1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/utils/win/SkDWriteGeometrySink.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,146 @@
1.4 +/*
1.5 + * Copyright 2012 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#include "SkTypes.h"
1.12 +
1.13 +#include "SkDWriteGeometrySink.h"
1.14 +#include "SkFloatUtils.h"
1.15 +#include "SkPath.h"
1.16 +
1.17 +#include <dwrite.h>
1.18 +#include <d2d1.h>
1.19 +
1.20 +SkDWriteGeometrySink::SkDWriteGeometrySink(SkPath* path) : fRefCount(1), fPath(path) { }
1.21 +
1.22 +SkDWriteGeometrySink::~SkDWriteGeometrySink() { }
1.23 +
1.24 +HRESULT STDMETHODCALLTYPE SkDWriteGeometrySink::QueryInterface(REFIID iid, void **object) {
1.25 + if (NULL == object) {
1.26 + return E_INVALIDARG;
1.27 + }
1.28 + if (iid == __uuidof(IUnknown) || iid == __uuidof(IDWriteGeometrySink)) {
1.29 + *object = static_cast<IDWriteGeometrySink*>(this);
1.30 + this->AddRef();
1.31 + return S_OK;
1.32 + } else {
1.33 + *object = NULL;
1.34 + return E_NOINTERFACE;
1.35 + }
1.36 +}
1.37 +
1.38 +ULONG STDMETHODCALLTYPE SkDWriteGeometrySink::AddRef(void) {
1.39 + return static_cast<ULONG>(InterlockedIncrement(&fRefCount));
1.40 +}
1.41 +
1.42 +ULONG STDMETHODCALLTYPE SkDWriteGeometrySink::Release(void) {
1.43 + ULONG res = static_cast<ULONG>(InterlockedDecrement(&fRefCount));
1.44 + if (0 == res) {
1.45 + delete this;
1.46 + }
1.47 + return res;
1.48 +}
1.49 +
1.50 +void STDMETHODCALLTYPE SkDWriteGeometrySink::SetFillMode(D2D1_FILL_MODE fillMode) {
1.51 + switch (fillMode) {
1.52 + case D2D1_FILL_MODE_ALTERNATE:
1.53 + fPath->setFillType(SkPath::kEvenOdd_FillType);
1.54 + break;
1.55 + case D2D1_FILL_MODE_WINDING:
1.56 + fPath->setFillType(SkPath::kWinding_FillType);
1.57 + break;
1.58 + default:
1.59 + SkDEBUGFAIL("Unknown D2D1_FILL_MODE.");
1.60 + break;
1.61 + }
1.62 +}
1.63 +
1.64 +void STDMETHODCALLTYPE SkDWriteGeometrySink::SetSegmentFlags(D2D1_PATH_SEGMENT vertexFlags) {
1.65 + if (vertexFlags == D2D1_PATH_SEGMENT_NONE || vertexFlags == D2D1_PATH_SEGMENT_FORCE_ROUND_LINE_JOIN) {
1.66 + SkDEBUGFAIL("Invalid D2D1_PATH_SEGMENT value.");
1.67 + }
1.68 +}
1.69 +
1.70 +void STDMETHODCALLTYPE SkDWriteGeometrySink::BeginFigure(D2D1_POINT_2F startPoint, D2D1_FIGURE_BEGIN figureBegin) {
1.71 + fPath->moveTo(startPoint.x, startPoint.y);
1.72 + if (figureBegin == D2D1_FIGURE_BEGIN_HOLLOW) {
1.73 + SkDEBUGFAIL("Invalid D2D1_FIGURE_BEGIN value.");
1.74 + }
1.75 +}
1.76 +
1.77 +void STDMETHODCALLTYPE SkDWriteGeometrySink::AddLines(const D2D1_POINT_2F *points, UINT pointsCount) {
1.78 + for (const D2D1_POINT_2F *end = &points[pointsCount]; points < end; ++points) {
1.79 + fPath->lineTo(points->x, points->y);
1.80 + }
1.81 +}
1.82 +
1.83 +static bool approximately_equal(float a, float b) {
1.84 + const SkFloatingPoint<float, 10> lhs(a), rhs(b);
1.85 + return lhs.AlmostEquals(rhs);
1.86 +}
1.87 +
1.88 +typedef struct {
1.89 + float x;
1.90 + float y;
1.91 +} Cubic[4], Quadratic[3];
1.92 +
1.93 +static bool check_quadratic(const Cubic& cubic, Quadratic& reduction) {
1.94 + float dx10 = cubic[1].x - cubic[0].x;
1.95 + float dx23 = cubic[2].x - cubic[3].x;
1.96 + float midX = cubic[0].x + dx10 * 3 / 2;
1.97 + //NOTE: !approximately_equal(midX - cubic[3].x, dx23 * 3 / 2)
1.98 + //does not work as subnormals get in between the left side and 0.
1.99 + if (!approximately_equal(midX, (dx23 * 3 / 2) + cubic[3].x)) {
1.100 + return false;
1.101 + }
1.102 + float dy10 = cubic[1].y - cubic[0].y;
1.103 + float dy23 = cubic[2].y - cubic[3].y;
1.104 + float midY = cubic[0].y + dy10 * 3 / 2;
1.105 + if (!approximately_equal(midY, (dy23 * 3 / 2) + cubic[3].y)) {
1.106 + return false;
1.107 + }
1.108 + reduction[0] = cubic[0];
1.109 + reduction[1].x = midX;
1.110 + reduction[1].y = midY;
1.111 + reduction[2] = cubic[3];
1.112 + return true;
1.113 +}
1.114 +
1.115 +void STDMETHODCALLTYPE SkDWriteGeometrySink::AddBeziers(const D2D1_BEZIER_SEGMENT *beziers, UINT beziersCount) {
1.116 + SkPoint lastPt;
1.117 + fPath->getLastPt(&lastPt);
1.118 + D2D1_POINT_2F prevPt = { SkScalarToFloat(lastPt.fX), SkScalarToFloat(lastPt.fY) };
1.119 +
1.120 + for (const D2D1_BEZIER_SEGMENT *end = &beziers[beziersCount]; beziers < end; ++beziers) {
1.121 + Cubic cubic = { { prevPt.x, prevPt.y },
1.122 + { beziers->point1.x, beziers->point1.y },
1.123 + { beziers->point2.x, beziers->point2.y },
1.124 + { beziers->point3.x, beziers->point3.y }, };
1.125 + Quadratic quadratic;
1.126 + if (check_quadratic(cubic, quadratic)) {
1.127 + fPath->quadTo(quadratic[1].x, quadratic[1].y,
1.128 + quadratic[2].x, quadratic[2].y);
1.129 + } else {
1.130 + fPath->cubicTo(beziers->point1.x, beziers->point1.y,
1.131 + beziers->point2.x, beziers->point2.y,
1.132 + beziers->point3.x, beziers->point3.y);
1.133 + }
1.134 + prevPt = beziers->point3;
1.135 + }
1.136 +}
1.137 +
1.138 +void STDMETHODCALLTYPE SkDWriteGeometrySink::EndFigure(D2D1_FIGURE_END figureEnd) {
1.139 + fPath->close();
1.140 +}
1.141 +
1.142 +HRESULT SkDWriteGeometrySink::Close() {
1.143 + return S_OK;
1.144 +}
1.145 +
1.146 +HRESULT SkDWriteGeometrySink::Create(SkPath* path, IDWriteGeometrySink** geometryToPath) {
1.147 + *geometryToPath = new SkDWriteGeometrySink(path);
1.148 + return S_OK;
1.149 +}
