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/* -*- Mode: c; c-basic-offset: 4; indent-tabs-mode: t; tab-width: 8; -*- */
/* cairo - a vector graphics library with display and print output
*
* Copyright © 2002 University of Southern California
* Copyright © 2005 Red Hat, Inc.
* Copyright © 2007 Adrian Johnson
*
* 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 University of Southern
* California.
*
* Contributor(s):
* Carl D. Worth <cworth@cworth.org>
* Adrian Johnson <ajohnson@redneon.com>
*/
#include "cairoint.h"
#include "cairo-error-private.h"
COMPILE_TIME_ASSERT ((int)CAIRO_STATUS_LAST_STATUS < (int)CAIRO_INT_STATUS_UNSUPPORTED);
COMPILE_TIME_ASSERT (CAIRO_INT_STATUS_LAST_STATUS <= 127);
/**
* SECTION:cairo-status
* @Title: Error handling
* @Short_Description: Decoding cairo's status
* @See_Also: cairo_status(), cairo_surface_status(), cairo_pattern_status(),
* cairo_font_face_status(), cairo_scaled_font_status(),
* cairo_region_status()
*
* Cairo uses a single status type to represent all kinds of errors. A status
* value of %CAIRO_STATUS_SUCCESS represents no error and has an integer value
* of zero. All other status values represent an error.
*
* Cairo's error handling is designed to be easy to use and safe. All major
* cairo objects <firstterm>retain</firstterm> an error status internally which
* can be queried anytime by the users using cairo*_status() calls. In
* the mean time, it is safe to call all cairo functions normally even if the
* underlying object is in an error status. This means that no error handling
* code is required before or after each individual cairo function call.
**/
/* Public stuff */
/**
* cairo_status_to_string:
* @status: a cairo status
*
* Provides a human-readable description of a #cairo_status_t.
*
* Returns: a string representation of the status
*
* Since: 1.0
**/
const char *
cairo_status_to_string (cairo_status_t status)
{
switch (status) {
case CAIRO_STATUS_SUCCESS:
return "no error has occurred";
case CAIRO_STATUS_NO_MEMORY:
return "out of memory";
case CAIRO_STATUS_INVALID_RESTORE:
return "cairo_restore() without matching cairo_save()";
case CAIRO_STATUS_INVALID_POP_GROUP:
return "no saved group to pop, i.e. cairo_pop_group() without matching cairo_push_group()";
case CAIRO_STATUS_NO_CURRENT_POINT:
return "no current point defined";
case CAIRO_STATUS_INVALID_MATRIX:
return "invalid matrix (not invertible)";
case CAIRO_STATUS_INVALID_STATUS:
return "invalid value for an input cairo_status_t";
case CAIRO_STATUS_NULL_POINTER:
return "NULL pointer";
case CAIRO_STATUS_INVALID_STRING:
return "input string not valid UTF-8";
case CAIRO_STATUS_INVALID_PATH_DATA:
return "input path data not valid";
case CAIRO_STATUS_READ_ERROR:
return "error while reading from input stream";
case CAIRO_STATUS_WRITE_ERROR:
return "error while writing to output stream";
case CAIRO_STATUS_SURFACE_FINISHED:
return "the target surface has been finished";
case CAIRO_STATUS_SURFACE_TYPE_MISMATCH:
return "the surface type is not appropriate for the operation";
case CAIRO_STATUS_PATTERN_TYPE_MISMATCH:
return "the pattern type is not appropriate for the operation";
case CAIRO_STATUS_INVALID_CONTENT:
return "invalid value for an input cairo_content_t";
case CAIRO_STATUS_INVALID_FORMAT:
return "invalid value for an input cairo_format_t";
case CAIRO_STATUS_INVALID_VISUAL:
return "invalid value for an input Visual*";
case CAIRO_STATUS_FILE_NOT_FOUND:
return "file not found";
case CAIRO_STATUS_INVALID_DASH:
return "invalid value for a dash setting";
case CAIRO_STATUS_INVALID_DSC_COMMENT:
return "invalid value for a DSC comment";
case CAIRO_STATUS_INVALID_INDEX:
return "invalid index passed to getter";
case CAIRO_STATUS_CLIP_NOT_REPRESENTABLE:
return "clip region not representable in desired format";
case CAIRO_STATUS_TEMP_FILE_ERROR:
return "error creating or writing to a temporary file";
case CAIRO_STATUS_INVALID_STRIDE:
return "invalid value for stride";
case CAIRO_STATUS_FONT_TYPE_MISMATCH:
return "the font type is not appropriate for the operation";
case CAIRO_STATUS_USER_FONT_IMMUTABLE:
return "the user-font is immutable";
case CAIRO_STATUS_USER_FONT_ERROR:
return "error occurred in a user-font callback function";
case CAIRO_STATUS_NEGATIVE_COUNT:
return "negative number used where it is not allowed";
case CAIRO_STATUS_INVALID_CLUSTERS:
return "input clusters do not represent the accompanying text and glyph arrays";
case CAIRO_STATUS_INVALID_SLANT:
return "invalid value for an input cairo_font_slant_t";
case CAIRO_STATUS_INVALID_WEIGHT:
return "invalid value for an input cairo_font_weight_t";
case CAIRO_STATUS_INVALID_SIZE:
return "invalid value (typically too big) for the size of the input (surface, pattern, etc.)";
case CAIRO_STATUS_USER_FONT_NOT_IMPLEMENTED:
return "user-font method not implemented";
case CAIRO_STATUS_DEVICE_TYPE_MISMATCH:
return "the device type is not appropriate for the operation";
case CAIRO_STATUS_DEVICE_ERROR:
return "an operation to the device caused an unspecified error";
case CAIRO_STATUS_INVALID_MESH_CONSTRUCTION:
return "invalid operation during mesh pattern construction";
case CAIRO_STATUS_DEVICE_FINISHED:
return "the target device has been finished";
case CAIRO_STATUS_JBIG2_GLOBAL_MISSING:
return "CAIRO_MIME_TYPE_JBIG2_GLOBAL_ID used but no CAIRO_MIME_TYPE_JBIG2_GLOBAL data provided";
default:
case CAIRO_STATUS_LAST_STATUS:
return "<unknown error status>";
}
}
/**
* cairo_glyph_allocate:
* @num_glyphs: number of glyphs to allocate
*
* Allocates an array of #cairo_glyph_t's.
* This function is only useful in implementations of
* #cairo_user_scaled_font_text_to_glyphs_func_t where the user
* needs to allocate an array of glyphs that cairo will free.
* For all other uses, user can use their own allocation method
* for glyphs.
*
* This function returns %NULL if @num_glyphs is not positive,
* or if out of memory. That means, the %NULL return value
* signals out-of-memory only if @num_glyphs was positive.
*
* Returns: the newly allocated array of glyphs that should be
* freed using cairo_glyph_free()
*
* Since: 1.8
**/
cairo_glyph_t *
cairo_glyph_allocate (int num_glyphs)
{
if (num_glyphs <= 0)
return NULL;
return _cairo_malloc_ab (num_glyphs, sizeof (cairo_glyph_t));
}
slim_hidden_def (cairo_glyph_allocate);
/**
* cairo_glyph_free:
* @glyphs: array of glyphs to free, or %NULL
*
* Frees an array of #cairo_glyph_t's allocated using cairo_glyph_allocate().
* This function is only useful to free glyph array returned
* by cairo_scaled_font_text_to_glyphs() where cairo returns
* an array of glyphs that the user will free.
* For all other uses, user can use their own allocation method
* for glyphs.
*
* Since: 1.8
**/
void
cairo_glyph_free (cairo_glyph_t *glyphs)
{
free (glyphs);
}
slim_hidden_def (cairo_glyph_free);
/**
* cairo_text_cluster_allocate:
* @num_clusters: number of text_clusters to allocate
*
* Allocates an array of #cairo_text_cluster_t's.
* This function is only useful in implementations of
* #cairo_user_scaled_font_text_to_glyphs_func_t where the user
* needs to allocate an array of text clusters that cairo will free.
* For all other uses, user can use their own allocation method
* for text clusters.
*
* This function returns %NULL if @num_clusters is not positive,
* or if out of memory. That means, the %NULL return value
* signals out-of-memory only if @num_clusters was positive.
*
* Returns: the newly allocated array of text clusters that should be
* freed using cairo_text_cluster_free()
*
* Since: 1.8
**/
cairo_text_cluster_t *
cairo_text_cluster_allocate (int num_clusters)
{
if (num_clusters <= 0)
return NULL;
return _cairo_malloc_ab (num_clusters, sizeof (cairo_text_cluster_t));
}
slim_hidden_def (cairo_text_cluster_allocate);
/**
* cairo_text_cluster_free:
* @clusters: array of text clusters to free, or %NULL
*
* Frees an array of #cairo_text_cluster's allocated using cairo_text_cluster_allocate().
* This function is only useful to free text cluster array returned
* by cairo_scaled_font_text_to_glyphs() where cairo returns
* an array of text clusters that the user will free.
* For all other uses, user can use their own allocation method
* for text clusters.
*
* Since: 1.8
**/
void
cairo_text_cluster_free (cairo_text_cluster_t *clusters)
{
free (clusters);
}
slim_hidden_def (cairo_text_cluster_free);
/* Private stuff */
/**
* _cairo_validate_text_clusters:
* @utf8: UTF-8 text
* @utf8_len: length of @utf8 in bytes
* @glyphs: array of glyphs
* @num_glyphs: number of glyphs
* @clusters: array of cluster mapping information
* @num_clusters: number of clusters in the mapping
* @cluster_flags: cluster flags
*
* Check that clusters cover the entire glyphs and utf8 arrays,
* and that cluster boundaries are UTF-8 boundaries.
*
* Return value: %CAIRO_STATUS_SUCCESS upon success, or
* %CAIRO_STATUS_INVALID_CLUSTERS on error.
* The error is either invalid UTF-8 input,
* or bad cluster mapping.
**/
cairo_status_t
_cairo_validate_text_clusters (const char *utf8,
int utf8_len,
const cairo_glyph_t *glyphs,
int num_glyphs,
const cairo_text_cluster_t *clusters,
int num_clusters,
cairo_text_cluster_flags_t cluster_flags)
{
cairo_status_t status;
unsigned int n_bytes = 0;
unsigned int n_glyphs = 0;
int i;
for (i = 0; i < num_clusters; i++) {
int cluster_bytes = clusters[i].num_bytes;
int cluster_glyphs = clusters[i].num_glyphs;
if (cluster_bytes < 0 || cluster_glyphs < 0)
goto BAD;
/* A cluster should cover at least one character or glyph.
* I can't see any use for a 0,0 cluster.
* I can't see an immediate use for a zero-text cluster
* right now either, but they don't harm.
* Zero-glyph clusters on the other hand are useful for
* things like U+200C ZERO WIDTH NON-JOINER */
if (cluster_bytes == 0 && cluster_glyphs == 0)
goto BAD;
/* Since n_bytes and n_glyphs are unsigned, but the rest of
* values involved are signed, we can detect overflow easily */
if (n_bytes+cluster_bytes > (unsigned int)utf8_len || n_glyphs+cluster_glyphs > (unsigned int)num_glyphs)
goto BAD;
/* Make sure we've got valid UTF-8 for the cluster */
status = _cairo_utf8_to_ucs4 (utf8+n_bytes, cluster_bytes, NULL, NULL);
if (unlikely (status))
return _cairo_error (CAIRO_STATUS_INVALID_CLUSTERS);
n_bytes += cluster_bytes ;
n_glyphs += cluster_glyphs;
}
if (n_bytes != (unsigned int) utf8_len || n_glyphs != (unsigned int) num_glyphs) {
BAD:
return _cairo_error (CAIRO_STATUS_INVALID_CLUSTERS);
}
return CAIRO_STATUS_SUCCESS;
}
/**
* _cairo_operator_bounded_by_mask:
* @op: a #cairo_operator_t
*
* A bounded operator is one where mask pixel
* of zero results in no effect on the destination image.
*
* Unbounded operators often require special handling; if you, for
* example, draw trapezoids with an unbounded operator, the effect
* extends past the bounding box of the trapezoids.
*
* Return value: %TRUE if the operator is bounded by the mask operand
**/
cairo_bool_t
_cairo_operator_bounded_by_mask (cairo_operator_t op)
{
switch (op) {
case CAIRO_OPERATOR_CLEAR:
case CAIRO_OPERATOR_SOURCE:
case CAIRO_OPERATOR_OVER:
case CAIRO_OPERATOR_ATOP:
case CAIRO_OPERATOR_DEST:
case CAIRO_OPERATOR_DEST_OVER:
case CAIRO_OPERATOR_DEST_OUT:
case CAIRO_OPERATOR_XOR:
case CAIRO_OPERATOR_ADD:
case CAIRO_OPERATOR_SATURATE:
case CAIRO_OPERATOR_MULTIPLY:
case CAIRO_OPERATOR_SCREEN:
case CAIRO_OPERATOR_OVERLAY:
case CAIRO_OPERATOR_DARKEN:
case CAIRO_OPERATOR_LIGHTEN:
case CAIRO_OPERATOR_COLOR_DODGE:
case CAIRO_OPERATOR_COLOR_BURN:
case CAIRO_OPERATOR_HARD_LIGHT:
case CAIRO_OPERATOR_SOFT_LIGHT:
case CAIRO_OPERATOR_DIFFERENCE:
case CAIRO_OPERATOR_EXCLUSION:
case CAIRO_OPERATOR_HSL_HUE:
case CAIRO_OPERATOR_HSL_SATURATION:
case CAIRO_OPERATOR_HSL_COLOR:
case CAIRO_OPERATOR_HSL_LUMINOSITY:
return TRUE;
case CAIRO_OPERATOR_OUT:
case CAIRO_OPERATOR_IN:
case CAIRO_OPERATOR_DEST_IN:
case CAIRO_OPERATOR_DEST_ATOP:
return FALSE;
}
ASSERT_NOT_REACHED;
return FALSE;
}
/**
* _cairo_operator_bounded_by_source:
* @op: a #cairo_operator_t
*
* A bounded operator is one where source pixels of zero
* (in all four components, r, g, b and a) effect no change
* in the resulting destination image.
*
* Unbounded operators often require special handling; if you, for
* example, copy a surface with the SOURCE operator, the effect
* extends past the bounding box of the source surface.
*
* Return value: %TRUE if the operator is bounded by the source operand
**/
cairo_bool_t
_cairo_operator_bounded_by_source (cairo_operator_t op)
{
switch (op) {
case CAIRO_OPERATOR_OVER:
case CAIRO_OPERATOR_ATOP:
case CAIRO_OPERATOR_DEST:
case CAIRO_OPERATOR_DEST_OVER:
case CAIRO_OPERATOR_DEST_OUT:
case CAIRO_OPERATOR_XOR:
case CAIRO_OPERATOR_ADD:
case CAIRO_OPERATOR_SATURATE:
case CAIRO_OPERATOR_MULTIPLY:
case CAIRO_OPERATOR_SCREEN:
case CAIRO_OPERATOR_OVERLAY:
case CAIRO_OPERATOR_DARKEN:
case CAIRO_OPERATOR_LIGHTEN:
case CAIRO_OPERATOR_COLOR_DODGE:
case CAIRO_OPERATOR_COLOR_BURN:
case CAIRO_OPERATOR_HARD_LIGHT:
case CAIRO_OPERATOR_SOFT_LIGHT:
case CAIRO_OPERATOR_DIFFERENCE:
case CAIRO_OPERATOR_EXCLUSION:
case CAIRO_OPERATOR_HSL_HUE:
case CAIRO_OPERATOR_HSL_SATURATION:
case CAIRO_OPERATOR_HSL_COLOR:
case CAIRO_OPERATOR_HSL_LUMINOSITY:
return TRUE;
case CAIRO_OPERATOR_CLEAR:
case CAIRO_OPERATOR_SOURCE:
case CAIRO_OPERATOR_OUT:
case CAIRO_OPERATOR_IN:
case CAIRO_OPERATOR_DEST_IN:
case CAIRO_OPERATOR_DEST_ATOP:
return FALSE;
}
ASSERT_NOT_REACHED;
return FALSE;
}
uint32_t
_cairo_operator_bounded_by_either (cairo_operator_t op)
{
switch (op) {
default:
ASSERT_NOT_REACHED;
case CAIRO_OPERATOR_OVER:
case CAIRO_OPERATOR_ATOP:
case CAIRO_OPERATOR_DEST:
case CAIRO_OPERATOR_DEST_OVER:
case CAIRO_OPERATOR_DEST_OUT:
case CAIRO_OPERATOR_XOR:
case CAIRO_OPERATOR_ADD:
case CAIRO_OPERATOR_SATURATE:
case CAIRO_OPERATOR_MULTIPLY:
case CAIRO_OPERATOR_SCREEN:
case CAIRO_OPERATOR_OVERLAY:
case CAIRO_OPERATOR_DARKEN:
case CAIRO_OPERATOR_LIGHTEN:
case CAIRO_OPERATOR_COLOR_DODGE:
case CAIRO_OPERATOR_COLOR_BURN:
case CAIRO_OPERATOR_HARD_LIGHT:
case CAIRO_OPERATOR_SOFT_LIGHT:
case CAIRO_OPERATOR_DIFFERENCE:
case CAIRO_OPERATOR_EXCLUSION:
case CAIRO_OPERATOR_HSL_HUE:
case CAIRO_OPERATOR_HSL_SATURATION:
case CAIRO_OPERATOR_HSL_COLOR:
case CAIRO_OPERATOR_HSL_LUMINOSITY:
return CAIRO_OPERATOR_BOUND_BY_MASK | CAIRO_OPERATOR_BOUND_BY_SOURCE;
case CAIRO_OPERATOR_CLEAR:
case CAIRO_OPERATOR_SOURCE:
return CAIRO_OPERATOR_BOUND_BY_MASK;
case CAIRO_OPERATOR_OUT:
case CAIRO_OPERATOR_IN:
case CAIRO_OPERATOR_DEST_IN:
case CAIRO_OPERATOR_DEST_ATOP:
return 0;
}
}
#if DISABLE_SOME_FLOATING_POINT
/* This function is identical to the C99 function lround(), except that it
* performs arithmetic rounding (floor(d + .5) instead of away-from-zero rounding) and
* has a valid input range of (INT_MIN, INT_MAX] instead of
* [INT_MIN, INT_MAX]. It is much faster on both x86 and FPU-less systems
* than other commonly used methods for rounding (lround, round, rint, lrint
* or float (d + 0.5)).
*
* The reason why this function is much faster on x86 than other
* methods is due to the fact that it avoids the fldcw instruction.
* This instruction incurs a large performance penalty on modern Intel
* processors due to how it prevents efficient instruction pipelining.
*
* The reason why this function is much faster on FPU-less systems is for
* an entirely different reason. All common rounding methods involve multiple
* floating-point operations. Each one of these operations has to be
* emulated in software, which adds up to be a large performance penalty.
* This function doesn't perform any floating-point calculations, and thus
* avoids this penalty.
*/
int
_cairo_lround (double d)
{
uint32_t top, shift_amount, output;
union {
double d;
uint64_t ui64;
uint32_t ui32[2];
} u;
u.d = d;
/* If the integer word order doesn't match the float word order, we swap
* the words of the input double. This is needed because we will be
* treating the whole double as a 64-bit unsigned integer. Notice that we
* use WORDS_BIGENDIAN to detect the integer word order, which isn't
* exactly correct because WORDS_BIGENDIAN refers to byte order, not word
* order. Thus, we are making the assumption that the byte order is the
* same as the integer word order which, on the modern machines that we
* care about, is OK.
*/
#if ( defined(FLOAT_WORDS_BIGENDIAN) && !defined(WORDS_BIGENDIAN)) || \
(!defined(FLOAT_WORDS_BIGENDIAN) && defined(WORDS_BIGENDIAN))
{
uint32_t temp = u.ui32[0];
u.ui32[0] = u.ui32[1];
u.ui32[1] = temp;
}
#endif
#ifdef WORDS_BIGENDIAN
#define MSW (0) /* Most Significant Word */
#define LSW (1) /* Least Significant Word */
#else
#define MSW (1)
#define LSW (0)
#endif
/* By shifting the most significant word of the input double to the
* right 20 places, we get the very "top" of the double where the exponent
* and sign bit lie.
*/
top = u.ui32[MSW] >> 20;
/* Here, we calculate how much we have to shift the mantissa to normalize
* it to an integer value. We extract the exponent "top" by masking out the
* sign bit, then we calculate the shift amount by subtracting the exponent
* from the bias. Notice that the correct bias for 64-bit doubles is
* actually 1075, but we use 1053 instead for two reasons:
*
* 1) To perform rounding later on, we will first need the target
* value in a 31.1 fixed-point format. Thus, the bias needs to be one
* less: (1075 - 1: 1074).
*
* 2) To avoid shifting the mantissa as a full 64-bit integer (which is
* costly on certain architectures), we break the shift into two parts.
* First, the upper and lower parts of the mantissa are shifted
* individually by a constant amount that all valid inputs will require
* at the very least. This amount is chosen to be 21, because this will
* allow the two parts of the mantissa to later be combined into a
* single 32-bit representation, on which the remainder of the shift
* will be performed. Thus, we decrease the bias by an additional 21:
* (1074 - 21: 1053).
*/
shift_amount = 1053 - (top & 0x7FF);
/* We are done with the exponent portion in "top", so here we shift it off
* the end.
*/
top >>= 11;
/* Before we perform any operations on the mantissa, we need to OR in
* the implicit 1 at the top (see the IEEE-754 spec). We needn't mask
* off the sign bit nor the exponent bits because these higher bits won't
* make a bit of difference in the rest of our calculations.
*/
u.ui32[MSW] |= 0x100000;
/* If the input double is negative, we have to decrease the mantissa
* by a hair. This is an important part of performing arithmetic rounding,
* as negative numbers must round towards positive infinity in the
* halfwase case of -x.5. Since "top" contains only the sign bit at this
* point, we can just decrease the mantissa by the value of "top".
*/
u.ui64 -= top;
/* By decrementing "top", we create a bitmask with a value of either
* 0x0 (if the input was negative) or 0xFFFFFFFF (if the input was positive
* and thus the unsigned subtraction underflowed) that we'll use later.
*/
top--;
/* Here, we shift the mantissa by the constant value as described above.
* We can emulate a 64-bit shift right by 21 through shifting the top 32
* bits left 11 places and ORing in the bottom 32 bits shifted 21 places
* to the right. Both parts of the mantissa are now packed into a single
* 32-bit integer. Although we severely truncate the lower part in the
* process, we still have enough significant bits to perform the conversion
* without error (for all valid inputs).
*/
output = (u.ui32[MSW] << 11) | (u.ui32[LSW] >> 21);
/* Next, we perform the shift that converts the X.Y fixed-point number
* currently found in "output" to the desired 31.1 fixed-point format
* needed for the following rounding step. It is important to consider
* all possible values for "shift_amount" at this point:
*
* - {shift_amount < 0} Since shift_amount is an unsigned integer, it
* really can't have a value less than zero. But, if the shift_amount
* calculation above caused underflow (which would happen with
* input > INT_MAX or input <= INT_MIN) then shift_amount will now be
* a very large number, and so this shift will result in complete
* garbage. But that's OK, as the input was out of our range, so our
* output is undefined.
*
* - {shift_amount > 31} If the magnitude of the input was very small
* (i.e. |input| << 1.0), shift_amount will have a value greater than
* 31. Thus, this shift will also result in garbage. After performing
* the shift, we will zero-out "output" if this is the case.
*
* - {0 <= shift_amount < 32} In this case, the shift will properly convert
* the mantissa into a 31.1 fixed-point number.
*/
output >>= shift_amount;
/* This is where we perform rounding with the 31.1 fixed-point number.
* Since what we're after is arithmetic rounding, we simply add the single
* fractional bit into the integer part of "output", and just keep the
* integer part.
*/
output = (output >> 1) + (output & 1);
/* Here, we zero-out the result if the magnitude if the input was very small
* (as explained in the section above). Notice that all input out of the
* valid range is also caught by this condition, which means we produce 0
* for all invalid input, which is a nice side effect.
*
* The most straightforward way to do this would be:
*
* if (shift_amount > 31)
* output = 0;
*
* But we can use a little trick to avoid the potential branch. The
* expression (shift_amount > 31) will be either 1 or 0, which when
* decremented will be either 0x0 or 0xFFFFFFFF (unsigned underflow),
* which can be used to conditionally mask away all the bits in "output"
* (in the 0x0 case), effectively zeroing it out. Certain, compilers would
* have done this for us automatically.
*/
output &= ((shift_amount > 31) - 1);
/* If the input double was a negative number, then we have to negate our
* output. The most straightforward way to do this would be:
*
* if (!top)
* output = -output;
*
* as "top" at this point is either 0x0 (if the input was negative) or
* 0xFFFFFFFF (if the input was positive). But, we can use a trick to
* avoid the branch. Observe that the following snippet of code has the
* same effect as the reference snippet above:
*
* if (!top)
* output = 0 - output;
* else
* output = output - 0;
*
* Armed with the bitmask found in "top", we can condense the two statements
* into the following:
*
* output = (output & top) - (output & ~top);
*
* where, in the case that the input double was negative, "top" will be 0,
* and the statement will be equivalent to:
*
* output = (0) - (output);
*
* and if the input double was positive, "top" will be 0xFFFFFFFF, and the
* statement will be equivalent to:
*
* output = (output) - (0);
*
* Which, as pointed out earlier, is equivalent to the original reference
* snippet.
*/
output = (output & top) - (output & ~top);
return output;
#undef MSW
#undef LSW
}
#endif
/* Convert a 32-bit IEEE single precision floating point number to a
* 'half' representation (s10.5)
*/
uint16_t
_cairo_half_from_float (float f)
{
union {
uint32_t ui;
float f;
} u;
int s, e, m;
u.f = f;
s = (u.ui >> 16) & 0x00008000;
e = ((u.ui >> 23) & 0x000000ff) - (127 - 15);
m = u.ui & 0x007fffff;
if (e <= 0) {
if (e < -10) {
/* underflow */
return 0;
}
m = (m | 0x00800000) >> (1 - e);
/* round to nearest, round 0.5 up. */
if (m & 0x00001000)
m += 0x00002000;
return s | (m >> 13);
} else if (e == 0xff - (127 - 15)) {
if (m == 0) {
/* infinity */
return s | 0x7c00;
} else {
/* nan */
m >>= 13;
return s | 0x7c00 | m | (m == 0);
}
} else {
/* round to nearest, round 0.5 up. */
if (m & 0x00001000) {
m += 0x00002000;
if (m & 0x00800000) {
m = 0;
e += 1;
}
}
if (e > 30) {
/* overflow -> infinity */
return s | 0x7c00;
}
return s | (e << 10) | (m >> 13);
}
}
#ifndef __BIONIC__
# include <locale.h>
const char *
cairo_get_locale_decimal_point (void)
{
struct lconv *locale_data = localeconv ();
return locale_data->decimal_point;
}
#else
/* Android's Bionic libc doesn't provide decimal_point */
const char *
cairo_get_locale_decimal_point (void)
{
return ".";
}
#endif
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
/* We require Windows 2000 features such as ETO_PDY */
#if !defined(WINVER) || (WINVER < 0x0500)
# define WINVER 0x0500
#endif
#if !defined(_WIN32_WINNT) || (_WIN32_WINNT < 0x0500)
# define _WIN32_WINNT 0x0500
#endif
#include <windows.h>
#include <io.h>
#if !_WIN32_WCE
/* tmpfile() replacement for Windows.
*
* On Windows tmpfile() creates the file in the root directory. This
* may fail due to unsufficient privileges. However, this isn't a
* problem on Windows CE so we don't use it there.
*/
FILE *
_cairo_win32_tmpfile (void)
{
DWORD path_len;
WCHAR path_name[MAX_PATH + 1];
WCHAR file_name[MAX_PATH + 1];
HANDLE handle;
int fd;
FILE *fp;
path_len = GetTempPathW (MAX_PATH, path_name);
if (path_len <= 0 || path_len >= MAX_PATH)
return NULL;
if (GetTempFileNameW (path_name, L"ps_", 0, file_name) == 0)
return NULL;
handle = CreateFileW (file_name,
GENERIC_READ | GENERIC_WRITE,
0,
NULL,
CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_DELETE_ON_CLOSE,
NULL);
if (handle == INVALID_HANDLE_VALUE) {
DeleteFileW (file_name);
return NULL;
}
fd = _open_osfhandle((intptr_t) handle, 0);
if (fd < 0) {
CloseHandle (handle);
return NULL;
}
fp = fdopen(fd, "w+b");
if (fp == NULL) {
_close(fd);
return NULL;
}
return fp;
}
#endif /* !_WIN32_WCE */
#endif /* _WIN32 */
typedef struct _cairo_intern_string {
cairo_hash_entry_t hash_entry;
int len;
char *string;
} cairo_intern_string_t;
static cairo_hash_table_t *_cairo_intern_string_ht;
static unsigned long
_intern_string_hash (const char *str, int len)
{
const signed char *p = (const signed char *) str;
unsigned int h = *p;
for (p += 1; --len; p++)
h = (h << 5) - h + *p;
return h;
}
static cairo_bool_t
_intern_string_equal (const void *_a, const void *_b)
{
const cairo_intern_string_t *a = _a;
const cairo_intern_string_t *b = _b;
if (a->len != b->len)
return FALSE;
return memcmp (a->string, b->string, a->len) == 0;
}
cairo_status_t
_cairo_intern_string (const char **str_inout, int len)
{
char *str = (char *) *str_inout;
cairo_intern_string_t tmpl, *istring;
cairo_status_t status = CAIRO_STATUS_SUCCESS;
if (CAIRO_INJECT_FAULT ())
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
if (len < 0)
len = strlen (str);
tmpl.hash_entry.hash = _intern_string_hash (str, len);
tmpl.len = len;
tmpl.string = (char *) str;
CAIRO_MUTEX_LOCK (_cairo_intern_string_mutex);
if (_cairo_intern_string_ht == NULL) {
_cairo_intern_string_ht = _cairo_hash_table_create (_intern_string_equal);
if (unlikely (_cairo_intern_string_ht == NULL)) {
status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
goto BAIL;
}
}
istring = _cairo_hash_table_lookup (_cairo_intern_string_ht,
&tmpl.hash_entry);
if (istring == NULL) {
istring = malloc (sizeof (cairo_intern_string_t) + len + 1);
if (likely (istring != NULL)) {
istring->hash_entry.hash = tmpl.hash_entry.hash;
istring->len = tmpl.len;
istring->string = (char *) (istring + 1);
memcpy (istring->string, str, len);
istring->string[len] = '\0';
status = _cairo_hash_table_insert (_cairo_intern_string_ht,
&istring->hash_entry);
if (unlikely (status)) {
free (istring);
goto BAIL;
}
} else {
status = _cairo_error (CAIRO_STATUS_NO_MEMORY);
goto BAIL;
}
}
*str_inout = istring->string;
BAIL:
CAIRO_MUTEX_UNLOCK (_cairo_intern_string_mutex);
return status;
}
static void
_intern_string_pluck (void *entry, void *closure)
{
_cairo_hash_table_remove (closure, entry);
free (entry);
}
void
_cairo_intern_string_reset_static_data (void)
{
CAIRO_MUTEX_LOCK (_cairo_intern_string_mutex);
if (_cairo_intern_string_ht != NULL) {
_cairo_hash_table_foreach (_cairo_intern_string_ht,
_intern_string_pluck,
_cairo_intern_string_ht);
_cairo_hash_table_destroy(_cairo_intern_string_ht);
_cairo_intern_string_ht = NULL;
}
CAIRO_MUTEX_UNLOCK (_cairo_intern_string_mutex);
}