add cairo

1 files changed, 395 insertions, 0 deletions

diff --git a/libs/cairo-1.16.0/src/cairo-fixed-private.h b/libs/cairo-1.16.0/src/cairo-fixed-private.h
new file mode 100644
index 0000000..5f9ce68
--- /dev/null
+++ b/libs/cairo-1.16.0/src/cairo-fixed-private.h
@@ -0,0 +1,395 @@
+/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
+/* Cairo - a vector graphics library with display and print output
+ *
+ * Copyright © 2007 Mozilla Corporation
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ * The Original Code is the cairo graphics library.
+ *
+ * The Initial Developer of the Original Code is Mozilla Foundation
+ *
+ * Contributor(s):
+ *	Vladimir Vukicevic <vladimir@pobox.com>
+ */
+
+#ifndef CAIRO_FIXED_PRIVATE_H
+#define CAIRO_FIXED_PRIVATE_H
+
+#include "cairo-fixed-type-private.h"
+
+#include "cairo-wideint-private.h"
+#include "cairoint.h"
+
+/* Implementation */
+
+#if (CAIRO_FIXED_BITS != 32)
+# error CAIRO_FIXED_BITS must be 32, and the type must be a 32-bit type.
+# error To remove this limitation, you will have to fix the tessellator.
+#endif
+
+#define CAIRO_FIXED_ONE        ((cairo_fixed_t)(1 << CAIRO_FIXED_FRAC_BITS))
+#define CAIRO_FIXED_ONE_DOUBLE ((double)(1 << CAIRO_FIXED_FRAC_BITS))
+#define CAIRO_FIXED_EPSILON    ((cairo_fixed_t)(1))
+
+#define CAIRO_FIXED_ERROR_DOUBLE (1. / (2 * CAIRO_FIXED_ONE_DOUBLE))
+
+#define CAIRO_FIXED_FRAC_MASK  ((cairo_fixed_t)(((cairo_fixed_unsigned_t)(-1)) >> (CAIRO_FIXED_BITS - CAIRO_FIXED_FRAC_BITS)))
+#define CAIRO_FIXED_WHOLE_MASK (~CAIRO_FIXED_FRAC_MASK)
+
+static inline cairo_fixed_t
+_cairo_fixed_from_int (int i)
+{
+    return i << CAIRO_FIXED_FRAC_BITS;
+}
+
+/* This is the "magic number" approach to converting a double into fixed
+ * point as described here:
+ *
+ * http://www.stereopsis.com/sree/fpu2006.html (an overview)
+ * http://www.d6.com/users/checker/pdfs/gdmfp.pdf (in detail)
+ *
+ * The basic idea is to add a large enough number to the double that the
+ * literal floating point is moved up to the extent that it forces the
+ * double's value to be shifted down to the bottom of the mantissa (to make
+ * room for the large number being added in). Since the mantissa is, at a
+ * given moment in time, a fixed point integer itself, one can convert a
+ * float to various fixed point representations by moving around the point
+ * of a floating point number through arithmetic operations. This behavior
+ * is reliable on most modern platforms as it is mandated by the IEEE-754
+ * standard for floating point arithmetic.
+ *
+ * For our purposes, a "magic number" must be carefully selected that is
+ * both large enough to produce the desired point-shifting effect, and also
+ * has no lower bits in its representation that would interfere with our
+ * value at the bottom of the mantissa. The magic number is calculated as
+ * follows:
+ *
+ *          (2 ^ (MANTISSA_SIZE - FRACTIONAL_SIZE)) * 1.5
+ *
+ * where in our case:
+ *  - MANTISSA_SIZE for 64-bit doubles is 52
+ *  - FRACTIONAL_SIZE for 16.16 fixed point is 16
+ *
+ * Although this approach provides a very large speedup of this function
+ * on a wide-array of systems, it does come with two caveats:
+ *
+ * 1) It uses banker's rounding as opposed to arithmetic rounding.
+ * 2) It doesn't function properly if the FPU is in single-precision
+ *    mode.
+ */
+
+/* The 16.16 number must always be available */
+#define CAIRO_MAGIC_NUMBER_FIXED_16_16 (103079215104.0)
+
+#if CAIRO_FIXED_BITS <= 32
+#define CAIRO_MAGIC_NUMBER_FIXED ((1LL << (52 - CAIRO_FIXED_FRAC_BITS)) * 1.5)
+
+/* For 32-bit fixed point numbers */
+static inline cairo_fixed_t
+_cairo_fixed_from_double (double d)
+{
+    union {
+        double d;
+        int32_t i[2];
+    } u;
+
+    u.d = d + CAIRO_MAGIC_NUMBER_FIXED;
+#ifdef FLOAT_WORDS_BIGENDIAN
+    return u.i[1];
+#else
+    return u.i[0];
+#endif
+}
+
+#else
+# error Please define a magic number for your fixed point type!
+# error See cairo-fixed-private.h for details.
+#endif
+
+static inline cairo_fixed_t
+_cairo_fixed_from_26_6 (uint32_t i)
+{
+#if CAIRO_FIXED_FRAC_BITS > 6
+    return i << (CAIRO_FIXED_FRAC_BITS - 6);
+#else
+    return i >> (6 - CAIRO_FIXED_FRAC_BITS);
+#endif
+}
+
+static inline cairo_fixed_t
+_cairo_fixed_from_16_16 (uint32_t i)
+{
+#if CAIRO_FIXED_FRAC_BITS > 16
+    return i << (CAIRO_FIXED_FRAC_BITS - 16);
+#else
+    return i >> (16 - CAIRO_FIXED_FRAC_BITS);
+#endif
+}
+
+static inline double
+_cairo_fixed_to_double (cairo_fixed_t f)
+{
+    return ((double) f) / CAIRO_FIXED_ONE_DOUBLE;
+}
+
+static inline int
+_cairo_fixed_is_integer (cairo_fixed_t f)
+{
+    return (f & CAIRO_FIXED_FRAC_MASK) == 0;
+}
+
+static inline cairo_fixed_t
+_cairo_fixed_floor (cairo_fixed_t f)
+{
+    return f & ~CAIRO_FIXED_FRAC_MASK;
+}
+
+static inline cairo_fixed_t
+_cairo_fixed_ceil (cairo_fixed_t f)
+{
+    return _cairo_fixed_floor (f + CAIRO_FIXED_FRAC_MASK);
+}
+
+static inline cairo_fixed_t
+_cairo_fixed_round (cairo_fixed_t f)
+{
+    return _cairo_fixed_floor (f + (CAIRO_FIXED_FRAC_MASK+1)/2);
+}
+
+static inline cairo_fixed_t
+_cairo_fixed_round_down (cairo_fixed_t f)
+{
+    return _cairo_fixed_floor (f + CAIRO_FIXED_FRAC_MASK/2);
+}
+
+static inline int
+_cairo_fixed_integer_part (cairo_fixed_t f)
+{
+    return f >> CAIRO_FIXED_FRAC_BITS;
+}
+
+static inline int
+_cairo_fixed_integer_round (cairo_fixed_t f)
+{
+    return _cairo_fixed_integer_part (f + (CAIRO_FIXED_FRAC_MASK+1)/2);
+}
+
+static inline int
+_cairo_fixed_integer_round_down (cairo_fixed_t f)
+{
+    return _cairo_fixed_integer_part (f + CAIRO_FIXED_FRAC_MASK/2);
+}
+
+static inline int
+_cairo_fixed_fractional_part (cairo_fixed_t f)
+{
+    return f & CAIRO_FIXED_FRAC_MASK;
+}
+
+static inline int
+_cairo_fixed_integer_floor (cairo_fixed_t f)
+{
+    if (f >= 0)
+        return f >> CAIRO_FIXED_FRAC_BITS;
+    else
+        return -((-f - 1) >> CAIRO_FIXED_FRAC_BITS) - 1;
+}
+
+static inline int
+_cairo_fixed_integer_ceil (cairo_fixed_t f)
+{
+    if (f > 0)
+	return ((f - 1)>>CAIRO_FIXED_FRAC_BITS) + 1;
+    else
+	return - ((cairo_fixed_t)(-(cairo_fixed_unsigned_t)f) >> CAIRO_FIXED_FRAC_BITS);
+}
+
+/* A bunch of explicit 16.16 operators; we need these
+ * to interface with pixman and other backends that require
+ * 16.16 fixed point types.
+ */
+static inline cairo_fixed_16_16_t
+_cairo_fixed_to_16_16 (cairo_fixed_t f)
+{
+#if (CAIRO_FIXED_FRAC_BITS == 16) && (CAIRO_FIXED_BITS == 32)
+    return f;
+#elif CAIRO_FIXED_FRAC_BITS > 16
+    /* We're just dropping the low bits, so we won't ever got over/underflow here */
+    return f >> (CAIRO_FIXED_FRAC_BITS - 16);
+#else
+    cairo_fixed_16_16_t x;
+
+    /* Handle overflow/underflow by clamping to the lowest/highest
+     * value representable as 16.16
+     */
+    if ((f >> CAIRO_FIXED_FRAC_BITS) < INT16_MIN) {
+	x = INT32_MIN;
+    } else if ((f >> CAIRO_FIXED_FRAC_BITS) > INT16_MAX) {
+	x = INT32_MAX;
+    } else {
+	x = f << (16 - CAIRO_FIXED_FRAC_BITS);
+    }
+
+    return x;
+#endif
+}
+
+static inline cairo_fixed_16_16_t
+_cairo_fixed_16_16_from_double (double d)
+{
+    union {
+        double d;
+        int32_t i[2];
+    } u;
+
+    u.d = d + CAIRO_MAGIC_NUMBER_FIXED_16_16;
+#ifdef FLOAT_WORDS_BIGENDIAN
+    return u.i[1];
+#else
+    return u.i[0];
+#endif
+}
+
+static inline int
+_cairo_fixed_16_16_floor (cairo_fixed_16_16_t f)
+{
+    if (f >= 0)
+	return f >> 16;
+    else
+	return -((-f - 1) >> 16) - 1;
+}
+
+static inline double
+_cairo_fixed_16_16_to_double (cairo_fixed_16_16_t f)
+{
+    return ((double) f) / (double) (1 << 16);
+}
+
+#if CAIRO_FIXED_BITS == 32
+
+static inline cairo_fixed_t
+_cairo_fixed_mul (cairo_fixed_t a, cairo_fixed_t b)
+{
+    cairo_int64_t temp = _cairo_int32x32_64_mul (a, b);
+    return _cairo_int64_to_int32(_cairo_int64_rsl (temp, CAIRO_FIXED_FRAC_BITS));
+}
+
+/* computes round (a * b / c) */
+static inline cairo_fixed_t
+_cairo_fixed_mul_div (cairo_fixed_t a, cairo_fixed_t b, cairo_fixed_t c)
+{
+    cairo_int64_t ab  = _cairo_int32x32_64_mul (a, b);
+    cairo_int64_t c64 = _cairo_int32_to_int64 (c);
+    return _cairo_int64_to_int32 (_cairo_int64_divrem (ab, c64).quo);
+}
+
+/* computes floor (a * b / c) */
+static inline cairo_fixed_t
+_cairo_fixed_mul_div_floor (cairo_fixed_t a, cairo_fixed_t b, cairo_fixed_t c)
+{
+    return _cairo_int64_32_div (_cairo_int32x32_64_mul (a, b), c);
+}
+
+/* compute y from x so that (x,y), p1, and p2 are collinear */
+static inline cairo_fixed_t
+_cairo_edge_compute_intersection_y_for_x (const cairo_point_t *p1,
+					  const cairo_point_t *p2,
+					  cairo_fixed_t x)
+{
+    cairo_fixed_t y, dx;
+
+    if (x == p1->x)
+	return p1->y;
+    if (x == p2->x)
+	return p2->y;
+
+    y = p1->y;
+    dx = p2->x - p1->x;
+    if (dx != 0)
+	y += _cairo_fixed_mul_div_floor (x - p1->x, p2->y - p1->y, dx);
+
+    return y;
+}
+
+/* compute x from y so that (x,y), p1, and p2 are collinear */
+static inline cairo_fixed_t
+_cairo_edge_compute_intersection_x_for_y (const cairo_point_t *p1,
+					  const cairo_point_t *p2,
+					  cairo_fixed_t y)
+{
+    cairo_fixed_t x, dy;
+
+    if (y == p1->y)
+	return p1->x;
+    if (y == p2->y)
+	return p2->x;
+
+    x = p1->x;
+    dy = p2->y - p1->y;
+    if (dy != 0)
+	x += _cairo_fixed_mul_div_floor (y - p1->y, p2->x - p1->x, dy);
+
+    return x;
+}
+
+/* Intersect two segments based on the algorithm described at
+ * http://paulbourke.net/geometry/pointlineplane/. This implementation
+ * uses floating point math. */
+static inline cairo_bool_t
+_slow_segment_intersection (const cairo_point_t *seg1_p1,
+			    const cairo_point_t *seg1_p2,
+			    const cairo_point_t *seg2_p1,
+			    const cairo_point_t *seg2_p2,
+			    cairo_point_t *intersection)
+{
+    double denominator, u_a, u_b;
+    double seg1_dx, seg1_dy, seg2_dx, seg2_dy, seg_start_dx, seg_start_dy;
+
+    seg1_dx = _cairo_fixed_to_double (seg1_p2->x - seg1_p1->x);
+    seg1_dy = _cairo_fixed_to_double (seg1_p2->y - seg1_p1->y);
+    seg2_dx = _cairo_fixed_to_double (seg2_p2->x - seg2_p1->x);
+    seg2_dy = _cairo_fixed_to_double (seg2_p2->y - seg2_p1->y);
+    denominator = (seg2_dy * seg1_dx) - (seg2_dx * seg1_dy);
+    if (denominator == 0)
+	return FALSE;
+
+    seg_start_dx = _cairo_fixed_to_double (seg1_p1->x - seg2_p1->x);
+    seg_start_dy = _cairo_fixed_to_double (seg1_p1->y - seg2_p1->y);
+    u_a = ((seg2_dx * seg_start_dy) - (seg2_dy * seg_start_dx)) / denominator;
+    u_b = ((seg1_dx * seg_start_dy) - (seg1_dy * seg_start_dx)) / denominator;
+
+    if (u_a <= 0 || u_a >= 1 || u_b <= 0 || u_b >= 1)
+	return FALSE;
+
+    intersection->x = seg1_p1->x + _cairo_fixed_from_double ((u_a * seg1_dx));
+    intersection->y = seg1_p1->y + _cairo_fixed_from_double ((u_a * seg1_dy));
+    return TRUE;
+}
+
+#else
+# error Please define multiplication and other operands for your fixed-point type size
+#endif
+
+#endif /* CAIRO_FIXED_PRIVATE_H */