#include "maths.h"
#include "plat.h"
#include "render.h"

static int font_w = 960;
static unsigned font_data[] = {
	0x00000000, 0x00003000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x0cc0c000, 0x8000301b, 0x60601803, 0x00000000, 0x20000000,
	0x0780c078, 0x83f0e01e, 0xe0783f07, 0x60000001, 0x1e018000,
	0x07e0c078, 0xe3f87e1f, 0xe0cc1e0f, 0x1e638f01, 0x1f0c6318,
	0x07e1f07e, 0xc330fc1e, 0x30cc318c, 0x021e0fc3, 0x000101e0,
	0x00e00000, 0x0000e000, 0xc00e0007, 0x3c038c00, 0x00000000,
	0x00000000, 0x00001000, 0x00000000, 0x30380000, 0x0000c070,
	0x0cc1e000, 0xc630f81b, 0xc0301806, 0x00000cc0, 0x30000000,
	0x0cc0f0cc, 0xc030f033, 0x30cc330c, 0x30000003, 0x33030000,
	0x8cc1e0cc, 0xc230cc33, 0xc0cc3308, 0x0c630600, 0x318ce3b8,
	0x0cc318cc, 0xc330b433, 0x30cc318c, 0x06060cc3, 0x00038180,
	0x00c00018, 0x8000c000, 0x000c000d, 0x30030000, 0x00000000,
	0x00000000, 0x00001800, 0x00000000, 0x300c0000, 0x0409e0c0,
	0x8481e000, 0xc3300c3f, 0x80180c06, 0x000c0781, 0x18000000,
	0x0c00c0ec, 0xc1f0d830, 0x30cc1800, 0x180c0303, 0x30060000,
	0x8cc330ec, 0xc0318c01, 0xc0cc3180, 0x0c330600, 0x318de3f8,
	0x0cc318cc, 0xc3303003, 0x3078318c, 0x0c060643, 0x0006c180,
	0x07c0f018, 0x81e0f81e, 0xf06c3701, 0x30330f00, 0x1e07c1f8,
	0x0ee37076, 0xc330fc3e, 0x30c6318c, 0x300c0fc3, 0x0e0f20c0,
	0x0001e000, 0x8180781b, 0x80180013, 0x000c1fe1, 0x0c000000,
	0x0600c0dc, 0xc300cc1c, 0xe0780c07, 0x0c0c0303, 0x180c03f0,
	0x87c330ec, 0xc1f18c01, 0xc0fc0187, 0x0c1f0600, 0x318fe358,
	0x07c3187c, 0xc330300e, 0xe030358c, 0x18060301, 0x000c6180,
	0x0cc18030, 0xc330cc33, 0xc0dc1987, 0x301b0c00, 0x330cc358,
	0x0dc198cc, 0xc3301803, 0x306c358c, 0x00060643, 0x1b060180,
	0x0000c000, 0xc0c0c01b, 0x8018001e, 0x003f0781, 0x060003f0,
	0x0300c0cc, 0xc301fc30, 0x00cc0c0c, 0x0c000003, 0x0c0c0000,
	0x8cc3f00c, 0xc0318c01, 0xc0cc3980, 0x0c330660, 0x318f6318,
	0x06c3980c, 0xc3303018, 0xc078358c, 0x30060180, 0x00000180,
	0x0cc1f000, 0x83f0cc03, 0xc0cc1981, 0x301f0c00, 0x330cc358,
	0x00c198cc, 0xc330181e, 0x3038358c, 0x300c0303, 0x318000c0,
	0x80000000, 0xc6607c3f, 0xc030000c, 0x300c0cc0, 0x03030000,
	0x0180c0cc, 0xc330c033, 0x30cc0c0c, 0x180c0303, 0x000603f0,
	0x8cc3308c, 0xc230cc33, 0xc0cc3300, 0x8c630660, 0x318e6318,
	0x0cc1f00c, 0x83303033, 0xc0cc1f07, 0x600609c0, 0x00000180,
	0x0cc19800, 0x8030cc33, 0xc0cc1f01, 0x30330cc0, 0x330cc358,
	0x00c198cc, 0x8330d830, 0xe06c1f07, 0x300c0981, 0x318000c0,
	0x0000c000, 0x8630301b, 0x6060001b, 0x300c0000, 0x01830000,
	0x0fc3f078, 0x81e0c01e, 0xe0780c07, 0x300c0301, 0x0c030000,
	0x07e33078, 0xe3f87e1f, 0xe0cc3e01, 0xfe6383c1, 0x1f0c6318,
	0x0ce3c01e, 0x01e0781e, 0xe0cc1b03, 0xc01e0fc1, 0x000001e0,
	0x07e3f000, 0xc1e0f81e, 0xf0ce1803, 0xfc338783, 0x1e0cc318,
	0x01e1f07c, 0x06e0701f, 0x80c61b03, 0x30380fc1, 0x3f800070,
	0x0000c000, 0x0000301b, 0x00000000, 0x18000000, 0x00800000,
	0x00000000, 0x00000000, 0x00000000, 0x60060000, 0x00018000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x80000000, 0x7f800000,
	0x00000000, 0x00000000, 0x00000f00, 0x00000000, 0x00000000,
	0x0001800c, 0x00000000, 0xf0000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
	0x0003c01e, 0x00000000, 0x00000000, 0x00000000, 0x00000000
};

Colour make_colour(unsigned rgb, unsigned char a) {
	Colour r;
	r.r = (unsigned char)(rgb >> 16);
	r.g = (unsigned char)(rgb >> 8);
	r.b = (unsigned char)rgb;
	r.a = a;
	return r;
}

Colour make_red(void) {
	return make_colour(0xff0000, 0xff);
}

Colour make_green(void) {
	return make_colour(0x00ff00, 0xff);
}

Colour make_blue(void) {
	return make_colour(0x0000ff, 0xff);
}

Colour make_cyan(void) {
	return make_colour(0x00ffff, 0xff);
}

Colour make_pink(void) {
	return make_colour(0xff00ff, 0xff);
}

Colour make_yellow(void) {
	return make_colour(0xffff00, 0xff);
}

Colour make_aliceblue(void) {
	return make_colour(0xf0f8ff, 0xff);
}

Colour blend(Colour dst, Colour src) {
	int ima;
	ima = 0xff - src.a;
	dst.r = (unsigned char)(((src.r * src.a) + (dst.r * ima)) >> 8);
	dst.g = (unsigned char)(((src.g * src.a) + (dst.g * ima)) >> 8);
	dst.b = (unsigned char)(((src.b * src.a) + (dst.b * ima)) >> 8);
	return dst;
}

Colour blend_mod(Colour dst, Colour src, Colour mod) {
	int ima;
	src.a = (src.a * mod.a) >> 8;
	ima = 0xff - src.a;
	dst.r = (unsigned char)(((src.r * mod.r * src.a) >> 16) + ((dst.r * ima) >> 8));
	dst.g = (unsigned char)(((src.g * mod.g * src.a) >> 16) + ((dst.g * ima) >> 8));
	dst.b = (unsigned char)(((src.b * mod.b * src.a) >> 16) + ((dst.b * ima) >> 8));
	return dst;
}


void ren_begin(Renderer* r, Colour* t, int* d, int w, int h) {
	r->t = t;
	r->w = w;
	r->h = h;
	r->d = d;
	r->clip.x = 0;
	r->clip.y = 0;
	r->clip.w = w;
	r->clip.h = h;
}

void ren_end(Renderer* r) {
	(void)r;
}

void ren_clear(Renderer* r) {
	Colour* d = r->t, b = { 0 };
	int i = 0, e = r->w * r->h;
	for (i = 0; i < e; i++, d++)
		*d = b;
}

void ren_clearc(Renderer* r, Colour c) {
	Colour* d = r->t;
	int i = 0, e = r->w * r->h;
	for (i = 0; i < e; i++, d++)
		*d = c;
}

void ren_cleard(Renderer* r, int depth) {
	int* d = r->d;
	int i = 0, e = r->w * r->h;
	for (i = 0; i < e; i++, d++)
		*d = depth;
}

void ren_clip(Renderer* r, const Rect* c) {
	r->clip = *c;
}

void ren_point(Renderer* r, Colour c, int x, int y) {
	if (x < 0) return;
	if (y < 0) return;
	if (x >= r->w) return;
	if (y >= r->h) return;
	r->t[x + y * r->w] = c;
}

void ren_char(
	Renderer* r,
	Colour c,
	int x,
	int y,
	char ch
) {
	int i, j, k, l, ex, ey, s;
	Colour* dst;
	Rect re = { 0, 0, 10, 10 };
	Rect sub = { 0, 0, 10, 10 };
	re.x = x;
	re.y = y;
	sub.x = (ch - ' ') * 10;
	rect_clips(&re, &sub, &r->clip);
	ex = re.x + re.w;
	ey = re.y + re.h;
	dst = r->t + (re.x + re.y * r->w);
	s = r->w - re.w;
	for (j = re.y, l = sub.y; j < ey; j++, l++) {
		for (i = re.x, k = sub.x; i < ex; i++, k++) {
			int si = k + l * font_w;
			unsigned bits = font_data[si >> 5];
			int bit = bits & 1 << (si & 0x1f);
			if (bit)
				*dst = blend(*dst, c);
			dst++;
		}
		dst += s;
	}
}

void ren_text(
	Renderer* r,
	Colour c,
	int x,
	int y,
	const char* t
) {
	const char* s;
	for (s = t; *s; s++, x += 10)
		ren_char(r, c, x, y, *s);
}

void swap_vert(int* a, int* b, int ec) {
	int t, i;
	for (i = 0; i < ec; i++) {
		t = a[i];
		a[i] = b[i];
		b[i] = t;
	}
}

int tri_hand(
	const int* v0,
	const int* v1,
	const int* v2
) {
	return
		(v1[0] - v0[0]) * (v2[1] - v0[1]) -
		(v2[0] - v0[0]) * (v1[1] - v0[1]) > 0;
}

#define max_tri_ec 8

void ren_tri(
	Renderer* r,
	Colour c,
	const int* iv0,
	const int* iv1,
	const int* iv2,
	Tri_Mode mode
) {
	int ec, sx, ex, x, y, me, ms, e, ha;
	int sb = 0, * d;
	int v0[max_tri_ec], v1[max_tri_ec], v2[max_tri_ec];
	switch (mode) {
		case tri_mode_flat:
			ec = 2;
			break;
		default: assert(0);
	}
	vec_cpy(v0, iv0, ec);
	vec_cpy(v1, iv1, ec);
	vec_cpy(v2, iv2, ec);
	if (v0[1] > v1[1])
		swap_vert(v0, v1, ec);
	if (v1[1] > v2[1])
		swap_vert(v1, v2, ec);
	if (v0[1] > v1[1])
		swap_vert(v0, v1, ec);
	ha = tri_hand(v0, v1, v2);
	sb = v1[1] == v2[1];
	if (v0[1] == v1[1]) goto rb;
	if (ha) {
		ms =
			((v2[0] - v0[0]) << fbits) /
			(v2[1] - v0[1]);
		me =
			((v1[0] - v0[0]) << fbits) /
			(v1[1] - v0[1]);
		sx = v0[0] << fbits;
		ex = v0[0] << fbits;
	} else {
		ms =
			((v1[0] - v0[0]) << fbits) /
			(v1[1] - v0[1]);
		me =
			((v2[0] - v0[0]) << fbits) /
			(v2[1] - v0[1]);
		sx = v0[0] << fbits;
		ex = v0[0] << fbits;
	}
	for (
		y  = v0[1];
		y <= v1[1];
		y++, sx += ms, ex += me
	) for (
			x = sx >> fbits,
			e = ex >> fbits;
			x < e;
			x++
		) {
			d = &r->d[x + y * r->w];
			if (*d > v0[2]) {
				*d = v0[2];
				r->t[x + y * r->w] = c;
			}
		}
rb:
	if (sb) return;
	if (ha) {
		ms = ((v2[0] - v0[0]) << fbits) /
			(v2[1] - v0[1]);
		me =
			((v2[0] - v1[0]) << fbits) /
			(v2[1] - v1[1]);
		sx =
			(v0[0] << fbits) + (v1[1] - v0[1]) * ms + 1;
		ex = v1[0] << fbits;
	} else {
		me =
			((v2[0] - v0[0]) << fbits) /
			(v2[1] - v0[1]);
		ms = 
			((v2[0] - v1[0]) << fbits) /
			(v2[1] - v1[1]);
		sx = v1[0] << fbits;
		ex =
			(v0[0] << fbits) + (v1[1] - v0[1]) * me + 1;
	}
	for (
		y = v1[1];
		y <= v2[1];
		y++, sx += ms, ex += me
	) for (
			x = sx >> fbits,
			e = ex >> fbits;
			x < e;
			x++
		) {
			d = &r->d[x + y * r->w];
			if (*d > v0[2]) {
				*d = v0[2];
				r->t[x + y * r->w] = c;
			}
		}
}