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Merge "Tweak the threshold for conic path quads computation." into mnc-dev

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ztenghui
2015-05-29 22:17:29 +00:00
committed by Android (Google) Code Review
parent 8c176dd22e 21ef8205a1
commit e9d8480fc1
3 changed files with 62 additions and 33 deletions
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60
libs/hwui/PathTessellator.cpp
View File

@@ -56,7 +56,7 @@
namespace android {
namespace uirenderer {
#define OUTLINE_REFINE_THRESHOLD_SQUARED (0.5f * 0.5f)
#define OUTLINE_REFINE_THRESHOLD 0.5f
#define ROUND_CAP_THRESH 0.25f
#define PI 3.1415926535897932f
#define MAX_DEPTH 15
@@ -739,9 +739,10 @@ void PathTessellator::tessellatePath(const SkPath &path, const SkPaint* paint,
// force close if we're filling the path, since fill path expects closed perimeter.
bool forceClose = paintInfo.style != SkPaint::kStroke_Style;
PathApproximationInfo approximationInfo(threshInvScaleX, threshInvScaleY,
OUTLINE_REFINE_THRESHOLD);
bool wasClosed = approximatePathOutlineVertices(path, forceClose,
threshInvScaleX * threshInvScaleX, threshInvScaleY * threshInvScaleY,
OUTLINE_REFINE_THRESHOLD_SQUARED, tempVertices);
approximationInfo, tempVertices);
if (!tempVertices.size()) {
// path was empty, return without allocating vertex buffer
@@ -819,10 +820,9 @@ void PathTessellator::tessellatePoints(const float* points, int count, const SkP
// calculate outline
Vector<Vertex> outlineVertices;
approximatePathOutlineVertices(path, true,
paintInfo.inverseScaleX * paintInfo.inverseScaleX,
paintInfo.inverseScaleY * paintInfo.inverseScaleY,
OUTLINE_REFINE_THRESHOLD_SQUARED, outlineVertices);
PathApproximationInfo approximationInfo(paintInfo.inverseScaleX, paintInfo.inverseScaleY,
OUTLINE_REFINE_THRESHOLD);
approximatePathOutlineVertices(path, true, approximationInfo, outlineVertices);
if (!outlineVertices.size()) return;
@@ -899,9 +899,10 @@ void PathTessellator::tessellateLines(const float* points, int count, const SkPa
// Simple path line approximation
///////////////////////////////////////////////////////////////////////////////
bool PathTessellator::approximatePathOutlineVertices(const SkPath& path, float thresholdSquared,
bool PathTessellator::approximatePathOutlineVertices(const SkPath& path, float threshold,
Vector<Vertex>& outputVertices) {
return approximatePathOutlineVertices(path, true, 1.0f, 1.0f, thresholdSquared, outputVertices);
PathApproximationInfo approximationInfo(1.0f, 1.0f, threshold);
return approximatePathOutlineVertices(path, true, approximationInfo, outputVertices);
}
void pushToVector(Vector<Vertex>& vertices, float x, float y) {
@@ -946,8 +947,7 @@ private:
};
bool PathTessellator::approximatePathOutlineVertices(const SkPath& path, bool forceClose,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
Vector<Vertex>& outputVertices) {
const PathApproximationInfo& approximationInfo, Vector<Vertex>& outputVertices) {
ATRACE_CALL();
// TODO: to support joins other than sharp miter, join vertices should be labelled in the
@@ -978,7 +978,7 @@ bool PathTessellator::approximatePathOutlineVertices(const SkPath& path, bool fo
pts[0].x(), pts[0].y(),
pts[2].x(), pts[2].y(),
pts[1].x(), pts[1].y(),
sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices);
approximationInfo, outputVertices);
clockwiseEnforcer.addPoint(pts[1]);
clockwiseEnforcer.addPoint(pts[2]);
break;
@@ -989,7 +989,7 @@ bool PathTessellator::approximatePathOutlineVertices(const SkPath& path, bool fo
pts[1].x(), pts[1].y(),
pts[3].x(), pts[3].y(),
pts[2].x(), pts[2].y(),
sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices);
approximationInfo, outputVertices);
clockwiseEnforcer.addPoint(pts[1]);
clockwiseEnforcer.addPoint(pts[2]);
clockwiseEnforcer.addPoint(pts[3]);
@@ -998,14 +998,14 @@ bool PathTessellator::approximatePathOutlineVertices(const SkPath& path, bool fo
ALOGV("kConic_Verb");
SkAutoConicToQuads converter;
const SkPoint* quads = converter.computeQuads(pts, iter.conicWeight(),
thresholdSquared);
approximationInfo.thresholdForConicQuads);
for (int i = 0; i < converter.countQuads(); ++i) {
const int offset = 2 * i;
recursiveQuadraticBezierVertices(
quads[offset].x(), quads[offset].y(),
quads[offset+2].x(), quads[offset+2].y(),
quads[offset+1].x(), quads[offset+1].y(),
sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices);
approximationInfo, outputVertices);
}
clockwiseEnforcer.addPoint(pts[1]);
clockwiseEnforcer.addPoint(pts[2]);
@@ -1031,12 +1031,23 @@ bool PathTessellator::approximatePathOutlineVertices(const SkPath& path, bool fo
///////////////////////////////////////////////////////////////////////////////
// Bezier approximation
//
// All the inputs and outputs here are in path coordinates.
// We convert the error threshold from screen coordinates into path coordinates.
///////////////////////////////////////////////////////////////////////////////
// Get a threshold in path coordinates, by scaling the thresholdSquared from screen coordinates.
// TODO: Document the math behind this algorithm.
static inline float getThreshold(const PathApproximationInfo& info, float dx, float dy) {
// multiplying by sqrInvScaleY/X equivalent to multiplying in dimensional scale factors
float scale = (dx * dx * info.sqrInvScaleY + dy * dy * info.sqrInvScaleX);
return info.thresholdSquared * scale;
}
void PathTessellator::recursiveCubicBezierVertices(
float p1x, float p1y, float c1x, float c1y,
float p2x, float p2y, float c2x, float c2y,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
const PathApproximationInfo& approximationInfo,
Vector<Vertex>& outputVertices, int depth) {
float dx = p2x - p1x;
float dy = p2y - p1y;
@@ -1044,9 +1055,8 @@ void PathTessellator::recursiveCubicBezierVertices(
float d2 = fabs((c2x - p2x) * dy - (c2y - p2y) * dx);
float d = d1 + d2;
// multiplying by sqrInvScaleY/X equivalent to multiplying in dimensional scale factors
if (depth >= MAX_DEPTH
|| d * d <= thresholdSquared * (dx * dx * sqrInvScaleY + dy * dy * sqrInvScaleX)) {
|| d * d <= getThreshold(approximationInfo, dx, dy)) {
// below thresh, draw line by adding endpoint
pushToVector(outputVertices, p2x, p2y);
} else {
@@ -1070,11 +1080,11 @@ void PathTessellator::recursiveCubicBezierVertices(
recursiveCubicBezierVertices(
p1x, p1y, p1c1x, p1c1y,
mx, my, p1c1c2x, p1c1c2y,
sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices, depth + 1);
approximationInfo, outputVertices, depth + 1);
recursiveCubicBezierVertices(
mx, my, p2c1c2x, p2c1c2y,
p2x, p2y, p2c2x, p2c2y,
sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices, depth + 1);
approximationInfo, outputVertices, depth + 1);
}
}
@@ -1082,15 +1092,15 @@ void PathTessellator::recursiveQuadraticBezierVertices(
float ax, float ay,
float bx, float by,
float cx, float cy,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
const PathApproximationInfo& approximationInfo,
Vector<Vertex>& outputVertices, int depth) {
float dx = bx - ax;
float dy = by - ay;
// d is the cross product of vector (B-A) and (C-B).
float d = (cx - bx) * dy - (cy - by) * dx;
// multiplying by sqrInvScaleY/X equivalent to multiplying in dimensional scale factors
if (depth >= MAX_DEPTH
|| d * d <= thresholdSquared * (dx * dx * sqrInvScaleY + dy * dy * sqrInvScaleX)) {
|| d * d <= getThreshold(approximationInfo, dx, dy)) {
// below thresh, draw line by adding endpoint
pushToVector(outputVertices, bx, by);
} else {
@@ -1104,9 +1114,9 @@ void PathTessellator::recursiveQuadraticBezierVertices(
float my = (acy + bcy) * 0.5f;
recursiveQuadraticBezierVertices(ax, ay, mx, my, acx, acy,
sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices, depth + 1);
approximationInfo, outputVertices, depth + 1);
recursiveQuadraticBezierVertices(mx, my, bx, by, bcx, bcy,
sqrInvScaleX, sqrInvScaleY, thresholdSquared, outputVertices, depth + 1);
approximationInfo, outputVertices, depth + 1);
}
}

31
libs/hwui/PathTessellator.h
View File

@@ -27,6 +27,26 @@
namespace android {
namespace uirenderer {
/**
* Structure used for threshold values in outline path tessellation.
*
* TODO: PaintInfo should store one of this object, and initialized all values in constructor
* depending on its type (point, line or path).
*/
struct PathApproximationInfo {
PathApproximationInfo(float invScaleX, float invScaleY, float pixelThreshold)
: thresholdSquared(pixelThreshold * pixelThreshold)
, sqrInvScaleX(invScaleX * invScaleX)
, sqrInvScaleY(invScaleY * invScaleY)
, thresholdForConicQuads(pixelThreshold * MathUtils::min(invScaleX, invScaleY) / 2.0f) {
};
const float thresholdSquared;
const float sqrInvScaleX;
const float sqrInvScaleY;
const float thresholdForConicQuads;
};
class PathTessellator {
public:
/**
@@ -85,16 +105,15 @@ public:
* Approximates a convex outline into a clockwise Vector of 2d vertices.
*
* @param path The outline to be approximated
* @param thresholdSquared The threshold of acceptable error (in pixels) when approximating
* @param threshold The threshold of acceptable error (in pixels) when approximating
* @param outputVertices An empty Vector which will be populated with the output
*/
static bool approximatePathOutlineVertices(const SkPath &path, float thresholdSquared,
static bool approximatePathOutlineVertices(const SkPath &path, float threshold,
Vector<Vertex> &outputVertices);
private:
static bool approximatePathOutlineVertices(const SkPath &path, bool forceClose,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
Vector<Vertex> &outputVertices);
const PathApproximationInfo& approximationInfo, Vector<Vertex> &outputVertices);
/*
endpoints a & b,
@@ -104,7 +123,7 @@ private:
float ax, float ay,
float bx, float by,
float cx, float cy,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
const PathApproximationInfo& approximationInfo,
Vector<Vertex> &outputVertices, int depth = 0);
/*
@@ -116,7 +135,7 @@ private:
float c1x, float c1y,
float p2x, float p2y,
float c2x, float c2y,
float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared,
const PathApproximationInfo& approximationInfo,
Vector<Vertex> &outputVertices, int depth = 0);
};

4
libs/hwui/TessellationCache.cpp
View File

@@ -226,9 +226,9 @@ static void tessellateShadows(
// tessellate caster outline into a 2d polygon
Vector<Vertex> casterVertices2d;
const float casterRefinementThresholdSquared = 4.0f;
const float casterRefinementThreshold = 2.0f;
PathTessellator::approximatePathOutlineVertices(*casterPerimeter,
casterRefinementThresholdSquared, casterVertices2d);
casterRefinementThreshold, casterVertices2d);
// Shadow requires CCW for now. TODO: remove potential double-reverse
reverseVertexArray(casterVertices2d.editArray(), casterVertices2d.size());