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common shape: support rounded rectangle.

Browse source 
Also remove arcTo implementation since curveTo could covers it.

Change-Id: Icc63eca55e51622fc80b57672f308f25f2301f85
This commit is contained in:
Hermet Park 2020-04-26 15:00:29 +09:00
parent a15e2c9ca0
commit e655471e09
5 changed files with 24 additions and 249 deletions
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24
src/lib/tvgShapeNode.cpp
View file

@ -23,6 +23,7 @@
/************************************************************************/ /************************************************************************/
/* Internal Class Implementation */ /* Internal Class Implementation */
/************************************************************************/ /************************************************************************/
constexpr auto PATH_KAPPA = 0.552284f;
struct ShapeFill struct ShapeFill
{ {
@ -139,8 +140,14 @@ int ShapeNode::appendCircle(float cx, float cy, float radius) noexcept
auto impl = pImpl.get(); auto impl = pImpl.get();
assert(impl); assert(impl);
impl->path->reserve(5, 13); //decide size experimentally (move + curve * 4) auto halfKappa = radius * PATH_KAPPA;
impl->path->arcTo(cx - radius, cy - radius, 2 * radius, 2 * radius, 0, 360);
impl->path->reserve(6, 13);
impl->path->moveTo(cx, cy - radius);
impl->path->cubicTo(cx + halfKappa, cy - radius, cx + radius, cy - halfKappa, cx + radius, cy);
impl->path->cubicTo(cx + radius, cy + halfKappa, cx + halfKappa, cy + radius, cx, cy + radius);
impl->path->cubicTo(cx - halfKappa, cy + radius, cx - radius, cy + halfKappa, cx - radius, cy);
impl->path->cubicTo(cx - radius, cy - halfKappa, cx - halfKappa, cy - radius, cx, cy - radius);
impl->path->close(); impl->path->close();
return 0; return 0;
@ -168,7 +175,18 @@ int ShapeNode::appendRect(float x, float y, float w, float h, float cornerRadius
} else if (w == h && cornerRadius * 2 == w) { } else if (w == h && cornerRadius * 2 == w) {
return appendCircle(x + (w * 0.5f), y + (h * 0.5f), cornerRadius); return appendCircle(x + (w * 0.5f), y + (h * 0.5f), cornerRadius);
} else { } else {
//... auto halfKappa = cornerRadius * 0.5;
impl->path->reserve(10, 17);
impl->path->moveTo(x + cornerRadius, y);
impl->path->lineTo(x + w - cornerRadius, y);
impl->path->cubicTo(x + w - cornerRadius + halfKappa, y, x + w, y + cornerRadius - halfKappa, x + w, y + cornerRadius);
impl->path->lineTo(x + w, y + h - cornerRadius);
impl->path->cubicTo(x + w, y + h - cornerRadius + halfKappa, x + w - cornerRadius + halfKappa, y + h, x + w - cornerRadius, y + h);
impl->path->lineTo(x + cornerRadius, y + h);
impl->path->cubicTo(x + cornerRadius - halfKappa, y + h, x, y + h - cornerRadius + halfKappa, x, y + h - cornerRadius);
impl->path->lineTo(x, y + cornerRadius);
impl->path->cubicTo(x, y + cornerRadius - halfKappa, x + cornerRadius - halfKappa, y, x + cornerRadius, y);
impl->path->close();
} }
return 0; return 0;

243
src/lib/tvgShapePath.h
View file

@ -23,14 +23,6 @@
/* Internal Class Implementation */ /* Internal Class Implementation */
/************************************************************************/ /************************************************************************/
constexpr auto PATH_KAPPA = 0.552284f;
struct ShapePath;
static float _arcAngle(float angle);
static int _arcToCubic(ShapePath& path, const Point* pts, size_t ptsCnt);
static void _findEllipseCoords(float x, float y, float w, float h, float startAngle, float sweepAngle, Point& ptStart, Point& ptEnd);
struct ShapePath struct ShapePath
{ {
PathCommand* cmds = nullptr; PathCommand* cmds = nullptr;
@ -120,144 +112,6 @@ struct ShapePath
} }
int arcTo(float x, float y, float w, float h, float startAngle, float sweepAngle)
{
if ((fabsf(w) < FLT_EPSILON) || (fabsf(h) < FLT_EPSILON)) return -1;
if (fabsf(sweepAngle) < FLT_EPSILON) return -1;
if (sweepAngle > 360) sweepAngle = 360;
else if (sweepAngle < -360) sweepAngle = -360;
auto half_w = w * 0.5f;
auto half_h = h * 0.5f;
auto half_w_kappa = half_w * PATH_KAPPA;
auto half_h_kappa = half_h * PATH_KAPPA;
//Curves for arc
Point pts[13] {
//start point: 0 degree
{x + w, y + half_h},
//0 -> 90 degree
{x + w, y + half_h + half_h_kappa},
{x + half_w + half_w_kappa, y + h},
{x + half_w, y + h},
//90 -> 180 degree
{x + half_w - half_w_kappa, y + h},
{x, y + half_h + half_h_kappa},
{x, y + half_h},
//180 -> 270 degree
{x, y + half_h - half_h_kappa},
{x + half_w - half_w_kappa, y},
{x + half_w, y},
//270 -> 0 degree
{x + half_w + half_w_kappa, y},
{x + w, y + half_h - half_h_kappa},
{x + w, y + half_w}
};
auto ptsCnt = 1; //one is reserved for the start point
Point curves[13];
//perfect circle: special case fast paths
if (fabsf(startAngle) <= FLT_EPSILON) {
if (fabsf(sweepAngle - 360) <= FLT_EPSILON) {
for (int i = 11; i >= 0; --i) {
curves[ptsCnt++] = pts[i];
}
curves[0] = pts[12];
return _arcToCubic(*this, curves, ptsCnt);
} else if (fabsf(sweepAngle + 360) <= FLT_EPSILON) {
for (int i = 1; i <= 12; ++i) {
curves[ptsCnt++] = pts[i];
}
curves[0] = pts[0];
return _arcToCubic(*this, curves, ptsCnt);
}
}
auto startSegment = static_cast<int>(floor(startAngle / 90));
auto endSegment = static_cast<int>(floor((startAngle + sweepAngle) / 90));
auto startDelta = (startAngle - (startSegment * 90)) / 90;
auto endDelta = ((startAngle + sweepAngle) - (endSegment * 90)) / 90;
auto delta = sweepAngle > 0 ? 1 : -1;
if (delta < 0) {
startDelta = 1 - startDelta;
endDelta = 1 - endDelta;
}
//avoid empty start segment
if (fabsf(startDelta - 1) < FLT_EPSILON) {
startDelta = 0;
startSegment += delta;
}
//avoid empty end segment
if (fabsf(endDelta) < FLT_EPSILON) {
endDelta = 1;
endSegment -= delta;
}
startDelta = _arcAngle(startDelta * 90);
endDelta = _arcAngle(endDelta * 90);
auto splitAtStart = (fabsf(startDelta) >= FLT_EPSILON) ? true : false;
auto splitAtEnd = (fabsf(endDelta - 1.0f) >= FLT_EPSILON) ? true : false;
auto end = endSegment + delta;
//empty arc?
if (startSegment == end) {
auto quadrant = 3 - ((startSegment % 4) + 4) % 4;
auto i = 3 * quadrant;
curves[0] = (delta > 0) ? pts[i + 3] : pts[i];
return _arcToCubic(*this, curves, ptsCnt);
}
Point ptStart, ptEnd;
_findEllipseCoords(x, y, w, h, startAngle, sweepAngle, ptStart, ptEnd);
for (auto i = startSegment; i != end; i += delta) {
//auto quadrant = 3 - ((i % 4) + 4) % 4;
//auto j = 3 * quadrant;
if (delta > 0) {
//TODO: bezier
} else {
//TODO: bezier
}
//empty arc?
if (startSegment == endSegment && (fabsf(startDelta - endDelta) < FLT_EPSILON)) {
curves[0] = ptStart;
return _arcToCubic(*this, curves, ptsCnt);
}
if (i == startSegment) {
if (i == endSegment && splitAtEnd) {
//TODO: bezier
} else if (splitAtStart) {
//TODO: bezier
}
} else if (i == endSegment && splitAtEnd) {
//TODO: bezier
}
//push control points
//curves[ptsCnt++] = ctrlPt1;
//curves[ptsCnt++] = ctrlPt2;
//curves[ptsCnt++] = endPt;
cout << "ArcTo: Not Implemented!" << endl;
}
curves[ptsCnt - 1] = ptEnd;
return _arcToCubic(*this, curves, ptsCnt);
}
int close() int close()
{ {
if (cmdCnt + 1 > reservedCmdCnt) reserveCmd((cmdCnt + 1) * 2); if (cmdCnt + 1 > reservedCmdCnt) reserveCmd((cmdCnt + 1) * 2);
@ -289,101 +143,4 @@ struct ShapePath
} }
}; };
static float _arcAngle(float angle)
{
if (angle < FLT_EPSILON) return 0;
if (fabsf(angle - 90) < FLT_EPSILON) return 1;
auto radian = (angle / 180) * M_PI;
auto cosAngle = cos(radian);
auto sinAngle = sin(radian);
//initial guess
auto tc = angle / 90;
/* do some iterations of newton's method to approximate cosAngle
finds the zero of the function b.pointAt(tc).x() - cosAngle */
tc -= ((((2 - 3 * PATH_KAPPA) * tc + 3 * (PATH_KAPPA - 1)) * tc) * tc + 1 - cosAngle) // value
/ (((6 - 9 * PATH_KAPPA) * tc + 6 * (PATH_KAPPA - 1)) * tc); // derivative
tc -= ((((2 - 3 * PATH_KAPPA) * tc + 3 * (PATH_KAPPA - 1)) * tc) * tc + 1 - cosAngle) // value
/ (((6 - 9 * PATH_KAPPA) * tc + 6 * (PATH_KAPPA - 1)) * tc); // derivative
// initial guess
auto ts = tc;
/* do some iterations of newton's method to approximate sin_angle
finds the zero of the function b.pointAt(tc).y() - sinAngle */
ts -= ((((3 * PATH_KAPPA - 2) * ts - 6 * PATH_KAPPA + 3) * ts + 3 * PATH_KAPPA) * ts - sinAngle)
/ (((9 * PATH_KAPPA - 6) * ts + 12 * PATH_KAPPA - 6) * ts + 3 * PATH_KAPPA);
ts -= ((((3 * PATH_KAPPA - 2) * ts - 6 * PATH_KAPPA + 3) * ts + 3 * PATH_KAPPA) * ts - sinAngle)
/ (((9 * PATH_KAPPA - 6) * ts + 12 * PATH_KAPPA - 6) * ts + 3 * PATH_KAPPA);
//use the average of the t that best approximates cos_angle and the t that best approximates sin_angle
return (0.5 * (tc + ts));
}
static int _arcToCubic(ShapePath& path, const Point* pts, size_t ptsCnt)
{
assert(pts);
if (path.cmdCnt > 0 && path.cmds[path.cmdCnt] != PathCommand::Close) {
if (path.lineTo(pts[0].x, pts[0].y)) return -1;
} else {
if (path.moveTo(pts[0].x, pts[0].y)) return -1;
}
for (size_t i = 1; i < ptsCnt; i += 3) {
if (path.cubicTo(pts[i].x, pts[i].y, pts[i+1].x, pts[i+1].y, pts[i+2].x, pts[i+2].y)) {
return -1;
}
}
return 0;
}
static void _findEllipseCoords(float x, float y, float w, float h, float startAngle, float sweepAngle, Point& ptStart, Point& ptEnd)
{
float angles[2] = {startAngle, startAngle + sweepAngle};
float half_w = w * 0.5f;
float half_h = h * 0.5f;
float cx = x + half_w;
float cy = y + half_h;
Point* pts[2] = {&ptStart, &ptEnd};
for (auto i = 0; i < 2; ++i) {
auto theta = angles[i] - 360 * floor(angles[i] / 360);
auto t = theta / 90;
auto quadrant = static_cast<int>(t); //truncate
t -= quadrant;
t = _arcAngle(90 * t);
//swap x and y?
if (quadrant & 1) t = (1 - t);
//bezier coefficients
auto m = 1 - t;
auto b = m * m;
auto c = t * t;
auto d = c * t;
auto a = b * m;
b *= 3 * t;
c *= 3 * m;
auto px = a + b + c * PATH_KAPPA;
auto py = d + c + b * PATH_KAPPA;
//left quadrants
if (quadrant == 1 || quadrant == 2) px = -px;
//top quadrants
if (quadrant == 0 || quadrant == 1) py = -py;
pts[i]->x = cx + half_w * px;
pts[i]->y = cy + half_h * py;
}
}
#endif //_TVG_SHAPE_PATH_CPP_ #endif //_TVG_SHAPE_PATH_CPP_

2
test/testMultipleShapes.cpp
View file

@ -19,7 +19,7 @@ void tvgtest()
//Prepare Rectangle //Prepare Rectangle
auto shape1 = tvg::ShapeNode::gen(); auto shape1 = tvg::ShapeNode::gen();
shape1->appendRect(0, 0, 400, 400, 0); //x, y, w, h, corner_radius shape1->appendRect(0, 0, 400, 400, 50); //x, y, w, h, cornerRadius
shape1->fill(0, 255, 0, 255); //r, g, b, a shape1->fill(0, 255, 0, 255); //r, g, b, a
canvas->push(move(shape1)); canvas->push(move(shape1));

2
test/testShape.cpp
View file

@ -18,7 +18,7 @@ void tvgtest()
//Prepare a Shape (Rectangle) //Prepare a Shape (Rectangle)
auto shape1 = tvg::ShapeNode::gen(); auto shape1 = tvg::ShapeNode::gen();
shape1->appendRect(0, 0, 400, 400, 0); //x, y, w, h, corner_radius shape1->appendRect(0, 0, 400, 400, 0); //x, y, w, h, cornerRadius
shape1->fill(255, 0, 0, 255); //r, g, b, a shape1->fill(255, 0, 0, 255); //r, g, b, a
/* Push the shape into the Canvas drawing list /* Push the shape into the Canvas drawing list

2
test/testStroke.cpp
View file

@ -17,7 +17,7 @@ int main(int argc, char **argv)
//Prepare a Shape //Prepare a Shape
auto shape1 = tvg::ShapeNode::gen(); auto shape1 = tvg::ShapeNode::gen();
shape1->rect(0, 0, 400, 400, 0.1); //x, y, w, h, corner_radius shape1->rect(0, 0, 400, 400, 0.1); //x, y, w, h, cornerRadius
shape1->fill(0, 255, 0, 255); shape1->fill(0, 255, 0, 255);
//Stroke Style //Stroke Style