From bc7f43cd0294d8e1c9f05a3595615573a73028d5 Mon Sep 17 00:00:00 2001 From: aavit Date: Tue, 31 May 2011 11:51:10 +0200 Subject: [PATCH] Still use midpoint rendering of aliased ellipses 37c329a removed this, but it is required to get correct fills, particularly for small radii Reviewed-by: gunnar (cherry picked from commit 9d0104d3da01e262d2178c864b4ba94f620eaa3b) Change-Id: I41a5093f3cf725aee3abffde4d871566f0f8151e Reviewed-on: http://codereview.qt.nokia.com/608 Reviewed-by: Qt Sanity Bot Reviewed-by: Lars Knoll --- src/gui/painting/qpaintengine_raster.cpp | 160 +++++++++++++++++++++++++++++++ src/gui/painting/qpaintengine_raster_p.h | 1 + 2 files changed, 161 insertions(+) diff --git a/src/gui/painting/qpaintengine_raster.cpp b/src/gui/painting/qpaintengine_raster.cpp index fa7ca85..9db6c4f 100644 --- a/src/gui/painting/qpaintengine_raster.cpp +++ b/src/gui/painting/qpaintengine_raster.cpp @@ -160,6 +160,10 @@ enum LineDrawMode { LineDrawIncludeLastPixel }; +static void drawEllipse_midpoint_i(const QRect &rect, const QRect &clip, + ProcessSpans pen_func, ProcessSpans brush_func, + QSpanData *pen_data, QSpanData *brush_data); + struct QRasterFloatPoint { qreal x; qreal y; @@ -3030,6 +3034,19 @@ QRasterPaintEnginePrivate::getBrushFunc(const QRectF &rect, return isUnclipped(rect, 0) ? data->unclipped_blend : data->blend; } +inline ProcessSpans +QRasterPaintEnginePrivate::getPenFunc(const QRectF &rect, + const QSpanData *data) const +{ + Q_Q(const QRasterPaintEngine); + const QRasterPaintEngineState *s = q->state(); + + if (!s->flags.fast_pen && s->matrix.type() > QTransform::TxTranslate) + return data->blend; + const int penWidth = s->flags.fast_pen ? 1 : qCeil(s->lastPen.widthF()); + return isUnclipped(rect, penWidth) ? data->unclipped_blend : data->blend; +} + /*! \reimp */ @@ -3314,6 +3331,30 @@ void QRasterPaintEngine::drawLines(const QLineF *lines, int lineCount) */ void QRasterPaintEngine::drawEllipse(const QRectF &rect) { + Q_D(QRasterPaintEngine); + QRasterPaintEngineState *s = state(); + + ensurePen(); + if (((qpen_style(s->lastPen) == Qt::SolidLine && s->flags.fast_pen) + || (qpen_style(s->lastPen) == Qt::NoPen)) + && !s->flags.antialiased + && qMax(rect.width(), rect.height()) < QT_RASTER_COORD_LIMIT + && !rect.isEmpty() + && s->matrix.type() <= QTransform::TxScale) // no shear + { + ensureBrush(); + const QRectF r = s->matrix.mapRect(rect); + ProcessSpans penBlend = d->getPenFunc(r, &s->penData); + ProcessSpans brushBlend = d->getBrushFunc(r, &s->brushData); + const QRect brect = QRect(int(r.x()), int(r.y()), + int_dim(r.x(), r.width()), + int_dim(r.y(), r.height())); + if (brect == r) { + drawEllipse_midpoint_i(brect, d->deviceRect, penBlend, brushBlend, + &s->penData, &s->brushData); + return; + } + } QPaintEngineEx::drawEllipse(rect); } @@ -4998,6 +5039,125 @@ void QSpanData::initTexture(const QImage *image, int alpha, QTextureData::Type _ adjustSpanMethods(); } +/*! + \internal + \a x and \a y is relative to the midpoint of \a rect. +*/ +static inline void drawEllipsePoints(int x, int y, int length, + const QRect &rect, + const QRect &clip, + ProcessSpans pen_func, ProcessSpans brush_func, + QSpanData *pen_data, QSpanData *brush_data) +{ + if (length == 0) + return; + + QT_FT_Span outline[4]; + const int midx = rect.x() + (rect.width() + 1) / 2; + const int midy = rect.y() + (rect.height() + 1) / 2; + + x = x + midx; + y = midy - y; + + // topleft + outline[0].x = midx + (midx - x) - (length - 1) - (rect.width() & 0x1); + outline[0].len = qMin(length, x - outline[0].x); + outline[0].y = y; + outline[0].coverage = 255; + + // topright + outline[1].x = x; + outline[1].len = length; + outline[1].y = y; + outline[1].coverage = 255; + + // bottomleft + outline[2].x = outline[0].x; + outline[2].len = outline[0].len; + outline[2].y = midy + (midy - y) - (rect.height() & 0x1); + outline[2].coverage = 255; + + // bottomright + outline[3].x = x; + outline[3].len = length; + outline[3].y = outline[2].y; + outline[3].coverage = 255; + + if (brush_func && outline[0].x + outline[0].len < outline[1].x) { + QT_FT_Span fill[2]; + + // top fill + fill[0].x = outline[0].x + outline[0].len - 1; + fill[0].len = qMax(0, outline[1].x - fill[0].x); + fill[0].y = outline[1].y; + fill[0].coverage = 255; + + // bottom fill + fill[1].x = outline[2].x + outline[2].len - 1; + fill[1].len = qMax(0, outline[3].x - fill[1].x); + fill[1].y = outline[3].y; + fill[1].coverage = 255; + + int n = (fill[0].y >= fill[1].y ? 1 : 2); + n = qt_intersect_spans(fill, n, clip); + if (n > 0) + brush_func(n, fill, brush_data); + } + if (pen_func) { + int n = (outline[1].y >= outline[2].y ? 2 : 4); + n = qt_intersect_spans(outline, n, clip); + if (n > 0) + pen_func(n, outline, pen_data); + } +} + +/*! + \internal + Draws an ellipse using the integer point midpoint algorithm. +*/ +static void drawEllipse_midpoint_i(const QRect &rect, const QRect &clip, + ProcessSpans pen_func, ProcessSpans brush_func, + QSpanData *pen_data, QSpanData *brush_data) +{ + const qreal a = qreal(rect.width()) / 2; + const qreal b = qreal(rect.height()) / 2; + qreal d = b*b - (a*a*b) + 0.25*a*a; + + int x = 0; + int y = (rect.height() + 1) / 2; + int startx = x; + + // region 1 + while (a*a*(2*y - 1) > 2*b*b*(x + 1)) { + if (d < 0) { // select E + d += b*b*(2*x + 3); + ++x; + } else { // select SE + d += b*b*(2*x + 3) + a*a*(-2*y + 2); + drawEllipsePoints(startx, y, x - startx + 1, rect, clip, + pen_func, brush_func, pen_data, brush_data); + startx = ++x; + --y; + } + } + drawEllipsePoints(startx, y, x - startx + 1, rect, clip, + pen_func, brush_func, pen_data, brush_data); + + // region 2 + d = b*b*(x + 0.5)*(x + 0.5) + a*a*((y - 1)*(y - 1) - b*b); + const int miny = rect.height() & 0x1; + while (y > miny) { + if (d < 0) { // select SE + d += b*b*(2*x + 2) + a*a*(-2*y + 3); + ++x; + } else { // select S + d += a*a*(-2*y + 3); + } + --y; + drawEllipsePoints(x, y, 1, rect, clip, + pen_func, brush_func, pen_data, brush_data); + } +} /*! \fn void QRasterPaintEngine::drawPoints(const QPoint *points, int pointCount) diff --git a/src/gui/painting/qpaintengine_raster_p.h b/src/gui/painting/qpaintengine_raster_p.h index 2bf25f9..8774fda 100644 --- a/src/gui/painting/qpaintengine_raster_p.h +++ b/src/gui/painting/qpaintengine_raster_p.h @@ -327,6 +327,7 @@ public: bool isUnclipped_normalized(const QRect &rect) const; bool isUnclipped(const QRect &rect, int penWidth) const; bool isUnclipped(const QRectF &rect, int penWidth) const; + ProcessSpans getPenFunc(const QRectF &rect, const QSpanData *data) const; ProcessSpans getBrushFunc(const QRect &rect, const QSpanData *data) const; ProcessSpans getBrushFunc(const QRectF &rect, const QSpanData *data) const; -- 2.7.4