Mercurial > hg > svcore
diff base/ZoomConstraint.h @ 1551:4de4284d0596
Merge from branch zoom
author | Chris Cannam |
---|---|
date | Wed, 10 Oct 2018 08:44:15 +0100 |
parents | 1f72a44f5638 |
children | 05c3fbaec8ea |
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--- a/base/ZoomConstraint.h Wed Oct 03 15:45:57 2018 +0100 +++ b/base/ZoomConstraint.h Wed Oct 10 08:44:15 2018 +0100 @@ -18,6 +18,8 @@ #include <stdlib.h> +#include "ZoomLevel.h" + /** * ZoomConstraint is a simple interface that describes a limitation on * the available zoom sizes for a view, for example based on cache @@ -39,30 +41,42 @@ }; /** - * Given the "ideal" block size (frames per pixel) for a given - * zoom level, return the nearest viable block size for this - * constraint. + * Given an "ideal" zoom level (frames per pixel or pixels per + * frame) for a given zoom level, return the nearest viable block + * size for this constraint. * * For example, if a block size of 1523 frames per pixel is * requested but the underlying model only supports value * summaries at powers-of-two block sizes, return 1024 or 2048 * depending on the rounding direction supplied. */ - virtual int getNearestBlockSize(int requestedBlockSize, - RoundingDirection = RoundNearest) + virtual ZoomLevel getNearestZoomLevel(ZoomLevel requestedZoomLevel, + RoundingDirection = RoundNearest) const { - if (requestedBlockSize > getMaxZoomLevel()) return getMaxZoomLevel(); - else return requestedBlockSize; + if (getMaxZoomLevel() < requestedZoomLevel) return getMaxZoomLevel(); + else return requestedZoomLevel; } /** + * Return the minimum zoom level within range for this constraint. + * Individual views will probably want to limit this, for example + * in order to ensure that at least one or two samples fit in the + * current window size, or in order to save on interpolation cost. + */ + virtual ZoomLevel getMinZoomLevel() const { + return { ZoomLevel::PixelsPerFrame, 512 }; + } + + /** * Return the maximum zoom level within range for this constraint. * This is quite large -- individual views will probably want to * limit how far a user might reasonably zoom out based on other * factors such as the duration of the file. */ - virtual int getMaxZoomLevel() const { return 4194304; } // 2^22, arbitrarily + virtual ZoomLevel getMaxZoomLevel() const { + return { ZoomLevel::FramesPerPixel, 4194304 }; // 2^22, arbitrarily + } }; #endif