Chris@1035: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@1035: 
Chris@1035: /*
Chris@1035:     Sonic Visualiser
Chris@1035:     An audio file viewer and annotation editor.
Chris@1035:     Centre for Digital Music, Queen Mary, University of London.
Chris@1035:     
Chris@1035:     This program is free software; you can redistribute it and/or
Chris@1035:     modify it under the terms of the GNU General Public License as
Chris@1035:     published by the Free Software Foundation; either version 2 of the
Chris@1035:     License, or (at your option) any later version.  See the file
Chris@1035:     COPYING included with this distribution for more information.
Chris@1035: */
Chris@1035: 
Chris@1035: #include "ScrollableImageCache.h"
Chris@1035: 
Chris@1035: #include <iostream>
Chris@1035: using namespace std;
Chris@1035: 
Chris@1035: #define DEBUG_SCROLLABLE_IMAGE_CACHE 1
Chris@1035: 
Chris@1035: void
Chris@1035: ScrollableImageCache::scrollTo(sv_frame_t newStartFrame)
Chris@1035: {
Chris@1035:     if (!m_v) throw std::logic_error("ScrollableImageCache: not associated with a LayerGeometryProvider");
Chris@1035: 	
Chris@1035:     int dx = (m_v->getXForFrame(m_startFrame) -
Chris@1035: 	      m_v->getXForFrame(newStartFrame));
Chris@1035: 
Chris@1035: #ifdef DEBUG_SCROLLABLE_IMAGE_CACHE
Chris@1035:     cerr << "ScrollableImageCache::scrollTo: start frame " << m_startFrame
Chris@1035: 	 << " -> " << newStartFrame << ", dx = " << dx << endl;
Chris@1035: #endif
Chris@1035:     
Chris@1035:     m_startFrame = newStartFrame;
Chris@1035: 	
Chris@1035:     if (!isValid()) {
Chris@1035: 	return;
Chris@1035:     }
Chris@1035: 
Chris@1035:     int w = m_image.width();
Chris@1035: 
Chris@1035:     if (dx == 0) {
Chris@1035: 	// haven't moved
Chris@1035: 	return;
Chris@1035:     }
Chris@1035: 
Chris@1035:     if (dx <= -w || dx >= w) {
Chris@1035: 	// scrolled entirely off
Chris@1035: 	invalidate();
Chris@1035: 	return;
Chris@1035:     }
Chris@1035: 	
Chris@1035:     // dx is in range, cache is scrollable
Chris@1035: 
Chris@1035:     int dxp = dx;
Chris@1035:     if (dxp < 0) dxp = -dxp;
Chris@1035: 
Chris@1035:     int copylen = (w - dxp) * int(sizeof(QRgb));
Chris@1035:     for (int y = 0; y < m_image.height(); ++y) {
Chris@1035: 	QRgb *line = (QRgb *)m_image.scanLine(y);
Chris@1035: 	if (dx < 0) {
Chris@1035: 	    memmove(line, line + dxp, copylen);
Chris@1035: 	} else {
Chris@1035: 	    memmove(line + dxp, line, copylen);
Chris@1035: 	}
Chris@1035:     }
Chris@1035: 	
Chris@1035:     // update valid area
Chris@1035:         
Chris@1035:     int px = m_left;
Chris@1035:     int pw = m_width;
Chris@1035: 	
Chris@1035:     px += dx;
Chris@1035: 	
Chris@1035:     if (dx < 0) {
Chris@1035: 	// we scrolled left
Chris@1035: 	if (px < 0) {
Chris@1035: 	    pw += px;
Chris@1035: 	    px = 0;
Chris@1035: 	    if (pw < 0) {
Chris@1035: 		pw = 0;
Chris@1035: 	    }
Chris@1035: 	}
Chris@1035:     } else {
Chris@1035: 	// we scrolled right
Chris@1035: 	if (px + pw > w) {
Chris@1035: 	    pw = w - px;
Chris@1035: 	    if (pw < 0) {
Chris@1035: 		pw = 0;
Chris@1035: 	    }
Chris@1035: 	}
Chris@1035:     }
Chris@1035: 
Chris@1035:     m_left = px;
Chris@1035:     m_width = pw;
Chris@1035: }
Chris@1035: 
Chris@1035: void
Chris@1035: ScrollableImageCache::adjustToTouchValidArea(int &left, int &width,
Chris@1035: 					     bool &isLeftOfValidArea) const
Chris@1035: {
Chris@1035:     if (left < m_left) {
Chris@1035: 	isLeftOfValidArea = true;
Chris@1035: 	if (left + width < m_left + m_width) {
Chris@1035: 	    width = m_left - left;
Chris@1035: 	}
Chris@1035:     } else {
Chris@1035: 	isLeftOfValidArea = false;
Chris@1035: 	width = left + width - (m_left + m_width);
Chris@1035: 	left = m_left + m_width;
Chris@1035: 	if (width < 0) width = 0;
Chris@1035:     }
Chris@1035: }
Chris@1035:     
Chris@1035: void
Chris@1035: ScrollableImageCache::drawImage(int left,
Chris@1035: 				int width,
Chris@1035: 				QImage image,
Chris@1035: 				int imageLeft,
Chris@1035: 				int imageWidth)
Chris@1035: {
Chris@1035:     if (image.height() != m_image.height()) {
Chris@1035: 	cerr << "ScrollableImageCache::drawImage: ERROR: Supplied image height "
Chris@1035: 	     << image.height() << " does not match cache height "
Chris@1035: 	     << m_image.height() << endl;
Chris@1035: 	throw std::logic_error("Image height must match cache height in ScrollableImageCache::drawImage");
Chris@1035:     }
Chris@1035:     if (left < 0 || width < 0 || left + width > m_image.width()) {
Chris@1035: 	cerr << "ScrollableImageCache::drawImage: ERROR: Target area (left = "
Chris@1035: 	     << left << ", width = " << width << ") out of bounds for cache of "
Chris@1035: 	     << "width " << m_image.width() << endl;
Chris@1035: 	throw std::logic_error("Target area out of bounds in ScrollableImageCache::drawImage");
Chris@1035:     }
Chris@1035:     if (imageLeft < 0 || imageWidth < 0 ||
Chris@1035: 	imageLeft + imageWidth > image.width()) {
Chris@1035: 	cerr << "ScrollableImageCache::drawImage: ERROR: Source area (left = "
Chris@1035: 	     << imageLeft << ", width = " << imageWidth
Chris@1035: 	     << ") out of bounds for image of "
Chris@1035: 	     << "width " << image.width() << endl;
Chris@1035: 	throw std::logic_error("Source area out of bounds in ScrollableImageCache::drawImage");
Chris@1035:     }
Chris@1035: 	
Chris@1035:     QPainter painter(&m_image);
Chris@1035:     painter.drawImage(QRect(left, 0, width, m_image.height()),
Chris@1035: 		      image,
Chris@1035: 		      QRect(imageLeft, 0, imageWidth, image.height()));
Chris@1035:     painter.end();
Chris@1035: 
Chris@1035:     if (!isValid()) {
Chris@1035: 	m_left = left;
Chris@1035: 	m_width = width;
Chris@1035: 	return;
Chris@1035:     }
Chris@1035: 	
Chris@1035:     if (left < m_left) {
Chris@1035: 	if (left + width > m_left + m_width) {
Chris@1035: 	    // new image completely contains the old valid area --
Chris@1035: 	    // use the new area as is
Chris@1035: 	    m_left = left;
Chris@1035: 	    m_width = width;
Chris@1035: 	} else if (left + width < m_left) {
Chris@1035: 	    // new image completely off left of old valid area --
Chris@1035: 	    // we can't extend the valid area because the bit in
Chris@1035: 	    // between is not valid, so must use the new area only
Chris@1035: 	    m_left = left;
Chris@1035: 	    m_width = width;
Chris@1035: 	} else {
Chris@1035: 	    // new image overlaps old valid area on left side --
Chris@1035: 	    // use new left edge, and extend width to existing
Chris@1035: 	    // right edge
Chris@1035: 	    m_width = (m_left + m_width) - left;
Chris@1035: 	    m_left = left;
Chris@1035: 	}
Chris@1035:     } else {
Chris@1035: 	if (left > m_left + m_width) {
Chris@1035: 	    // new image completely off right of old valid area --
Chris@1035: 	    // we can't extend the valid area because the bit in
Chris@1035: 	    // between is not valid, so must use the new area only
Chris@1035: 	    m_left = left;
Chris@1035: 	    m_width = width;
Chris@1035: 	} else if (left + width > m_left + m_width) {
Chris@1035: 	    // new image overlaps old valid area on right side --
Chris@1035: 	    // use existing left edge, and extend width to new
Chris@1035: 	    // right edge
Chris@1035: 	    m_width = (left + width) - m_left;
Chris@1035: 	    // (m_left unchanged)
Chris@1035: 	} else {
Chris@1035: 	    // new image completely contained within old valid
Chris@1035: 	    // area -- leave the old area unchanged
Chris@1035: 	}
Chris@1035:     }
Chris@1035: }
Chris@1035: