зеркало из https://github.com/mozilla/gecko-dev.git
1242 строки
49 KiB
C++
1242 строки
49 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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/* utility functions for drawing borders and backgrounds */
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#include "nsCSSRenderingGradients.h"
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#include "gfx2DGlue.h"
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#include "mozilla/ArrayUtils.h"
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#include "mozilla/ComputedStyle.h"
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#include "mozilla/DebugOnly.h"
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#include "mozilla/gfx/2D.h"
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#include "mozilla/gfx/Helpers.h"
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#include "mozilla/MathAlgorithms.h"
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#include "nsStyleConsts.h"
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#include "nsPresContext.h"
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#include "nsPoint.h"
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#include "nsRect.h"
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#include "nsCSSColorUtils.h"
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#include "gfxContext.h"
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#include "nsStyleStructInlines.h"
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#include "nsCSSProps.h"
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#include "gfxUtils.h"
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#include "gfxGradientCache.h"
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#include "mozilla/layers/StackingContextHelper.h"
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#include "mozilla/layers/WebRenderLayerManager.h"
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#include "mozilla/webrender/WebRenderTypes.h"
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#include "mozilla/webrender/WebRenderAPI.h"
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#include "Units.h"
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using namespace mozilla;
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using namespace mozilla::gfx;
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static gfxFloat
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ConvertGradientValueToPixels(const nsStyleCoord& aCoord,
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gfxFloat aFillLength,
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int32_t aAppUnitsPerPixel)
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{
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switch (aCoord.GetUnit()) {
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case eStyleUnit_Percent:
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return aCoord.GetPercentValue() * aFillLength;
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case eStyleUnit_Coord:
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return NSAppUnitsToFloatPixels(aCoord.GetCoordValue(), aAppUnitsPerPixel);
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case eStyleUnit_Calc: {
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const nsStyleCoord::Calc *calc = aCoord.GetCalcValue();
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return calc->mPercent * aFillLength +
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NSAppUnitsToFloatPixels(calc->mLength, aAppUnitsPerPixel);
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}
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default:
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NS_WARNING("Unexpected coord unit");
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return 0;
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}
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}
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// Given a box with size aBoxSize and origin (0,0), and an angle aAngle,
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// and a starting point for the gradient line aStart, find the endpoint of
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// the gradient line --- the intersection of the gradient line with a line
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// perpendicular to aAngle that passes through the farthest corner in the
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// direction aAngle.
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static gfxPoint
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ComputeGradientLineEndFromAngle(const gfxPoint& aStart,
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double aAngle,
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const gfxSize& aBoxSize)
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{
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double dx = cos(-aAngle);
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double dy = sin(-aAngle);
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gfxPoint farthestCorner(dx > 0 ? aBoxSize.width : 0,
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dy > 0 ? aBoxSize.height : 0);
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gfxPoint delta = farthestCorner - aStart;
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double u = delta.x*dy - delta.y*dx;
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return farthestCorner + gfxPoint(-u*dy, u*dx);
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}
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// Compute the start and end points of the gradient line for a linear gradient.
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static void
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ComputeLinearGradientLine(nsPresContext* aPresContext,
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nsStyleGradient* aGradient,
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const gfxSize& aBoxSize,
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gfxPoint* aLineStart,
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gfxPoint* aLineEnd)
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{
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if (aGradient->mBgPosX.GetUnit() == eStyleUnit_None) {
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double angle;
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if (aGradient->mAngle.IsAngleValue()) {
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angle = aGradient->mAngle.GetAngleValueInRadians();
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if (!aGradient->mLegacySyntax) {
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angle = M_PI_2 - angle;
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}
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} else {
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angle = -M_PI_2; // defaults to vertical gradient starting from top
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}
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gfxPoint center(aBoxSize.width/2, aBoxSize.height/2);
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*aLineEnd = ComputeGradientLineEndFromAngle(center, angle, aBoxSize);
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*aLineStart = gfxPoint(aBoxSize.width, aBoxSize.height) - *aLineEnd;
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} else if (!aGradient->mLegacySyntax) {
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float xSign = aGradient->mBgPosX.GetPercentValue() * 2 - 1;
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float ySign = 1 - aGradient->mBgPosY.GetPercentValue() * 2;
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double angle = atan2(ySign * aBoxSize.width, xSign * aBoxSize.height);
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gfxPoint center(aBoxSize.width/2, aBoxSize.height/2);
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*aLineEnd = ComputeGradientLineEndFromAngle(center, angle, aBoxSize);
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*aLineStart = gfxPoint(aBoxSize.width, aBoxSize.height) - *aLineEnd;
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} else {
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int32_t appUnitsPerPixel = aPresContext->AppUnitsPerDevPixel();
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*aLineStart = gfxPoint(
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ConvertGradientValueToPixels(aGradient->mBgPosX, aBoxSize.width,
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appUnitsPerPixel),
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ConvertGradientValueToPixels(aGradient->mBgPosY, aBoxSize.height,
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appUnitsPerPixel));
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if (aGradient->mAngle.IsAngleValue()) {
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MOZ_ASSERT(aGradient->mLegacySyntax);
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double angle = aGradient->mAngle.GetAngleValueInRadians();
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*aLineEnd = ComputeGradientLineEndFromAngle(*aLineStart, angle, aBoxSize);
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} else {
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// No angle, the line end is just the reflection of the start point
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// through the center of the box
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*aLineEnd = gfxPoint(aBoxSize.width, aBoxSize.height) - *aLineStart;
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}
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}
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}
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// Compute the start and end points of the gradient line for a radial gradient.
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// Also returns the horizontal and vertical radii defining the circle or
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// ellipse to use.
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static void
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ComputeRadialGradientLine(nsPresContext* aPresContext,
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nsStyleGradient* aGradient,
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const gfxSize& aBoxSize,
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gfxPoint* aLineStart,
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gfxPoint* aLineEnd,
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double* aRadiusX,
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double* aRadiusY)
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{
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if (aGradient->mBgPosX.GetUnit() == eStyleUnit_None) {
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// Default line start point is the center of the box
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*aLineStart = gfxPoint(aBoxSize.width/2, aBoxSize.height/2);
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} else {
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int32_t appUnitsPerPixel = aPresContext->AppUnitsPerDevPixel();
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*aLineStart = gfxPoint(
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ConvertGradientValueToPixels(aGradient->mBgPosX, aBoxSize.width,
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appUnitsPerPixel),
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ConvertGradientValueToPixels(aGradient->mBgPosY, aBoxSize.height,
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appUnitsPerPixel));
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}
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// Compute gradient shape: the x and y radii of an ellipse.
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double radiusX, radiusY;
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double leftDistance = Abs(aLineStart->x);
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double rightDistance = Abs(aBoxSize.width - aLineStart->x);
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double topDistance = Abs(aLineStart->y);
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double bottomDistance = Abs(aBoxSize.height - aLineStart->y);
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switch (aGradient->mSize) {
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case NS_STYLE_GRADIENT_SIZE_CLOSEST_SIDE:
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radiusX = std::min(leftDistance, rightDistance);
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radiusY = std::min(topDistance, bottomDistance);
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if (aGradient->mShape == NS_STYLE_GRADIENT_SHAPE_CIRCULAR) {
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radiusX = radiusY = std::min(radiusX, radiusY);
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}
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break;
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case NS_STYLE_GRADIENT_SIZE_CLOSEST_CORNER: {
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// Compute x and y distances to nearest corner
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double offsetX = std::min(leftDistance, rightDistance);
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double offsetY = std::min(topDistance, bottomDistance);
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if (aGradient->mShape == NS_STYLE_GRADIENT_SHAPE_CIRCULAR) {
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radiusX = radiusY = NS_hypot(offsetX, offsetY);
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} else {
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// maintain aspect ratio
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radiusX = offsetX*M_SQRT2;
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radiusY = offsetY*M_SQRT2;
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}
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break;
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}
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case NS_STYLE_GRADIENT_SIZE_FARTHEST_SIDE:
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radiusX = std::max(leftDistance, rightDistance);
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radiusY = std::max(topDistance, bottomDistance);
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if (aGradient->mShape == NS_STYLE_GRADIENT_SHAPE_CIRCULAR) {
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radiusX = radiusY = std::max(radiusX, radiusY);
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}
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break;
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case NS_STYLE_GRADIENT_SIZE_FARTHEST_CORNER: {
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// Compute x and y distances to nearest corner
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double offsetX = std::max(leftDistance, rightDistance);
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double offsetY = std::max(topDistance, bottomDistance);
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if (aGradient->mShape == NS_STYLE_GRADIENT_SHAPE_CIRCULAR) {
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radiusX = radiusY = NS_hypot(offsetX, offsetY);
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} else {
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// maintain aspect ratio
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radiusX = offsetX*M_SQRT2;
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radiusY = offsetY*M_SQRT2;
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}
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break;
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}
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case NS_STYLE_GRADIENT_SIZE_EXPLICIT_SIZE: {
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int32_t appUnitsPerPixel = aPresContext->AppUnitsPerDevPixel();
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radiusX = ConvertGradientValueToPixels(aGradient->mRadiusX,
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aBoxSize.width, appUnitsPerPixel);
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radiusY = ConvertGradientValueToPixels(aGradient->mRadiusY,
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aBoxSize.height, appUnitsPerPixel);
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break;
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}
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default:
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radiusX = radiusY = 0;
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MOZ_ASSERT(false, "unknown radial gradient sizing method");
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}
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*aRadiusX = radiusX;
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*aRadiusY = radiusY;
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double angle;
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if (aGradient->mAngle.IsAngleValue()) {
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angle = aGradient->mAngle.GetAngleValueInRadians();
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} else {
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// Default angle is 0deg
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angle = 0.0;
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}
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// The gradient line end point is where the gradient line intersects
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// the ellipse.
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*aLineEnd = *aLineStart + gfxPoint(radiusX*cos(-angle), radiusY*sin(-angle));
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}
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static float Interpolate(float aF1, float aF2, float aFrac)
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{
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return aF1 + aFrac * (aF2 - aF1);
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}
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// Returns aFrac*aC2 + (1 - aFrac)*C1. The interpolation is done
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// in unpremultiplied space, which is what SVG gradients and cairo
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// gradients expect.
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static Color
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InterpolateColor(const Color& aC1, const Color& aC2, float aFrac)
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{
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double other = 1 - aFrac;
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return Color(aC2.r*aFrac + aC1.r*other,
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aC2.g*aFrac + aC1.g*other,
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aC2.b*aFrac + aC1.b*other,
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aC2.a*aFrac + aC1.a*other);
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}
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static nscoord
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FindTileStart(nscoord aDirtyCoord, nscoord aTilePos, nscoord aTileDim)
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{
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NS_ASSERTION(aTileDim > 0, "Non-positive tile dimension");
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double multiples = floor(double(aDirtyCoord - aTilePos)/aTileDim);
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return NSToCoordRound(multiples*aTileDim + aTilePos);
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}
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static gfxFloat
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LinearGradientStopPositionForPoint(const gfxPoint& aGradientStart,
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const gfxPoint& aGradientEnd,
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const gfxPoint& aPoint)
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{
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gfxPoint d = aGradientEnd - aGradientStart;
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gfxPoint p = aPoint - aGradientStart;
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/**
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* Compute a parameter t such that a line perpendicular to the
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* d vector, passing through aGradientStart + d*t, also
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* passes through aPoint.
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*
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* t is given by
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* (p.x - d.x*t)*d.x + (p.y - d.y*t)*d.y = 0
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*
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* Solving for t we get
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* numerator = d.x*p.x + d.y*p.y
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* denominator = d.x^2 + d.y^2
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* t = numerator/denominator
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*
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* In nsCSSRendering::PaintGradient we know the length of d
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* is not zero.
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*/
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double numerator = d.x * p.x + d.y * p.y;
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double denominator = d.x * d.x + d.y * d.y;
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return numerator / denominator;
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}
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static bool
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RectIsBeyondLinearGradientEdge(const gfxRect& aRect,
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const gfxMatrix& aPatternMatrix,
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const nsTArray<ColorStop>& aStops,
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const gfxPoint& aGradientStart,
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const gfxPoint& aGradientEnd,
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Color* aOutEdgeColor)
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{
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gfxFloat topLeft = LinearGradientStopPositionForPoint(
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aGradientStart, aGradientEnd, aPatternMatrix.TransformPoint(aRect.TopLeft()));
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gfxFloat topRight = LinearGradientStopPositionForPoint(
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aGradientStart, aGradientEnd, aPatternMatrix.TransformPoint(aRect.TopRight()));
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gfxFloat bottomLeft = LinearGradientStopPositionForPoint(
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aGradientStart, aGradientEnd, aPatternMatrix.TransformPoint(aRect.BottomLeft()));
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gfxFloat bottomRight = LinearGradientStopPositionForPoint(
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aGradientStart, aGradientEnd, aPatternMatrix.TransformPoint(aRect.BottomRight()));
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const ColorStop& firstStop = aStops[0];
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if (topLeft < firstStop.mPosition && topRight < firstStop.mPosition &&
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bottomLeft < firstStop.mPosition && bottomRight < firstStop.mPosition) {
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*aOutEdgeColor = firstStop.mColor;
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return true;
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}
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const ColorStop& lastStop = aStops.LastElement();
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if (topLeft >= lastStop.mPosition && topRight >= lastStop.mPosition &&
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bottomLeft >= lastStop.mPosition && bottomRight >= lastStop.mPosition) {
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*aOutEdgeColor = lastStop.mColor;
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return true;
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}
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return false;
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}
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static void ResolveMidpoints(nsTArray<ColorStop>& stops)
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{
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for (size_t x = 1; x < stops.Length() - 1;) {
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if (!stops[x].mIsMidpoint) {
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x++;
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continue;
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}
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Color color1 = stops[x-1].mColor;
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Color color2 = stops[x+1].mColor;
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float offset1 = stops[x-1].mPosition;
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float offset2 = stops[x+1].mPosition;
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float offset = stops[x].mPosition;
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// check if everything coincides. If so, ignore the midpoint.
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if (offset - offset1 == offset2 - offset) {
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stops.RemoveElementAt(x);
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continue;
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}
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// Check if we coincide with the left colorstop.
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if (offset1 == offset) {
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// Morph the midpoint to a regular stop with the color of the next
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// color stop.
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stops[x].mColor = color2;
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stops[x].mIsMidpoint = false;
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continue;
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}
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// Check if we coincide with the right colorstop.
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if (offset2 == offset) {
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// Morph the midpoint to a regular stop with the color of the previous
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// color stop.
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stops[x].mColor = color1;
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stops[x].mIsMidpoint = false;
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continue;
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}
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float midpoint = (offset - offset1) / (offset2 - offset1);
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ColorStop newStops[9];
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if (midpoint > .5f) {
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for (size_t y = 0; y < 7; y++) {
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newStops[y].mPosition = offset1 + (offset - offset1) * (7 + y) / 13;
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}
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newStops[7].mPosition = offset + (offset2 - offset) / 3;
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newStops[8].mPosition = offset + (offset2 - offset) * 2 / 3;
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} else {
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newStops[0].mPosition = offset1 + (offset - offset1) / 3;
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newStops[1].mPosition = offset1 + (offset - offset1) * 2 / 3;
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for (size_t y = 0; y < 7; y++) {
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newStops[y+2].mPosition = offset + (offset2 - offset) * y / 13;
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}
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}
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// calculate colors
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for (auto& newStop : newStops) {
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// Calculate the intermediate color stops per the formula of the CSS images
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// spec. http://dev.w3.org/csswg/css-images/#color-stop-syntax
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// 9 points were chosen since it is the minimum number of stops that always
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// give the smoothest appearace regardless of midpoint position and difference
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// in luminance of the end points.
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float relativeOffset = (newStop.mPosition - offset1) / (offset2 - offset1);
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float multiplier = powf(relativeOffset, logf(.5f) / logf(midpoint));
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gfx::Float red = color1.r + multiplier * (color2.r - color1.r);
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gfx::Float green = color1.g + multiplier * (color2.g - color1.g);
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gfx::Float blue = color1.b + multiplier * (color2.b - color1.b);
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gfx::Float alpha = color1.a + multiplier * (color2.a - color1.a);
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newStop.mColor = Color(red, green, blue, alpha);
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}
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stops.ReplaceElementsAt(x, 1, newStops, 9);
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x += 9;
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}
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}
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static Color
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Premultiply(const Color& aColor)
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{
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gfx::Float a = aColor.a;
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return Color(aColor.r * a, aColor.g * a, aColor.b * a, a);
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}
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static Color
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Unpremultiply(const Color& aColor)
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{
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gfx::Float a = aColor.a;
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return (a > 0.f)
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? Color(aColor.r / a, aColor.g / a, aColor.b / a, a)
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: aColor;
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}
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static Color
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TransparentColor(Color aColor) {
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aColor.a = 0;
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return aColor;
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}
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// Adjusts and adds color stops in such a way that drawing the gradient with
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// unpremultiplied interpolation looks nearly the same as if it were drawn with
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// premultiplied interpolation.
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static const float kAlphaIncrementPerGradientStep = 0.1f;
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static void
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ResolvePremultipliedAlpha(nsTArray<ColorStop>& aStops)
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{
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for (size_t x = 1; x < aStops.Length(); x++) {
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const ColorStop leftStop = aStops[x - 1];
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const ColorStop rightStop = aStops[x];
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// if the left and right stop have the same alpha value, we don't need
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// to do anything. Hardstops should be instant, and also should never
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// require dealing with interpolation.
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if (leftStop.mColor.a == rightStop.mColor.a ||
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leftStop.mPosition == rightStop.mPosition) {
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continue;
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}
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// Is the stop on the left 100% transparent? If so, have it adopt the color
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// of the right stop
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if (leftStop.mColor.a == 0) {
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aStops[x - 1].mColor = TransparentColor(rightStop.mColor);
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continue;
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}
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// Is the stop on the right completely transparent?
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// If so, duplicate it and assign it the color on the left.
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if (rightStop.mColor.a == 0) {
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ColorStop newStop = rightStop;
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newStop.mColor = TransparentColor(leftStop.mColor);
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aStops.InsertElementAt(x, newStop);
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x++;
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continue;
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}
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// Now handle cases where one or both of the stops are partially transparent.
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if (leftStop.mColor.a != 1.0f || rightStop.mColor.a != 1.0f) {
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Color premulLeftColor = Premultiply(leftStop.mColor);
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Color premulRightColor = Premultiply(rightStop.mColor);
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// Calculate how many extra steps. We do a step per 10% transparency.
|
|
size_t stepCount = NSToIntFloor(fabsf(leftStop.mColor.a - rightStop.mColor.a) / kAlphaIncrementPerGradientStep);
|
|
for (size_t y = 1; y < stepCount; y++) {
|
|
float frac = static_cast<float>(y) / stepCount;
|
|
ColorStop newStop(Interpolate(leftStop.mPosition, rightStop.mPosition, frac), false,
|
|
Unpremultiply(InterpolateColor(premulLeftColor, premulRightColor, frac)));
|
|
aStops.InsertElementAt(x, newStop);
|
|
x++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static ColorStop
|
|
InterpolateColorStop(const ColorStop& aFirst, const ColorStop& aSecond,
|
|
double aPosition, const Color& aDefault)
|
|
{
|
|
MOZ_ASSERT(aFirst.mPosition <= aPosition);
|
|
MOZ_ASSERT(aPosition <= aSecond.mPosition);
|
|
|
|
double delta = aSecond.mPosition - aFirst.mPosition;
|
|
|
|
if (delta < 1e-6) {
|
|
return ColorStop(aPosition, false, aDefault);
|
|
}
|
|
|
|
return ColorStop(aPosition, false,
|
|
Unpremultiply(InterpolateColor(Premultiply(aFirst.mColor),
|
|
Premultiply(aSecond.mColor),
|
|
(aPosition - aFirst.mPosition) / delta)));
|
|
}
|
|
|
|
// Clamp and extend the given ColorStop array in-place to fit exactly into the
|
|
// range [0, 1].
|
|
static void
|
|
ClampColorStops(nsTArray<ColorStop>& aStops)
|
|
{
|
|
MOZ_ASSERT(aStops.Length() > 0);
|
|
|
|
// If all stops are outside the range, then get rid of everything and replace
|
|
// with a single colour.
|
|
if (aStops.Length() < 2 || aStops[0].mPosition > 1 ||
|
|
aStops.LastElement().mPosition < 0) {
|
|
Color c = aStops[0].mPosition > 1 ? aStops[0].mColor : aStops.LastElement().mColor;
|
|
aStops.Clear();
|
|
aStops.AppendElement(ColorStop(0, false, c));
|
|
return;
|
|
}
|
|
|
|
// Create the 0 and 1 points if they fall in the range of |aStops|, and discard
|
|
// all stops outside the range [0, 1].
|
|
// XXX: If we have stops positioned at 0 or 1, we only keep the innermost of
|
|
// those stops. This should be fine for the current user(s) of this function.
|
|
for (size_t i = aStops.Length() - 1; i > 0; i--) {
|
|
if (aStops[i - 1].mPosition < 1 && aStops[i].mPosition >= 1) {
|
|
// Add a point to position 1.
|
|
aStops[i] = InterpolateColorStop(aStops[i - 1], aStops[i],
|
|
/* aPosition = */ 1,
|
|
aStops[i - 1].mColor);
|
|
// Remove all the elements whose position is greater than 1.
|
|
aStops.RemoveElementsAt(i + 1, aStops.Length() - (i + 1));
|
|
}
|
|
if (aStops[i - 1].mPosition <= 0 && aStops[i].mPosition > 0) {
|
|
// Add a point to position 0.
|
|
aStops[i - 1] = InterpolateColorStop(aStops[i - 1], aStops[i],
|
|
/* aPosition = */ 0,
|
|
aStops[i].mColor);
|
|
// Remove all of the preceding stops -- they are all negative.
|
|
aStops.RemoveElementsAt(0, i - 1);
|
|
break;
|
|
}
|
|
}
|
|
|
|
MOZ_ASSERT(aStops[0].mPosition >= -1e6);
|
|
MOZ_ASSERT(aStops.LastElement().mPosition - 1 <= 1e6);
|
|
|
|
// The end points won't exist yet if they don't fall in the original range of
|
|
// |aStops|. Create them if needed.
|
|
if (aStops[0].mPosition > 0) {
|
|
aStops.InsertElementAt(0, ColorStop(0, false, aStops[0].mColor));
|
|
}
|
|
if (aStops.LastElement().mPosition < 1) {
|
|
aStops.AppendElement(ColorStop(1, false, aStops.LastElement().mColor));
|
|
}
|
|
}
|
|
|
|
namespace mozilla {
|
|
|
|
static Maybe<double>
|
|
GetSpecifiedGradientPosition(const nsStyleCoord& aCoord,
|
|
int32_t aAppUnitsPerPixel,
|
|
gfxFloat aLineLength)
|
|
{
|
|
auto GetCoord = [&](nscoord aCoord) -> double {
|
|
if (aLineLength < 1e-6) {
|
|
return 0.0;
|
|
}
|
|
return NSAppUnitsToFloatPixels(aCoord, aAppUnitsPerPixel) / aLineLength;
|
|
};
|
|
|
|
switch (aCoord.GetUnit()) {
|
|
case eStyleUnit_None:
|
|
return Nothing();
|
|
case eStyleUnit_Percent:
|
|
return Some(aCoord.GetPercentValue());
|
|
case eStyleUnit_Coord:
|
|
return Some(GetCoord(aCoord.GetCoordValue()));
|
|
case eStyleUnit_Calc: {
|
|
const nsStyleCoord::Calc* calc = aCoord.GetCalcValue();
|
|
return Some(calc->mPercent + GetCoord(calc->mLength));
|
|
}
|
|
default:
|
|
MOZ_ASSERT_UNREACHABLE("Unknown unit in gradient color stop position?");
|
|
return Nothing();
|
|
}
|
|
}
|
|
|
|
static nsTArray<ColorStop>
|
|
ComputeColorStops(ComputedStyle* aComputedStyle,
|
|
const nsStyleGradient& aGradient,
|
|
int32_t aAppUnitsPerPixel,
|
|
gfxFloat aLineLength)
|
|
{
|
|
MOZ_ASSERT(aGradient.mStops.Length() >= 2,
|
|
"The parser should reject gradients with less than two stops");
|
|
|
|
nsTArray<ColorStop> stops(aGradient.mStops.Length());
|
|
|
|
// If there is a run of stops before stop i that did not have specified
|
|
// positions, then this is the index of the first stop in that run, otherwise
|
|
// it's -1.
|
|
int32_t firstUnsetPosition = -1;
|
|
for (uint32_t i = 0; i < aGradient.mStops.Length(); ++i) {
|
|
const nsStyleGradientStop& stop = aGradient.mStops[i];
|
|
double position;
|
|
|
|
Maybe<double> specifiedPosition =
|
|
GetSpecifiedGradientPosition(stop.mLocation,
|
|
aAppUnitsPerPixel,
|
|
aLineLength);
|
|
|
|
if (specifiedPosition) {
|
|
position = *specifiedPosition;
|
|
} else if (i == 0) {
|
|
// First stop defaults to position 0.0
|
|
position = 0.0;
|
|
} else if (i == aGradient.mStops.Length() - 1) {
|
|
// Last stop defaults to position 1.0
|
|
position = 1.0;
|
|
} else {
|
|
// Other stops with no specified position get their position assigned
|
|
// later by interpolation, see below.
|
|
// Remember where the run of stops with no specified position starts,
|
|
// if it starts here.
|
|
if (firstUnsetPosition < 0) {
|
|
firstUnsetPosition = i;
|
|
}
|
|
auto stopColor = stop.mColor.CalcColor(aComputedStyle);
|
|
stops.AppendElement(ColorStop(0, stop.mIsInterpolationHint,
|
|
Color::FromABGR(stopColor)));
|
|
continue;
|
|
}
|
|
|
|
if (i > 0) {
|
|
// Prevent decreasing stop positions by advancing this position
|
|
// to the previous stop position, if necessary
|
|
double previousPosition = firstUnsetPosition > 0
|
|
? stops[firstUnsetPosition - 1].mPosition
|
|
: stops[i - 1].mPosition;
|
|
position = std::max(position, previousPosition);
|
|
}
|
|
auto stopColor = stop.mColor.CalcColor(aComputedStyle);
|
|
stops.AppendElement(ColorStop(position, stop.mIsInterpolationHint,
|
|
Color::FromABGR(stopColor)));
|
|
if (firstUnsetPosition > 0) {
|
|
// Interpolate positions for all stops that didn't have a specified position
|
|
double p = stops[firstUnsetPosition - 1].mPosition;
|
|
double d = (stops[i].mPosition - p)/(i - firstUnsetPosition + 1);
|
|
for (uint32_t j = firstUnsetPosition; j < i; ++j) {
|
|
p += d;
|
|
stops[j].mPosition = p;
|
|
}
|
|
firstUnsetPosition = -1;
|
|
}
|
|
}
|
|
|
|
return stops;
|
|
}
|
|
|
|
nsCSSGradientRenderer
|
|
nsCSSGradientRenderer::Create(nsPresContext* aPresContext,
|
|
ComputedStyle* aComputedStyle,
|
|
nsStyleGradient* aGradient,
|
|
const nsSize& aIntrinsicSize)
|
|
{
|
|
nscoord appUnitsPerDevPixel = aPresContext->AppUnitsPerDevPixel();
|
|
gfxSize srcSize = gfxSize(gfxFloat(aIntrinsicSize.width)/appUnitsPerDevPixel,
|
|
gfxFloat(aIntrinsicSize.height)/appUnitsPerDevPixel);
|
|
|
|
// Compute "gradient line" start and end relative to the intrinsic size of
|
|
// the gradient.
|
|
gfxPoint lineStart, lineEnd;
|
|
double radiusX = 0, radiusY = 0; // for radial gradients only
|
|
if (aGradient->mShape == NS_STYLE_GRADIENT_SHAPE_LINEAR) {
|
|
ComputeLinearGradientLine(aPresContext, aGradient, srcSize,
|
|
&lineStart, &lineEnd);
|
|
} else {
|
|
ComputeRadialGradientLine(aPresContext, aGradient, srcSize,
|
|
&lineStart, &lineEnd, &radiusX, &radiusY);
|
|
}
|
|
// Avoid sending Infs or Nans to downwind draw targets.
|
|
if (!lineStart.IsFinite() || !lineEnd.IsFinite()) {
|
|
lineStart = lineEnd = gfxPoint(0, 0);
|
|
}
|
|
gfxFloat lineLength = NS_hypot(lineEnd.x - lineStart.x,
|
|
lineEnd.y - lineStart.y);
|
|
|
|
// Build color stop array and compute stop positions
|
|
nsTArray<ColorStop> stops =
|
|
ComputeColorStops(aComputedStyle, *aGradient, appUnitsPerDevPixel, lineLength);
|
|
|
|
ResolveMidpoints(stops);
|
|
|
|
nsCSSGradientRenderer renderer;
|
|
renderer.mPresContext = aPresContext;
|
|
renderer.mGradient = aGradient;
|
|
renderer.mStops = std::move(stops);
|
|
renderer.mLineStart = lineStart;
|
|
renderer.mLineEnd = lineEnd;
|
|
renderer.mRadiusX = radiusX;
|
|
renderer.mRadiusY = radiusY;
|
|
return renderer;
|
|
}
|
|
|
|
void
|
|
nsCSSGradientRenderer::Paint(gfxContext& aContext,
|
|
const nsRect& aDest,
|
|
const nsRect& aFillArea,
|
|
const nsSize& aRepeatSize,
|
|
const CSSIntRect& aSrc,
|
|
const nsRect& aDirtyRect,
|
|
float aOpacity)
|
|
{
|
|
AUTO_PROFILER_LABEL("nsCSSGradientRenderer::Paint", GRAPHICS);
|
|
|
|
if (aDest.IsEmpty() || aFillArea.IsEmpty()) {
|
|
return;
|
|
}
|
|
|
|
nscoord appUnitsPerDevPixel = mPresContext->AppUnitsPerDevPixel();
|
|
|
|
gfxFloat lineLength = NS_hypot(mLineEnd.x - mLineStart.x,
|
|
mLineEnd.y - mLineStart.y);
|
|
bool cellContainsFill = aDest.Contains(aFillArea);
|
|
|
|
// If a non-repeating linear gradient is axis-aligned and there are no gaps
|
|
// between tiles, we can optimise away most of the work by converting to a
|
|
// repeating linear gradient and filling the whole destination rect at once.
|
|
bool forceRepeatToCoverTiles =
|
|
mGradient->mShape == NS_STYLE_GRADIENT_SHAPE_LINEAR &&
|
|
(mLineStart.x == mLineEnd.x) != (mLineStart.y == mLineEnd.y) &&
|
|
aRepeatSize.width == aDest.width && aRepeatSize.height == aDest.height &&
|
|
!mGradient->mRepeating && !aSrc.IsEmpty() && !cellContainsFill;
|
|
|
|
gfxMatrix matrix;
|
|
if (forceRepeatToCoverTiles) {
|
|
// Length of the source rectangle along the gradient axis.
|
|
double rectLen;
|
|
// The position of the start of the rectangle along the gradient.
|
|
double offset;
|
|
|
|
// The gradient line is "backwards". Flip the line upside down to make
|
|
// things easier, and then rotate the matrix to turn everything back the
|
|
// right way up.
|
|
if (mLineStart.x > mLineEnd.x || mLineStart.y > mLineEnd.y) {
|
|
std::swap(mLineStart, mLineEnd);
|
|
matrix.PreScale(-1, -1);
|
|
}
|
|
|
|
// Fit the gradient line exactly into the source rect.
|
|
// aSrc is relative to aIntrinsincSize.
|
|
// srcRectDev will be relative to srcSize, so in the same coordinate space
|
|
// as lineStart / lineEnd.
|
|
gfxRect srcRectDev = nsLayoutUtils::RectToGfxRect(
|
|
CSSPixel::ToAppUnits(aSrc), appUnitsPerDevPixel);
|
|
if (mLineStart.x != mLineEnd.x) {
|
|
rectLen = srcRectDev.width;
|
|
offset = (srcRectDev.x - mLineStart.x) / lineLength;
|
|
mLineStart.x = srcRectDev.x;
|
|
mLineEnd.x = srcRectDev.XMost();
|
|
} else {
|
|
rectLen = srcRectDev.height;
|
|
offset = (srcRectDev.y - mLineStart.y) / lineLength;
|
|
mLineStart.y = srcRectDev.y;
|
|
mLineEnd.y = srcRectDev.YMost();
|
|
}
|
|
|
|
// Adjust gradient stop positions for the new gradient line.
|
|
double scale = lineLength / rectLen;
|
|
for (size_t i = 0; i < mStops.Length(); i++) {
|
|
mStops[i].mPosition = (mStops[i].mPosition - offset) * fabs(scale);
|
|
}
|
|
|
|
// Clamp or extrapolate gradient stops to exactly [0, 1].
|
|
ClampColorStops(mStops);
|
|
|
|
lineLength = rectLen;
|
|
}
|
|
|
|
// Eliminate negative-position stops if the gradient is radial.
|
|
double firstStop = mStops[0].mPosition;
|
|
if (mGradient->mShape != NS_STYLE_GRADIENT_SHAPE_LINEAR && firstStop < 0.0) {
|
|
if (mGradient->mRepeating) {
|
|
// Choose an instance of the repeated pattern that gives us all positive
|
|
// stop-offsets.
|
|
double lastStop = mStops[mStops.Length() - 1].mPosition;
|
|
double stopDelta = lastStop - firstStop;
|
|
// If all the stops are in approximately the same place then logic below
|
|
// will kick in that makes us draw just the last stop color, so don't
|
|
// try to do anything in that case. We certainly need to avoid
|
|
// dividing by zero.
|
|
if (stopDelta >= 1e-6) {
|
|
double instanceCount = ceil(-firstStop/stopDelta);
|
|
// Advance stops by instanceCount multiples of the period of the
|
|
// repeating gradient.
|
|
double offset = instanceCount*stopDelta;
|
|
for (uint32_t i = 0; i < mStops.Length(); i++) {
|
|
mStops[i].mPosition += offset;
|
|
}
|
|
}
|
|
} else {
|
|
// Move negative-position stops to position 0.0. We may also need
|
|
// to set the color of the stop to the color the gradient should have
|
|
// at the center of the ellipse.
|
|
for (uint32_t i = 0; i < mStops.Length(); i++) {
|
|
double pos = mStops[i].mPosition;
|
|
if (pos < 0.0) {
|
|
mStops[i].mPosition = 0.0;
|
|
// If this is the last stop, we don't need to adjust the color,
|
|
// it will fill the entire area.
|
|
if (i < mStops.Length() - 1) {
|
|
double nextPos = mStops[i + 1].mPosition;
|
|
// If nextPos is approximately equal to pos, then we don't
|
|
// need to adjust the color of this stop because it's
|
|
// not going to be displayed.
|
|
// If nextPos is negative, we don't need to adjust the color of
|
|
// this stop since it's not going to be displayed because
|
|
// nextPos will also be moved to 0.0.
|
|
if (nextPos >= 0.0 && nextPos - pos >= 1e-6) {
|
|
// Compute how far the new position 0.0 is along the interval
|
|
// between pos and nextPos.
|
|
// XXX Color interpolation (in cairo, too) should use the
|
|
// CSS 'color-interpolation' property!
|
|
float frac = float((0.0 - pos)/(nextPos - pos));
|
|
mStops[i].mColor =
|
|
InterpolateColor(mStops[i].mColor, mStops[i + 1].mColor, frac);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
firstStop = mStops[0].mPosition;
|
|
MOZ_ASSERT(firstStop >= 0.0, "Failed to fix stop offsets");
|
|
}
|
|
|
|
if (mGradient->mShape != NS_STYLE_GRADIENT_SHAPE_LINEAR && !mGradient->mRepeating) {
|
|
// Direct2D can only handle a particular class of radial gradients because
|
|
// of the way the it specifies gradients. Setting firstStop to 0, when we
|
|
// can, will help us stay on the fast path. Currently we don't do this
|
|
// for repeating gradients but we could by adjusting the stop collection
|
|
// to start at 0
|
|
firstStop = 0;
|
|
}
|
|
|
|
double lastStop = mStops[mStops.Length() - 1].mPosition;
|
|
// Cairo gradients must have stop positions in the range [0, 1]. So,
|
|
// stop positions will be normalized below by subtracting firstStop and then
|
|
// multiplying by stopScale.
|
|
double stopScale;
|
|
double stopOrigin = firstStop;
|
|
double stopEnd = lastStop;
|
|
double stopDelta = lastStop - firstStop;
|
|
bool zeroRadius = mGradient->mShape != NS_STYLE_GRADIENT_SHAPE_LINEAR &&
|
|
(mRadiusX < 1e-6 || mRadiusY < 1e-6);
|
|
if (stopDelta < 1e-6 || lineLength < 1e-6 || zeroRadius) {
|
|
// Stops are all at the same place. Map all stops to 0.0.
|
|
// For repeating radial gradients, or for any radial gradients with
|
|
// a zero radius, we need to fill with the last stop color, so just set
|
|
// both radii to 0.
|
|
if (mGradient->mRepeating || zeroRadius) {
|
|
mRadiusX = mRadiusY = 0.0;
|
|
}
|
|
stopDelta = 0.0;
|
|
}
|
|
|
|
// Don't normalize non-repeating or degenerate gradients below 0..1
|
|
// This keeps the gradient line as large as the box and doesn't
|
|
// lets us avoiding having to get padding correct for stops
|
|
// at 0 and 1
|
|
if (!mGradient->mRepeating || stopDelta == 0.0) {
|
|
stopOrigin = std::min(stopOrigin, 0.0);
|
|
stopEnd = std::max(stopEnd, 1.0);
|
|
}
|
|
stopScale = 1.0/(stopEnd - stopOrigin);
|
|
|
|
// Create the gradient pattern.
|
|
RefPtr<gfxPattern> gradientPattern;
|
|
gfxPoint gradientStart;
|
|
gfxPoint gradientEnd;
|
|
if (mGradient->mShape == NS_STYLE_GRADIENT_SHAPE_LINEAR) {
|
|
// Compute the actual gradient line ends we need to pass to cairo after
|
|
// stops have been normalized.
|
|
gradientStart = mLineStart + (mLineEnd - mLineStart)*stopOrigin;
|
|
gradientEnd = mLineStart + (mLineEnd - mLineStart)*stopEnd;
|
|
|
|
if (stopDelta == 0.0) {
|
|
// Stops are all at the same place. For repeating gradients, this will
|
|
// just paint the last stop color. We don't need to do anything.
|
|
// For non-repeating gradients, this should render as two colors, one
|
|
// on each "side" of the gradient line segment, which is a point. All
|
|
// our stops will be at 0.0; we just need to set the direction vector
|
|
// correctly.
|
|
gradientEnd = gradientStart + (mLineEnd - mLineStart);
|
|
}
|
|
|
|
gradientPattern = new gfxPattern(gradientStart.x, gradientStart.y,
|
|
gradientEnd.x, gradientEnd.y);
|
|
} else {
|
|
NS_ASSERTION(firstStop >= 0.0,
|
|
"Negative stops not allowed for radial gradients");
|
|
|
|
// To form an ellipse, we'll stretch a circle vertically, if necessary.
|
|
// So our radii are based on radiusX.
|
|
double innerRadius = mRadiusX*stopOrigin;
|
|
double outerRadius = mRadiusX*stopEnd;
|
|
if (stopDelta == 0.0) {
|
|
// Stops are all at the same place. See above (except we now have
|
|
// the inside vs. outside of an ellipse).
|
|
outerRadius = innerRadius + 1;
|
|
}
|
|
gradientPattern = new gfxPattern(mLineStart.x, mLineStart.y, innerRadius,
|
|
mLineStart.x, mLineStart.y, outerRadius);
|
|
if (mRadiusX != mRadiusY) {
|
|
// Stretch the circles into ellipses vertically by setting a transform
|
|
// in the pattern.
|
|
// Recall that this is the transform from user space to pattern space.
|
|
// So to stretch the ellipse by factor of P vertically, we scale
|
|
// user coordinates by 1/P.
|
|
matrix.PreTranslate(mLineStart);
|
|
matrix.PreScale(1.0, mRadiusX/mRadiusY);
|
|
matrix.PreTranslate(-mLineStart);
|
|
}
|
|
}
|
|
// Use a pattern transform to take account of source and dest rects
|
|
matrix.PreTranslate(gfxPoint(mPresContext->CSSPixelsToDevPixels(aSrc.x),
|
|
mPresContext->CSSPixelsToDevPixels(aSrc.y)));
|
|
matrix.PreScale(gfxFloat(nsPresContext::CSSPixelsToAppUnits(aSrc.width))/aDest.width,
|
|
gfxFloat(nsPresContext::CSSPixelsToAppUnits(aSrc.height))/aDest.height);
|
|
gradientPattern->SetMatrix(matrix);
|
|
|
|
if (stopDelta == 0.0) {
|
|
// Non-repeating gradient with all stops in same place -> just add
|
|
// first stop and last stop, both at position 0.
|
|
// Repeating gradient with all stops in the same place, or radial
|
|
// gradient with radius of 0 -> just paint the last stop color.
|
|
// We use firstStop offset to keep |stops| with same units (will later normalize to 0).
|
|
Color firstColor(mStops[0].mColor);
|
|
Color lastColor(mStops.LastElement().mColor);
|
|
mStops.Clear();
|
|
|
|
if (!mGradient->mRepeating && !zeroRadius) {
|
|
mStops.AppendElement(ColorStop(firstStop, false, firstColor));
|
|
}
|
|
mStops.AppendElement(ColorStop(firstStop, false, lastColor));
|
|
}
|
|
|
|
ResolvePremultipliedAlpha(mStops);
|
|
|
|
bool isRepeat = mGradient->mRepeating || forceRepeatToCoverTiles;
|
|
|
|
// Now set normalized color stops in pattern.
|
|
// Offscreen gradient surface cache (not a tile):
|
|
// On some backends (e.g. D2D), the GradientStops object holds an offscreen surface
|
|
// which is a lookup table used to evaluate the gradient. This surface can use
|
|
// much memory (ram and/or GPU ram) and can be expensive to create. So we cache it.
|
|
// The cache key correlates 1:1 with the arguments for CreateGradientStops (also the implied backend type)
|
|
// Note that GradientStop is a simple struct with a stop value (while GradientStops has the surface).
|
|
nsTArray<gfx::GradientStop> rawStops(mStops.Length());
|
|
rawStops.SetLength(mStops.Length());
|
|
for(uint32_t i = 0; i < mStops.Length(); i++) {
|
|
rawStops[i].color = mStops[i].mColor;
|
|
rawStops[i].color.a *= aOpacity;
|
|
rawStops[i].offset = stopScale * (mStops[i].mPosition - stopOrigin);
|
|
}
|
|
RefPtr<mozilla::gfx::GradientStops> gs =
|
|
gfxGradientCache::GetOrCreateGradientStops(aContext.GetDrawTarget(),
|
|
rawStops,
|
|
isRepeat ? gfx::ExtendMode::REPEAT : gfx::ExtendMode::CLAMP);
|
|
gradientPattern->SetColorStops(gs);
|
|
|
|
// Paint gradient tiles. This isn't terribly efficient, but doing it this
|
|
// way is simple and sure to get pixel-snapping right. We could speed things
|
|
// up by drawing tiles into temporary surfaces and copying those to the
|
|
// destination, but after pixel-snapping tiles may not all be the same size.
|
|
nsRect dirty;
|
|
if (!dirty.IntersectRect(aDirtyRect, aFillArea))
|
|
return;
|
|
|
|
gfxRect areaToFill =
|
|
nsLayoutUtils::RectToGfxRect(aFillArea, appUnitsPerDevPixel);
|
|
gfxRect dirtyAreaToFill = nsLayoutUtils::RectToGfxRect(dirty, appUnitsPerDevPixel);
|
|
dirtyAreaToFill.RoundOut();
|
|
|
|
Matrix ctm = aContext.CurrentMatrix();
|
|
bool isCTMPreservingAxisAlignedRectangles = ctm.PreservesAxisAlignedRectangles();
|
|
|
|
// xStart/yStart are the top-left corner of the top-left tile.
|
|
nscoord xStart = FindTileStart(dirty.x, aDest.x, aRepeatSize.width);
|
|
nscoord yStart = FindTileStart(dirty.y, aDest.y, aRepeatSize.height);
|
|
nscoord xEnd = forceRepeatToCoverTiles ? xStart + aDest.width : dirty.XMost();
|
|
nscoord yEnd = forceRepeatToCoverTiles ? yStart + aDest.height : dirty.YMost();
|
|
|
|
if (TryPaintTilesWithExtendMode(aContext,
|
|
gradientPattern,
|
|
xStart,
|
|
yStart,
|
|
dirtyAreaToFill,
|
|
aDest,
|
|
aRepeatSize,
|
|
forceRepeatToCoverTiles)) {
|
|
return;
|
|
}
|
|
|
|
// x and y are the top-left corner of the tile to draw
|
|
for (nscoord y = yStart; y < yEnd; y += aRepeatSize.height) {
|
|
for (nscoord x = xStart; x < xEnd; x += aRepeatSize.width) {
|
|
// The coordinates of the tile
|
|
gfxRect tileRect = nsLayoutUtils::RectToGfxRect(
|
|
nsRect(x, y, aDest.width, aDest.height),
|
|
appUnitsPerDevPixel);
|
|
// The actual area to fill with this tile is the intersection of this
|
|
// tile with the overall area we're supposed to be filling
|
|
gfxRect fillRect =
|
|
forceRepeatToCoverTiles ? areaToFill : tileRect.Intersect(areaToFill);
|
|
// Try snapping the fill rect. Snap its top-left and bottom-right
|
|
// independently to preserve the orientation.
|
|
gfxPoint snappedFillRectTopLeft = fillRect.TopLeft();
|
|
gfxPoint snappedFillRectTopRight = fillRect.TopRight();
|
|
gfxPoint snappedFillRectBottomRight = fillRect.BottomRight();
|
|
// Snap three points instead of just two to ensure we choose the
|
|
// correct orientation if there's a reflection.
|
|
if (isCTMPreservingAxisAlignedRectangles &&
|
|
aContext.UserToDevicePixelSnapped(snappedFillRectTopLeft, true) &&
|
|
aContext.UserToDevicePixelSnapped(snappedFillRectBottomRight, true) &&
|
|
aContext.UserToDevicePixelSnapped(snappedFillRectTopRight, true)) {
|
|
if (snappedFillRectTopLeft.x == snappedFillRectBottomRight.x ||
|
|
snappedFillRectTopLeft.y == snappedFillRectBottomRight.y) {
|
|
// Nothing to draw; avoid scaling by zero and other weirdness that
|
|
// could put the context in an error state.
|
|
continue;
|
|
}
|
|
// Set the context's transform to the transform that maps fillRect to
|
|
// snappedFillRect. The part of the gradient that was going to
|
|
// exactly fill fillRect will fill snappedFillRect instead.
|
|
gfxMatrix transform = gfxUtils::TransformRectToRect(fillRect,
|
|
snappedFillRectTopLeft, snappedFillRectTopRight,
|
|
snappedFillRectBottomRight);
|
|
aContext.SetMatrixDouble(transform);
|
|
}
|
|
aContext.NewPath();
|
|
aContext.Rectangle(fillRect);
|
|
|
|
gfxRect dirtyFillRect = fillRect.Intersect(dirtyAreaToFill);
|
|
gfxRect fillRectRelativeToTile = dirtyFillRect - tileRect.TopLeft();
|
|
Color edgeColor;
|
|
if (mGradient->mShape == NS_STYLE_GRADIENT_SHAPE_LINEAR && !isRepeat &&
|
|
RectIsBeyondLinearGradientEdge(fillRectRelativeToTile, matrix, mStops,
|
|
gradientStart, gradientEnd, &edgeColor)) {
|
|
edgeColor.a *= aOpacity;
|
|
aContext.SetColor(edgeColor);
|
|
} else {
|
|
aContext.SetMatrixDouble(
|
|
aContext.CurrentMatrixDouble().Copy().PreTranslate(tileRect.TopLeft()));
|
|
aContext.SetPattern(gradientPattern);
|
|
}
|
|
aContext.Fill();
|
|
aContext.SetMatrix(ctm);
|
|
}
|
|
}
|
|
}
|
|
|
|
bool
|
|
nsCSSGradientRenderer::TryPaintTilesWithExtendMode(gfxContext& aContext,
|
|
gfxPattern* aGradientPattern,
|
|
nscoord aXStart,
|
|
nscoord aYStart,
|
|
const gfxRect& aDirtyAreaToFill,
|
|
const nsRect& aDest,
|
|
const nsSize& aRepeatSize,
|
|
bool aForceRepeatToCoverTiles)
|
|
{
|
|
// If we have forced a non-repeating gradient to repeat to cover tiles,
|
|
// then it will be faster to just paint it once using that optimization
|
|
if (aForceRepeatToCoverTiles) {
|
|
return false;
|
|
}
|
|
|
|
nscoord appUnitsPerDevPixel = mPresContext->AppUnitsPerDevPixel();
|
|
|
|
// We can only use this fast path if we don't have to worry about pixel
|
|
// snapping, and there is no spacing between tiles. We could handle spacing
|
|
// by increasing the size of tileSurface and leaving it transparent, but I'm
|
|
// not sure it's worth it
|
|
bool canUseExtendModeForTiling =
|
|
(aXStart % appUnitsPerDevPixel == 0) &&
|
|
(aYStart % appUnitsPerDevPixel == 0) &&
|
|
(aDest.width % appUnitsPerDevPixel == 0) &&
|
|
(aDest.height % appUnitsPerDevPixel == 0) &&
|
|
(aRepeatSize.width == aDest.width) &&
|
|
(aRepeatSize.height == aDest.height);
|
|
|
|
if (!canUseExtendModeForTiling) {
|
|
return false;
|
|
}
|
|
|
|
IntSize tileSize {
|
|
NSAppUnitsToIntPixels(aDest.width, appUnitsPerDevPixel),
|
|
NSAppUnitsToIntPixels(aDest.height, appUnitsPerDevPixel),
|
|
};
|
|
|
|
// Check whether this is a reasonable surface size and doesn't overflow
|
|
// before doing calculations with the tile size
|
|
if (!Factory::ReasonableSurfaceSize(tileSize)) {
|
|
return false;
|
|
}
|
|
|
|
// We only want to do this when there are enough tiles to justify the
|
|
// overhead of painting to an offscreen surface. The heuristic here
|
|
// is when we will be painting at least 16 tiles or more, this is kind
|
|
// of arbitrary
|
|
bool shouldUseExtendModeForTiling =
|
|
aDirtyAreaToFill.Area() > (tileSize.width * tileSize.height) * 16.0;
|
|
|
|
if (!shouldUseExtendModeForTiling) {
|
|
return false;
|
|
}
|
|
|
|
// Draw the gradient pattern into a surface for our single tile
|
|
RefPtr<gfx::SourceSurface> tileSurface;
|
|
{
|
|
RefPtr<gfx::DrawTarget> tileTarget = aContext.
|
|
GetDrawTarget()->
|
|
CreateSimilarDrawTarget(tileSize, gfx::SurfaceFormat::B8G8R8A8);
|
|
if (!tileTarget || !tileTarget->IsValid()) {
|
|
return false;
|
|
}
|
|
|
|
RefPtr<gfxContext> tileContext = gfxContext::CreateOrNull(tileTarget);
|
|
|
|
tileContext->SetPattern(aGradientPattern);
|
|
tileContext->Paint();
|
|
|
|
tileContext = nullptr;
|
|
tileSurface = tileTarget->Snapshot();
|
|
tileTarget = nullptr;
|
|
}
|
|
|
|
// Draw the gradient using tileSurface as a repeating pattern masked by
|
|
// the dirtyRect
|
|
Matrix tileTransform = Matrix::Translation(
|
|
NSAppUnitsToFloatPixels(aXStart, appUnitsPerDevPixel),
|
|
NSAppUnitsToFloatPixels(aYStart, appUnitsPerDevPixel));
|
|
|
|
aContext.NewPath();
|
|
aContext.Rectangle(aDirtyAreaToFill);
|
|
aContext.Fill(SurfacePattern(
|
|
tileSurface,
|
|
ExtendMode::REPEAT,
|
|
tileTransform));
|
|
|
|
return true;
|
|
}
|
|
|
|
void
|
|
nsCSSGradientRenderer::BuildWebRenderParameters(float aOpacity,
|
|
wr::ExtendMode& aMode,
|
|
nsTArray<wr::GradientStop>& aStops,
|
|
LayoutDevicePoint& aLineStart,
|
|
LayoutDevicePoint& aLineEnd,
|
|
LayoutDeviceSize& aGradientRadius)
|
|
{
|
|
aMode = mGradient->mRepeating ? wr::ExtendMode::Repeat : wr::ExtendMode::Clamp;
|
|
|
|
aStops.SetLength(mStops.Length());
|
|
for(uint32_t i = 0; i < mStops.Length(); i++) {
|
|
aStops[i].color.r = mStops[i].mColor.r;
|
|
aStops[i].color.g = mStops[i].mColor.g;
|
|
aStops[i].color.b = mStops[i].mColor.b;
|
|
aStops[i].color.a = mStops[i].mColor.a * aOpacity;
|
|
aStops[i].offset = mStops[i].mPosition;
|
|
}
|
|
|
|
aLineStart = LayoutDevicePoint(mLineStart.x, mLineStart.y);
|
|
aLineEnd = LayoutDevicePoint(mLineEnd.x, mLineEnd.y);
|
|
aGradientRadius = LayoutDeviceSize(mRadiusX, mRadiusY);
|
|
}
|
|
|
|
void
|
|
nsCSSGradientRenderer::BuildWebRenderDisplayItems(wr::DisplayListBuilder& aBuilder,
|
|
const layers::StackingContextHelper& aSc,
|
|
const nsRect& aDest,
|
|
const nsRect& aFillArea,
|
|
const nsSize& aRepeatSize,
|
|
const CSSIntRect& aSrc,
|
|
bool aIsBackfaceVisible,
|
|
float aOpacity)
|
|
{
|
|
if (aDest.IsEmpty() || aFillArea.IsEmpty()) {
|
|
return;
|
|
}
|
|
|
|
wr::ExtendMode extendMode;
|
|
nsTArray<wr::GradientStop> stops;
|
|
LayoutDevicePoint lineStart;
|
|
LayoutDevicePoint lineEnd;
|
|
LayoutDeviceSize gradientRadius;
|
|
BuildWebRenderParameters(aOpacity, extendMode, stops, lineStart, lineEnd, gradientRadius);
|
|
|
|
nscoord appUnitsPerDevPixel = mPresContext->AppUnitsPerDevPixel();
|
|
|
|
nsPoint firstTile = nsPoint(FindTileStart(aFillArea.x, aDest.x, aRepeatSize.width),
|
|
FindTileStart(aFillArea.y, aDest.y, aRepeatSize.height));
|
|
|
|
// Translate the parameters into device coordinates
|
|
LayoutDeviceRect clipBounds = LayoutDevicePixel::FromAppUnits(aFillArea, appUnitsPerDevPixel);
|
|
LayoutDeviceRect firstTileBounds = LayoutDevicePixel::FromAppUnits(nsRect(firstTile, aDest.Size()), appUnitsPerDevPixel);
|
|
LayoutDeviceSize tileRepeat = LayoutDevicePixel::FromAppUnits(aRepeatSize, appUnitsPerDevPixel);
|
|
|
|
// Calculate the bounds of the gradient display item, which starts at the first
|
|
// tile and extends to the end of clip bounds
|
|
LayoutDevicePoint tileToClip = clipBounds.BottomRight() - firstTileBounds.TopLeft();
|
|
LayoutDeviceRect gradientBounds = LayoutDeviceRect(firstTileBounds.TopLeft(),
|
|
LayoutDeviceSize(tileToClip.x, tileToClip.y));
|
|
|
|
// Calculate the tile spacing, which is the repeat size minus the tile size
|
|
LayoutDeviceSize tileSpacing = tileRepeat - firstTileBounds.Size();
|
|
|
|
// srcTransform is used for scaling the gradient to match aSrc
|
|
LayoutDeviceRect srcTransform = LayoutDeviceRect(nsPresContext::CSSPixelsToAppUnits(aSrc.x),
|
|
nsPresContext::CSSPixelsToAppUnits(aSrc.y),
|
|
aDest.width / ((float)nsPresContext::CSSPixelsToAppUnits(aSrc.width)),
|
|
aDest.height / ((float)nsPresContext::CSSPixelsToAppUnits(aSrc.height)));
|
|
|
|
lineStart.x = (lineStart.x - srcTransform.x) * srcTransform.width;
|
|
lineStart.y = (lineStart.y - srcTransform.y) * srcTransform.height;
|
|
|
|
if (mGradient->mShape == NS_STYLE_GRADIENT_SHAPE_LINEAR) {
|
|
lineEnd.x = (lineEnd.x - srcTransform.x) * srcTransform.width;
|
|
lineEnd.y = (lineEnd.y - srcTransform.y) * srcTransform.height;
|
|
|
|
aBuilder.PushLinearGradient(
|
|
mozilla::wr::ToLayoutRect(gradientBounds),
|
|
mozilla::wr::ToLayoutRect(clipBounds),
|
|
aIsBackfaceVisible,
|
|
mozilla::wr::ToLayoutPoint(lineStart),
|
|
mozilla::wr::ToLayoutPoint(lineEnd),
|
|
stops,
|
|
extendMode,
|
|
mozilla::wr::ToLayoutSize(firstTileBounds.Size()),
|
|
mozilla::wr::ToLayoutSize(tileSpacing));
|
|
} else {
|
|
gradientRadius.width *= srcTransform.width;
|
|
gradientRadius.height *= srcTransform.height;
|
|
|
|
aBuilder.PushRadialGradient(
|
|
mozilla::wr::ToLayoutRect(gradientBounds),
|
|
mozilla::wr::ToLayoutRect(clipBounds),
|
|
aIsBackfaceVisible,
|
|
mozilla::wr::ToLayoutPoint(lineStart),
|
|
mozilla::wr::ToLayoutSize(gradientRadius),
|
|
stops,
|
|
extendMode,
|
|
mozilla::wr::ToLayoutSize(firstTileBounds.Size()),
|
|
mozilla::wr::ToLayoutSize(tileSpacing));
|
|
}
|
|
}
|
|
|
|
} // namespace mozilla
|