On 07/06/2011 04:38 PM, Soeren Sandmann wrote:
RENDER is a very commonly used X extension that currently is not supported very well in SPICE. This leads to the QXL X driver having to read back pixels from the device, render in software, then transmit an image. This is currently the biggest performance issue with SPICE for X.The specification for this extension can be found here: http://cgit.freedesktop.org/xorg/proto/renderproto/tree/renderproto.txt Pixman is essentially a software implementation of Render, so there should be no issues getting the client to draw it. The issue is how to add support to the SPICE protocol A straightforward way to is to add a new draw command, "Composite" containing all of the required attributes for render pictures: RED_DISPLAY_DRAW_COMPOSITE: OPERATOR op ADDRESS source_image POINT src_x, src_y TRANSFORM src_transform REPEAT src_repeat FILTER src_filter ADDRESS mask_iamge POINT mask_x, mask_y, TRANSFORM mask_transform, REPEAT mask_repeat FILTER mask_filter where: TRANSFORM is 6 fixpoint numbers describing an affine transform REPEAT is one of { NONE, NORMAL, REFLECT, PAD } FILTER is one of { NEAREST, BILINEAR } This is quite a lot of data to send for each request though. There are some way to reduce the amount of data: - REPEAT, FILTER could be stored in the same field since they have to few possible values - If transform is identity, it could be represented as a NULL address instead of as six numbers. - The fields for op, source and mask could be combined The result would be this new command: RED_DISPLAY_DRAW_COMPOSITE: UINT32_T info ADDRESS source_image ADDRESS source_transform [ may be NULL ] POINT16 src_origin ADDRESS mask_image [ may be NULL ] ADDRESS mask_transform [ may be NULL ] POINT16 mask_origin where info is a bitfield: [ operator : 8 src_filter : 2 mask_filter : 2 src_repeat : 2 mask_repeat : 2 component_alpha : 1 padding : 15 // must be zero ] Comments appreciated. Soren _______________________________________________ Spice-devel mailing list Spice-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/spice-devel
Hi, It looks like Render overlaps QXL_DRAW_ROP3. Maybe QXLRop3 can be exploited? Cheers, Yonit. _______________________________________________ Spice-devel mailing list Spice-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/spice-devel
