• Zhigang Gong's avatar
    glamor : Add dynamic texture uploading feature. · 355334fc
    Zhigang Gong authored
    Major refactoring.
    1. Rewrite the pixmap texture uploading and downloading functions.
       Add some new functions for both the prepare/finish access and
       the new performance feature dynamic texture uploading, which
       could download and upload the current image to/from a private
       texture/fbo. In the uploading or downloading phase, we need to
       handle two things:
       The first is the yInverted option, If it set, then we don't need
       to flip y. If not set, if it is from a dynamic texture uploading
       then we don't need to flip either if the current drawing process
       will flip it latter. If it is from finish_access, then we must
       flip the y axis.
       The second thing is the alpha channel hanlding, if the pixmap's
       format is something like x8a8r8g8, x1r5g5b5 which means it doesn't
       has alpha channel, but it do has those extra bits. Then we need to
       wire those bits to 1.
    2. Add almost all the required picture format support.
       This is not as trivial as it looks like. The previous implementation
       only support GL_a8,GL_a8r8g8b8,GL_x8r8g8b8. All the other format,
       we have to fallback to cpu. The reason why we can't simply add those
       other color format is because the exists of picture. one drawable
       pixmap may has one or even more container pictures. The drawable pixmap's
       depth can't map to a specified color format, for example depth 16 can
       mapped to r5g6b5, x1r5g5b5, a1r5g5b5, or even b5g6r5. So we can't get
       get the color format just from the depth value. But the pixmap do not
       has a pict_format element. We have to make a new one in the pixmap
       private data structure. Reroute the CreatePicture to glamor_create_picture
       and then store the picture's format to the pixmap's private structure.
       This is not an ideal solution, as there may be more than one pictures
       refer to the same pixmap. Then we will have trouble. There is an example
       in glamor_composite_with_shader. The source and mask often share the
       same pixmap, but use different picture format. Our current solution is to
       combine those two different picture formats to one which will not lose any
       data. Then change the source's format to this new format and then upload
       the pixmap to texture once. It works. If we fail to find a matched new
       format then we fallback.
       There still is a potential problem, if two pictures refer to the same
       pixmap, and one of them destroy the picture, but the other still remained
       to be used latter. We don't handle that situation currently. To be fixed.
    3. Dynamic texture uploading.
       This is a performance feature. Although we don't like the client to hold
       a pixmap data to shared memory and we can't accelerate it. And even worse,
       we may need to fallback all the required pixmaps to cpu memory and then
       process them on CPU. This feature is to mitigate this penalty. When the
       target pixmap has a valid gl fbo attached to it. But the other pixmaps are
       not. Then it will be more efficient to upload the other pixmaps to GPU and
       then do the blitting or rendering on GPU than fallback all the pixmaps to CPU.
       To enable this feature, I experienced a significant performance improvement
       in the Game "Mines" :).
    4. Debug facility.
       Modify the debug output mechanism. Now add a new macro:
       glamor_debug_output(_level_, _format_,...) to conditional output some messages
       according to the environment variable GLAMOR_DEBUG. We have the following
       levels currently.
        exports GLAMOR_DEBUG to 3 will enable all the above messages.
    5. Changes in pixmap private data structure.
       Add some for the full color format supports and relate it to the pictures which
       already described. Also Add the following new elements:
       gl_fbo - to indicates whether this pixmap is on gpu only.
       gl_tex - to indicates whether the tex is valid and is containing the pixmap's
                image originally.
       As we bring the dynamic pixmap uploading feature, so a cpu memory pixmap may
       also has a valid fbo or tex attached to it. So we will have to use the above
       new element to check it true type.
    After this commit, we can pass the rendercheck testing for all the picture formats.
    And is much much fater than fallback to cpu when doing rendercheck testing.
    Signed-off-by: default avatarZhigang Gong <zhigang.gong@linux.intel.com>