/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "VectorDrawableUtils.h"
#include "PathParser.h"
#include <math.h>
#include <utils/Log.h>
namespace android {
namespace uirenderer {
class PathResolver {
public:
float currentX = 0;
float currentY = 0;
float ctrlPointX = 0;
float ctrlPointY = 0;
float currentSegmentStartX = 0;
float currentSegmentStartY = 0;
void addCommand(SkPath* outPath, char previousCmd, char cmd, const std::vector<float>* points,
size_t start, size_t end);
};
bool VectorDrawableUtils::canMorph(const PathData& morphFrom, const PathData& morphTo) {
if (morphFrom.verbs.size() != morphTo.verbs.size()) {
return false;
}
for (unsigned int i = 0; i < morphFrom.verbs.size(); i++) {
if (morphFrom.verbs[i] != morphTo.verbs[i] ||
morphFrom.verbSizes[i] != morphTo.verbSizes[i]) {
return false;
}
}
return true;
}
bool VectorDrawableUtils::interpolatePathData(PathData* outData, const PathData& morphFrom,
const PathData& morphTo, float fraction) {
if (!canMorph(morphFrom, morphTo)) {
return false;
}
interpolatePaths(outData, morphFrom, morphTo, fraction);
return true;
}
/**
* Convert an array of PathVerb to Path.
*/
void VectorDrawableUtils::verbsToPath(SkPath* outPath, const PathData& data) {
PathResolver resolver;
char previousCommand = 'm';
size_t start = 0;
outPath->reset();
for (unsigned int i = 0; i < data.verbs.size(); i++) {
size_t verbSize = data.verbSizes[i];
resolver.addCommand(outPath, previousCommand, data.verbs[i], &data.points, start,
start + verbSize);
previousCommand = data.verbs[i];
start += verbSize;
}
}
/**
* The current PathVerb will be interpolated between the
* <code>nodeFrom</code> and <code>nodeTo</code> according to the
* <code>fraction</code>.
*
* @param nodeFrom The start value as a PathVerb.
* @param nodeTo The end value as a PathVerb
* @param fraction The fraction to interpolate.
*/
void VectorDrawableUtils::interpolatePaths(PathData* outData, const PathData& from,
const PathData& to, float fraction) {
outData->points.resize(from.points.size());
outData->verbSizes = from.verbSizes;
outData->verbs = from.verbs;
for (size_t i = 0; i < from.points.size(); i++) {
outData->points[i] = from.points[i] * (1 - fraction) + to.points[i] * fraction;
}
}
// Use the given verb, and points in the range [start, end) to insert a command into the SkPath.
void PathResolver::addCommand(SkPath* outPath, char previousCmd, char cmd,
const std::vector<float>* points, size_t start, size_t end) {
int incr = 2;
float reflectiveCtrlPointX;
float reflectiveCtrlPointY;
switch (cmd) {
case 'z':
case 'Z':
outPath->close();
// Path is closed here, but we need to move the pen to the
// closed position. So we cache the segment's starting position,
// and restore it here.
currentX = currentSegmentStartX;
currentY = currentSegmentStartY;
ctrlPointX = currentSegmentStartX;
ctrlPointY = currentSegmentStartY;
outPath->moveTo(currentX, currentY);
break;
case 'm':
case 'M':
case 'l':
case 'L':
case 't':
case 'T':
incr = 2;
break;
case 'h':
case 'H':
case 'v':
case 'V':
incr = 1;
break;
case 'c':
case 'C':
incr = 6;
break;
case 's':
case 'S':
case 'q':
case 'Q':
incr = 4;
break;
case 'a':
case 'A':
incr = 7;
break;
}
for (unsigned int k = start; k < end; k += incr) {
switch (cmd) {
case 'm': // moveto - Start a new sub-path (relative)
currentX += points->at(k + 0);
currentY += points->at(k + 1);
if (k > start) {
// According to the spec, if a moveto is followed by multiple
// pairs of coordinates, the subsequent pairs are treated as
// implicit lineto commands.
outPath->rLineTo(points->at(k + 0), points->at(k + 1));
} else {
outPath->rMoveTo(points->at(k + 0), points->at(k + 1));
currentSegmentStartX = currentX;
currentSegmentStartY = currentY;
}
break;
case 'M': // moveto - Start a new sub-path
currentX = points->at(k + 0);
currentY = points->at(k + 1);
if (k > start) {
// According to the spec, if a moveto is followed by multiple
// pairs of coordinates, the subsequent pairs are treated as
// implicit lineto commands.
outPath->lineTo(points->at(k + 0), points->at(k + 1));
} else {
outPath->moveTo(points->at(k + 0), points->at(k + 1));
currentSegmentStartX = currentX;
currentSegmentStartY = currentY;
}
break;
case 'l': // lineto - Draw a line from the current point (relative)
outPath->rLineTo(points->at(k + 0), points->at(k + 1));
currentX += points->at(k + 0);
currentY += points->at(k + 1);
break;
case 'L': // lineto - Draw a line from the current point
outPath->lineTo(points->at(k + 0), points->at(k + 1));
currentX = points->at(k + 0);
currentY = points->at(k + 1);
break;
case 'h': // horizontal lineto - Draws a horizontal line (relative)
outPath->rLineTo(points->at(k + 0), 0);
currentX += points->at(k + 0);
break;
case 'H': // horizontal lineto - Draws a horizontal line
outPath->lineTo(points->at(k + 0), currentY);
currentX = points->at(k + 0);
break;
case 'v': // vertical lineto - Draws a vertical line from the current point (r)
outPath->rLineTo(0, points->at(k + 0));
currentY += points->at(k + 0);
break;
case 'V': // vertical lineto - Draws a vertical line from the current point
outPath->lineTo(currentX, points->at(k + 0));
currentY = points->at(k + 0);
break;
case 'c': // curveto - Draws a cubic Bézier curve (relative)
outPath->rCubicTo(points->at(k + 0), points->at(k + 1), points->at(k + 2),
points->at(k + 3), points->at(k + 4), points->at(k + 5));
ctrlPointX = currentX + points->at(k + 2);
ctrlPointY = currentY + points->at(k + 3);
currentX += points->at(k + 4);
currentY += points->at(k + 5);
break;
case 'C': // curveto - Draws a cubic Bézier curve
outPath->cubicTo(points->at(k + 0), points->at(k + 1), points->at(k + 2),
points->at(k + 3), points->at(k + 4), points->at(k + 5));
currentX = points->at(k + 4);
currentY = points->at(k + 5);
ctrlPointX = points->at(k + 2);
ctrlPointY = points->at(k + 3);
break;
case 's': // smooth curveto - Draws a cubic Bézier curve (reflective cp)
reflectiveCtrlPointX = 0;
reflectiveCtrlPointY = 0;
if (previousCmd == 'c' || previousCmd == 's' || previousCmd == 'C' ||
previousCmd == 'S') {
reflectiveCtrlPointX = currentX - ctrlPointX;
reflectiveCtrlPointY = currentY - ctrlPointY;
}
outPath->rCubicTo(reflectiveCtrlPointX, reflectiveCtrlPointY, points->at(k + 0),
points->at(k + 1), points->at(k + 2), points->at(k + 3));
ctrlPointX = currentX + points->at(k + 0);
ctrlPointY = currentY + points->at(k + 1);
currentX += points->at(k + 2);
currentY += points->at(k + 3);
break;
case 'S': // shorthand/smooth curveto Draws a cubic Bézier curve(reflective cp)
reflectiveCtrlPointX = currentX;
reflectiveCtrlPointY = currentY;
if (previousCmd == 'c' || previousCmd == 's' || previousCmd == 'C' ||
previousCmd == 'S') {
reflectiveCtrlPointX = 2 * currentX - ctrlPointX;
reflectiveCtrlPointY = 2 * currentY - ctrlPointY;
}
outPath->cubicTo(reflectiveCtrlPointX, reflectiveCtrlPointY, points->at(k + 0),
points->at(k + 1), points->at(k + 2), points->at(k + 3));
ctrlPointX = points->at(k + 0);
ctrlPointY = points->at(k + 1);
currentX = points->at(k + 2);
currentY = points->at(k + 3);
break;
case 'q': // Draws a quadratic Bézier (relative)
outPath->rQuadTo(points->at(k + 0), points->at(k + 1), points->at(k + 2),
points->at(k + 3));
ctrlPointX = currentX + points->at(k + 0);
ctrlPointY = currentY + points->at(k + 1);
currentX += points->at(k + 2);
currentY += points->at(k + 3);
break;
case 'Q': // Draws a quadratic Bézier
outPath->quadTo(points->at(k + 0), points->at(k + 1), points->at(k + 2),
points->at(k + 3));
ctrlPointX = points->at(k + 0);
ctrlPointY = points->at(k + 1);
currentX = points->at(k + 2);
currentY = points->at(k + 3);
break;
case 't': // Draws a quadratic Bézier curve(reflective control point)(relative)
reflectiveCtrlPointX = 0;
reflectiveCtrlPointY = 0;
if (previousCmd == 'q' || previousCmd == 't' || previousCmd == 'Q' ||
previousCmd == 'T') {
reflectiveCtrlPointX = currentX - ctrlPointX;
reflectiveCtrlPointY = currentY - ctrlPointY;
}
outPath->rQuadTo(reflectiveCtrlPointX, reflectiveCtrlPointY, points->at(k + 0),
points->at(k + 1));
ctrlPointX = currentX + reflectiveCtrlPointX;
ctrlPointY = currentY + reflectiveCtrlPointY;
currentX += points->at(k + 0);
currentY += points->at(k + 1);
break;
case 'T': // Draws a quadratic Bézier curve (reflective control point)
reflectiveCtrlPointX = currentX;
reflectiveCtrlPointY = currentY;
if (previousCmd == 'q' || previousCmd == 't' || previousCmd == 'Q' ||
previousCmd == 'T') {
reflectiveCtrlPointX = 2 * currentX - ctrlPointX;
reflectiveCtrlPointY = 2 * currentY - ctrlPointY;
}
outPath->quadTo(reflectiveCtrlPointX, reflectiveCtrlPointY, points->at(k + 0),
points->at(k + 1));
ctrlPointX = reflectiveCtrlPointX;
ctrlPointY = reflectiveCtrlPointY;
currentX = points->at(k + 0);
currentY = points->at(k + 1);
break;
case 'a': // Draws an elliptical arc
// (rx ry x-axis-rotation large-arc-flag sweep-flag x y)
outPath->arcTo(points->at(k + 0), points->at(k + 1), points->at(k + 2),
(SkPath::ArcSize) (points->at(k + 3) != 0),
(SkPath::Direction) (points->at(k + 4) == 0),
points->at(k + 5) + currentX, points->at(k + 6) + currentY);
currentX += points->at(k + 5);
currentY += points->at(k + 6);
ctrlPointX = currentX;
ctrlPointY = currentY;
break;
case 'A': // Draws an elliptical arc
outPath->arcTo(points->at(k + 0), points->at(k + 1), points->at(k + 2),
(SkPath::ArcSize) (points->at(k + 3) != 0),
(SkPath::Direction) (points->at(k + 4) == 0),
points->at(k + 5), points->at(k + 6));
currentX = points->at(k + 5);
currentY = points->at(k + 6);
ctrlPointX = currentX;
ctrlPointY = currentY;
break;
default:
LOG_ALWAYS_FATAL("Unsupported command: %c", cmd);
break;
}
previousCmd = cmd;
}
}
} // namespace uirenderer
} // namespace android