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40 lines
1.1 KiB
Text
40 lines
1.1 KiB
Text
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0. Goals/Philosophy.
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The basic philosophy behind this library's design is simple: the X server is
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a shared resource that multiplexes poorly. Therefore, the server is touched
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as late as possible, and X memory is conserved (as is for some things main
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memory). This makes the worst case much better, but likely makes the best
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case worse.
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1. Planes.
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In displaying images, data has to be moved between client and the server,
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and perhaps scaled. The concept underlying this is that of a plane.
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The original images data is at the original/source plane, and all the other
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planes get the data from it or some other plane. Various scenarios are handled
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by stacking planes in a different order.
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e.g., here is how a basic displaying looks:
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RawPixmapPlane
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^
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RawImagePlane <- - - (data from loader)
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and a client-side scaling scenario:
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RawPixmapPlane
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^
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ScaledImagePlane
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^
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RawImagePlane <- - - (data from loader)
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All planes above the lowest RawImagePlane treat their data as tiles,
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and limit the actual resources they use by using the appropriate tile cache
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to allocate them.
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