SkPathOpsTightBounds.cpp File Reference

#include "include/core/SkPath.h"
#include "include/core/SkPathTypes.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkScalar.h"
#include "include/pathops/SkPathOps.h"
#include "src/base/SkArenaAlloc.h"
#include "src/core/SkPathPriv.h"
#include "src/pathops/SkOpContour.h"
#include "src/pathops/SkOpEdgeBuilder.h"
#include "src/pathops/SkPathOpsBounds.h"
#include "src/pathops/SkPathOpsCommon.h"
#include "src/pathops/SkPathOpsTypes.h"
#include <algorithm>

Go to the source code of this file.

Functions
bool	TightBounds (const SkPath &path, SkRect *result)

Function Documentation

TightBounds()

bool TightBounds	(	const SkPath &	path,
		SkRect *	result
	)

Set the resulting rectangle to the tight bounds of the path.

Parameters

path	The path measured.
result	The tight bounds of the path.

Returns

True if the bounds could be computed.

Definition at line 23 of file SkPathOpsTightBounds.cpp.

                                                     {
    SkRect moveBounds = { SK_ScalarMax, SK_ScalarMax, SK_ScalarMin, SK_ScalarMin };
    bool wellBehaved = true;
    for (auto [verb, pts, w] : SkPathPriv::Iterate(path)) {
        switch (verb) {
            case SkPathVerb::kMove:
                moveBounds.fLeft = std::min(moveBounds.fLeft, pts[0].fX);
                moveBounds.fTop = std::min(moveBounds.fTop, pts[0].fY);
                moveBounds.fRight = std::max(moveBounds.fRight, pts[0].fX);
                moveBounds.fBottom = std::max(moveBounds.fBottom, pts[0].fY);
                break;
            case SkPathVerb::kQuad:
            case SkPathVerb::kConic:
                if (!wellBehaved) {
                    break;
                }
                wellBehaved &= between(pts[0].fX, pts[1].fX, pts[2].fX);
                wellBehaved &= between(pts[0].fY, pts[1].fY, pts[2].fY);
                break;
            case SkPathVerb::kCubic:
                if (!wellBehaved) {
                    break;
                }
                wellBehaved &= between(pts[0].fX, pts[1].fX, pts[3].fX);
                wellBehaved &= between(pts[0].fY, pts[1].fY, pts[3].fY);
                wellBehaved &= between(pts[0].fX, pts[2].fX, pts[3].fX);
                wellBehaved &= between(pts[0].fY, pts[2].fY, pts[3].fY);
                break;
            default:
                break;
        }
    }
    if (wellBehaved) {
        *result = path.getBounds();
        return true;
    }
    SkSTArenaAlloc<4096> allocator;  // FIXME: constant-ize, tune
    SkOpContour contour;
    SkOpContourHead* contourList = static_cast<SkOpContourHead*>(&contour);
    SkOpGlobalState globalState(contourList, &allocator  SkDEBUGPARAMS(false)
            SkDEBUGPARAMS(nullptr));
    // turn path into list of segments
    SkOpEdgeBuilder builder(path, contourList, &globalState);
    if (!builder.finish()) {
        return false;
    }
    if (!SortContourList(&contourList, false, false)) {
        *result = moveBounds;
        return true;
    }
    SkOpContour* current = contourList;
    SkPathOpsBounds bounds = current->bounds();
    while ((current = current->next())) {
        bounds.add(current->bounds());
    }
    *result = bounds;
    if (!moveBounds.isEmpty()) {
        result->join(moveBounds);
    }
    return true;
}