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Diffstat (limited to 'src/gui/painting/qcosmeticstroker.cpp')
| -rw-r--r-- | src/gui/painting/qcosmeticstroker.cpp | 1010 |
1 files changed, 1010 insertions, 0 deletions
diff --git a/src/gui/painting/qcosmeticstroker.cpp b/src/gui/painting/qcosmeticstroker.cpp new file mode 100644 index 0000000..cdc0978 --- /dev/null +++ b/src/gui/painting/qcosmeticstroker.cpp @@ -0,0 +1,1010 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtGui module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qcosmeticstroker_p.h" +#include "private/qpainterpath_p.h" +#include <qdebug.h> +#include <math.h> + +QT_BEGIN_NAMESPACE + +#if 0 +inline QString capString(int caps) +{ + QString str; + if (caps & QCosmeticStroker::CapBegin) { + str += "CapBegin "; + } + if (caps & QCosmeticStroker::CapEnd) { + str += "CapEnd "; + } + return str; +} +#endif + +#define toF26Dot6(x) ((int)((x)*64.)) + +static inline uint sourceOver(uint d, uint color) +{ + return color + BYTE_MUL(d, qAlpha(~color)); +} + +inline static int F16Dot16FixedDiv(int x, int y) +{ + if (qAbs(x) > 0x7fff) + return (((qlonglong)x) << 16) / y; + return (x << 16) / y; +} + +typedef void (*DrawPixel)(QCosmeticStroker *stroker, int x, int y, int coverage); + +namespace { + +struct Dasher { + QCosmeticStroker *stroker; + int *pattern; + int offset; + int dashIndex; + int dashOn; + + Dasher(QCosmeticStroker *s, bool reverse, int start, int stop) + : stroker(s) + { + int delta = stop - start; + if (reverse) { + pattern = stroker->reversePattern; + offset = stroker->patternLength - stroker->patternOffset - delta - ((start & 63) - 32); + dashOn = 0; + } else { + pattern = stroker->pattern; + offset = stroker->patternOffset - ((start & 63) - 32); + dashOn = 1; + } + offset %= stroker->patternLength; + if (offset < 0) + offset += stroker->patternLength; + + dashIndex = 0; + while (offset>= pattern[dashIndex]) + ++dashIndex; + +// qDebug() << " dasher" << offset/64. << reverse << dashIndex; + stroker->patternOffset += delta; + stroker->patternOffset %= stroker->patternLength; + } + + bool on() const { + return (dashIndex + dashOn) & 1; + } + void adjust() { + offset += 64; + if (offset >= pattern[dashIndex]) { + ++dashIndex; + dashIndex %= stroker->patternSize; + } + offset %= stroker->patternLength; +// qDebug() << "dasher.adjust" << offset/64. << dashIndex; + } +}; + +struct NoDasher { + NoDasher(QCosmeticStroker *, bool, int, int) {} + bool on() const { return true; } + void adjust(int = 0) {} +}; + +}; + +template<DrawPixel drawPixel, class Dasher> +static void drawLine(QCosmeticStroker *stroker, qreal x1, qreal y1, qreal x2, qreal y2, int caps); +template<DrawPixel drawPixel, class Dasher> +static void drawLineAA(QCosmeticStroker *stroker, qreal x1, qreal y1, qreal x2, qreal y2, int caps); + +inline void drawPixel(QCosmeticStroker *stroker, int x, int y, int coverage) +{ + const QRect &cl = stroker->clip; + if (x < cl.x() || x > cl.right() || y < cl.y() || y > cl.bottom()) + return; + + int lastx = stroker->spans[stroker->current_span-1].x + stroker->spans[stroker->current_span-1].len ; + int lasty = stroker->spans[stroker->current_span-1].y; + + if (stroker->current_span == QCosmeticStroker::NSPANS || y < lasty || (y == lasty && x < lastx)) { + stroker->blend(stroker->current_span, stroker->spans, &stroker->state->penData); + stroker->current_span = 0; + } + + stroker->spans[stroker->current_span].x = ushort(x); + stroker->spans[stroker->current_span].len = 1; + stroker->spans[stroker->current_span].y = y; + stroker->spans[stroker->current_span].coverage = coverage*stroker->opacity >> 8; + ++stroker->current_span; +} + +inline void drawPixelARGB32(QCosmeticStroker *stroker, int x, int y, int coverage) +{ + const QRect &cl = stroker->clip; + if (x < cl.x() || x > cl.right() || y < cl.y() || y > cl.bottom()) + return; + + int offset = x + stroker->ppl*y; + uint c = BYTE_MUL(stroker->color, coverage); + stroker->pixels[offset] = sourceOver(stroker->pixels[offset], c); +} + +inline void drawPixelARGB32Opaque(QCosmeticStroker *stroker, int x, int y, int) +{ + const QRect &cl = stroker->clip; + if (x < cl.x() || x > cl.right() || y < cl.y() || y > cl.bottom()) + return; + + int offset = x + stroker->ppl*y; + stroker->pixels[offset] = sourceOver(stroker->pixels[offset], stroker->color); +} + +enum StrokeSelection { + Aliased = 0, + AntiAliased = 1, + Solid = 0, + Dashed = 2, + RegularDraw = 0, + FastDraw = 4 +}; + +static StrokeLine strokeLine(int strokeSelection) +{ + StrokeLine stroke; + + switch (strokeSelection) { + case Aliased|Solid|RegularDraw: + stroke = &QT_PREPEND_NAMESPACE(drawLine)<drawPixel, NoDasher>; + break; + case Aliased|Solid|FastDraw: + stroke = &QT_PREPEND_NAMESPACE(drawLine)<drawPixelARGB32Opaque, NoDasher>; + break; + case Aliased|Dashed|RegularDraw: + stroke = &QT_PREPEND_NAMESPACE(drawLine)<drawPixel, Dasher>; + break; + case Aliased|Dashed|FastDraw: + stroke = &QT_PREPEND_NAMESPACE(drawLine)<drawPixelARGB32Opaque, Dasher>; + break; + case AntiAliased|Solid|RegularDraw: + stroke = &QT_PREPEND_NAMESPACE(drawLineAA)<drawPixel, NoDasher>; + break; + case AntiAliased|Solid|FastDraw: + stroke = &QT_PREPEND_NAMESPACE(drawLineAA)<drawPixelARGB32, NoDasher>; + break; + case AntiAliased|Dashed|RegularDraw: + stroke = &QT_PREPEND_NAMESPACE(drawLineAA)<drawPixel, Dasher>; + break; + case AntiAliased|Dashed|FastDraw: + stroke = &QT_PREPEND_NAMESPACE(drawLineAA)<drawPixelARGB32, Dasher>; + break; + default: + Q_ASSERT(false); + stroke = 0; + } + return stroke; +} + +void QCosmeticStroker::setup() +{ + blend = state->penData.blend; + if (state->clip && state->clip->enabled && state->clip->hasRectClip && !state->clip->clipRect.isEmpty()) { + clip &= state->clip->clipRect; + blend = state->penData.unclipped_blend; + } + + int strokeSelection = 0; + if (blend == state->penData.unclipped_blend + && state->penData.type == QSpanData::Solid + && (state->penData.rasterBuffer->format == QImage::Format_ARGB32_Premultiplied + || state->penData.rasterBuffer->format == QImage::Format_RGB32) + && state->compositionMode() == QPainter::CompositionMode_SourceOver) + strokeSelection |= FastDraw; + + if (state->renderHints & QPainter::Antialiasing) + strokeSelection |= AntiAliased; + + const QVector<qreal> &penPattern = state->lastPen.dashPattern(); + if (penPattern.isEmpty()) { + Q_ASSERT(!pattern && !reversePattern); + pattern = 0; + reversePattern = 0; + patternLength = 0; + patternSize = 0; + } else { + pattern = (int *)malloc(penPattern.size()*sizeof(int)); + reversePattern = (int *)malloc(penPattern.size()*sizeof(int)); + patternSize = penPattern.size(); + + patternLength = 0; + for (int i = 0; i < patternSize; ++i) { + patternLength += (int) qMax(1. , penPattern.at(i)*64.); + pattern[i] = patternLength; + } + patternLength = 0; + for (int i = 0; i < patternSize; ++i) { + patternLength += (int) qMax(1., penPattern.at(patternSize - 1 - i)*64.); + reversePattern[i] = patternLength; + } + strokeSelection |= Dashed; +// qDebug() << "setup: size=" << patternSize << "length=" << patternLength/64.; + } + + stroke = strokeLine(strokeSelection); + + qreal width = state->lastPen.widthF(); + if (width == 0) + opacity = 256; + else if (state->lastPen.isCosmetic()) + opacity = (int) 256*width; + else + opacity = (int) 256*width*state->txscale; + opacity = qBound(0, opacity, 256); + + drawCaps = state->lastPen.capStyle() != Qt::FlatCap; + + if (strokeSelection & FastDraw) { + color = INTERPOLATE_PIXEL_256(state->penData.solid.color, opacity, 0, 0); + QRasterBuffer *buffer = state->penData.rasterBuffer; + pixels = (uint *)buffer->buffer(); + ppl = buffer->bytesPerLine()>>2; + } + + // setup FP clip bounds + xmin = clip.left() - 1; + xmax = clip.right() + 2; + ymin = clip.top() - 1; + ymax = clip.bottom() + 2; + + lastPixel.x = -1; +} + +// returns true if the whole line gets clipped away +bool QCosmeticStroker::clipLine(qreal &x1, qreal &y1, qreal &x2, qreal &y2) +{ + // basic/rough clipping is done in floating point coordinates to avoid + // integer overflow problems. + if (x1 < xmin) { + if (x2 <= xmin) + goto clipped; + y1 += (y2 - y1)/(x2 - x1) * (xmin - x1); + x1 = xmin; + } else if (x1 > xmax) { + if (x2 >= xmax) + goto clipped; + y1 += (y2 - y1)/(x2 - x1) * (xmax - x1); + x1 = xmax; + } + if (x2 < xmin) { + lastPixel.x = -1; + y2 += (y2 - y1)/(x2 - x1) * (xmin - x2); + x2 = xmin; + } else if (x2 > xmax) { + lastPixel.x = -1; + y2 += (y2 - y1)/(x2 - x1) * (xmax - x2); + x2 = xmax; + } + + if (y1 < ymin) { + if (y2 <= ymin) + goto clipped; + x1 += (x2 - x1)/(y2 - y1) * (ymin - y1); + y1 = ymin; + } else if (y1 > ymax) { + if (y2 >= ymax) + goto clipped; + x1 += (x2 - x1)/(y2 - y1) * (ymax - y1); + y1 = ymax; + } + if (y2 < ymin) { + lastPixel.x = -1; + x2 += (x2 - x1)/(y2 - y1) * (ymin - y2); + y2 = ymin; + } else if (y2 > ymax) { + lastPixel.x = -1; + x2 += (x2 - x1)/(y2 - y1) * (ymax - y2); + y2 = ymax; + } + + return false; + + clipped: + lastPixel.x = -1; + return true; +} + + +void QCosmeticStroker::drawLine(const QPointF &p1, const QPointF &p2) +{ + QPointF start = p1 * state->matrix; + QPointF end = p2 * state->matrix; + + patternOffset = state->lastPen.dashOffset()*64; + lastPixel.x = -1; + + stroke(this, start.x(), start.y(), end.x(), end.y(), drawCaps ? CapBegin|CapEnd : 0); + + blend(current_span, spans, &state->penData); + current_span = 0; +} + +void QCosmeticStroker::drawPoints(const QPoint *points, int num) +{ + const QPoint *end = points + num; + while (points < end) { + QPointF p = QPointF(*points) * state->matrix; + drawPixel(this, qRound(p.x()), qRound(p.y()), 255); + ++points; + } + + blend(current_span, spans, &state->penData); + current_span = 0; +} + +void QCosmeticStroker::drawPoints(const QPointF *points, int num) +{ + const QPointF *end = points + num; + while (points < end) { + QPointF p = (*points) * state->matrix; + drawPixel(this, qRound(p.x()), qRound(p.y()), 255); + ++points; + } + + blend(current_span, spans, &state->penData); + current_span = 0; +} + +void QCosmeticStroker::calculateLastPoint(qreal rx1, qreal ry1, qreal rx2, qreal ry2) +{ + // this is basically the same code as used in the aliased stroke method, + // but it only determines the direction and last point of a line + // + // This is being used to have proper dropout control for closed contours + // by calculating the direction and last pixel of the last segment in the contour. + // the info is then used to perform dropout control when drawing the first line segment + // of the contour + lastPixel.x = -1; + lastPixel.y = -1; + + if (clipLine(rx1, ry1, rx2, ry2)) + return; + + const int half = 32; + int x1 = toF26Dot6(rx1) + half; + int y1 = toF26Dot6(ry1) + half; + int x2 = toF26Dot6(rx2) + half; + int y2 = toF26Dot6(ry2) + half; + + int dx = qAbs(x2 - x1); + int dy = qAbs(y2 - y1); + + if (dx < dy) { + // vertical + bool swapped = false; + if (y1 > y2) { + swapped = true; + qSwap(y1, y2); + qSwap(x1, x2); + --x1; --x2; --y1; --y2; + } + int xinc = F16Dot16FixedDiv(x2 - x1, y2 - y1); + int x = x1 << 10; + + int y = (y1+32) >> 6; + int ys = (y2+32) >> 6; + + if (y != ys) { + x += ( ((((y << 6) + 32 - y1))) * xinc ) >> 6; + + if (swapped) { + lastPixel.x = x >> 16; + lastPixel.y = y; + lastDir = QCosmeticStroker::BottomToTop; + } else { + lastPixel.x = (x + (ys - y - 1)*xinc) >> 16; + lastPixel.y = ys - 1; + lastDir = QCosmeticStroker::TopToBottom; + } + lastAxisAligned = qAbs(xinc) < (1 << 14); + } + } else { + // horizontal + if (!dx) + return; + + bool swapped = false; + if (x1 > x2) { + swapped = true; + qSwap(x1, x2); + qSwap(y1, y2); + --x1; --x2; --y1; --y2; + } + int yinc = F16Dot16FixedDiv(y2 - y1, x2 - x1); + int y = y1 << 10; + + int x = (x1+32) >> 6; + int xs = (x2+32) >> 6; + + if (x != xs) { + y += ( ((((x << 6) + 32 - x1))) * yinc ) >> 6; + + if (swapped) { + lastPixel.x = x; + lastPixel.y = y >> 16; + lastDir = QCosmeticStroker::RightToLeft; + } else { + lastPixel.x = xs - 1; + lastPixel.y = (y + (xs - x - 1)*yinc) >> 16; + lastDir = QCosmeticStroker::LeftToRight; + } + lastAxisAligned = qAbs(yinc) < (1 << 14); + } + } +// qDebug() << " moveTo: setting last pixel to x/y dir" << lastPixel.x << lastPixel.y << lastDir; +} + +static inline const QPainterPath::ElementType *subPath(const QPainterPath::ElementType *t, const QPainterPath::ElementType *end, + const qreal *points, bool *closed) +{ + const QPainterPath::ElementType *start = t; + ++t; + + // find out if the subpath is closed + while (t < end) { + if (*t == QPainterPath::MoveToElement) + break; + ++t; + } + + int offset = t - start - 1; +// qDebug() << "subpath" << offset << points[0] << points[1] << points[2*offset] << points[2*offset+1]; + *closed = (points[0] == points[2*offset] && points[1] == points[2*offset + 1]); + + return t; +} + +void QCosmeticStroker::drawPath(const QVectorPath &path) +{ +// qDebug() << ">>>> drawpath" << path.convertToPainterPath() +// << "antialiasing:" << (bool)(state->renderHints & QPainter::Antialiasing) << " implicit close:" << path.hasImplicitClose(); + if (path.isEmpty()) + return; + + const qreal *points = path.points(); + const QPainterPath::ElementType *type = path.elements(); + + if (type) { + const QPainterPath::ElementType *end = type + path.elementCount(); + + while (type < end) { + Q_ASSERT(type == path.elements() || *type == QPainterPath::MoveToElement); + + QPointF p = QPointF(points[0], points[1]) * state->matrix; + QPointF movedTo = p; + patternOffset = state->lastPen.dashOffset()*64; + lastPixel.x = -1; + + bool closed; + const QPainterPath::ElementType *e = subPath(type, end, points, &closed); + if (closed) { + const qreal *p = points + 2*(e-type); + QPointF p1 = QPointF(p[-4], p[-3]) * state->matrix; + QPointF p2 = QPointF(p[-2], p[-1]) * state->matrix; + calculateLastPoint(p1.x(), p1.y(), p2.x(), p2.y()); + } + int caps = (!closed & drawCaps) ? CapBegin : NoCaps; +// qDebug() << "closed =" << closed << capString(caps); + + points += 2; + ++type; + + while (type < e) { + QPointF p2 = QPointF(points[0], points[1]) * state->matrix; + switch (*type) { + case QPainterPath::MoveToElement: + Q_ASSERT(!"Logic error"); + break; + + case QPainterPath::LineToElement: + if (!closed && drawCaps && type == e - 1) + caps |= CapEnd; + stroke(this, p.x(), p.y(), p2.x(), p2.y(), caps); + p = p2; + points += 2; + ++type; + break; + + case QPainterPath::CurveToElement: { + if (!closed && drawCaps && type == e - 3) + caps |= CapEnd; + QPointF p3 = QPointF(points[2], points[3]) * state->matrix; + QPointF p4 = QPointF(points[4], points[5]) * state->matrix; + renderCubic(p, p2, p3, p4, caps); + p = p4; + type += 3; + points += 6; + break; + } + case QPainterPath::CurveToDataElement: + Q_ASSERT(!"QPainterPath::toSubpathPolygons(), bad element type"); + break; + } + caps = NoCaps; + } + } + } else { // !type, simple polygon + QPointF p = QPointF(points[0], points[1]) * state->matrix; + QPointF movedTo = p; + patternOffset = state->lastPen.dashOffset()*64; + lastPixel.x = -1; + + const qreal *end = points + 2*path.elementCount(); + // handle closed path case + bool closed = path.hasImplicitClose() || (points[0] == end[-2] && points[1] == end[-1]); + int caps = (!closed & drawCaps) ? CapBegin : NoCaps; + if (closed) { + QPointF p2 = QPointF(end[-2], end[-1]) * state->matrix; + calculateLastPoint(p2.x(), p2.y(), p.x(), p.y()); + } + + points += 2; + while (points < end) { + QPointF p2 = QPointF(points[0], points[1]) * state->matrix; + + if (!closed && drawCaps && points == end - 2) + caps |= CapEnd; + + stroke(this, p.x(), p.y(), p2.x(), p2.y(), caps); + + p = p2; + points += 2; + caps = NoCaps; + } + if (path.hasImplicitClose()) + stroke(this, p.x(), p.y(), movedTo.x(), movedTo.y(), NoCaps); + } + + + blend(current_span, spans, &state->penData); + current_span = 0; +} + +void QCosmeticStroker::renderCubic(const QPointF &p1, const QPointF &p2, const QPointF &p3, const QPointF &p4, int caps) +{ +// qDebug() << ">>>> renderCubic" << p1 << p2 << p3 << p4 << capString(caps); + const int maxSubDivisions = 6; + PointF points[3*maxSubDivisions + 4]; + + points[3].x = p1.x(); + points[3].y = p1.y(); + points[2].x = p2.x(); + points[2].y = p2.y(); + points[1].x = p3.x(); + points[1].y = p3.y(); + points[0].x = p4.x(); + points[0].y = p4.y(); + + PointF *p = points; + int level = maxSubDivisions; + + renderCubicSubdivision(p, level, caps); +} + +static void splitCubic(QCosmeticStroker::PointF *points) +{ + const qreal half = .5; + qreal a, b, c, d; + + points[6].x = points[3].x; + c = points[1].x; + d = points[2].x; + points[1].x = a = ( points[0].x + c ) * half; + points[5].x = b = ( points[3].x + d ) * half; + c = ( c + d ) * half; + points[2].x = a = ( a + c ) * half; + points[4].x = b = ( b + c ) * half; + points[3].x = ( a + b ) * half; + + points[6].y = points[3].y; + c = points[1].y; + d = points[2].y; + points[1].y = a = ( points[0].y + c ) * half; + points[5].y = b = ( points[3].y + d ) * half; + c = ( c + d ) * half; + points[2].y = a = ( a + c ) * half; + points[4].y = b = ( b + c ) * half; + points[3].y = ( a + b ) * half; +} + +void QCosmeticStroker::renderCubicSubdivision(QCosmeticStroker::PointF *points, int level, int caps) +{ + if (level) { + qreal dx = points[3].x - points[0].x; + qreal dy = points[3].y - points[0].y; + qreal len = ((qreal).25) * (qAbs(dx) + qAbs(dy)); + + if (qAbs(dx * (points[0].y - points[2].y) - dy * (points[0].x - points[2].x)) >= len || + qAbs(dx * (points[0].y - points[1].y) - dy * (points[0].x - points[1].x)) >= len) { + splitCubic(points); + + --level; + renderCubicSubdivision(points + 3, level, caps & CapBegin); + renderCubicSubdivision(points, level, caps & CapEnd); + return; + } + } + + stroke(this, points[3].x, points[3].y, points[0].x, points[0].y, caps); +} + +static inline int swapCaps(int caps) +{ + return ((caps & QCosmeticStroker::CapBegin) << 1) | + ((caps & QCosmeticStroker::CapEnd) >> 1); +} + +// adjust line by half a pixel +static inline void capAdjust(int caps, int &x1, int &x2, int &y, int yinc) +{ + if (caps & QCosmeticStroker::CapBegin) { + x1 -= 32; + y -= yinc >> 1; + } + if (caps & QCosmeticStroker::CapEnd) { + x2 += 32; + } +} + +/* + The hard part about this is dropout control and avoiding douple drawing of points when + the drawing shifts from horizontal to vertical or back. + */ +template<DrawPixel drawPixel, class Dasher> +static void drawLine(QCosmeticStroker *stroker, qreal rx1, qreal ry1, qreal rx2, qreal ry2, int caps) +{ + if (stroker->clipLine(rx1, ry1, rx2, ry2)) + return; + + static const int half = 32; + int x1 = toF26Dot6(rx1) + half; + int y1 = toF26Dot6(ry1) + half; + int x2 = toF26Dot6(rx2) + half; + int y2 = toF26Dot6(ry2) + half; + + int dx = qAbs(x2 - x1); + int dy = qAbs(y2 - y1); + + QCosmeticStroker::Point last = stroker->lastPixel; + +// qDebug() << "stroke" << x1/64. << y1/64. << x2/64. << y2/64. << capString(caps); + + if (dx < dy) { + // vertical + + bool swapped = false; + if (y1 > y2) { + swapped = true; + qSwap(y1, y2); + qSwap(x1, x2); + caps = swapCaps(caps); + --x1; --x2; --y1; --y2; + } + int xinc = F16Dot16FixedDiv(x2 - x1, y2 - y1); + int x = x1 << 10; + + capAdjust(caps, y1, y2, x, xinc); + + int y = (y1+32) >> 6; + int ys = (y2+32) >> 6; + + if (y != ys) { + x += ( ((((y << 6) + 32 - y1))) * xinc ) >> 6; + + // calculate first and last pixel and perform dropout control + QCosmeticStroker::Direction dir = QCosmeticStroker::TopToBottom; + QCosmeticStroker::Point first; + first.x = x >> 16; + first.y = y; + last.x = (x + (ys - y - 1)*xinc) >> 16; + last.y = ys - 1; + if (swapped) { + qSwap(first, last); + dir = QCosmeticStroker::BottomToTop; + } + bool axisAligned = qAbs(xinc) < (1 << 14); + if (stroker->lastPixel.x >= 0) { + if (first.x == stroker->lastPixel.x && + first.y == stroker->lastPixel.y) { + // remove duplicated pixel + if (swapped) { + --ys; + } else { + ++y; + x += xinc; + } + } else if (stroker->lastDir != dir && + (((axisAligned && stroker->lastAxisAligned) && + stroker->lastPixel.x != first.x && stroker->lastPixel.y != first.y) || + (qAbs(stroker->lastPixel.x - first.x) > 1 && + qAbs(stroker->lastPixel.y - first.y) > 1))) { + // have a missing pixel, insert it + if (swapped) { + ++ys; + } else { + --y; + x -= xinc; + } + } + } + stroker->lastDir = dir; + stroker->lastAxisAligned = axisAligned; + + Dasher dasher(stroker, swapped, y << 6, ys << 6); + + do { + if (dasher.on()) + drawPixel(stroker, x >> 16, y, 255); + dasher.adjust(); + x += xinc; + } while (++y < ys); + } + } else { + // horizontal + if (!dx) + return; + + bool swapped = false; + if (x1 > x2) { + swapped = true; + qSwap(x1, x2); + qSwap(y1, y2); + caps = swapCaps(caps); + --x1; --x2; --y1; --y2; + } + int yinc = F16Dot16FixedDiv(y2 - y1, x2 - x1); + int y = y1 << 10; + + capAdjust(caps, x1, x2, y, yinc); + + int x = (x1+32) >> 6; + int xs = (x2+32) >> 6; + + + if (x != xs) { + y += ( ((((x << 6) + 32 - x1))) * yinc ) >> 6; + + // calculate first and last pixel to perform dropout control + QCosmeticStroker::Direction dir = QCosmeticStroker::LeftToRight; + QCosmeticStroker::Point first; + first.x = x; + first.y = y >> 16; + last.x = xs - 1; + last.y = (y + (xs - x - 1)*yinc) >> 16; + if (swapped) { + qSwap(first, last); + dir = QCosmeticStroker::RightToLeft; + } + bool axisAligned = qAbs(yinc) < (1 << 14); + if (stroker->lastPixel.x >= 0) { + if (first.x == stroker->lastPixel.x && first.y == stroker->lastPixel.y) { + // remove duplicated pixel + if (swapped) { + --xs; + } else { + ++x; + y += yinc; + } + } else if (stroker->lastDir != dir && + (((axisAligned && stroker->lastAxisAligned) && + stroker->lastPixel.x != first.x && stroker->lastPixel.y != first.y) || + (qAbs(stroker->lastPixel.x - first.x) > 1 && + qAbs(stroker->lastPixel.y - first.y) > 1))) { + // have a missing pixel, insert it + if (swapped) { + ++xs; + } else { + --x; + y -= yinc; + } + } + } + stroker->lastDir = dir; + stroker->lastAxisAligned = axisAligned; + + Dasher dasher(stroker, swapped, x << 6, xs << 6); + + do { + if (dasher.on()) + drawPixel(stroker, x, y >> 16, 255); + dasher.adjust(); + y += yinc; + } while (++x < xs); + } + } + stroker->lastPixel = last; +} + + +template<DrawPixel drawPixel, class Dasher> +static void drawLineAA(QCosmeticStroker *stroker, qreal rx1, qreal ry1, qreal rx2, qreal ry2, int caps) +{ + if (stroker->clipLine(rx1, ry1, rx2, ry2)) + return; + + int x1 = toF26Dot6(rx1); + int y1 = toF26Dot6(ry1); + int x2 = toF26Dot6(rx2); + int y2 = toF26Dot6(ry2); + + int dx = x2 - x1; + int dy = y2 - y1; + + if (qAbs(dx) < qAbs(dy)) { + // vertical + + int xinc = F16Dot16FixedDiv(dx, dy); + + bool swapped = false; + if (y1 > y2) { + qSwap(y1, y2); + qSwap(x1, x2); + swapped = true; + caps = swapCaps(caps); + } + + int x = (x1 - 32) << 10; + x -= ( ((y1 & 63) - 32) * xinc ) >> 6; + + capAdjust(caps, y1, y2, x, xinc); + + Dasher dasher(stroker, swapped, y1, y2); + + int y = y1 >> 6; + int ys = y2 >> 6; + + int alphaStart, alphaEnd; + if (y == ys) { + alphaStart = y2 - y1; + Q_ASSERT(alphaStart >= 0 && alphaStart < 64); + alphaEnd = 0; + } else { + alphaStart = 64 - (y1 & 63); + alphaEnd = (y2 & 63); + } +// qDebug() << "vertical" << x1/64. << y1/64. << x2/64. << y2/64.; +// qDebug() << " x=" << x << "dx=" << dx << "xi=" << (x>>16) << "xsi=" << ((x+(ys-y)*dx)>>16) << "y=" << y << "ys=" << ys; + + // draw first pixel + if (dasher.on()) { + uint alpha = (quint8)(x >> 8); + drawPixel(stroker, x>>16, y, (255-alpha) * alphaStart >> 6); + drawPixel(stroker, (x>>16) + 1, y, alpha * alphaStart >> 6); + } + dasher.adjust(); + x += xinc; + ++y; + if (y < ys) { + do { + if (dasher.on()) { + uint alpha = (quint8)(x >> 8); + drawPixel(stroker, x>>16, y, (255-alpha)); + drawPixel(stroker, (x>>16) + 1, y, alpha); + } + dasher.adjust(); + x += xinc; + } while (++y < ys); + } + // draw last pixel + if (alphaEnd && dasher.on()) { + uint alpha = (quint8)(x >> 8); + drawPixel(stroker, x>>16, y, (255-alpha) * alphaEnd >> 6); + drawPixel(stroker, (x>>16) + 1, y, alpha * alphaEnd >> 6); + } + } else { + // horizontal + if (!dx) + return; + + int yinc = F16Dot16FixedDiv(dy, dx); + + bool swapped = false; + if (x1 > x2) { + qSwap(x1, x2); + qSwap(y1, y2); + swapped = true; + caps = swapCaps(caps); + } + + int y = (y1 - 32) << 10; + y -= ( ((x1 & 63) - 32) * yinc ) >> 6; + + capAdjust(caps, x1, x2, y, yinc); + + Dasher dasher(stroker, swapped, x1, x2); + + int x = x1 >> 6; + int xs = x2 >> 6; + +// qDebug() << "horizontal" << x1/64. << y1/64. << x2/64. << y2/64.; +// qDebug() << " y=" << y << "dy=" << dy << "x=" << x << "xs=" << xs << "yi=" << (y>>16) << "ysi=" << ((y+(xs-x)*dy)>>16); + int alphaStart, alphaEnd; + if (x == xs) { + alphaStart = x2 - x1; + Q_ASSERT(alphaStart >= 0 && alphaStart < 64); + alphaEnd = 0; + } else { + alphaStart = 64 - (x1 & 63); + alphaEnd = (x2 & 63); + } + + // draw first pixel + if (dasher.on()) { + uint alpha = (quint8)(y >> 8); + drawPixel(stroker, x, y>>16, (255-alpha) * alphaStart >> 6); + drawPixel(stroker, x, (y>>16) + 1, alpha * alphaStart >> 6); + } + dasher.adjust(); + y += yinc; + ++x; + // draw line + if (x < xs) { + do { + if (dasher.on()) { + uint alpha = (quint8)(y >> 8); + drawPixel(stroker, x, y>>16, (255-alpha)); + drawPixel(stroker, x, (y>>16) + 1, alpha); + } + dasher.adjust(); + y += yinc; + } while (++x < xs); + } + // draw last pixel + if (alphaEnd && dasher.on()) { + uint alpha = (quint8)(y >> 8); + drawPixel(stroker, x, y>>16, (255-alpha) * alphaEnd >> 6); + drawPixel(stroker, x, (y>>16) + 1, alpha * alphaEnd >> 6); + } + } +} + +QT_END_NAMESPACE |