48 lines
1.6 KiB
C++
48 lines
1.6 KiB
C++
#include "qimageview.h"
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#include <cmath>
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QImageView::QImageView(QWidget *parent): QGraphicsView(parent)
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{
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// 隐藏水平/竖直滚动条
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setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
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setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
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//QPainter::Antialiasing //绘图抗锯齿
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//QPainter::TextAntialiasing //绘制的字体抗锯齿
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setRenderHints(QPainter::Antialiasing);
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//设置背景笔刷
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setBackgroundBrush(BackgroundColor);
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}
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void QImageView::drawBackground(QPainter *painter, const QRectF &r)
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{
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QGraphicsView::drawBackground(painter, r);
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auto drawGrid = [&](double gridStep) {
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QRect windowRect = rect();
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QPointF tl = mapToScene(windowRect.topLeft());
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QPointF br = mapToScene(windowRect.bottomRight());
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double left = std::floor(tl.x() / gridStep - 0.5);
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double right = std::floor(br.x() / gridStep + 1.0);
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double bottom = std::floor(tl.y() / gridStep - 0.5);
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double top = std::floor(br.y() / gridStep + 1.0);
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// vertical lines
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for (int xi = int(left); xi <= int(right); ++xi)
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{
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QLineF line(xi * gridStep, bottom * gridStep, xi * gridStep, top * gridStep);
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painter->drawLine(line);
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}
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// horizontal lines
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for (int yi = int(bottom); yi <= int(top); ++yi)
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{
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QLineF line(left * gridStep, yi * gridStep, right * gridStep, yi * gridStep);
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painter->drawLine(line);
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}
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};
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QPen pfine(FineGridColor, 1.0);
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painter->setPen(pfine);
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drawGrid(15);
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QPen p(CoarseGridColor, 1.0);
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painter->setPen(p);
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drawGrid(150);
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}
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