workbench/libs/gallium/createpipescreen.c

   1 /*
   2     Copyright © 2010-2013, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include "gallium_intern.h"
   7 #include <proto/utility.h>
   8 #include <aros/debug.h>
   9
  10 #undef HiddGalliumAttrBase
  11 #define HiddGalliumAttrBase GB(GalliumBase)->galliumAttrBase
  12
  13 /*****************************************************************************
  14
  15     NAME */
  16
  17       AROS_LH1(struct pipe_screen *, CreatePipeScreen,
  18
  19 /*  SYNOPSIS */
  20       AROS_LHA(struct TagItem *, tags, A0),
  21
  22 /*  LOCATION */
  23       struct Library *, GalliumBase, 5, Gallium)
  24
  25 /*  FUNCTION
  26         Creates a gallium pipe screen.
  27
  28     INPUTS
  29         tags - a pointer to tags to be used during creation.
  30
  31     TAGS
  32         CPS_GalliumInterfaceVersion - Indicates a version of gallium interface
  33             that a client is expected to receive. The client expected version
  34             must ideally match with the version that the driver provides,
  35             because gallium interface is not backwards compatible. This tag is
  36             required. Unless otherwise needed, the value
  37             GALLIUM_INTERFACE_VERSION should be passed.
  38             See also CreatePipeScreenV.
  39
  40     RESULT
  41         A valid pipe screen instance or NULL if creation was not successful.
  42
  43     BUGS
  44
  45     INTERNALS
  46
  47 *****************************************************************************/
  48 {
  49     AROS_LIBFUNC_INIT
  50
  51     struct pipe_screen * screen = NULL;
  52     LONG requestedinterfaceversion =
  53         GetTagData(CPS_GalliumInterfaceVersion, -1, tags);
  54
  55     /* The tag is missing */
  56     if (requestedinterfaceversion == -1)
  57         return NULL;
  58
  59     ObtainSemaphore(&GB(GalliumBase)->driversemaphore);
  60
  61     if (!GB(GalliumBase)->driver)
  62         GB(GalliumBase)->driver = SelectGalliumDriver(requestedinterfaceversion, GalliumBase);
  63
  64     if(GB(GalliumBase)->driver)
  65     {
  66         /* Validate driver gallium interface version */
  67         if (IsVersionMatching(requestedinterfaceversion, GB(GalliumBase)->driver, GalliumBase))
  68         {
  69             /* Create screen */
  70             struct pHidd_Gallium_CreatePipeScreen cpsmsg;
  71
  72             cpsmsg.mID = OOP_GetMethodID(IID_Hidd_Gallium, moHidd_Gallium_CreatePipeScreen);
  73             screen = (struct pipe_screen *)OOP_DoMethod(GB(GalliumBase)->driver, (OOP_Msg)&cpsmsg);
  74         }
  75         else
  76         {
  77             bug("[gallium.library] Requested gallium interface version does not match selected driver\n");
  78         }
  79     }
  80     else
  81     {
  82         bug("[gallium.library] Failed to acquire a driver\n");
  83     }
  84
  85     ReleaseSemaphore(&GB(GalliumBase)->driversemaphore);
  86
  87     return screen;
  88
  89     AROS_LIBFUNC_EXIT
  90 }