gecko-dev/layout/svg/nsCSSClipPathInstance.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
// Main header first:
#include "nsCSSClipPathInstance.h"
#include "gfx2DGlue.h"
#include "gfxPlatform.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/gfx/PathHelpers.h"
#include "nsCSSRendering.h"
#include "nsIFrame.h"
#include "nsRenderingContext.h"
#include "nsRuleNode.h"
using namespace mozilla;
using namespace mozilla::gfx;
/* static*/ void
nsCSSClipPathInstance::ApplyBasicShapeClip(gfxContext& aContext,
nsIFrame* aFrame)
{
auto& clipPathStyle = aFrame->StyleSVGReset()->mClipPath;
int32_t type = clipPathStyle.GetType();
MOZ_ASSERT(type != NS_STYLE_CLIP_PATH_NONE, "unexpected none value");
// In the future nsCSSClipPathInstance may handle <clipPath> references as
// well. For the time being return early.
if (type == NS_STYLE_CLIP_PATH_URL) {
return;
}
nsCSSClipPathInstance instance(aFrame, clipPathStyle);
aContext.NewPath();
RefPtr<Path> path = instance.CreateClipPath(aContext.GetDrawTarget());
aContext.SetPath(path);
aContext.Clip();
}
/* static*/ bool
nsCSSClipPathInstance::HitTestBasicShapeClip(nsIFrame* aFrame,
const gfxPoint& aPoint)
{
auto& clipPathStyle = aFrame->StyleSVGReset()->mClipPath;
int32_t type = clipPathStyle.GetType();
MOZ_ASSERT(type != NS_STYLE_CLIP_PATH_NONE, "unexpected none value");
// In the future nsCSSClipPathInstance may handle <clipPath> references as
// well. For the time being return early.
if (type == NS_STYLE_CLIP_PATH_URL) {
return false;
}
nsCSSClipPathInstance instance(aFrame, clipPathStyle);
RefPtr<DrawTarget> drawTarget =
gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
RefPtr<Path> path = instance.CreateClipPath(drawTarget);
float pixelRatio = float(nsPresContext::AppUnitsPerCSSPixel()) /
aFrame->PresContext()->AppUnitsPerDevPixel();
return path->ContainsPoint(ToPoint(aPoint) * pixelRatio, Matrix());
}
already_AddRefed<Path>
nsCSSClipPathInstance::CreateClipPath(DrawTarget* aDrawTarget)
{
nsRect r;
// XXXkrit SVG needs to use different boxes.
switch (mClipPathStyle.GetSizingBox()) {
case NS_STYLE_CLIP_SHAPE_SIZING_CONTENT:
r = mTargetFrame->GetContentRectRelativeToSelf();
break;
case NS_STYLE_CLIP_SHAPE_SIZING_PADDING:
r = mTargetFrame->GetPaddingRectRelativeToSelf();
break;
case NS_STYLE_CLIP_SHAPE_SIZING_MARGIN:
r = mTargetFrame->GetMarginRectRelativeToSelf();
break;
default: // Use the border box
r = mTargetFrame->GetRectRelativeToSelf();
}
if (mClipPathStyle.GetType() != NS_STYLE_CLIP_PATH_SHAPE) {
// TODO Clip to border-radius/reference box if no shape
// was specified.
RefPtr<PathBuilder> builder = aDrawTarget->CreatePathBuilder();
return builder->Finish();
}
nscoord appUnitsPerDevPixel =
mTargetFrame->PresContext()->AppUnitsPerDevPixel();
r = ToAppUnits(r.ToNearestPixels(appUnitsPerDevPixel), appUnitsPerDevPixel);
nsStyleBasicShape* basicShape = mClipPathStyle.GetBasicShape();
switch (basicShape->GetShapeType()) {
case nsStyleBasicShape::Type::eCircle:
return CreateClipPathCircle(aDrawTarget, r);
case nsStyleBasicShape::Type::eEllipse:
return CreateClipPathEllipse(aDrawTarget, r);
case nsStyleBasicShape::Type::ePolygon:
return CreateClipPathPolygon(aDrawTarget, r);
case nsStyleBasicShape::Type::eInset:
// XXXkrit support all basic shapes
break;
default:
MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Unexpected shape type");
}
// Return an empty Path:
RefPtr<PathBuilder> builder = aDrawTarget->CreatePathBuilder();
return builder->Finish();
}
static void
EnumerationToLength(nscoord& aCoord, int32_t aType,
nscoord aCenter, nscoord aPosMin, nscoord aPosMax)
{
nscoord dist1 = abs(aPosMin - aCenter);
nscoord dist2 = abs(aPosMax - aCenter);
switch (aType) {
case NS_RADIUS_FARTHEST_SIDE:
aCoord = dist1 > dist2 ? dist1 : dist2;
break;
case NS_RADIUS_CLOSEST_SIDE:
aCoord = dist1 > dist2 ? dist2 : dist1;
break;
default:
NS_NOTREACHED("unknown keyword");
break;
}
}
already_AddRefed<Path>
nsCSSClipPathInstance::CreateClipPathCircle(DrawTarget* aDrawTarget,
const nsRect& aRefBox)
{
nsStyleBasicShape* basicShape = mClipPathStyle.GetBasicShape();
RefPtr<PathBuilder> builder = aDrawTarget->CreatePathBuilder();
nsPoint topLeft, anchor;
nsSize size = nsSize(aRefBox.width, aRefBox.height);
nsImageRenderer::ComputeObjectAnchorPoint(basicShape->GetPosition(),
size, size,
&topLeft, &anchor);
Point center = Point(anchor.x + aRefBox.x, anchor.y + aRefBox.y);
const nsTArray<nsStyleCoord>& coords = basicShape->Coordinates();
MOZ_ASSERT(coords.Length() == 1, "wrong number of arguments");
float referenceLength = sqrt((aRefBox.width * aRefBox.width +
aRefBox.height * aRefBox.height) / 2.0);
nscoord r = 0;
if (coords[0].GetUnit() == eStyleUnit_Enumerated) {
nscoord horizontal, vertical;
EnumerationToLength(horizontal, coords[0].GetIntValue(),
center.x, aRefBox.x, aRefBox.x + aRefBox.width);
EnumerationToLength(vertical, coords[0].GetIntValue(),
center.y, aRefBox.y, aRefBox.y + aRefBox.height);
if (coords[0].GetIntValue() == NS_RADIUS_FARTHEST_SIDE) {
r = horizontal > vertical ? horizontal : vertical;
} else {
r = horizontal < vertical ? horizontal : vertical;
}
} else {
r = nsRuleNode::ComputeCoordPercentCalc(coords[0], referenceLength);
}
nscoord appUnitsPerDevPixel =
mTargetFrame->PresContext()->AppUnitsPerDevPixel();
builder->Arc(center / appUnitsPerDevPixel, r / appUnitsPerDevPixel,
0, Float(2 * M_PI));
builder->Close();
return builder->Finish();
}
already_AddRefed<Path>
nsCSSClipPathInstance::CreateClipPathEllipse(DrawTarget* aDrawTarget,
const nsRect& aRefBox)
{
nsStyleBasicShape* basicShape = mClipPathStyle.GetBasicShape();
RefPtr<PathBuilder> builder = aDrawTarget->CreatePathBuilder();
nsPoint topLeft, anchor;
nsSize size = nsSize(aRefBox.width, aRefBox.height);
nsImageRenderer::ComputeObjectAnchorPoint(basicShape->GetPosition(),
size, size,
&topLeft, &anchor);
Point center = Point(anchor.x + aRefBox.x, anchor.y + aRefBox.y);
const nsTArray<nsStyleCoord>& coords = basicShape->Coordinates();
MOZ_ASSERT(coords.Length() == 2, "wrong number of arguments");
nscoord rx = 0, ry = 0;
if (coords[0].GetUnit() == eStyleUnit_Enumerated) {
EnumerationToLength(rx, coords[0].GetIntValue(),
center.x, aRefBox.x, aRefBox.x + aRefBox.width);
} else {
rx = nsRuleNode::ComputeCoordPercentCalc(coords[0], aRefBox.width);
}
if (coords[1].GetUnit() == eStyleUnit_Enumerated) {
EnumerationToLength(ry, coords[1].GetIntValue(),
center.y, aRefBox.y, aRefBox.y + aRefBox.height);
} else {
ry = nsRuleNode::ComputeCoordPercentCalc(coords[1], aRefBox.height);
}
nscoord appUnitsPerDevPixel =
mTargetFrame->PresContext()->AppUnitsPerDevPixel();
EllipseToBezier(builder.get(),
center / appUnitsPerDevPixel,
Size(rx, ry) / appUnitsPerDevPixel);
builder->Close();
return builder->Finish();
}
already_AddRefed<Path>
nsCSSClipPathInstance::CreateClipPathPolygon(DrawTarget* aDrawTarget,
const nsRect& aRefBox)
{
nsStyleBasicShape* basicShape = mClipPathStyle.GetBasicShape();
const nsTArray<nsStyleCoord>& coords = basicShape->Coordinates();
MOZ_ASSERT(coords.Length() % 2 == 0 &&
coords.Length() >= 2, "wrong number of arguments");
FillRule fillRule = basicShape->GetFillRule() == NS_STYLE_FILL_RULE_NONZERO ?
FillRule::FILL_WINDING : FillRule::FILL_EVEN_ODD;
RefPtr<PathBuilder> builder = aDrawTarget->CreatePathBuilder(fillRule);
nscoord x = nsRuleNode::ComputeCoordPercentCalc(coords[0], aRefBox.width);
nscoord y = nsRuleNode::ComputeCoordPercentCalc(coords[1], aRefBox.height);
nscoord appUnitsPerDevPixel =
mTargetFrame->PresContext()->AppUnitsPerDevPixel();
builder->MoveTo(Point(aRefBox.x + x, aRefBox.y + y) / appUnitsPerDevPixel);
for (size_t i = 2; i < coords.Length(); i += 2) {
x = nsRuleNode::ComputeCoordPercentCalc(coords[i], aRefBox.width);
y = nsRuleNode::ComputeCoordPercentCalc(coords[i + 1], aRefBox.height);
builder->LineTo(Point(aRefBox.x + x, aRefBox.y + y) / appUnitsPerDevPixel);
}
builder->Close();
return builder->Finish();
}