diff --git a/NEWS.md b/NEWS.md
index 18f82673f64..f9201fd6afd 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -9,6 +9,7 @@
* Fixed hover highlight rendering with active parallax factor (#3669)
* Fixed updating of object selection outlines when changing parallax factor (#3669)
* Fixed "Offset Map" action to offset all objects when choosing "Whole Map" as bounds
+* Fixed several issues with drawing ellipses (#3776)
* Godot 4 plugin: Export custom tile properties as Custom Data Layers (with Kevin Harrison, #3653)
* AppImage: Updated to Sentry 0.6.4
* Qt 6: Increased the image allocation limit from 1 GB to 4 GB (#3616)
diff --git a/docs/manual/editing-tile-layers.rst b/docs/manual/editing-tile-layers.rst
index 46f29356d42..812d54e0c75 100644
--- a/docs/manual/editing-tile-layers.rst
+++ b/docs/manual/editing-tile-layers.rst
@@ -110,7 +110,16 @@ Shape Fill Tool
Shortcut: ``P`` |rectangle-fill|
This tool provides a quick way to fill rectangles or ellipses with a certain
-tile or pattern. Hold ``Shift`` to fill an exact square or circle.
+tile or pattern.
+
+- Holding ``Shift`` fills an exact square or circle.
+
+.. raw:: html
+
+ Since Tiled 1.10.2
+
+- Holding ``Alt`` draws the rectangle or ellipse centered around the starting
+ location.
You can also flip and rotate the current stamp as described for the
:ref:`stamp-tool`.
diff --git a/src/tiled/geometry.cpp b/src/tiled/geometry.cpp
index 7581f829ef8..eed67997754 100644
--- a/src/tiled/geometry.cpp
+++ b/src/tiled/geometry.cpp
@@ -1,6 +1,9 @@
/*
* geometry.cpp
* Copyright 2010-2011, Stefan Beller
+ * Copyright 2017, Benjamin Trotter
+ * Copyright 2020, Zingl Alois
+ * Copyright 2017-2023, Thorbjørn Lindeijer
*
* This file is part of Tiled.
*
@@ -26,142 +29,94 @@ namespace Tiled {
/**
* Returns a lists of points on an ellipse.
- * (x0,y0) is the midpoint
- * (x1,y1) determines the radius.
+ * (xm,ym) is the midpoint
+ * (a,b) determines the radii.
*
- * It is adapted from http://en.wikipedia.org/wiki/Midpoint_circle_algorithm
- * here is the original: http://homepage.smc.edu/kennedy_john/belipse.pdf
+ * From "Bresenham Curve Rasterizing Algorithms".
+ *
+ * @version V20.15 april 2020
+ * @copyright MIT open-source license software
+ * @url https://github.com/zingl/Bresenham
+ * @author Zingl Alois
*/
-QVector pointsOnEllipse(int x0, int y0, int x1, int y1)
+QVector pointsOnEllipse(int xm, int ym, int a, int b)
{
QVector ret;
- int x, y;
- int xChange, yChange;
- int ellipseError;
- int twoXSquare, twoYSquare;
- int stoppingX, stoppingY;
- int radiusX = x0 > x1 ? x0 - x1 : x1 - x0;
- int radiusY = y0 > y1 ? y0 - y1 : y1 - y0;
-
- if (radiusX == 0 && radiusY == 0)
- return ret;
-
- twoXSquare = 2 * radiusX * radiusX;
- twoYSquare = 2 * radiusY * radiusY;
- x = radiusX;
- y = 0;
- xChange = radiusY * radiusY * (1 - 2 * radiusX);
- yChange = radiusX * radiusX;
- ellipseError = 0;
- stoppingX = twoYSquare*radiusX;
- stoppingY = 0;
- while (stoppingX >= stoppingY) {
- ret += QPoint(x0 + x, y0 + y);
- ret += QPoint(x0 - x, y0 + y);
- ret += QPoint(x0 + x, y0 - y);
- ret += QPoint(x0 - x, y0 - y);
- y++;
- stoppingY += twoXSquare;
- ellipseError += yChange;
- yChange += twoXSquare;
- if ((2 * ellipseError + xChange) > 0) {
- x--;
- stoppingX -= twoYSquare;
- ellipseError += xChange;
- xChange += twoYSquare;
- }
- }
- x = 0;
- y = radiusY;
- xChange = radiusY * radiusY;
- yChange = radiusX * radiusX * (1 - 2 * radiusY);
- ellipseError = 0;
- stoppingX = 0;
- stoppingY = twoXSquare * radiusY;
- while (stoppingX <= stoppingY) {
- ret += QPoint(x0 + x, y0 + y);
- ret += QPoint(x0 - x, y0 + y);
- ret += QPoint(x0 + x, y0 - y);
- ret += QPoint(x0 - x, y0 - y);
- x++;
- stoppingX += twoYSquare;
- ellipseError += xChange;
- xChange += twoYSquare;
- if ((2 * ellipseError + yChange) > 0) {
- y--;
- stoppingY -= twoXSquare;
- ellipseError += yChange;
- yChange += twoXSquare;
- }
+
+ long x = -a, y = 0; /* II. quadrant from bottom left to top right */
+ long e2 = b, dx = (1+2*x)*e2*e2; /* error increment */
+ long dy = x*x, err = dx+dy; /* error of 1.step */
+
+ do {
+ ret += QPoint(xm-x, ym+y); /* I. Quadrant */
+ ret += QPoint(xm+x, ym+y); /* II. Quadrant */
+ ret += QPoint(xm+x, ym-y); /* III. Quadrant */
+ ret += QPoint(xm-x, ym-y); /* IV. Quadrant */
+ e2 = 2*err;
+ if (e2 >= dx) { x++; err += dx += 2*(long)b*b; } /* x step */
+ if (e2 <= dy) { y++; err += dy += 2*(long)a*a; } /* y step */
+ } while (x <= 0);
+
+ while (y++ < b) { /* too early stop for flat ellipses with a=1, */
+ ret += QPoint(xm, ym+y); /* -> finish tip of ellipse */
+ ret += QPoint(xm, ym-y);
}
return ret;
}
/**
- * returns an elliptical region centered at x0,y0 with radius determined by x1,y1
+ * Returns an elliptical region based on a rectangle given by x0,y0 (top-left)
+ * and x1,y1 (bottom-right), inclusive.
+ *
+ * From "Bresenham Curve Rasterizing Algorithms", adjusted to output a filled
+ * region instead of an outline.
+ *
+ * @version V20.15 april 2020
+ * @copyright MIT open-source license software
+ * @url https://github.com/zingl/Bresenham
+ * @author Zingl Alois
*/
QRegion ellipseRegion(int x0, int y0, int x1, int y1)
{
QRegion ret;
- int x, y;
- int xChange, yChange;
- int ellipseError;
- int twoXSquare, twoYSquare;
- int stoppingX, stoppingY;
- int radiusX = x0 > x1 ? x0 - x1 : x1 - x0;
- int radiusY = y0 > y1 ? y0 - y1 : y1 - y0;
-
- if (radiusX == 0 && radiusY == 0)
- return ret;
-
- twoXSquare = 2 * radiusX * radiusX;
- twoYSquare = 2 * radiusY * radiusY;
- x = radiusX;
- y = 0;
- xChange = radiusY * radiusY * (1 - 2 * radiusX);
- yChange = radiusX * radiusX;
- ellipseError = 0;
- stoppingX = twoYSquare*radiusX;
- stoppingY = 0;
- while (stoppingX >= stoppingY) {
- ret += QRect(-x, y, x * 2, 1);
- ret += QRect(-x, -y, x * 2, 1);
- y++;
- stoppingY += twoXSquare;
- ellipseError += yChange;
- yChange += twoXSquare;
- if ((2 * ellipseError + xChange) > 0) {
- x--;
- stoppingX -= twoYSquare;
- ellipseError += xChange;
- xChange += twoYSquare;
- }
- }
- x = 0;
- y = radiusY;
- xChange = radiusY * radiusY;
- yChange = radiusX * radiusX * (1 - 2 * radiusY);
- ellipseError = 0;
- stoppingX = 0;
- stoppingY = twoXSquare * radiusY;
- while (stoppingX <= stoppingY) {
- ret += QRect(-x, y, x * 2, 1);
- ret += QRect(-x, -y, x * 2, 1);
- x++;
- stoppingX += twoYSquare;
- ellipseError += xChange;
- xChange += twoYSquare;
- if ((2 * ellipseError + yChange) > 0) {
- y--;
- stoppingY -= twoXSquare;
- ellipseError += yChange;
- yChange += twoXSquare;
- }
+
+ auto addRect = [&ret](int x0, int y0, int x1, int y1) {
+ ret += QRect(QPoint(x0, y0), QPoint(x1, y1));
+ };
+
+ long a = abs(x1-x0), b = abs(y1-y0), b1 = b&1; /* diameter */
+ double dx = 4*(1.0-a)*b*b, dy = 4*(b1+1)*a*a; /* error increment */
+ double err = dx+dy+b1*a*a, e2; /* error of 1.step */
+
+ if (x0 > x1) { x0 = x1; x1 += a; } /* if called with swapped points */
+ if (y0 > y1) y0 = y1; /* .. exchange them */
+ y0 += (b+1)/2; y1 = y0-b1; /* starting pixel */
+ a = 8*a*a; b1 = 8*b*b;
+
+ do {
+ // (x1, y0) /* I. Quadrant */
+ // (x0, y0) /* II. Quadrant */
+ // (x0, y1) /* III. Quadrant */
+ // (x1, y1) /* IV. Quadrant */
+
+ addRect(x0, y0, x1, y0); /* Bottom half */
+ addRect(x0, y1, x1, y1); /* Top half */
+
+ e2 = 2*err;
+ if (e2 <= dy) { y0++; y1--; err += dy += a; } /* y step */
+ if (e2 >= dx || 2*err > dy) { x0++; x1--; err += dx += b1; } /* x step */
+ } while (x0 <= x1);
+
+ while (y0-y1 <= b) { /* too early stop of flat ellipses a=1 */
+ addRect(x0-1, y0, x1+1, y0); /* -> finish tip of ellipse */
+ addRect(x0-1, y1, x1+1, y1);
+ y0++;
+ y1--;
}
- return ret.translated(x0, y0);
-}
+ return ret;
+};
/**
* Returns the lists of points on a line from (x0,y0) to (x1,y1).
diff --git a/src/tiled/geometry.h b/src/tiled/geometry.h
index 8dfd059cc2e..726f3b5b551 100644
--- a/src/tiled/geometry.h
+++ b/src/tiled/geometry.h
@@ -1,6 +1,8 @@
/*
* geometry.h
* Copyright 2010-2011, Stefan Beller
+ * Copyright 2017, Benjamin Trotter
+ * Copyright 2017-2023, Thorbjørn Lindeijer
*
* This file is part of Tiled.
*
@@ -27,12 +29,15 @@
namespace Tiled {
-QVector pointsOnEllipse(int x0, int y0, int x1, int y1);
+QVector pointsOnEllipse(int xm, int ym, int a, int b);
QRegion ellipseRegion(int x0, int y0, int x1, int y1);
QVector pointsOnLine(int x0, int y0, int x1, int y1, bool manhattan = false);
-inline QVector pointsOnEllipse(QPoint a, QPoint b)
-{ return pointsOnEllipse(a.x(), a.y(), b.x(), b.y()); }
+inline QVector pointsOnEllipse(QPoint center, int radiusX, int radiusY)
+{ return pointsOnEllipse(center.x(), center.y(), radiusX, radiusY); }
+
+inline QRegion ellipseRegion(QRect rect)
+{ return ellipseRegion(rect.left(), rect.top(), rect.right(), rect.bottom()); }
inline QVector pointsOnLine(QPoint a, QPoint b, bool manhattan = false)
{ return pointsOnLine(a.x(), a.y(), b.x(), b.y(), manhattan); }
diff --git a/src/tiled/shapefilltool.cpp b/src/tiled/shapefilltool.cpp
index 6731b9540ea..155d6249ed6 100644
--- a/src/tiled/shapefilltool.cpp
+++ b/src/tiled/shapefilltool.cpp
@@ -21,16 +21,15 @@
#include "shapefilltool.h"
#include "actionmanager.h"
-#include "addremovetileset.h"
#include "brushitem.h"
#include "geometry.h"
#include "mapdocument.h"
-#include "painttilelayer.h"
#include "stampactions.h"
-#include
#include
+#include
#include
+#include
#include
@@ -62,9 +61,9 @@ ShapeFillTool::ShapeFillTool(QObject *parent)
ActionManager::registerAction(mRectFill, "ShapeFillTool.RectangleFill");
ActionManager::registerAction(mCircleFill, "ShapeFillTool.CircleFill");
- connect(mRectFill, &QAction::triggered,
+ connect(mRectFill, &QAction::triggered, this,
[this] { setCurrentShape(Rect); });
- connect(mCircleFill, &QAction::triggered,
+ connect(mCircleFill, &QAction::triggered, this,
[this] { setCurrentShape(Circle); });
setActionsEnabled(false);
@@ -207,27 +206,27 @@ void ShapeFillTool::updateFillOverlay()
dy = ((dy > 0) - (dy < 0)) * min;
}
- const QRect boundingRect(mStartCorner, mStartCorner + QPoint(dx, dy));
+ const bool alt = mModifiers & Qt::AltModifier;
+ const QPoint p1 = alt ? mStartCorner - QPoint(dx, dy)
+ : mStartCorner;
+ const QPoint p2 = mStartCorner + QPoint(dx, dy);
- switch (mCurrentShape) {
- case Rect: {
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
- QRect area = boundingRect.normalized();
- if (area.width() == 0)
- area.adjust(-1, 0, 1, 0);
- if (area.height() == 0)
- area.adjust(0, -1, 0, 1);
+ QRect area = QRect(p1, p2).normalized();
+ if (area.width() == 0)
+ area.adjust(-1, 0, 1, 0);
+ if (area.height() == 0)
+ area.adjust(0, -1, 0, 1);
#else
- QRect area = QRect::span(mStartCorner, mStartCorner + QPoint(dx, dy));
+ QRect area = QRect::span(p1, p2);
#endif
+
+ switch (mCurrentShape) {
+ case Rect:
updatePreview(area);
break;
- }
case Circle:
- updatePreview(ellipseRegion(boundingRect.left(),
- boundingRect.top(),
- boundingRect.right(),
- boundingRect.bottom()));
+ updatePreview(ellipseRegion(area));
break;
}
}
diff --git a/src/tiled/stampbrush.cpp b/src/tiled/stampbrush.cpp
index 70660d51542..d07bd79bed3 100644
--- a/src/tiled/stampbrush.cpp
+++ b/src/tiled/stampbrush.cpp
@@ -617,7 +617,9 @@ void StampBrush::updatePreview(QPoint tilePos)
drawPreviewLayer(pointsOnLine(mStampReference, tilePos));
break;
case CircleMidSet:
- drawPreviewLayer(pointsOnEllipse(mStampReference, tilePos));
+ drawPreviewLayer(pointsOnEllipse(mStampReference,
+ qAbs(mStampReference.x() - tilePos.x()),
+ qAbs(mStampReference.y() - tilePos.y())));
break;
case Capture:
// already handled above