Adding upstream version 2.10.34.upstream/2.10.34upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 666 insertions, 0 deletions

diff --git a/libgimpwidgets/gimpeevl.c b/libgimpwidgets/gimpeevl.c
new file mode 100644
index 0000000..55bf323
--- /dev/null
+++ b/libgimpwidgets/gimpeevl.c
@@ -0,0 +1,666 @@
+/* LIBGIMP - The GIMP Library
+ * Copyright (C) 1995-1997 Peter Mattis and Spencer Kimball
+ *
+ * gimpeevl.c
+ * Copyright (C) 2008 Fredrik Alstromer <roe@excu.se>
+ * Copyright (C) 2008 Martin Nordholts <martinn@svn.gnome.org>
+ *
+ * This library is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library.  If not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+/* Introducing eevl eva, the evaluator. A straightforward recursive
+ * descent parser, no fuss, no new dependencies. The lexer is hand
+ * coded, tedious, not extremely fast but works. It evaluates the
+ * expression as it goes along, and does not create a parse tree or
+ * anything, and will not optimize anything. It uses doubles for
+ * precision, with the given use case, that's enough to combat any
+ * rounding errors (as opposed to optimizing the evaluation).
+ *
+ * It relies on external unit resolving through a callback and does
+ * elementary dimensionality constraint check (e.g. "2 mm + 3 px * 4
+ * in" is an error, as L + L^2 is a mismatch). It uses setjmp/longjmp
+ * for try/catch like pattern on error, it uses g_strtod() for numeric
+ * conversions and it's non-destructive in terms of the parameters, and
+ * it's reentrant.
+ *
+ * EBNF:
+ *
+ *   expression    ::= term { ('+' | '-') term }*  |
+ *                     <empty string> ;
+ *
+ *   term          ::= ratio { ( '*' | '/' ) ratio }* ;
+ *
+ *   ratio         ::= signed factor { ':' signed factor }* ;
+ *
+ *   signed factor ::= ( '+' | '-' )? factor ;
+ *
+ *   factor        ::= quantity ( '^' signed factor )? ;
+ *
+ *   quantity      ::= number unit? | '(' expression ')' ;
+ *
+ *   number        ::= ? what g_strtod() consumes ? ;
+ *
+ *   unit          ::= simple unit ( '^' signed factor )? ;
+ *
+ *   simple unit   ::= ? what not g_strtod() consumes and not whitespace ? ;
+ *
+ * The code should match the EBNF rather closely (except for the
+ * non-terminal unit factor, which is inlined into factor) for
+ * maintainability reasons.
+ *
+ * It will allow 1++1 and 1+-1 (resulting in 2 and 0, respectively),
+ * but I figured one might want that, and I don't think it's going to
+ * throw anyone off.
+ */
+
+#include "config.h"
+
+#include <setjmp.h>
+#include <string.h>
+
+#include <glib-object.h>
+
+#include "libgimpmath/gimpmath.h"
+
+#include "gimpeevl.h"
+#include "gimpwidgets-error.h"
+
+#include "libgimp/libgimp-intl.h"
+
+
+typedef enum
+{
+  GIMP_EEVL_TOKEN_NUM        = 30000,
+  GIMP_EEVL_TOKEN_IDENTIFIER = 30001,
+
+  GIMP_EEVL_TOKEN_ANY        = 40000,
+
+  GIMP_EEVL_TOKEN_END        = 50000
+} GimpEevlTokenType;
+
+
+typedef struct
+{
+  GimpEevlTokenType type;
+
+  union
+  {
+    gdouble fl;
+
+    struct
+    {
+      const gchar *c;
+      gint         size;
+    };
+
+  } value;
+
+} GimpEevlToken;
+
+typedef struct
+{
+  const gchar     *string;
+  GimpEevlOptions  options;
+
+  GimpEevlToken    current_token;
+  const gchar     *start_of_current_token;
+
+  jmp_buf          catcher;
+  const gchar     *error_message;
+
+} GimpEevl;
+
+
+static void             gimp_eevl_init                     (GimpEevl              *eva,
+                                                            const gchar           *string,
+                                                            const GimpEevlOptions *options);
+static GimpEevlQuantity gimp_eevl_complete                 (GimpEevl              *eva);
+static GimpEevlQuantity gimp_eevl_expression               (GimpEevl              *eva);
+static GimpEevlQuantity gimp_eevl_term                     (GimpEevl              *eva);
+static GimpEevlQuantity gimp_eevl_ratio                    (GimpEevl              *eva);
+static GimpEevlQuantity gimp_eevl_signed_factor            (GimpEevl              *eva);
+static GimpEevlQuantity gimp_eevl_factor                   (GimpEevl              *eva);
+static GimpEevlQuantity gimp_eevl_quantity                 (GimpEevl              *eva);
+static gboolean         gimp_eevl_accept                   (GimpEevl              *eva,
+                                                            GimpEevlTokenType      token_type,
+                                                            GimpEevlToken         *consumed_token);
+static void             gimp_eevl_lex                      (GimpEevl              *eva);
+static void             gimp_eevl_lex_accept_count          (GimpEevl              *eva,
+                                                            gint                   count,
+                                                            GimpEevlTokenType      token_type);
+static void             gimp_eevl_lex_accept_to             (GimpEevl              *eva,
+                                                            gchar                 *to,
+                                                            GimpEevlTokenType      token_type);
+static void             gimp_eevl_move_past_whitespace     (GimpEevl              *eva);
+static gboolean         gimp_eevl_unit_identifier_start    (gunichar               c);
+static gboolean         gimp_eevl_unit_identifier_continue (gunichar               c);
+static gint             gimp_eevl_unit_identifier_size     (const gchar           *s,
+                                                            gint                   start);
+static void             gimp_eevl_expect                   (GimpEevl              *eva,
+                                                            GimpEevlTokenType      token_type,
+                                                            GimpEevlToken         *value);
+static void             gimp_eevl_error                    (GimpEevl              *eva,
+                                                            gchar                 *msg);
+
+
+/**
+ * gimp_eevl_evaluate:
+ * @string:        The NULL-terminated string to be evaluated.
+ * @options:       Evaluations options.
+ * @result:        Result of evaluation.
+ * @error_pos:     Will point to the position within the string,
+ *                 before which the parse / evaluation error
+ *                 occurred. Will be set to null of no error occurred.
+ * @error_message: Will point to a static string with a semi-descriptive
+ *                 error message if parsing / evaluation failed.
+ *
+ * Evaluates the given arithmetic expression, along with an optional dimension
+ * analysis, and basic unit conversions.
+ *
+ * All units conversions factors are relative to some implicit
+ * base-unit (which in GIMP is inches). This is also the unit of the
+ * returned value.
+ *
+ * Returns: A #GimpEevlQuantity with a value given in the base unit along with
+ * the order of the dimension (i.e. if the base unit is inches, a dimension
+ * order of two means in^2).
+ **/
+gboolean
+gimp_eevl_evaluate (const gchar            *string,
+                    const GimpEevlOptions  *options,
+                    GimpEevlQuantity       *result,
+                    const gchar           **error_pos,
+                    GError                **error)
+{
+  GimpEevl eva;
+
+  g_return_val_if_fail (g_utf8_validate (string, -1, NULL), FALSE);
+  g_return_val_if_fail (options != NULL, FALSE);
+  g_return_val_if_fail (options->unit_resolver_proc != NULL, FALSE);
+  g_return_val_if_fail (result != NULL, FALSE);
+  g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
+
+  gimp_eevl_init (&eva,
+                  string,
+                  options);
+
+  if (!setjmp (eva.catcher))  /* try... */
+    {
+      *result = gimp_eevl_complete (&eva);
+
+      return TRUE;
+    }
+  else   /* catch.. */
+    {
+      if (error_pos)
+        *error_pos = eva.start_of_current_token;
+
+      g_set_error_literal (error,
+                           GIMP_WIDGETS_ERROR,
+                           GIMP_WIDGETS_PARSE_ERROR,
+                           eva.error_message);
+
+      return FALSE;
+    }
+}
+
+static void
+gimp_eevl_init (GimpEevl              *eva,
+                const gchar           *string,
+                const GimpEevlOptions *options)
+{
+  eva->string  = string;
+  eva->options = *options;
+
+  eva->current_token.type  = GIMP_EEVL_TOKEN_END;
+
+  eva->error_message       = NULL;
+
+  /* Preload symbol... */
+  gimp_eevl_lex (eva);
+}
+
+static GimpEevlQuantity
+gimp_eevl_complete (GimpEevl *eva)
+{
+  GimpEevlQuantity result = {0, 0};
+  GimpEevlQuantity default_unit_factor;
+  gdouble          default_unit_offset;
+
+  /* Empty expression evaluates to 0 */
+  if (gimp_eevl_accept (eva, GIMP_EEVL_TOKEN_END, NULL))
+    return result;
+
+  result = gimp_eevl_expression (eva);
+
+  /* There should be nothing left to parse by now */
+  gimp_eevl_expect (eva, GIMP_EEVL_TOKEN_END, 0);
+
+  eva->options.unit_resolver_proc (NULL,
+                                   &default_unit_factor,
+                                   &default_unit_offset,
+                                   eva->options.data);
+
+  /* Entire expression is dimensionless, apply default unit if
+   * applicable
+   */
+  if (result.dimension == 0 && default_unit_factor.dimension != 0)
+    {
+      result.value     /= default_unit_factor.value;
+      result.value     += default_unit_offset;
+      result.dimension  = default_unit_factor.dimension;
+    }
+  return result;
+}
+
+static GimpEevlQuantity
+gimp_eevl_expression (GimpEevl *eva)
+{
+  gboolean         subtract;
+  GimpEevlQuantity evaluated_terms;
+
+  evaluated_terms = gimp_eevl_term (eva);
+
+  /* continue evaluating terms, chained with + or -. */
+  for (subtract = FALSE;
+       gimp_eevl_accept (eva, '+', NULL) ||
+       (subtract = gimp_eevl_accept (eva, '-', NULL));
+       subtract = FALSE)
+    {
+      GimpEevlQuantity new_term = gimp_eevl_term (eva);
+
+      /* If dimensions mismatch, attempt default unit assignment */
+      if (new_term.dimension != evaluated_terms.dimension)
+        {
+          GimpEevlQuantity default_unit_factor;
+          gdouble          default_unit_offset;
+
+          eva->options.unit_resolver_proc (NULL,
+                                           &default_unit_factor,
+                                           &default_unit_offset,
+                                           eva->options.data);
+
+          if (new_term.dimension == 0 &&
+              evaluated_terms.dimension == default_unit_factor.dimension)
+            {
+              new_term.value     /= default_unit_factor.value;
+              new_term.value     += default_unit_offset;
+              new_term.dimension  = default_unit_factor.dimension;
+            }
+          else if (evaluated_terms.dimension == 0 &&
+                   new_term.dimension == default_unit_factor.dimension)
+            {
+              evaluated_terms.value     /= default_unit_factor.value;
+              evaluated_terms.value     += default_unit_offset;
+              evaluated_terms.dimension  = default_unit_factor.dimension;
+            }
+          else
+            {
+              gimp_eevl_error (eva, "Dimension mismatch during addition");
+            }
+        }
+
+      evaluated_terms.value += (subtract ? -new_term.value : new_term.value);
+    }
+
+  return evaluated_terms;
+}
+
+static GimpEevlQuantity
+gimp_eevl_term (GimpEevl *eva)
+{
+  gboolean         division;
+  GimpEevlQuantity evaluated_ratios;
+
+  evaluated_ratios = gimp_eevl_ratio (eva);
+
+  for (division = FALSE;
+       gimp_eevl_accept (eva, '*', NULL) ||
+       (division = gimp_eevl_accept (eva, '/', NULL));
+       division = FALSE)
+    {
+      GimpEevlQuantity new_ratio = gimp_eevl_ratio (eva);
+
+      if (division)
+        {
+          evaluated_ratios.value     /= new_ratio.value;
+          evaluated_ratios.dimension -= new_ratio.dimension;
+        }
+      else
+        {
+          evaluated_ratios.value     *= new_ratio.value;
+          evaluated_ratios.dimension += new_ratio.dimension;
+        }
+    }
+
+  return evaluated_ratios;
+}
+
+static GimpEevlQuantity
+gimp_eevl_ratio (GimpEevl *eva)
+{
+  GimpEevlQuantity evaluated_signed_factors;
+
+  if (! eva->options.ratio_expressions)
+    return gimp_eevl_signed_factor (eva);
+
+  evaluated_signed_factors = gimp_eevl_signed_factor (eva);
+
+  while (gimp_eevl_accept (eva, ':', NULL))
+    {
+      GimpEevlQuantity new_signed_factor = gimp_eevl_signed_factor (eva);
+
+      if (eva->options.ratio_invert)
+        {
+          GimpEevlQuantity temp;
+
+          temp                     = evaluated_signed_factors;
+          evaluated_signed_factors = new_signed_factor;
+          new_signed_factor        = temp;
+        }
+
+      evaluated_signed_factors.value     *= eva->options.ratio_quantity.value /
+                                            new_signed_factor.value;
+      evaluated_signed_factors.dimension += eva->options.ratio_quantity.dimension -
+                                            new_signed_factor.dimension;
+    }
+
+  return evaluated_signed_factors;
+}
+
+static GimpEevlQuantity
+gimp_eevl_signed_factor (GimpEevl *eva)
+{
+  GimpEevlQuantity result;
+  gboolean         negate = FALSE;
+
+  if (! gimp_eevl_accept (eva, '+', NULL))
+    negate = gimp_eevl_accept (eva, '-', NULL);
+
+  result = gimp_eevl_factor (eva);
+
+  if (negate) result.value = -result.value;
+
+  return result;
+}
+
+static GimpEevlQuantity
+gimp_eevl_factor (GimpEevl *eva)
+{
+  GimpEevlQuantity evaluated_factor;
+
+  evaluated_factor = gimp_eevl_quantity (eva);
+
+  if (gimp_eevl_accept (eva, '^', NULL))
+    {
+      GimpEevlQuantity evaluated_exponent;
+
+      evaluated_exponent = gimp_eevl_signed_factor (eva);
+
+      if (evaluated_exponent.dimension != 0)
+        gimp_eevl_error (eva, "Exponent is not a dimensionless quantity");
+
+      evaluated_factor.value      = pow (evaluated_factor.value,
+                                         evaluated_exponent.value);
+      evaluated_factor.dimension *= evaluated_exponent.value;
+    }
+
+  return evaluated_factor;
+}
+
+static GimpEevlQuantity
+gimp_eevl_quantity (GimpEevl *eva)
+{
+  GimpEevlQuantity evaluated_quantity = { 0, 0 };
+  GimpEevlToken    consumed_token;
+
+  if (gimp_eevl_accept (eva,
+                        GIMP_EEVL_TOKEN_NUM,
+                        &consumed_token))
+    {
+      evaluated_quantity.value = consumed_token.value.fl;
+    }
+  else if (gimp_eevl_accept (eva, '(', NULL))
+    {
+      evaluated_quantity = gimp_eevl_expression (eva);
+      gimp_eevl_expect (eva, ')', 0);
+    }
+  else
+    {
+      gimp_eevl_error (eva, "Expected number or '('");
+    }
+
+  if (eva->current_token.type == GIMP_EEVL_TOKEN_IDENTIFIER)
+    {
+      gchar            *identifier;
+      GimpEevlQuantity  factor;
+      gdouble           offset;
+
+      gimp_eevl_accept (eva,
+                        GIMP_EEVL_TOKEN_ANY,
+                        &consumed_token);
+
+      identifier = g_newa (gchar, consumed_token.value.size + 1);
+
+      strncpy (identifier, consumed_token.value.c, consumed_token.value.size);
+      identifier[consumed_token.value.size] = '\0';
+
+      if (eva->options.unit_resolver_proc (identifier,
+                                           &factor,
+                                           &offset,
+                                           eva->options.data))
+        {
+          if (gimp_eevl_accept (eva, '^', NULL))
+            {
+              GimpEevlQuantity evaluated_exponent;
+
+              evaluated_exponent = gimp_eevl_signed_factor (eva);
+
+              if (evaluated_exponent.dimension != 0)
+                {
+                  gimp_eevl_error (eva,
+                                   "Exponent is not a dimensionless quantity");
+                }
+
+              if (offset != 0.0)
+                {
+                  gimp_eevl_error (eva,
+                                   "Invalid unit exponent");
+                }
+
+              factor.value      = pow (factor.value, evaluated_exponent.value);
+              factor.dimension *= evaluated_exponent.value;
+            }
+
+          evaluated_quantity.value     /= factor.value;
+          evaluated_quantity.value     += offset;
+          evaluated_quantity.dimension += factor.dimension;
+        }
+      else
+        {
+          gimp_eevl_error (eva, "Unit was not resolved");
+        }
+    }
+
+  return evaluated_quantity;
+}
+
+static gboolean
+gimp_eevl_accept (GimpEevl          *eva,
+                  GimpEevlTokenType  token_type,
+                  GimpEevlToken     *consumed_token)
+{
+  gboolean existed = FALSE;
+
+  if (token_type == eva->current_token.type ||
+      token_type == GIMP_EEVL_TOKEN_ANY)
+    {
+      existed = TRUE;
+
+      if (consumed_token)
+        *consumed_token = eva->current_token;
+
+      /* Parse next token */
+      gimp_eevl_lex (eva);
+    }
+
+  return existed;
+}
+
+static void
+gimp_eevl_lex (GimpEevl *eva)
+{
+  const gchar *s;
+
+  gimp_eevl_move_past_whitespace (eva);
+  s = eva->string;
+  eva->start_of_current_token = s;
+
+  if (! s || s[0] == '\0')
+    {
+      /* We're all done */
+      eva->current_token.type = GIMP_EEVL_TOKEN_END;
+    }
+  else if (s[0] == '+' || s[0] == '-')
+    {
+      /* Snatch these before the g_strtod() does, otherwise they might
+       * be used in a numeric conversion.
+       */
+      gimp_eevl_lex_accept_count (eva, 1, s[0]);
+    }
+  else
+    {
+      /* Attempt to parse a numeric value */
+      gchar  *endptr = NULL;
+      gdouble value      = g_strtod (s, &endptr);
+
+      if (endptr && endptr != s)
+        {
+          /* A numeric could be parsed, use it */
+          eva->current_token.value.fl = value;
+
+          gimp_eevl_lex_accept_to (eva, endptr, GIMP_EEVL_TOKEN_NUM);
+        }
+      else if (gimp_eevl_unit_identifier_start (s[0]))
+        {
+          /* Unit identifier */
+          eva->current_token.value.c    = s;
+          eva->current_token.value.size = gimp_eevl_unit_identifier_size (s, 0);
+
+          gimp_eevl_lex_accept_count (eva,
+                                      eva->current_token.value.size,
+                                      GIMP_EEVL_TOKEN_IDENTIFIER);
+        }
+      else
+        {
+          /* Everything else is a single character token */
+          gimp_eevl_lex_accept_count (eva, 1, s[0]);
+        }
+    }
+}
+
+static void
+gimp_eevl_lex_accept_count (GimpEevl          *eva,
+                            gint               count,
+                            GimpEevlTokenType  token_type)
+{
+  eva->current_token.type  = token_type;
+  eva->string             += count;
+}
+
+static void
+gimp_eevl_lex_accept_to (GimpEevl          *eva,
+                         gchar             *to,
+                         GimpEevlTokenType  token_type)
+{
+  eva->current_token.type = token_type;
+  eva->string             = to;
+}
+
+static void
+gimp_eevl_move_past_whitespace (GimpEevl *eva)
+{
+  if (! eva->string)
+    return;
+
+  while (g_ascii_isspace (*eva->string))
+    eva->string++;
+}
+
+static gboolean
+gimp_eevl_unit_identifier_start (gunichar c)
+{
+  return (g_unichar_isalpha (c) ||
+          c == (gunichar) '%'   ||
+          c == (gunichar) '\'');
+}
+
+static gboolean
+gimp_eevl_unit_identifier_continue (gunichar c)
+{
+  return (gimp_eevl_unit_identifier_start (c) ||
+          g_unichar_isdigit (c));
+}
+
+/**
+ * gimp_eevl_unit_identifier_size:
+ * @s:
+ * @start:
+ *
+ * Returns: Size of identifier in bytes (not including NULL
+ * terminator).
+ **/
+static gint
+gimp_eevl_unit_identifier_size (const gchar *string,
+                                gint         start_offset)
+{
+  const gchar *start  = g_utf8_offset_to_pointer (string, start_offset);
+  const gchar *s      = start;
+  gunichar     c      = g_utf8_get_char (s);
+  gint         length = 0;
+
+  if (gimp_eevl_unit_identifier_start (c))
+    {
+      s = g_utf8_next_char (s);
+      c = g_utf8_get_char (s);
+      length++;
+
+      while (gimp_eevl_unit_identifier_continue (c))
+        {
+          s = g_utf8_next_char (s);
+          c = g_utf8_get_char (s);
+          length++;
+        }
+    }
+
+  return g_utf8_offset_to_pointer (start, length) - start;
+}
+
+static void
+gimp_eevl_expect (GimpEevl          *eva,
+                  GimpEevlTokenType  token_type,
+                  GimpEevlToken     *value)
+{
+  if (! gimp_eevl_accept (eva, token_type, value))
+    gimp_eevl_error (eva, "Unexpected token");
+}
+
+static void
+gimp_eevl_error (GimpEevl *eva,
+                 gchar    *msg)
+{
+  eva->error_message = msg;
+  longjmp (eva->catcher, 1);
+}