Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

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

1 files changed, 286 insertions, 0 deletions

diff --git a/dom/svg/SVGPathSegUtils.h b/dom/svg/SVGPathSegUtils.h
new file mode 100644
index 0000000000..0f16c066a9
--- /dev/null
+++ b/dom/svg/SVGPathSegUtils.h
@@ -0,0 +1,286 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DOM_SVG_SVGPATHSEGUTILS_H_
+#define DOM_SVG_SVGPATHSEGUTILS_H_
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/dom/SVGPathSegBinding.h"
+#include "mozilla/gfx/Point.h"
+#include "mozilla/gfx/Rect.h"
+#include "nsDebug.h"
+
+namespace mozilla {
+
+struct StylePathCommand;
+
+#define NS_SVG_PATH_SEG_MAX_ARGS 7
+#define NS_SVG_PATH_SEG_FIRST_VALID_TYPE \
+  dom::SVGPathSeg_Binding::PATHSEG_CLOSEPATH
+#define NS_SVG_PATH_SEG_LAST_VALID_TYPE \
+  dom::SVGPathSeg_Binding::PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL
+#define NS_SVG_PATH_SEG_TYPE_COUNT (NS_SVG_PATH_SEG_LAST_VALID_TYPE + 1)
+
+/**
+ * Code that works with path segments can use an instance of this class to
+ * store/provide information about the start of the current subpath and the
+ * last path segment (if any).
+ */
+struct SVGPathTraversalState {
+  using Point = gfx::Point;
+
+  enum TraversalMode { eUpdateAll, eUpdateOnlyStartAndCurrentPos };
+
+  SVGPathTraversalState()
+      : start(0.0, 0.0),
+        pos(0.0, 0.0),
+        cp1(0.0, 0.0),
+        cp2(0.0, 0.0),
+        length(0.0),
+        mode(eUpdateAll) {}
+
+  bool ShouldUpdateLengthAndControlPoints() { return mode == eUpdateAll; }
+
+  Point start;  // start point of current sub path (reset each moveto)
+
+  Point pos;  // current position (end point of previous segment)
+
+  Point cp1;  // quadratic control point - if the previous segment was a
+              // quadratic bezier curve then this is set to the absolute
+              // position of its control point, otherwise its set to pos
+
+  Point cp2;  // cubic control point - if the previous segment was a cubic
+              // bezier curve then this is set to the absolute position of
+              // its second control point, otherwise it's set to pos
+
+  float length;  // accumulated path length
+
+  TraversalMode mode;  // indicates what to track while traversing a path
+};
+
+/**
+ * This class is just a collection of static methods - it doesn't have any data
+ * members, and it's not possible to create instances of this class. This class
+ * exists purely as a convenient place to gather together a bunch of methods
+ * related to manipulating and answering questions about path segments.
+ * Internally we represent path segments purely as an array of floats. See the
+ * comment documenting SVGPathData for more info on that.
+ *
+ * The DOM wrapper classes for encoded path segments (data contained in
+ * instances of SVGPathData) is DOMSVGPathSeg and its sub-classes. Note that
+ * there are multiple different DOM classes for path segs - one for each of the
+ * 19 SVG 1.1 segment types.
+ */
+class SVGPathSegUtils {
+ private:
+  SVGPathSegUtils() = default;  // private to prevent instances
+
+ public:
+  static void GetValueAsString(const float* aSeg, nsAString& aValue);
+
+  /**
+   * Encode a segment type enum to a float.
+   *
+   * At some point in the future we will likely want to encode other
+   * information into the float, such as whether the command was explicit or
+   * not. For now all this method does is save on int to float runtime
+   * conversion by requiring uint32_t and float to be of the same size so we
+   * can simply do a bitwise uint32_t<->float copy.
+   */
+  static float EncodeType(uint32_t aType) {
+    static_assert(sizeof(uint32_t) == sizeof(float),
+                  "sizeof uint32_t and float must be the same");
+    MOZ_ASSERT(IsValidType(aType), "Seg type not recognized");
+    return *(reinterpret_cast<float*>(&aType));
+  }
+
+  static uint32_t DecodeType(float aType) {
+    static_assert(sizeof(uint32_t) == sizeof(float),
+                  "sizeof uint32_t and float must be the same");
+    uint32_t type = *(reinterpret_cast<uint32_t*>(&aType));
+    MOZ_ASSERT(IsValidType(type), "Seg type not recognized");
+    return type;
+  }
+
+  static char16_t GetPathSegTypeAsLetter(uint32_t aType) {
+    MOZ_ASSERT(IsValidType(aType), "Seg type not recognized");
+
+    static const char16_t table[] = {
+        char16_t('x'),  //  0 == PATHSEG_UNKNOWN
+        char16_t('z'),  //  1 == PATHSEG_CLOSEPATH
+        char16_t('M'),  //  2 == PATHSEG_MOVETO_ABS
+        char16_t('m'),  //  3 == PATHSEG_MOVETO_REL
+        char16_t('L'),  //  4 == PATHSEG_LINETO_ABS
+        char16_t('l'),  //  5 == PATHSEG_LINETO_REL
+        char16_t('C'),  //  6 == PATHSEG_CURVETO_CUBIC_ABS
+        char16_t('c'),  //  7 == PATHSEG_CURVETO_CUBIC_REL
+        char16_t('Q'),  //  8 == PATHSEG_CURVETO_QUADRATIC_ABS
+        char16_t('q'),  //  9 == PATHSEG_CURVETO_QUADRATIC_REL
+        char16_t('A'),  // 10 == PATHSEG_ARC_ABS
+        char16_t('a'),  // 11 == PATHSEG_ARC_REL
+        char16_t('H'),  // 12 == PATHSEG_LINETO_HORIZONTAL_ABS
+        char16_t('h'),  // 13 == PATHSEG_LINETO_HORIZONTAL_REL
+        char16_t('V'),  // 14 == PATHSEG_LINETO_VERTICAL_ABS
+        char16_t('v'),  // 15 == PATHSEG_LINETO_VERTICAL_REL
+        char16_t('S'),  // 16 == PATHSEG_CURVETO_CUBIC_SMOOTH_ABS
+        char16_t('s'),  // 17 == PATHSEG_CURVETO_CUBIC_SMOOTH_REL
+        char16_t('T'),  // 18 == PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS
+        char16_t('t')   // 19 == PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL
+    };
+    static_assert(MOZ_ARRAY_LENGTH(table) == NS_SVG_PATH_SEG_TYPE_COUNT,
+                  "Unexpected table size");
+
+    return table[aType];
+  }
+
+  static uint32_t ArgCountForType(uint32_t aType) {
+    MOZ_ASSERT(IsValidType(aType), "Seg type not recognized");
+
+    static const uint8_t table[] = {
+        0,  //  0 == PATHSEG_UNKNOWN
+        0,  //  1 == PATHSEG_CLOSEPATH
+        2,  //  2 == PATHSEG_MOVETO_ABS
+        2,  //  3 == PATHSEG_MOVETO_REL
+        2,  //  4 == PATHSEG_LINETO_ABS
+        2,  //  5 == PATHSEG_LINETO_REL
+        6,  //  6 == PATHSEG_CURVETO_CUBIC_ABS
+        6,  //  7 == PATHSEG_CURVETO_CUBIC_REL
+        4,  //  8 == PATHSEG_CURVETO_QUADRATIC_ABS
+        4,  //  9 == PATHSEG_CURVETO_QUADRATIC_REL
+        7,  // 10 == PATHSEG_ARC_ABS
+        7,  // 11 == PATHSEG_ARC_REL
+        1,  // 12 == PATHSEG_LINETO_HORIZONTAL_ABS
+        1,  // 13 == PATHSEG_LINETO_HORIZONTAL_REL
+        1,  // 14 == PATHSEG_LINETO_VERTICAL_ABS
+        1,  // 15 == PATHSEG_LINETO_VERTICAL_REL
+        4,  // 16 == PATHSEG_CURVETO_CUBIC_SMOOTH_ABS
+        4,  // 17 == PATHSEG_CURVETO_CUBIC_SMOOTH_REL
+        2,  // 18 == PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS
+        2   // 19 == PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL
+    };
+    static_assert(MOZ_ARRAY_LENGTH(table) == NS_SVG_PATH_SEG_TYPE_COUNT,
+                  "Unexpected table size");
+
+    return table[aType];
+  }
+
+  /**
+   * Convenience so that callers can pass a float containing an encoded type
+   * and have it decoded implicitly.
+   */
+  static uint32_t ArgCountForType(float aType) {
+    return ArgCountForType(DecodeType(aType));
+  }
+
+  static bool IsValidType(uint32_t aType) {
+    return aType >= NS_SVG_PATH_SEG_FIRST_VALID_TYPE &&
+           aType <= NS_SVG_PATH_SEG_LAST_VALID_TYPE;
+  }
+
+  static bool IsCubicType(uint32_t aType) {
+    return aType == dom::SVGPathSeg_Binding::PATHSEG_CURVETO_CUBIC_REL ||
+           aType == dom::SVGPathSeg_Binding::PATHSEG_CURVETO_CUBIC_ABS ||
+           aType == dom::SVGPathSeg_Binding::PATHSEG_CURVETO_CUBIC_SMOOTH_REL ||
+           aType == dom::SVGPathSeg_Binding::PATHSEG_CURVETO_CUBIC_SMOOTH_ABS;
+  }
+
+  static bool IsQuadraticType(uint32_t aType) {
+    return aType == dom::SVGPathSeg_Binding::PATHSEG_CURVETO_QUADRATIC_REL ||
+           aType == dom::SVGPathSeg_Binding::PATHSEG_CURVETO_QUADRATIC_ABS ||
+           aType ==
+               dom::SVGPathSeg_Binding::PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL ||
+           aType ==
+               dom::SVGPathSeg_Binding::PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS;
+  }
+
+  static bool IsArcType(uint32_t aType) {
+    return aType == dom::SVGPathSeg_Binding::PATHSEG_ARC_ABS ||
+           aType == dom::SVGPathSeg_Binding::PATHSEG_ARC_REL;
+  }
+
+  static bool IsRelativeOrAbsoluteType(uint32_t aType) {
+    MOZ_ASSERT(IsValidType(aType), "Seg type not recognized");
+
+    // When adding a new path segment type, ensure that the returned condition
+    // below is still correct.
+    static_assert(
+        NS_SVG_PATH_SEG_LAST_VALID_TYPE ==
+            dom::SVGPathSeg_Binding::PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL,
+        "Unexpected type");
+
+    return aType >= dom::SVGPathSeg_Binding::PATHSEG_MOVETO_ABS;
+  }
+
+  static bool IsRelativeType(uint32_t aType) {
+    MOZ_ASSERT(IsRelativeOrAbsoluteType(aType),
+               "IsRelativeType called with segment type that does not come in "
+               "relative and absolute forms");
+
+    // When adding a new path segment type, ensure that the returned condition
+    // below is still correct.
+    static_assert(
+        NS_SVG_PATH_SEG_LAST_VALID_TYPE ==
+            dom::SVGPathSeg_Binding::PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL,
+        "Unexpected type");
+
+    return aType & 1;
+  }
+
+  static uint32_t RelativeVersionOfType(uint32_t aType) {
+    MOZ_ASSERT(IsRelativeOrAbsoluteType(aType),
+               "RelativeVersionOfType called with segment type that does not "
+               "come in relative and absolute forms");
+
+    // When adding a new path segment type, ensure that the returned condition
+    // below is still correct.
+    static_assert(
+        NS_SVG_PATH_SEG_LAST_VALID_TYPE ==
+            dom::SVGPathSeg_Binding::PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL,
+        "Unexpected type");
+
+    return aType | 1;
+  }
+
+  static uint32_t SameTypeModuloRelativeness(uint32_t aType1, uint32_t aType2) {
+    if (!IsRelativeOrAbsoluteType(aType1)) {
+      return aType1 == aType2;
+    }
+
+    return RelativeVersionOfType(aType1) == RelativeVersionOfType(aType2);
+  }
+
+  /**
+   * Traverse the given path segment and update the SVGPathTraversalState
+   * object.
+   */
+  static void TraversePathSegment(const float* aData,
+                                  SVGPathTraversalState& aState);
+
+  /**
+   * Traverse the given path segment and update the SVGPathTraversalState
+   * object. This is identical to the above one but accepts StylePathCommand.
+   */
+  static void TraversePathSegment(const StylePathCommand& aCommand,
+                                  SVGPathTraversalState& aState);
+};
+
+/// Detect whether the path represents a rectangle (for both filling AND
+/// stroking) and if so returns it.
+///
+/// This is typically useful for google slides which has many of these rectangle
+/// shaped paths. It handles the same scenarios as skia's
+/// SkPathPriv::IsRectContour which it is inspried from, including zero-length
+/// edges and multiple points on edges of the rectangle, and doesn't attempt to
+/// detect flat curves (that could easily be added but the expectation is that
+/// since skia doesn't fast path it we're not likely to run into it in
+/// practice).
+///
+/// We could implement something similar for polygons.
+Maybe<gfx::Rect> SVGPathToAxisAlignedRect(Span<const StylePathCommand> aPath);
+
+}  // namespace mozilla
+
+#endif  // DOM_SVG_SVGPATHSEGUTILS_H_