gecko-dev/layout/painting/nsCSSRenderingBorders.h

/* -*- 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 NS_CSS_RENDERING_BORDERS_H
#define NS_CSS_RENDERING_BORDERS_H

#include "gfxRect.h"
#include "mozilla/Attributes.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/BezierUtils.h"
#include "mozilla/gfx/PathHelpers.h"
#include "mozilla/RefPtr.h"
#include "nsColor.h"
#include "nsCOMPtr.h"
#include "nsIFrame.h"
#include "nsImageRenderer.h"
#include "gfxUtils.h"

struct nsBorderColors;

namespace mozilla {
class nsDisplayItem;
class nsDisplayList;
class nsDisplayListBuilder;

class nsDisplayBorder;
class nsDisplayButtonBorder;
class nsDisplayButtonForeground;
class nsDisplayOutline;

enum class StyleBorderStyle : uint8_t;
enum class StyleBorderImageRepeat : uint8_t;

namespace gfx {
class GradientStops;
}  // namespace gfx
namespace layers {
class StackingContextHelper;
}  // namespace layers
}  // namespace mozilla

// define this to enable a bunch of debug dump info
#undef DEBUG_NEW_BORDERS

/*
 * Helper class that handles border rendering.
 *
 * aDrawTarget -- the DrawTarget to which the border should be rendered
 * outsideRect -- the rectangle on the outer edge of the border
 *
 * For any parameter where an array of side values is passed in,
 * they are in top, right, bottom, left order.
 *
 * borderStyles -- one border style enum per side
 * borderWidths -- one border width per side
 * borderRadii -- a RectCornerRadii struct describing the w/h for each rounded
 * corner. If the corner doesn't have a border radius, 0,0 should be given for
 * it. borderColors -- one nscolor per side
 *
 * skipSides -- a bit mask specifying which sides, if any, to skip
 * backgroundColor -- the background color of the element.
 *    Used in calculating colors for 2-tone borders, such as inset and outset
 * gapRect - a rectangle that should be clipped out to leave a gap in a border,
 *    or nullptr if none.
 */

typedef enum {
  BorderColorStyleNone,
  BorderColorStyleSolid,
  BorderColorStyleLight,
  BorderColorStyleDark
} BorderColorStyle;

class nsPresContext;

class nsCSSBorderRenderer final {
  typedef mozilla::gfx::Bezier Bezier;
  typedef mozilla::gfx::ColorPattern ColorPattern;
  typedef mozilla::gfx::DrawTarget DrawTarget;
  typedef mozilla::gfx::Float Float;
  typedef mozilla::gfx::Path Path;
  typedef mozilla::gfx::Point Point;
  typedef mozilla::gfx::Rect Rect;
  typedef mozilla::gfx::RectCornerRadii RectCornerRadii;
  typedef mozilla::gfx::StrokeOptions StrokeOptions;

  friend class mozilla::nsDisplayOutline;
  friend class mozilla::nsDisplayButtonBorder;
  friend class mozilla::nsDisplayButtonForeground;

 public:
  nsCSSBorderRenderer(nsPresContext* aPresContext, DrawTarget* aDrawTarget,
                      const Rect& aDirtyRect, Rect& aOuterRect,
                      const mozilla::StyleBorderStyle* aBorderStyles,
                      const Float* aBorderWidths, RectCornerRadii& aBorderRadii,
                      const nscolor* aBorderColors, bool aBackfaceIsVisible,
                      const mozilla::Maybe<Rect>& aClipRect);

  // draw the entire border
  void DrawBorders();

  void CreateWebRenderCommands(
      mozilla::nsDisplayItem* aItem, mozilla::wr::DisplayListBuilder& aBuilder,
      mozilla::wr::IpcResourceUpdateQueue& aResources,
      const mozilla::layers::StackingContextHelper& aSc);

  // utility function used for background painting as well as borders
  static void ComputeInnerRadii(const RectCornerRadii& aRadii,
                                const Float* aBorderSizes,
                                RectCornerRadii* aInnerRadiiRet);

  // Given aRadii as the border radii for a rectangle, compute the
  // appropriate radii for another rectangle *outside* that rectangle
  // by increasing the radii, except keeping sharp corners sharp.
  // Used for spread box-shadows
  static void ComputeOuterRadii(const RectCornerRadii& aRadii,
                                const Float* aBorderSizes,
                                RectCornerRadii* aOuterRadiiRet);

  static bool AllCornersZeroSize(const RectCornerRadii& corners);

 private:
  RectCornerRadii mBorderCornerDimensions;

  nsPresContext* mPresContext;

  // destination DrawTarget and dirty rect
  DrawTarget* mDrawTarget;
  Rect mDirtyRect;

  // the rectangle of the outside and the inside of the border
  Rect mOuterRect;
  Rect mInnerRect;

  // the style and size of the border
  mozilla::StyleBorderStyle mBorderStyles[4];
  Float mBorderWidths[4];
  RectCornerRadii mBorderRadii;

  // the colors for 'border-top-color' et. al.
  nscolor mBorderColors[4];

  // calculated values
  bool mAllBordersSameStyle;
  bool mAllBordersSameWidth;
  bool mOneUnitBorder;
  bool mNoBorderRadius;
  bool mAvoidStroke;
  bool mBackfaceIsVisible;
  mozilla::Maybe<Rect> mLocalClip;

  // For all the sides in the bitmask, would they be rendered
  // in an identical color and style?
  bool AreBorderSideFinalStylesSame(mozilla::SideBits aSides);

  // For the given style, is the given corner a solid color?
  bool IsSolidCornerStyle(mozilla::StyleBorderStyle aStyle,
                          mozilla::Corner aCorner);

  // For the given corner, is the given corner mergeable into one dot?
  bool IsCornerMergeable(mozilla::Corner aCorner);

  // For the given solid corner, what color style should be used?
  BorderColorStyle BorderColorStyleForSolidCorner(
      mozilla::StyleBorderStyle aStyle, mozilla::Corner aCorner);

  //
  // Path generation functions
  //

  // Get the Rect for drawing the given corner
  Rect GetCornerRect(mozilla::Corner aCorner);
  // add the path for drawing the given side without any adjacent corners to the
  // context
  Rect GetSideClipWithoutCornersRect(mozilla::Side aSide);

  // Create a clip path for the wedge that this side of
  // the border should take up.  This is only called
  // when we're drawing separate border sides, so we know
  // that ADD compositing is taking place.
  //
  // This code needs to make sure that the individual pieces
  // don't ever (mathematically) overlap; the pixel overlap
  // is taken care of by the ADD compositing.
  already_AddRefed<Path> GetSideClipSubPath(mozilla::Side aSide);

  // Return start or end point for dashed/dotted side
  Point GetStraightBorderPoint(mozilla::Side aSide, mozilla::Corner aCorner,
                               bool* aIsUnfilled, Float aDotOffset = 0.0f);

  // Return bezier control points for the outer and the inner curve for given
  // corner
  void GetOuterAndInnerBezier(Bezier* aOuterBezier, Bezier* aInnerBezier,
                              mozilla::Corner aCorner);

  // Given a set of sides to fill and a color, do so in the fastest way.
  //
  // Stroke tends to be faster for smaller borders because it doesn't go
  // through the tessellator, which has initialization overhead.  If
  // we're rendering all sides, we can use stroke at any thickness; we
  // also do TL/BR pairs at 1px thickness using stroke.
  //
  // If we can't stroke, then if it's a TL/BR pair, we use the specific
  // TL/BR paths.  Otherwise, we do the full path and fill.
  //
  // Calling code is expected to only set up a clip as necessary; no
  // clip is needed if we can render the entire border in 1 or 2 passes.
  void FillSolidBorder(const Rect& aOuterRect, const Rect& aInnerRect,
                       const RectCornerRadii& aBorderRadii,
                       const Float* aBorderSizes, mozilla::SideBits aSides,
                       const ColorPattern& aColor);

  //
  // core rendering
  //

  // draw the border for the given sides, using the style of the first side
  // present in the bitmask
  void DrawBorderSides(mozilla::SideBits aSides);

  // Setup the stroke options for the given dashed/dotted side
  void SetupDashedOptions(StrokeOptions* aStrokeOptions, Float aDash[2],
                          mozilla::Side aSide, Float aBorderLength,
                          bool isCorner);

  // Draw the given dashed/dotte side
  void DrawDashedOrDottedSide(mozilla::Side aSide);

  // Draw the given dotted side, each dot separately
  void DrawDottedSideSlow(mozilla::Side aSide);

  // Draw the given dashed/dotted corner
  void DrawDashedOrDottedCorner(mozilla::Side aSide, mozilla::Corner aCorner);

  // Draw the given dotted corner, each segment separately
  void DrawDottedCornerSlow(mozilla::Side aSide, mozilla::Corner aCorner);

  // Draw the given dashed corner, each dot separately
  void DrawDashedCornerSlow(mozilla::Side aSide, mozilla::Corner aCorner);

  // Draw the given dashed/dotted corner with solid style
  void DrawFallbackSolidCorner(mozilla::Side aSide, mozilla::Corner aCorner);

  // Analyze if all border sides have the same width.
  bool AllBordersSameWidth();

  // Analyze if all borders are 'solid' this also considers hidden or 'none'
  // borders because they can be considered 'solid' borders of 0 width and
  // with no color effect.
  bool AllBordersSolid();

  // Draw a solid color border that is uniformly the same width.
  void DrawSingleWidthSolidBorder();

  // Draw any border which is solid on all sides.
  void DrawSolidBorder();
};

class nsCSSBorderImageRenderer final {
  typedef mozilla::nsImageRenderer nsImageRenderer;

 public:
  static mozilla::Maybe<nsCSSBorderImageRenderer> CreateBorderImageRenderer(
      nsPresContext* aPresContext, nsIFrame* aForFrame,
      const nsRect& aBorderArea, const nsStyleBorder& aStyleBorder,
      const nsRect& aDirtyRect, nsIFrame::Sides aSkipSides, uint32_t aFlags,
      mozilla::image::ImgDrawResult* aDrawResult);

  mozilla::image::ImgDrawResult DrawBorderImage(nsPresContext* aPresContext,
                                                gfxContext& aRenderingContext,
                                                nsIFrame* aForFrame,
                                                const nsRect& aDirtyRect);
  mozilla::image::ImgDrawResult CreateWebRenderCommands(
      mozilla::nsDisplayItem* aItem, nsIFrame* aForFrame,
      mozilla::wr::DisplayListBuilder& aBuilder,
      mozilla::wr::IpcResourceUpdateQueue& aResources,
      const mozilla::layers::StackingContextHelper& aSc,
      mozilla::layers::RenderRootStateManager* aManager,
      mozilla::nsDisplayListBuilder* aDisplayListBuilder);

  nsCSSBorderImageRenderer(const nsCSSBorderImageRenderer& aRhs);
  nsCSSBorderImageRenderer& operator=(const nsCSSBorderImageRenderer& aRhs);

 private:
  nsCSSBorderImageRenderer(nsIFrame* aForFrame, const nsRect& aBorderArea,
                           const nsStyleBorder& aStyleBorder,
                           nsIFrame::Sides aSkipSides,
                           const nsImageRenderer& aImageRenderer);

  nsImageRenderer mImageRenderer;
  nsSize mImageSize;
  nsMargin mSlice;
  nsMargin mWidths;
  nsMargin mImageOutset;
  nsRect mArea;
  nsRect mClip;
  mozilla::StyleBorderImageRepeat mRepeatModeHorizontal;
  mozilla::StyleBorderImageRepeat mRepeatModeVertical;
  bool mFill;

  friend class mozilla::nsDisplayBorder;
  friend struct nsCSSRendering;
};

namespace mozilla {
#ifdef DEBUG_NEW_BORDERS
#  include <stdarg.h>

static inline void PrintAsString(const mozilla::gfx::Point& p) {
  fprintf(stderr, "[%f,%f]", p.x, p.y);
}

static inline void PrintAsString(const mozilla::gfx::Size& s) {
  fprintf(stderr, "[%f %f]", s.width, s.height);
}

static inline void PrintAsString(const mozilla::gfx::Rect& r) {
  fprintf(stderr, "[%f %f %f %f]", r.X(), r.Y(), r.Width(), r.Height());
}

static inline void PrintAsString(const mozilla::gfx::Float f) {
  fprintf(stderr, "%f", f);
}

static inline void PrintAsString(const char* s) { fprintf(stderr, "%s", s); }

static inline void PrintAsStringNewline(const char* s = nullptr) {
  if (s) fprintf(stderr, "%s", s);
  fprintf(stderr, "\n");
  fflush(stderr);
}

static inline MOZ_FORMAT_PRINTF(1, 2) void PrintAsFormatString(const char* fmt,
                                                               ...) {
  va_list vl;
  va_start(vl, fmt);
  vfprintf(stderr, fmt, vl);
  va_end(vl);
}

#else
static inline void PrintAsString(const mozilla::gfx::Point& p) {}
static inline void PrintAsString(const mozilla::gfx::Size& s) {}
static inline void PrintAsString(const mozilla::gfx::Rect& r) {}
static inline void PrintAsString(const mozilla::gfx::Float f) {}
static inline void PrintAsString(const char* s) {}
static inline void PrintAsStringNewline(const char* s = nullptr) {}
static inline MOZ_FORMAT_PRINTF(1, 2) void PrintAsFormatString(const char* fmt,
                                                               ...) {}
#endif

}  // namespace mozilla

#endif /* NS_CSS_RENDERING_BORDERS_H */