rom/hidds/graphics/OverlayClass.c

   1 /*
   2     Copyright © 2010, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Overlay hidd class description
   6     Lang: english
   7 */
   8
   9 /*
  10  * This file contains only documentation. Currently no overlay base class is developed.
  11  * So far there's no need to compile this file.
  12  */
  13
  14 /*****************************************************************************************
  15
  16     NAME
  17         --background_overlay--
  18
  19     LOCATION
  20         hidd.graphics.overlay
  21
  22     NOTES
  23         Objects of overlay class represent hardware video overlays.
  24
  25         Current hardware supports only one video overlay per screen, however in future
  26         the situation may change.
  27
  28         hidd.graphics.overlay is an interface name. There's no such public ID since
  29         there's actually no base class for the overlay. The whole implementation is
  30         hardware-dependant and needs to be done separately for every driver.
  31
  32         Overlay classes do not need to be public. It's up to display drivers to manage
  33         them. A moHidd_Gfx_NewOverlay method of graphics driver class is used to create
  34         overlay objects.
  35
  36 *****************************************************************************************/
  37
  38 /*****************************************************************************************
  39
  40     NAME
  41         aoHidd_Overlay_SrcWidth
  42
  43     SYNOPSIS
  44         [I..], ULONG
  45
  46     LOCATION
  47         hidd.graphics.overlay
  48
  49     FUNCTION
  50         Specifies source data width in pixels.
  51
  52     NOTES
  53
  54     EXAMPLE
  55
  56     BUGS
  57
  58     SEE ALSO
  59         aoHidd_Overlay_SrcHeight
  60
  61     INTERNALS
  62
  63 *****************************************************************************************/
  64
  65 /*****************************************************************************************
  66
  67     NAME
  68         aoHidd_Overlay_SrcHeight
  69
  70     SYNOPSIS
  71         [I..], ULONG
  72
  73     LOCATION
  74         hidd.graphics.overlay
  75
  76     FUNCTION
  77         Specifies source data height in pixels.
  78
  79     NOTES
  80
  81     EXAMPLE
  82
  83     BUGS
  84
  85     SEE ALSO
  86         aoHidd_Overlay_SrcWidth
  87
  88     INTERNALS
  89
  90 *****************************************************************************************/
  91
  92 /*****************************************************************************************
  93
  94     NAME
  95         aoHidd_Overlay_SrcFormat
  96
  97     SYNOPSIS
  98         [I..], ULONG
  99
 100     LOCATION
 101         hidd.graphics.overlay
 102
 103     FUNCTION
 104         Specifies source data pixel format. The value should be one of SRCFMT_... constants
 105         defined in cybergraphx/cgxvideo.h:
 106
 107           SRCFMT_YUV16   - 16-but YUV
 108           SRCFMT_YCbCr16 - 16-bit YCbCr
 109           SRCFMT_RGB15PC - R5G5B5, little-endian
 110           SRCFMT_RGB16PC - R5G6B5, little-endian
 111
 112     NOTES
 113         Not all formats can be supported by all drivers. Use aoHidd_Overlay_Error attribute
 114         in order to get an explanation why overlay creation fails.
 115
 116     EXAMPLE
 117
 118     BUGS
 119
 120     SEE ALSO
 121
 122     INTERNALS
 123
 124 *****************************************************************************************/
 125
 126 /*****************************************************************************************
 127
 128     NAME
 129         aoHidd_Overlay_Error
 130
 131     SYNOPSIS
 132         [I..], ULONG *
 133
 134     LOCATION
 135         hidd.graphics.overlay
 136
 137     FUNCTION
 138         Specifies a pointer to ULONG location where error code will be written.
 139
 140         This attribute can be used for overlay creation in order to be able to get an
 141         information about the actual failure reason.
 142
 143         Resulting error code can be one of VOERR_... values defined in
 144         cybergraphx/cgxvideo.h:
 145
 146           VOERR_OK          - there was no error
 147           VOERR_INVSCRMODE  - no (more) hardware overlays are supported on this card
 148           VOERR_NOOVLMEMORY - there is not enough VRAM to hold overlay data
 149           VOERR_INVSRCFMT   - given source pixel format is not supported by the card
 150           VOERR_NOMEMORY    - there is not enough system RAM for internal driver needs
 151
 152     NOTES
 153
 154     EXAMPLE
 155
 156     BUGS
 157
 158     SEE ALSO
 159
 160     INTERNALS
 161
 162 *****************************************************************************************/