blob: b7ef88ba3b654923881d3ca8b1939be0487928c0 [file] [log] [blame]
/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkTypes.h"
#include "SkDWriteGeometrySink.h"
#include "SkFloatUtils.h"
#include "SkPath.h"
#include <dwrite.h>
#include <d2d1.h>
SkDWriteGeometrySink::SkDWriteGeometrySink(SkPath* path) : fRefCount(1), fPath(path) { }
SkDWriteGeometrySink::~SkDWriteGeometrySink() { }
HRESULT STDMETHODCALLTYPE SkDWriteGeometrySink::QueryInterface(REFIID iid, void **object) {
if (NULL == object) {
return E_INVALIDARG;
}
if (iid == __uuidof(IUnknown) || iid == __uuidof(IDWriteGeometrySink)) {
*object = static_cast<IDWriteGeometrySink*>(this);
this->AddRef();
return S_OK;
} else {
*object = NULL;
return E_NOINTERFACE;
}
}
ULONG STDMETHODCALLTYPE SkDWriteGeometrySink::AddRef(void) {
return static_cast<ULONG>(InterlockedIncrement(&fRefCount));
}
ULONG STDMETHODCALLTYPE SkDWriteGeometrySink::Release(void) {
ULONG res = static_cast<ULONG>(InterlockedDecrement(&fRefCount));
if (0 == res) {
delete this;
}
return res;
}
void STDMETHODCALLTYPE SkDWriteGeometrySink::SetFillMode(D2D1_FILL_MODE fillMode) {
switch (fillMode) {
case D2D1_FILL_MODE_ALTERNATE:
fPath->setFillType(SkPath::kEvenOdd_FillType);
break;
case D2D1_FILL_MODE_WINDING:
fPath->setFillType(SkPath::kWinding_FillType);
break;
default:
SkDEBUGFAIL("Unknown D2D1_FILL_MODE.");
break;
}
}
void STDMETHODCALLTYPE SkDWriteGeometrySink::SetSegmentFlags(D2D1_PATH_SEGMENT vertexFlags) {
if (vertexFlags == D2D1_PATH_SEGMENT_NONE || vertexFlags == D2D1_PATH_SEGMENT_FORCE_ROUND_LINE_JOIN) {
SkDEBUGFAIL("Invalid D2D1_PATH_SEGMENT value.");
}
}
void STDMETHODCALLTYPE SkDWriteGeometrySink::BeginFigure(D2D1_POINT_2F startPoint, D2D1_FIGURE_BEGIN figureBegin) {
fPath->moveTo(startPoint.x, startPoint.y);
if (figureBegin == D2D1_FIGURE_BEGIN_HOLLOW) {
SkDEBUGFAIL("Invalid D2D1_FIGURE_BEGIN value.");
}
}
void STDMETHODCALLTYPE SkDWriteGeometrySink::AddLines(const D2D1_POINT_2F *points, UINT pointsCount) {
for (const D2D1_POINT_2F *end = &points[pointsCount]; points < end; ++points) {
fPath->lineTo(points->x, points->y);
}
}
static bool approximately_equal(float a, float b) {
const SkFloatingPoint<float, 10> lhs(a), rhs(b);
return lhs.AlmostEquals(rhs);
}
typedef struct {
float x;
float y;
} Cubic[4], Quadratic[3];
static bool check_quadratic(const Cubic& cubic, Quadratic& reduction) {
float dx10 = cubic[1].x - cubic[0].x;
float dx23 = cubic[2].x - cubic[3].x;
float midX = cubic[0].x + dx10 * 3 / 2;
//NOTE: !approximately_equal(midX - cubic[3].x, dx23 * 3 / 2)
//does not work as subnormals get in between the left side and 0.
if (!approximately_equal(midX, (dx23 * 3 / 2) + cubic[3].x)) {
return false;
}
float dy10 = cubic[1].y - cubic[0].y;
float dy23 = cubic[2].y - cubic[3].y;
float midY = cubic[0].y + dy10 * 3 / 2;
if (!approximately_equal(midY, (dy23 * 3 / 2) + cubic[3].y)) {
return false;
}
reduction[0] = cubic[0];
reduction[1].x = midX;
reduction[1].y = midY;
reduction[2] = cubic[3];
return true;
}
void STDMETHODCALLTYPE SkDWriteGeometrySink::AddBeziers(const D2D1_BEZIER_SEGMENT *beziers, UINT beziersCount) {
SkPoint lastPt;
fPath->getLastPt(&lastPt);
D2D1_POINT_2F prevPt = { SkScalarToFloat(lastPt.fX), SkScalarToFloat(lastPt.fY) };
for (const D2D1_BEZIER_SEGMENT *end = &beziers[beziersCount]; beziers < end; ++beziers) {
Cubic cubic = { { prevPt.x, prevPt.y },
{ beziers->point1.x, beziers->point1.y },
{ beziers->point2.x, beziers->point2.y },
{ beziers->point3.x, beziers->point3.y }, };
Quadratic quadratic;
if (check_quadratic(cubic, quadratic)) {
fPath->quadTo(quadratic[1].x, quadratic[1].y,
quadratic[2].x, quadratic[2].y);
} else {
fPath->cubicTo(beziers->point1.x, beziers->point1.y,
beziers->point2.x, beziers->point2.y,
beziers->point3.x, beziers->point3.y);
}
prevPt = beziers->point3;
}
}
void STDMETHODCALLTYPE SkDWriteGeometrySink::EndFigure(D2D1_FIGURE_END figureEnd) {
fPath->close();
}
HRESULT SkDWriteGeometrySink::Close() {
return S_OK;
}
HRESULT SkDWriteGeometrySink::Create(SkPath* path, IDWriteGeometrySink** geometryToPath) {
*geometryToPath = new SkDWriteGeometrySink(path);
return S_OK;
}