Method buildCanvasMaps

3rdparty/qwt/src/qwt_plot_renderer.cpp:969–1024

! Calculated the scale maps for rendering the canvas \param plot Plot widget \param canvasRect Target rectangle \param maps Scale maps to be calculated */

   \param maps Scale maps to be calculated
 */
void QwtPlotRenderer::buildCanvasMaps( const QwtPlot* plot,
    const QRectF& canvasRect, QwtScaleMap maps[] ) const
{
    for ( int axisPos = 0; axisPos < QwtAxis::AxisPositions; axisPos++ )
    {
        {
            const QwtAxisId axisId( axisPos );

            QwtScaleMap& scaleMap = maps[axisId];

            scaleMap.setTransformation(
                plot->axisScaleEngine( axisId )->transformation() );

            const QwtScaleDiv& scaleDiv = plot->axisScaleDiv( axisId );
            scaleMap.setScaleInterval(
                scaleDiv.lowerBound(), scaleDiv.upperBound() );

            double from, to;
            if ( plot->isAxisVisible( axisId ) )
            {
                const int sDist = plot->axisWidget( axisId )->startBorderDist();
                const int eDist = plot->axisWidget( axisId )->endBorderDist();
                const QRectF scaleRect = plot->plotLayout()->scaleRect( axisId );

                if ( QwtAxis::isXAxis( axisPos ) )
                {
                    from = scaleRect.left() + sDist;
                    to = scaleRect.right() - eDist;
                }
                else
                {
                    from = scaleRect.bottom() - eDist;
                    to = scaleRect.top() + sDist;
                }
            }
            else
            {
                int margin = 0;
                if ( !plot->plotLayout()->alignCanvasToScale( axisPos ) )
                    margin = plot->plotLayout()->canvasMargin( axisPos );

                if ( QwtAxis::isYAxis( axisPos ) )
                {
                    from = canvasRect.bottom() - margin;
                    to = canvasRect.top() + margin;
                }
                else
                {
                    from = canvasRect.left() + margin;
                    to = canvasRect.right() - margin;
                }
            }
            scaleMap.setPaintInterval( from, to );
        }
    }
}

bool QwtPlotRenderer::updateCanvasMargins( QwtPlot* plot,