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wg_engine: fix strokes triangulation artifacts

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Fixed detection of close vertices using comparison with epsilon and related artifacts in stencil buffer as extra pixels.
Fixed incorrect tessellation of curves using scaling.
This commit is contained in:
Sergii Liebodkin 2024-09-16 14:28:52 +00:00 • committed by Hermet Park
parent 79e5a0f3eb
commit 1daf6a010c
4 changed files with 48 additions and 43 deletions
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36
src/renderer/wg_engine/tvgWgGeometry.cpp
View file

@ -65,7 +65,10 @@ void WgPolyline::appendPoint(WgPoint pt)
{ {
if (pts.count > 0) { if (pts.count > 0) {
float distance = pts.last().dist(pt); float distance = pts.last().dist(pt);
if (distance > 0) { // adjust precision because of real user data points
// can be further than the accepted accuracy,
// but still be considered tha same
if (!tvg::zero(distance*1e-1)) {
// update min and max indexes // update min and max indexes
iminx = pts[iminx].x >= pt.x ? pts.count : iminx; iminx = pts[iminx].x >= pt.x ? pts.count : iminx;
imaxx = pts[imaxx].x <= pt.x ? pts.count : imaxx; imaxx = pts[imaxx].x <= pt.x ? pts.count : imaxx;
@ -217,13 +220,13 @@ void WgGeometryData::appendRect(WgPoint p0, WgPoint p1, WgPoint p2, WgPoint p3)
} }
void WgGeometryData::appendCircle(WgPoint center, float radius) void WgGeometryData::appendCircle(WgPoint center, float radius, float scale)
{ {
uint32_t indexCenter = positions.pts.count; uint32_t indexCenter = positions.pts.count;
positions.appendPoint(center); positions.appendPoint(center);
uint32_t index = positions.pts.count; uint32_t index = positions.pts.count;
positions.appendPoint({ center.x + gMath->sinus[0] * radius, center.y + gMath->cosin[0] * radius }); positions.appendPoint({ center.x + gMath->sinus[0] * radius, center.y + gMath->cosin[0] * radius });
uint32_t nPoints = (uint32_t)(radius * 2.0f); uint32_t nPoints = (uint32_t)(scale * radius * 2.0f);
nPoints = nPoints < 8 ? 8 : nPoints; nPoints = nPoints < 8 ? 8 : nPoints;
const uint32_t step = gMath->sinus.count / nPoints; const uint32_t step = gMath->sinus.count / nPoints;
for (uint32_t i = step; i < gMath->sinus.count; i += step) { for (uint32_t i = step; i < gMath->sinus.count; i += step) {
@ -279,7 +282,7 @@ void WgGeometryData::appendBlitBox()
} }
void WgGeometryData::appendStrokeDashed(const WgPolyline* polyline, const RenderStroke *stroke) void WgGeometryData::appendStrokeDashed(const WgPolyline* polyline, const RenderStroke *stroke, float scale)
{ {
assert(stroke); assert(stroke);
assert(polyline); assert(polyline);
@ -308,7 +311,7 @@ void WgGeometryData::appendStrokeDashed(const WgPolyline* polyline, const Render
currentLength += stroke->dashPattern[dashIndex]; currentLength += stroke->dashPattern[dashIndex];
// append stroke if dash // append stroke if dash
if (dashIndex % 2 != 0) { if (dashIndex % 2 != 0) {
appendStroke(&dashed, stroke); appendStroke(&dashed, stroke, scale);
dashed.clear(); dashed.clear();
} }
} }
@ -318,14 +321,14 @@ void WgGeometryData::appendStrokeDashed(const WgPolyline* polyline, const Render
// draw last subline // draw last subline
if (dashIndex % 2 == 0) { if (dashIndex % 2 == 0) {
dashed.appendPoint(pts.last()); dashed.appendPoint(pts.last());
appendStroke(&dashed, stroke); appendStroke(&dashed, stroke, scale);
dashed.clear(); dashed.clear();
} }
} }
} }
void WgGeometryData::appendStrokeJoin(const WgPoint& v0, const WgPoint& v1, const WgPoint& v2, StrokeJoin join, float halfWidth, float miterLimit) void WgGeometryData::appendStrokeJoin(const WgPoint& v0, const WgPoint& v1, const WgPoint& v2, StrokeJoin join, float halfWidth, float miterLimit, float scale)
{ {
WgPoint dir0 = (v1 - v0).normal(); WgPoint dir0 = (v1 - v0).normal();
WgPoint dir1 = (v2 - v1).normal(); WgPoint dir1 = (v2 - v1).normal();
@ -334,12 +337,13 @@ void WgGeometryData::appendStrokeJoin(const WgPoint& v0, const WgPoint& v1, cons
WgPoint offset0 = nrm0 * halfWidth; WgPoint offset0 = nrm0 * halfWidth;
WgPoint offset1 = nrm1 * halfWidth; WgPoint offset1 = nrm1 * halfWidth;
if (join == StrokeJoin::Round) { if (join == StrokeJoin::Round) {
appendCircle(v1, halfWidth); appendCircle(v1, halfWidth, scale);
} else if (join == StrokeJoin::Bevel) { } else if (join == StrokeJoin::Bevel) {
appendRect(v1 - offset0, v1 + offset1, v1 - offset1, v1 + offset0); appendRect(v1 - offset0, v1 + offset1, v1 - offset1, v1 + offset0);
} else if (join == StrokeJoin::Miter) { } else if (join == StrokeJoin::Miter) {
WgPoint nrm = (nrm0 + nrm1); WgPoint nrm = (nrm0 + nrm1);
if (!tvg::zero(dir0.x * dir1.y - dir0.y * dir1.x)) { // adjust precision because dot product could return above 1 that results acos returns Nan
if (!tvg::zero((dir0.x * dir1.y - dir0.y * dir1.x)*1e-1)) {
nrm.normalize(); nrm.normalize();
float cosine = nrm.dot(nrm0); float cosine = nrm.dot(nrm0);
float angle = std::acos(dir0.dot(dir1.negative())); float angle = std::acos(dir0.dot(dir1.negative()));
@ -355,7 +359,7 @@ void WgGeometryData::appendStrokeJoin(const WgPoint& v0, const WgPoint& v1, cons
} }
void WgGeometryData::appendStroke(const WgPolyline* polyline, const RenderStroke *stroke) void WgGeometryData::appendStroke(const WgPolyline* polyline, const RenderStroke *stroke, float scale)
{ {
assert(stroke); assert(stroke);
assert(polyline); assert(polyline);
@ -369,8 +373,8 @@ void WgGeometryData::appendStroke(const WgPolyline* polyline, const RenderStroke
WgPoint nrm0 = WgPoint{ -dir0.y, +dir0.x }; WgPoint nrm0 = WgPoint{ -dir0.y, +dir0.x };
if (stroke->cap == StrokeCap::Round) { if (stroke->cap == StrokeCap::Round) {
appendRect(v0 - nrm0 * wdt, v0 + nrm0 * wdt, v1 - nrm0 * wdt, v1 + nrm0 * wdt); appendRect(v0 - nrm0 * wdt, v0 + nrm0 * wdt, v1 - nrm0 * wdt, v1 + nrm0 * wdt);
appendCircle(polyline->pts[0], wdt); appendCircle(polyline->pts[0], wdt, scale);
appendCircle(polyline->pts[1], wdt); appendCircle(polyline->pts[1], wdt, scale);
} else if (stroke->cap == StrokeCap::Butt) { } else if (stroke->cap == StrokeCap::Butt) {
appendRect(v0 - nrm0 * wdt, v0 + nrm0 * wdt, v1 - nrm0 * wdt, v1 + nrm0 * wdt); appendRect(v0 - nrm0 * wdt, v0 + nrm0 * wdt, v1 - nrm0 * wdt, v1 + nrm0 * wdt);
} else if (stroke->cap == StrokeCap::Square) { } else if (stroke->cap == StrokeCap::Square) {
@ -384,7 +388,7 @@ void WgGeometryData::appendStroke(const WgPolyline* polyline, const RenderStroke
WgPoint v0 = polyline->pts[polyline->pts.count - 2]; WgPoint v0 = polyline->pts[polyline->pts.count - 2];
WgPoint v1 = polyline->pts[0]; WgPoint v1 = polyline->pts[0];
WgPoint v2 = polyline->pts[1]; WgPoint v2 = polyline->pts[1];
appendStrokeJoin(v0, v1, v2, stroke->join, wdt, stroke->miterlimit); appendStrokeJoin(v0, v1, v2, stroke->join, wdt, stroke->miterlimit, scale);
} else { } else {
// append first cap // append first cap
WgPoint v0 = polyline->pts[0]; WgPoint v0 = polyline->pts[0];
@ -392,7 +396,7 @@ void WgGeometryData::appendStroke(const WgPolyline* polyline, const RenderStroke
WgPoint dir0 = (v1 - v0) / polyline->dist[1]; WgPoint dir0 = (v1 - v0) / polyline->dist[1];
WgPoint nrm0 = WgPoint{ -dir0.y, +dir0.x }; WgPoint nrm0 = WgPoint{ -dir0.y, +dir0.x };
if (stroke->cap == StrokeCap::Round) { if (stroke->cap == StrokeCap::Round) {
appendCircle(v0, wdt); appendCircle(v0, wdt, scale);
} else if (stroke->cap == StrokeCap::Butt) { } else if (stroke->cap == StrokeCap::Butt) {
// no cap needed // no cap needed
} else if (stroke->cap == StrokeCap::Square) { } else if (stroke->cap == StrokeCap::Square) {
@ -405,7 +409,7 @@ void WgGeometryData::appendStroke(const WgPolyline* polyline, const RenderStroke
dir0 = (v1 - v0) / polyline->dist[polyline->pts.count - 1]; dir0 = (v1 - v0) / polyline->dist[polyline->pts.count - 1];
nrm0 = WgPoint{ -dir0.y, +dir0.x }; nrm0 = WgPoint{ -dir0.y, +dir0.x };
if (stroke->cap == StrokeCap::Round) { if (stroke->cap == StrokeCap::Round) {
appendCircle(v1, wdt); appendCircle(v1, wdt, scale);
} else if (stroke->cap == StrokeCap::Butt) { } else if (stroke->cap == StrokeCap::Butt) {
// no cap needed // no cap needed
} else if (stroke->cap == StrokeCap::Square) { } else if (stroke->cap == StrokeCap::Square) {
@ -425,7 +429,7 @@ void WgGeometryData::appendStroke(const WgPolyline* polyline, const RenderStroke
if (i > 0) { if (i > 0) {
WgPoint v0 = polyline->pts[i - 1]; WgPoint v0 = polyline->pts[i - 1];
appendStrokeJoin(v0, v1, v2, stroke->join, wdt, stroke->miterlimit); appendStrokeJoin(v0, v1, v2, stroke->join, wdt, stroke->miterlimit, scale);
} }
} }
} }

9
src/renderer/wg_engine/tvgWgGeometry.h
View file

@ -111,16 +111,15 @@ struct WgGeometryData
WgGeometryData(); WgGeometryData();
void clear(); void clear();
void appendCubic(WgPoint p1, WgPoint p2, WgPoint p3);
void appendBox(WgPoint pmin, WgPoint pmax); void appendBox(WgPoint pmin, WgPoint pmax);
void appendRect(WgPoint p0, WgPoint p1, WgPoint p2, WgPoint p3); void appendRect(WgPoint p0, WgPoint p1, WgPoint p2, WgPoint p3);
void appendCircle(WgPoint center, float radius); void appendCircle(WgPoint center, float radius, float scale = 1.0f);
void appendImageBox(float w, float h); void appendImageBox(float w, float h);
void appendBlitBox(); void appendBlitBox();
void appendStrokeDashed(const WgPolyline* polyline, const RenderStroke *stroke); void appendStrokeDashed(const WgPolyline* polyline, const RenderStroke *stroke, float scale);
void appendStrokeJoin(const WgPoint& v0, const WgPoint& v1, const WgPoint& v2, void appendStrokeJoin(const WgPoint& v0, const WgPoint& v1, const WgPoint& v2,
StrokeJoin join, float halfWidth, float miterLimit); StrokeJoin join, float halfWidth, float miterLimit, float scale);
void appendStroke(const WgPolyline* polyline, const RenderStroke *stroke); void appendStroke(const WgPolyline* polyline, const RenderStroke *stroke, float scale);
}; };
#endif // _TVG_WG_GEOMETRY_H_ #endif // _TVG_WG_GEOMETRY_H_

40
src/renderer/wg_engine/tvgWgRenderData.cpp
View file

@ -22,6 +22,7 @@
*/ */
#include <algorithm> #include <algorithm>
#include "tvgMath.h"
#include "tvgWgRenderData.h" #include "tvgWgRenderData.h"
#include "tvgWgShaderTypes.h" #include "tvgWgShaderTypes.h"
@ -327,11 +328,12 @@ void WgRenderDataShape::updateAABB(const Matrix& rt) {
} }
void WgRenderDataShape::updateMeshes(WgContext &context, const RenderShape &rshape, const Matrix& rt) void WgRenderDataShape::updateMeshes(WgContext &context, const RenderShape &rshape, const Matrix& tr)
{ {
releaseMeshes(context); releaseMeshes(context);
strokeFirst = rshape.stroke ? rshape.stroke->strokeFirst : false; strokeFirst = rshape.stroke ? rshape.stroke->strokeFirst : false;
float scale = std::max(sqrt(tr.e11*tr.e11 + tr.e21*tr.e21), 1.0f);
Array<WgPolyline*> polylines{}; Array<WgPolyline*> polylines{};
// decode path // decode path
size_t pntIndex = 0; size_t pntIndex = 0;
@ -349,16 +351,16 @@ void WgRenderDataShape::updateMeshes(WgContext &context, const RenderShape &rsha
polylines.last()->close(); polylines.last()->close();
} else if (cmd == PathCommand::CubicTo) { } else if (cmd == PathCommand::CubicTo) {
assert(polylines.last()->pts.count > 0); assert(polylines.last()->pts.count > 0);
WgPoint pt0 = polylines.last()->pts.last().trans(rt); WgPoint pt0 = polylines.last()->pts.last().trans(tr);
WgPoint pt1 = WgPoint(rshape.path.pts[pntIndex + 0]).trans(rt); WgPoint pt1 = WgPoint(rshape.path.pts[pntIndex + 0]).trans(tr);
WgPoint pt2 = WgPoint(rshape.path.pts[pntIndex + 1]).trans(rt); WgPoint pt2 = WgPoint(rshape.path.pts[pntIndex + 1]).trans(tr);
WgPoint pt3 = WgPoint(rshape.path.pts[pntIndex + 2]).trans(rt); WgPoint pt3 = WgPoint(rshape.path.pts[pntIndex + 2]).trans(tr);
uint32_t nsegs = (uint32_t)(pt0.dist(pt1) + pt1.dist(pt2) + pt2.dist(pt3)); uint32_t nsegs = std::max((uint32_t)(pt0.dist(pt1) + pt1.dist(pt2) + pt2.dist(pt3)), 32U);
polylines.last()->appendCubic( polylines.last()->appendCubic(
rshape.path.pts[pntIndex + 0], rshape.path.pts[pntIndex + 0],
rshape.path.pts[pntIndex + 1], rshape.path.pts[pntIndex + 1],
rshape.path.pts[pntIndex + 2], rshape.path.pts[pntIndex + 2],
nsegs / 2); nsegs / 4);
pntIndex += 3; pntIndex += 3;
} }
} }
@ -375,13 +377,13 @@ void WgRenderDataShape::updateMeshes(WgContext &context, const RenderShape &rsha
if (!rshape.stroke->strokeTrim(trimBegin, trimEnd)) { trimBegin = 0.0f; trimEnd = 1.0f; } if (!rshape.stroke->strokeTrim(trimBegin, trimEnd)) { trimBegin = 0.0f; trimEnd = 1.0f; }
if (rshape.stroke->trim.simultaneous) { if (rshape.stroke->trim.simultaneous) {
for (uint32_t i = 0; i < polylines.count; i++) for (uint32_t i = 0; i < polylines.count; i++)
updateStrokes(context, polylines[i], rshape.stroke, trimBegin, trimEnd); updateStrokes(context, polylines[i], rshape.stroke, scale, trimBegin, trimEnd);
} else { } else {
if (trimBegin <= trimEnd) { if (trimBegin <= trimEnd) {
updateStrokesList(context, polylines, rshape.stroke, totalLen, trimBegin, trimEnd); updateStrokesList(context, polylines, rshape.stroke, totalLen, scale, trimBegin, trimEnd);
} else { } else {
updateStrokesList(context, polylines, rshape.stroke, totalLen, 0.0f, trimEnd); updateStrokesList(context, polylines, rshape.stroke, totalLen, scale, 0.0f, trimEnd);
updateStrokesList(context, polylines, rshape.stroke, totalLen, trimBegin, 1.0f); updateStrokesList(context, polylines, rshape.stroke, totalLen, scale, trimBegin, 1.0f);
} }
} }
} }
@ -389,7 +391,7 @@ void WgRenderDataShape::updateMeshes(WgContext &context, const RenderShape &rsha
for (uint32_t i = 0; i < polylines.count; i++) for (uint32_t i = 0; i < polylines.count; i++)
delete polylines[i]; delete polylines[i];
// update shapes bbox // update shapes bbox
updateAABB(rt); updateAABB(tr);
meshDataBBox.update(context, pMin, pMax); meshDataBBox.update(context, pMin, pMax);
} }
@ -407,7 +409,7 @@ void WgRenderDataShape::updateShapes(WgContext& context, const WgPolyline* polyl
} }
} }
void WgRenderDataShape::updateStrokesList(WgContext& context, Array<WgPolyline*> polylines, const RenderStroke* rstroke, float totalLen, float trimBegin, float trimEnd) void WgRenderDataShape::updateStrokesList(WgContext& context, Array<WgPolyline*> polylines, const RenderStroke* rstroke, float scale, float totalLen, float trimBegin, float trimEnd)
{ {
float tp1 = totalLen * trimBegin; // trim point begin float tp1 = totalLen * trimBegin; // trim point begin
float tp2 = totalLen * trimEnd; // trim point end float tp2 = totalLen * trimEnd; // trim point end
@ -417,7 +419,7 @@ void WgRenderDataShape::updateStrokesList(WgContext& context, Array<WgPolyline*>
float trimBegin = ((pc <= tp1) && (pc + pl > tp1)) ? (tp1 - pc) / pl : 0.0f; float trimBegin = ((pc <= tp1) && (pc + pl > tp1)) ? (tp1 - pc) / pl : 0.0f;
float trimEnd = ((pc <= tp2) && (pc + pl > tp2)) ? (tp2 - pc) / pl : 1.0f; float trimEnd = ((pc <= tp2) && (pc + pl > tp2)) ? (tp2 - pc) / pl : 1.0f;
if ((pc + pl >= tp1) && (pc <= tp2)) if ((pc + pl >= tp1) && (pc <= tp2))
updateStrokes(context, polylines[i], rstroke, trimBegin, trimEnd); updateStrokes(context, polylines[i], rstroke, scale, trimBegin, trimEnd);
pc += pl; pc += pl;
// break if reached the tail // break if reached the tail
if (pc > tp2) break; if (pc > tp2) break;
@ -425,7 +427,7 @@ void WgRenderDataShape::updateStrokesList(WgContext& context, Array<WgPolyline*>
} }
void WgRenderDataShape::updateStrokes(WgContext& context, const WgPolyline* polyline, const RenderStroke* rstroke, float trimBegin, float trimEnd) void WgRenderDataShape::updateStrokes(WgContext& context, const WgPolyline* polyline, const RenderStroke* rstroke, float scale, float trimBegin, float trimEnd)
{ {
assert(polyline); assert(polyline);
// generate strokes geometry // generate strokes geometry
@ -442,7 +444,7 @@ void WgRenderDataShape::updateStrokes(WgContext& context, const WgPolyline* poly
polyline->trim(&trimmed, trimBegin, 1.0f); polyline->trim(&trimmed, trimBegin, 1.0f);
polyline->trim(&trimmed, 0.0f, trimEnd); polyline->trim(&trimmed, 0.0f, trimEnd);
} }
geometryData.appendStrokeDashed(&trimmed, rstroke); geometryData.appendStrokeDashed(&trimmed, rstroke, scale);
} else // trim -> stroke } else // trim -> stroke
if ((trimBegin != 0.0f) || (trimEnd != 1.0f)) { if ((trimBegin != 0.0f) || (trimEnd != 1.0f)) {
trimmed.clear(); trimmed.clear();
@ -452,12 +454,12 @@ void WgRenderDataShape::updateStrokes(WgContext& context, const WgPolyline* poly
polyline->trim(&trimmed, trimBegin, 1.0f); polyline->trim(&trimmed, trimBegin, 1.0f);
polyline->trim(&trimmed, 0.0f, trimEnd); polyline->trim(&trimmed, 0.0f, trimEnd);
} }
geometryData.appendStroke(&trimmed, rstroke); geometryData.appendStroke(&trimmed, rstroke, scale);
} else // split -> stroke } else // split -> stroke
if (rstroke->dashPattern) { if (rstroke->dashPattern) {
geometryData.appendStrokeDashed(polyline, rstroke); geometryData.appendStrokeDashed(polyline, rstroke, scale);
} else { // stroke } else { // stroke
geometryData.appendStroke(polyline, rstroke); geometryData.appendStroke(polyline, rstroke, scale);
} }
// append render meshes and bboxes // append render meshes and bboxes
if(geometryData.positions.pts.count >= 3) { if(geometryData.positions.pts.count >= 3) {

6
src/renderer/wg_engine/tvgWgRenderData.h
View file

@ -126,10 +126,10 @@ struct WgRenderDataShape: public WgRenderDataPaint
void updateBBox(WgPoint pmin, WgPoint pmax); void updateBBox(WgPoint pmin, WgPoint pmax);
void updateAABB(const Matrix& rt); void updateAABB(const Matrix& rt);
void updateMeshes(WgContext& context, const RenderShape& rshape, const Matrix& rt); void updateMeshes(WgContext& context, const RenderShape& rshape, const Matrix& tr);
void updateShapes(WgContext& context, const WgPolyline* polyline); void updateShapes(WgContext& context, const WgPolyline* polyline);
void updateStrokesList(WgContext& context, Array<WgPolyline*> polylines, const RenderStroke* rstroke, float totalLen, float trimBegin, float trimEnd); void updateStrokesList(WgContext& context, Array<WgPolyline*> polylines, const RenderStroke* rstroke, float scale, float totalLen, float trimBegin, float trimEnd);
void updateStrokes(WgContext& context, const WgPolyline* polyline, const RenderStroke* rstroke, float trimBegin, float trimEnd); void updateStrokes(WgContext& context, const WgPolyline* polyline, const RenderStroke* rstroke, float scale, float trimBegin, float trimEnd);
void releaseMeshes(WgContext& context); void releaseMeshes(WgContext& context);
void release(WgContext& context) override; void release(WgContext& context) override;
Type type() override { return Type::Shape; }; Type type() override { return Type::Shape; };