зеркало из https://github.com/mozilla/gecko-dev.git
112 строки
3.2 KiB
C++
112 строки
3.2 KiB
C++
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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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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#include "gfxPath.h"
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#include "gfxPoint.h"
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#include "cairo.h"
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gfxPath::gfxPath(cairo_path_t* aPath) : mPath(aPath)
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{
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}
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gfxPath::~gfxPath()
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{
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cairo_path_destroy(mPath);
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}
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gfxFlattenedPath::gfxFlattenedPath(cairo_path_t* aPath) : gfxPath(aPath)
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{
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}
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gfxFlattenedPath::~gfxFlattenedPath()
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{
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}
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static gfxFloat
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CalcSubLengthAndAdvance(cairo_path_data_t *aData,
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gfxPoint &aPathStart, gfxPoint &aCurrent)
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{
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float sublength = 0;
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switch (aData->header.type) {
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case CAIRO_PATH_MOVE_TO:
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{
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aCurrent = aPathStart = gfxPoint(aData[1].point.x,
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aData[1].point.y);
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break;
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}
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case CAIRO_PATH_LINE_TO:
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{
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gfxPoint diff =
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gfxPoint(aData[1].point.x, aData[1].point.y) - aCurrent;
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sublength = sqrt(diff.x * diff.x + diff.y * diff.y);
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aCurrent = gfxPoint(aData[1].point.x, aData[1].point.y);
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break;
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}
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case CAIRO_PATH_CURVE_TO:
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/* should never happen with a flattened path */
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NS_WARNING("curve_to in flattened path");
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break;
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case CAIRO_PATH_CLOSE_PATH:
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{
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gfxPoint diff = aPathStart - aCurrent;
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sublength = sqrt(diff.x * diff.x + diff.y * diff.y);
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aCurrent = aPathStart;
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break;
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}
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}
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return sublength;
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}
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gfxFloat
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gfxFlattenedPath::GetLength()
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{
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gfxPoint start(0, 0); // start of current subpath
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gfxPoint current(0, 0); // current point
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gfxFloat length = 0; // current summed length
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for (int32_t i = 0;
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i < mPath->num_data;
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i += mPath->data[i].header.length) {
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length += CalcSubLengthAndAdvance(&mPath->data[i], start, current);
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}
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return length;
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}
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gfxPoint
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gfxFlattenedPath::FindPoint(gfxPoint aOffset, gfxFloat *aAngle)
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{
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gfxPoint start(0, 0); // start of current subpath
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gfxPoint current(0, 0); // current point
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gfxFloat length = 0; // current summed length
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for (int32_t i = 0;
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i < mPath->num_data;
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i += mPath->data[i].header.length) {
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gfxPoint prev = current;
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gfxFloat sublength = CalcSubLengthAndAdvance(&mPath->data[i],
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start, current);
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gfxPoint diff = current - prev;
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if (aAngle)
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*aAngle = atan2(diff.y, diff.x);
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if (sublength != 0 && length + sublength >= aOffset.x) {
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gfxFloat ratio = (aOffset.x - length) / sublength;
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gfxFloat normalization =
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1.0 / sqrt(diff.x * diff.x + diff.y * diff.y);
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return prev * (1.0f - ratio) + current * ratio +
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gfxPoint(-diff.y, diff.x) * aOffset.y * normalization;
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}
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length += sublength;
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}
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// requested offset is past the end of the path - return last point
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return current;
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}
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