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#include "fitz.h"

#define MAX4(a,b,c,d) MAX(MAX(a,b), MAX(c,d))

#define MIN4(a,b,c,d) MIN(MIN(a,b), MIN(c,d))

/* Matrices, points and affine transformations */

const fz_matrix fz_identity = { 1, 0, 0, 1, 0, 0 };

fz_matrix

fz_concat(fz_matrix one, fz_matrix two)

{

	fz_matrix dst;

	dst.a = one.a * two.a + one.b * two.c;

	dst.b = one.a * two.b + one.b * two.d;

	dst.c = one.c * two.a + one.d * two.c;

	dst.d = one.c * two.b + one.d * two.d;

	dst.e = one.e * two.a + one.f * two.c + two.e;

	dst.f = one.e * two.b + one.f * two.d + two.f;

	return dst;

}

fz_matrix

fz_scale(float sx, float sy)

{

	fz_matrix m;

	m.a = sx; m.b = 0;

	m.c = 0; m.d = sy;

	m.e = 0; m.f = 0;

	return m;

}

fz_matrix

fz_shear(float h, float v)

{

	fz_matrix m;

	m.a = 1; m.b = v;

	m.c = h; m.d = 1;

	m.e = 0; m.f = 0;

	return m;

}

fz_matrix

fz_rotate(float theta)

{

	fz_matrix m;

	float s;

	float c;

	while (theta < 0)

		theta += 360;

	while (theta >= 360)

		theta -= 360;

	if (fabsf(0 - theta) < FLT_EPSILON)

	{

		s = 0;

		c = 1;

	}

	else if (fabsf(90.0f - theta) < FLT_EPSILON)

	{

		s = 1;

		c = 0;

	}

	else if (fabsf(180.0f - theta) < FLT_EPSILON)

	{

		s = 0;

		c = -1;

	}

	else if (fabsf(270.0f - theta) < FLT_EPSILON)

	{

		s = -1;

		c = 0;

	}

	else

	{

		s = sinf(theta * (float)M_PI / 180);

		c = cosf(theta * (float)M_PI / 180);

	}

	m.a = c; m.b = s;

	m.c = -s; m.d = c;

	m.e = 0; m.f = 0;

	return m;

}

fz_matrix

fz_translate(float tx, float ty)

{

	fz_matrix m;

	m.a = 1; m.b = 0;

	m.c = 0; m.d = 1;

	m.e = tx; m.f = ty;

	return m;

}

fz_matrix

fz_invert_matrix(fz_matrix src)

{

	fz_matrix dst;

	float rdet = 1 / (src.a * src.d - src.b * src.c);

	dst.a = src.d * rdet;

	dst.b = -src.b * rdet;

	dst.c = -src.c * rdet;

	dst.d = src.a * rdet;

	dst.e = -src.e * dst.a - src.f * dst.c;

	dst.f = -src.e * dst.b - src.f * dst.d;

	return dst;

}

int

fz_is_rectilinear(fz_matrix m)

{

	return (fabsf(m.b) < FLT_EPSILON && fabsf(m.c) < FLT_EPSILON) ||

		(fabsf(m.a) < FLT_EPSILON && fabsf(m.d) < FLT_EPSILON);

}

float

fz_matrix_expansion(fz_matrix m)

{

	return sqrtf(fabsf(m.a * m.d - m.b * m.c));

}

fz_point

fz_transform_point(fz_matrix m, fz_point p)

{

	fz_point t;

	t.x = p.x * m.a + p.y * m.c + m.e;

	t.y = p.x * m.b + p.y * m.d + m.f;

	return t;

}

fz_point

fz_transform_vector(fz_matrix m, fz_point p)

{

	fz_point t;

	t.x = p.x * m.a + p.y * m.c;

	t.y = p.x * m.b + p.y * m.d;

	return t;

}

/* Rectangles and bounding boxes */

const fz_rect fz_infinite_rect = { 1, 1, -1, -1 };

const fz_rect fz_empty_rect = { 0, 0, 0, 0 };

const fz_rect fz_unit_rect = { 0, 0, 1, 1 };

const fz_bbox fz_infinite_bbox = { 1, 1, -1, -1 };

const fz_bbox fz_empty_bbox = { 0, 0, 0, 0 };

const fz_bbox fz_unit_bbox = { 0, 0, 1, 1 };

fz_bbox

fz_round_rect(fz_rect f)

{

	fz_bbox i;

	i.x0 = floorf(f.x0 + 0.001f); /* adjust by 0.001 to compensate for precision errors */

	i.y0 = floorf(f.y0 + 0.001f);

	i.x1 = ceilf(f.x1 - 0.001f);

	i.y1 = ceilf(f.y1 - 0.001f);

	return i;

}

fz_rect

fz_intersect_rect(fz_rect a, fz_rect b)

{

	fz_rect r;

	if (fz_is_infinite_rect(a)) return b;

	if (fz_is_infinite_rect(b)) return a;

	if (fz_is_empty_rect(a)) return fz_empty_rect;

	if (fz_is_empty_rect(b)) return fz_empty_rect;

	r.x0 = MAX(a.x0, b.x0);

	r.y0 = MAX(a.y0, b.y0);

	r.x1 = MIN(a.x1, b.x1);

	r.y1 = MIN(a.y1, b.y1);

	return (r.x1 < r.x0 || r.y1 < r.y0) ? fz_empty_rect : r;

}

fz_rect

fz_union_rect(fz_rect a, fz_rect b)

{

	fz_rect r;

	if (fz_is_infinite_rect(a)) return a;

	if (fz_is_infinite_rect(b)) return b;

	if (fz_is_empty_rect(a)) return b;

	if (fz_is_empty_rect(b)) return a;

	r.x0 = MIN(a.x0, b.x0);

	r.y0 = MIN(a.y0, b.y0);

	r.x1 = MAX(a.x1, b.x1);

	r.y1 = MAX(a.y1, b.y1);

	return r;

}

fz_bbox

fz_intersect_bbox(fz_bbox a, fz_bbox b)

{

	fz_bbox r;

	if (fz_is_infinite_rect(a)) return b;

	if (fz_is_infinite_rect(b)) return a;

	if (fz_is_empty_rect(a)) return fz_empty_bbox;

	if (fz_is_empty_rect(b)) return fz_empty_bbox;

	r.x0 = MAX(a.x0, b.x0);

	r.y0 = MAX(a.y0, b.y0);

	r.x1 = MIN(a.x1, b.x1);

	r.y1 = MIN(a.y1, b.y1);

	return (r.x1 < r.x0 || r.y1 < r.y0) ? fz_empty_bbox : r;

}

fz_bbox

fz_union_bbox(fz_bbox a, fz_bbox b)

{

	fz_bbox r;

	if (fz_is_infinite_rect(a)) return a;

	if (fz_is_infinite_rect(b)) return b;

	if (fz_is_empty_rect(a)) return b;

	if (fz_is_empty_rect(b)) return a;

	r.x0 = MIN(a.x0, b.x0);

	r.y0 = MIN(a.y0, b.y0);

	r.x1 = MAX(a.x1, b.x1);

	r.y1 = MAX(a.y1, b.y1);

	return r;

}

fz_rect

fz_transform_rect(fz_matrix m, fz_rect r)

{

	fz_point s, t, u, v;

	if (fz_is_infinite_rect(r))

		return r;

	s.x = r.x0; s.y = r.y0;

	t.x = r.x0; t.y = r.y1;

	u.x = r.x1; u.y = r.y1;

	v.x = r.x1; v.y = r.y0;

	s = fz_transform_point(m, s);

	t = fz_transform_point(m, t);

	u = fz_transform_point(m, u);

	v = fz_transform_point(m, v);

	r.x0 = MIN4(s.x, t.x, u.x, v.x);

	r.y0 = MIN4(s.y, t.y, u.y, v.y);

	r.x1 = MAX4(s.x, t.x, u.x, v.x);

	r.y1 = MAX4(s.y, t.y, u.y, v.y);

	return r;

}

fz_bbox

fz_transform_bbox(fz_matrix m, fz_bbox b)

{

	fz_point s, t, u, v;

	if (fz_is_infinite_bbox(b))

		return b;

	s.x = b.x0; s.y = b.y0;

	t.x = b.x0; t.y = b.y1;

	u.x = b.x1; u.y = b.y1;

	v.x = b.x1; v.y = b.y0;

	s = fz_transform_point(m, s);

	t = fz_transform_point(m, t);

	u = fz_transform_point(m, u);

	v = fz_transform_point(m, v);

	b.x0 = MIN4(s.x, t.x, u.x, v.x);

	b.y0 = MIN4(s.y, t.y, u.y, v.y);

	b.x1 = MAX4(s.x, t.x, u.x, v.x);

	b.y1 = MAX4(s.y, t.y, u.y, v.y);

	return b;

}