# HG changeset patch
# User Chris Cannam
# Date 1454409064 0
# Node ID 44726e08859030892e97c3d1debfaf9ab0096979
# Parent  a2d05eba7b0b707e79f54dd670dc7abc512bc2d7
Revert last commit (wrong branch)

diff -r a2d05eba7b0b -r 44726e088590 layer/ScrollableImageCache.cpp
--- a/layer/ScrollableImageCache.cpp	Tue Feb 02 10:29:10 2016 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,194 +0,0 @@
-/* -*- 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 <iostream>
-using namespace std;
-
-#define DEBUG_SCROLLABLE_IMAGE_CACHE 1
-
-void
-ScrollableImageCache::scrollTo(sv_frame_t newStartFrame)
-{
-    if (!m_v) throw std::logic_error("ScrollableImageCache: not associated with a LayerGeometryProvider");
-	
-    int dx = (m_v->getXForFrame(m_startFrame) -
-	      m_v->getXForFrame(newStartFrame));
-
-#ifdef DEBUG_SCROLLABLE_IMAGE_CACHE
-    cerr << "ScrollableImageCache::scrollTo: start frame " << m_startFrame
-	 << " -> " << newStartFrame << ", dx = " << dx << endl;
-#endif
-    
-    m_startFrame = newStartFrame;
-	
-    if (!isValid()) {
-	return;
-    }
-
-    int w = m_image.width();
-
-    if (dx == 0) {
-	// haven't moved
-	return;
-    }
-
-    if (dx <= -w || dx >= w) {
-	// scrolled entirely off
-	invalidate();
-	return;
-    }
-	
-    // 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_left;
-    int pw = m_width;
-	
-    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_left = px;
-    m_width = pw;
-}
-
-void
-ScrollableImageCache::adjustToTouchValidArea(int &left, int &width,
-					     bool &isLeftOfValidArea) const
-{
-    if (left < m_left) {
-	isLeftOfValidArea = true;
-	if (left + width < m_left + m_width) {
-	    width = m_left - left;
-	}
-    } else {
-	isLeftOfValidArea = false;
-	width = left + width - (m_left + m_width);
-	left = m_left + m_width;
-	if (width < 0) width = 0;
-    }
-}
-    
-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 << ") 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
-	     << ") 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_left = left;
-	m_width = width;
-	return;
-    }
-	
-    if (left < m_left) {
-	if (left + width > m_left + m_width) {
-	    // new image completely contains the old valid area --
-	    // use the new area as is
-	    m_left = left;
-	    m_width = width;
-	} else if (left + width < m_left) {
-	    // 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_left = left;
-	    m_width = width;
-	} else {
-	    // new image overlaps old valid area on left side --
-	    // use new left edge, and extend width to existing
-	    // right edge
-	    m_width = (m_left + m_width) - left;
-	    m_left = left;
-	}
-    } else {
-	if (left > m_left + m_width) {
-	    // 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_left = left;
-	    m_width = width;
-	} else if (left + width > m_left + m_width) {
-	    // new image overlaps old valid area on right side --
-	    // use existing left edge, and extend width to new
-	    // right edge
-	    m_width = (left + width) - m_left;
-	    // (m_left unchanged)
-	} else {
-	    // new image completely contained within old valid
-	    // area -- leave the old area unchanged
-	}
-    }
-}
-