned long *colors = b->slices[idx].colors + 2*x1;

	for (i=0; i<d->cell_h; i++) {
		blitline8(dest, src, colors, w);
		dest += b->line_stride;
		src += s;
	}
}

void clear_cells(struct uudisp *d, int idx, int x1, int x2)
{
	struct dblbuf *b = (void *)&d->priv;
	int i;
	int cs = d->cell_w+7 >> 3;
	int cnt = (x2 - x1 + 1) * cs;
	int stride = d->w * cs;
	unsigned char *dest = b->slices[idx].bitmap + x1 * cs;

	memset(b->slices[idx].colors + 2*x1, 0, (x2-x1+1)*2*sizeof(long));
	for (i=d->cell_h; i; i--, dest += stride)
		memset(dest, 0, cnt);
}

void uudisp_draw_glyph(struct uudisp *d, int idx, int x, const void *glyph, int color)
{
	struct dblbuf *b = (void *)&d->priv;
	int i;
	int cs = d->cell_w+7 >> 3;
	int stride = d->w * cs;
	unsigned char *src = (void *)glyph;
	unsigned char *dest = b->slices[idx].bitmap + cs * x;

	b->slices[idx].colors[2*x] = (color&15)*(unsigned long)0x0101010101010101;
	b->slices[idx].colors[2*x+1] = b->slices[idx].colors[2*x]
		^ (color>>4)*(unsigned long)0x0101010101010101;
	for (i=d->cell_h; i; i--, dest += stride)
		*dest |= *src++;
}

void uudisp_refresh(struct uudisp *d, struct uuterm *t)
{
	struct dblbuf *b = (void *)&d->priv;
	int h = t->h < d->h ? t->h : d->h;
	int y;

	/* Clean up cursor first.. */
	blit_slice(d, t->rows[b->curs_y]->idx, b->curs_x, b->curs_x);
	//printf("--- %d\r\n", b->slices[t->rows[b->curs_y]->idx].y);

	for (y=0; y<h; y++) {
		int idx = t->rows[y]->idx;
		int x1 = t->rows[y]->x1;
		int x2 = t->rows[y]->x2;
		if (x2 >= x1) {
			clear_cells(d, idx, x1, x2);
			uuterm_refresh_row(d, t->rows[y], x1, x2);
			t->rows[y]->x1 = t->w;
			t->rows[y]->x2 = -1;
		}
		if (b->slices[idx].y != y) {
			b->slices[idx].y = y;
			x1 = 0;
			x2 = d->w-1;
		} else if (x2 < x1) continue;
		blit_slice(d, idx, x1, x2);
	}

	if (d->blink & 1) {
		int idx = t->rows[t->y]->idx;
		b->slices[idx].colors[2*t->x] ^= (unsigned long)0x0f0f0f0f0f0f0f0f;
		blit_slice(d, idx, t->x, t->x);
		b->slices[idx].colors[2*t->x] ^= (unsigned long)0x0f0f0f0f0f0f0f0f;
	}
	b->curs_x = t->x;
	b->curs_y = t->y;
	//printf("+++ %d\r\n", b->slices[t->rows[b->curs_y]->idx].y);
}

struct slice *dblbuf_setup_buf(int w, int h, int cs, int ch, unsigned char *mem)
{
	struct slice *slices = (void *)mem;
	int i;

	mem += sizeof(slices[0]) * h;

	for (i=0; i<h; i++, mem += w*2*sizeof(long)) {
		slices[i].y = -1;
		slices[i].colors = (unsigned long *)mem;
	}
	w *= cs * ch;
	for (i=0; i<h; i++, mem += w)
		slices[i].bitmap = mem;

	return slices;
}