gecko-dev/layout/base/ShapeUtils.cpp

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6.6 KiB
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/* -*- 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/. */
#include "mozilla/ShapeUtils.h"
#include <cstdlib>
#include "nsCSSRendering.h"
#include "nsMargin.h"
#include "nsStyleCoord.h"
#include "nsStyleStruct.h"
#include "SVGContentUtils.h"
namespace mozilla {
nscoord
ShapeUtils::ComputeShapeRadius(const StyleShapeRadius aType,
const nscoord aCenter,
const nscoord aPosMin,
const nscoord aPosMax)
{
nscoord dist1 = std::abs(aPosMin - aCenter);
nscoord dist2 = std::abs(aPosMax - aCenter);
nscoord length = 0;
switch (aType) {
case StyleShapeRadius::FarthestSide:
length = dist1 > dist2 ? dist1 : dist2;
break;
case StyleShapeRadius::ClosestSide:
length = dist1 > dist2 ? dist2 : dist1;
break;
}
return length;
}
nsPoint
ShapeUtils::ComputeCircleOrEllipseCenter(const UniquePtr<StyleBasicShape>& aBasicShape,
const nsRect& aRefBox)
{
MOZ_ASSERT(aBasicShape->GetShapeType() == StyleBasicShapeType::Circle ||
aBasicShape->GetShapeType() == StyleBasicShapeType::Ellipse,
"The basic shape must be circle() or ellipse!");
nsPoint topLeft, anchor;
nsSize size(aRefBox.Size());
nsImageRenderer::ComputeObjectAnchorPoint(aBasicShape->GetPosition(),
size, size,
&topLeft, &anchor);
return anchor + aRefBox.TopLeft();
}
nscoord
ShapeUtils::ComputeCircleRadius(const UniquePtr<StyleBasicShape>& aBasicShape,
const nsPoint& aCenter,
const nsRect& aRefBox)
{
MOZ_ASSERT(aBasicShape->GetShapeType() == StyleBasicShapeType::Circle,
"The basic shape must be circle()!");
const nsTArray<nsStyleCoord>& coords = aBasicShape->Coordinates();
MOZ_ASSERT(coords.Length() == 1, "wrong number of arguments");
nscoord r = 0;
if (coords[0].GetUnit() == eStyleUnit_Enumerated) {
const auto styleShapeRadius = coords[0].GetEnumValue<StyleShapeRadius>();
nscoord horizontal =
ComputeShapeRadius(styleShapeRadius, aCenter.x, aRefBox.x, aRefBox.XMost());
nscoord vertical =
ComputeShapeRadius(styleShapeRadius, aCenter.y, aRefBox.y, aRefBox.YMost());
r = styleShapeRadius == StyleShapeRadius::FarthestSide
? std::max(horizontal, vertical)
: std::min(horizontal, vertical);
} else {
// We resolve percent <shape-radius> value for circle() as defined here:
// https://drafts.csswg.org/css-shapes/#funcdef-circle
double referenceLength =
SVGContentUtils::ComputeNormalizedHypotenuse(aRefBox.width,
aRefBox.height);
r = coords[0].ComputeCoordPercentCalc(NSToCoordRound(referenceLength));
}
return r;
}
nsSize
ShapeUtils::ComputeEllipseRadii(const UniquePtr<StyleBasicShape>& aBasicShape,
const nsPoint& aCenter,
const nsRect& aRefBox)
{
MOZ_ASSERT(aBasicShape->GetShapeType() == StyleBasicShapeType::Ellipse,
"The basic shape must be ellipse()!");
const nsTArray<nsStyleCoord>& coords = aBasicShape->Coordinates();
MOZ_ASSERT(coords.Length() == 2, "wrong number of arguments");
nsSize radii;
if (coords[0].GetUnit() == eStyleUnit_Enumerated) {
const StyleShapeRadius radiusX = coords[0].GetEnumValue<StyleShapeRadius>();
radii.width = ComputeShapeRadius(radiusX, aCenter.x, aRefBox.x,
aRefBox.XMost());
} else {
radii.width = coords[0].ComputeCoordPercentCalc(aRefBox.width);
}
if (coords[1].GetUnit() == eStyleUnit_Enumerated) {
const StyleShapeRadius radiusY = coords[1].GetEnumValue<StyleShapeRadius>();
radii.height = ComputeShapeRadius(radiusY, aCenter.y, aRefBox.y,
aRefBox.YMost());
} else {
radii.height = coords[1].ComputeCoordPercentCalc(aRefBox.height);
}
return radii;
}
/* static */ nsRect
ShapeUtils::ComputeInsetRect(const UniquePtr<StyleBasicShape>& aBasicShape,
const nsRect& aRefBox)
{
MOZ_ASSERT(aBasicShape->GetShapeType() == StyleBasicShapeType::Inset,
"The basic shape must be inset()!");
const nsTArray<nsStyleCoord>& coords = aBasicShape->Coordinates();
MOZ_ASSERT(coords.Length() == 4, "wrong number of arguments");
nsMargin inset(coords[0].ComputeCoordPercentCalc(aRefBox.Height()),
coords[1].ComputeCoordPercentCalc(aRefBox.Width()),
coords[2].ComputeCoordPercentCalc(aRefBox.Height()),
coords[3].ComputeCoordPercentCalc(aRefBox.Width()));
nscoord x = aRefBox.X() + inset.left;
nscoord width = aRefBox.Width() - inset.LeftRight();
nscoord y = aRefBox.Y() + inset.top;
nscoord height = aRefBox.Height() - inset.TopBottom();
// Invert left and right, if necessary.
if (width < 0) {
width *= -1;
x -= width;
}
// Invert top and bottom, if necessary.
if (height < 0) {
height *= -1;
y -= height;
}
return nsRect(x, y, width, height);
}
/* static */ bool
ShapeUtils::ComputeInsetRadii(const UniquePtr<StyleBasicShape>& aBasicShape,
const nsRect& aInsetRect,
const nsRect& aRefBox,
nscoord aRadii[8])
{
const nsStyleCorners& radius = aBasicShape->GetRadius();
return nsIFrame::ComputeBorderRadii(radius, aInsetRect.Size(), aRefBox.Size(),
Sides(), aRadii);
}
/* static */ nsTArray<nsPoint>
ShapeUtils::ComputePolygonVertices(const UniquePtr<StyleBasicShape>& aBasicShape,
const nsRect& aRefBox)
{
MOZ_ASSERT(aBasicShape->GetShapeType() == StyleBasicShapeType::Polygon,
"The basic shape must be polygon()!");
const nsTArray<nsStyleCoord>& coords = aBasicShape->Coordinates();
MOZ_ASSERT(coords.Length() % 2 == 0 &&
coords.Length() >= 2, "Wrong number of arguments!");
nsTArray<nsPoint> vertices(coords.Length() / 2);
for (size_t i = 0; i + 1 < coords.Length(); i += 2) {
vertices.AppendElement(
nsPoint(coords[i].ComputeCoordPercentCalc(aRefBox.width),
coords[i + 1].ComputeCoordPercentCalc(aRefBox.height))
+ aRefBox.TopLeft());
}
return vertices;
}
} // namespace mozilla