Mercurial > hg > svgui
view layer/ScrollableImageCache.cpp @ 1228:dc6457ac4d07
Add method to scale pen widths for hi-res screens
author | Chris Cannam |
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date | Thu, 26 Jan 2017 21:17:19 +0000 |
parents | f2f43802718b |
children | a34a2a25907c |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #include "ScrollableImageCache.h" #include "base/HitCount.h" #include <iostream> using namespace std; //#define DEBUG_SCROLLABLE_IMAGE_CACHE 1 void ScrollableImageCache::scrollTo(const LayerGeometryProvider *v, sv_frame_t newStartFrame) { static HitCount count("ScrollableImageCache: scrolling"); int dx = (v->getXForFrame(m_startFrame) - v->getXForFrame(newStartFrame)); #ifdef DEBUG_SCROLLABLE_IMAGE_CACHE cerr << "ScrollableImageCache::scrollTo: start frame " << m_startFrame << " -> " << newStartFrame << ", dx = " << dx << endl; #endif if (m_startFrame == newStartFrame) { // haven't moved count.hit(); return; } m_startFrame = newStartFrame; if (!isValid()) { count.miss(); return; } int w = m_image.width(); if (dx == 0) { // haven't moved visibly (even though start frame may have changed) count.hit(); return; } if (dx <= -w || dx >= w) { // scrolled entirely off invalidate(); count.miss(); return; } count.partial(); // dx is in range, cache is scrollable int dxp = dx; if (dxp < 0) dxp = -dxp; int copylen = (w - dxp) * int(sizeof(QRgb)); for (int y = 0; y < m_image.height(); ++y) { QRgb *line = (QRgb *)m_image.scanLine(y); if (dx < 0) { memmove(line, line + dxp, copylen); } else { memmove(line + dxp, line, copylen); } } // update valid area int px = m_validLeft; int pw = m_validWidth; px += dx; if (dx < 0) { // we scrolled left if (px < 0) { pw += px; px = 0; if (pw < 0) { pw = 0; } } } else { // we scrolled right if (px + pw > w) { pw = w - px; if (pw < 0) { pw = 0; } } } m_validLeft = px; m_validWidth = pw; } void ScrollableImageCache::adjustToTouchValidArea(int &left, int &width, bool &isLeftOfValidArea) const { #ifdef DEBUG_SCROLLABLE_IMAGE_CACHE cerr << "ScrollableImageCache::adjustToTouchValidArea: left " << left << ", width " << width << endl; cerr << "ScrollableImageCache: my left " << m_validLeft << ", width " << m_validWidth << " so right " << (m_validLeft + m_validWidth) << endl; #endif if (left < m_validLeft) { isLeftOfValidArea = true; if (left + width <= m_validLeft + m_validWidth) { width = m_validLeft - left; } #ifdef DEBUG_SCROLLABLE_IMAGE_CACHE cerr << "ScrollableImageCache: we're left of valid area, adjusted width to " << width << endl; #endif } else { isLeftOfValidArea = false; width = left + width - (m_validLeft + m_validWidth); left = m_validLeft + m_validWidth; if (width < 0) width = 0; #ifdef DEBUG_SCROLLABLE_IMAGE_CACHE cerr << "ScrollableImageCache: we're right of valid area, adjusted left to " << left << ", width to " << width << endl; #endif } } void ScrollableImageCache::drawImage(int left, int width, QImage image, int imageLeft, int imageWidth) { if (image.height() != m_image.height()) { cerr << "ScrollableImageCache::drawImage: ERROR: Supplied image height " << image.height() << " does not match cache height " << m_image.height() << endl; throw std::logic_error("Image height must match cache height in ScrollableImageCache::drawImage"); } if (left < 0 || width < 0 || left + width > m_image.width()) { cerr << "ScrollableImageCache::drawImage: ERROR: Target area (left = " << left << ", width = " << width << ", so right = " << left + width << ") out of bounds for cache of width " << m_image.width() << endl; throw std::logic_error("Target area out of bounds in ScrollableImageCache::drawImage"); } if (imageLeft < 0 || imageWidth < 0 || imageLeft + imageWidth > image.width()) { cerr << "ScrollableImageCache::drawImage: ERROR: Source area (left = " << imageLeft << ", width = " << imageWidth << ", so right = " << imageLeft + imageWidth << ") out of bounds for image of " << "width " << image.width() << endl; throw std::logic_error("Source area out of bounds in ScrollableImageCache::drawImage"); } QPainter painter(&m_image); painter.drawImage(QRect(left, 0, width, m_image.height()), image, QRect(imageLeft, 0, imageWidth, image.height())); painter.end(); if (!isValid()) { m_validLeft = left; m_validWidth = width; return; } if (left < m_validLeft) { if (left + width > m_validLeft + m_validWidth) { // new image completely contains the old valid area -- // use the new area as is m_validLeft = left; m_validWidth = width; } else if (left + width < m_validLeft) { // new image completely off left of old valid area -- // we can't extend the valid area because the bit in // between is not valid, so must use the new area only m_validLeft = left; m_validWidth = width; } else { // new image overlaps old valid area on left side -- // use new left edge, and extend width to existing // right edge m_validWidth = (m_validLeft + m_validWidth) - left; m_validLeft = left; } } else { if (left > m_validLeft + m_validWidth) { // new image completely off right of old valid area -- // we can't extend the valid area because the bit in // between is not valid, so must use the new area only m_validLeft = left; m_validWidth = width; } else if (left + width > m_validLeft + m_validWidth) { // new image overlaps old valid area on right side -- // use existing left edge, and extend width to new // right edge m_validWidth = (left + width) - m_validLeft; // (m_validLeft unchanged) } else { // new image completely contained within old valid // area -- leave the old area unchanged } } }