include/tpl_drv_video.h File Reference

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Detailed Description

Video Driver Interface Definitions.

Note:

For AcessOS Version 1

Video drivers extend the common driver interface tpl_drv_common.h and must support _at least_ the IOCtl numbers defined in this file to be compatable with Acess.

IOCtls

As said, a compatable driver must implement these calls correctly, but they may choose not to allow direct user access to the framebuffer.

Contents

Writes to the driver's file while in component colour modes must correspond to a change of the contents of the screen. The framebuffer must start at offset 0 in the file. Reading from the screen must either return zero, or read from the framebuffer.

Support

All video drivers must support at least one text mode (Mode #0) For each graphics mode the driver exposes, there must be a corresponding text mode with the same resolution, this mode will be used when the user switches to a text Virtual Terminal while in graphics mode.

Go to the source code of this file.

Data Structures
struct	tVideo_IOCtl_Mode
	Mode Structure used in IOCtl Calls. More...
struct	tVideo_IOCtl_Pos
	Describes a position in the video framebuffer. More...
struct	tVT_Char
	Virtual Terminal Representation of a character. More...
struct	tDrvUtil_Video_2DHandlers
	Handlers for eTplVideo_2DCommands. More...
Defines
#define	DRV_VIDEO_IOCTLNAMES   "getset_mode", "find+mode", "mode_info", "set_buf_format", "set_cursor", "request_framebuffer"
Basic builtin colour definitions
#define	VT_COL_BLACK   0x0000
#define	VT_COL_GREY   0x0888
#define	VT_COL_LTGREY   0x0CCC
#define	VT_COL_WHITE   0x0FFF
Enumerations
enum	eTplVideo_IOCtl {   VIDEO_IOCTL_GETSETMODE = 4, VIDEO_IOCTL_FINDMODE, VIDEO_IOCTL_MODEINFO, VIDEO_IOCTL_SETBUFFORMAT,   VIDEO_IOCTL_SETCURSOR, VIDEO_IOCTL_REQLFB }
	Common Video IOCtl Calls. More...
enum	eTplVideo_BufFormats { VIDEO_BUFFMT_TEXT, VIDEO_BUFFMT_FRAMEBUFFER, VIDEO_BUFFMT_2DSTREAM, VIDEO_BUFFMT_3DSTREAM }
	Buffer Format Codes. More...
enum	eTplVideo_2DCommands {   VIDEO_2DOP_NOP, VIDEO_2DOP_FILL, VIDEO_2DOP_BLIT, VIDEO_2DOP_BLITBUF,   VIDEO_2DOP_BLITSCALEBUF, NUM_VIDEO_2DOPS }
	2D Accellerated Video Commands More...
Functions
void	VT_Font_Render (Uint32 Codepoint, void *Buffer, int Pitch, Uint32 BGC, Uint32 FGC)
	Driver helper that renders a character to a buffer.
Uint32	VT_Colour12to24 (Uint16 Col12)
	Converts a colour from 12bpp to 32bpp.
Uint64	DrvUtil_Video_2DStream (void *Ent, void *Buffer, int Length, tDrvUtil_Video_2DHandlers *Handlers, int SizeofHandlers)
	Handle a 2D operation stream for a driver.
Variables
int	giVT_CharWidth
	Defines the width of a rendered character.
int	giVT_CharHeight
	Defines the height of a rendered character.

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Enumeration Type Documentation

enum eTplVideo_2DCommands

2D Accellerated Video Commands

Commands passed in the command stream for VIDEO_BUFFMT_2DSTREAM

Enumerator:

VIDEO_2DOP_NOP	No Operation.
VIDEO_2DOP_FILL	Fill a region. Parameters: X  Uint16 - Leftmost pixels of the region Y  Uint16 - Topmost pixels of the region W  Uint16 - Width of the region H  Uint16 - Height of the region Colour  Uint32 - Value to fill with
VIDEO_2DOP_BLIT	Copy a region from one part of the framebuffer to another. Parameters: DestX  Uint16 - Leftmost pixels of the destination DestY  Uint16 - Topmost pixels of the destination SrcX  Uint16 - Leftmost pixels of the source SrcY  Uint16 - Topmost pixels of the source Width  Uint16 - Width of the region Height  Uint16 - Height of the region
VIDEO_2DOP_BLITBUF	Copy a region from video memory to the framebuffer.
VIDEO_2DOP_BLITSCALEBUF	Copy and scale a region from video memory to the framebuffer.

enum eTplVideo_BufFormats

Buffer Format Codes.

Enumerator:

VIDEO_BUFFMT_TEXT	Text Mode. The device file presents itself as an array of tVT_Char each describing a character cell on the screen. These cells are each giVT_CharWidth pixels wide and giVT_CharHeight high.
VIDEO_BUFFMT_FRAMEBUFFER	Framebuffer Mode. The device file presents as an array of 32-bpp pixels describing the entire screen. The format of a single pixel is in xRGB format (top 8 bits ignored, next 8 bits red, next 8 bits green and the bottom 8 bits blue)
VIDEO_BUFFMT_2DSTREAM	2D Accelerated Mode The device file acts as a character device, accepting a stream of commands described in eTplVideo_2DCommands when written to.
VIDEO_BUFFMT_3DSTREAM	3D Accelerated Mode The device file acts as a character device, accepting a stream of commands described in eTplVideo_3DCommands when written to.

enum eTplVideo_IOCtl

Common Video IOCtl Calls.

Enumerator:

VIDEO_IOCTL_GETSETMODE	Get/Set Mode. ioctl(..., int *mode) Returns: Current mode ID or -1 on error If mode is non-NULL, the current video mode is set to *mode. This updated ID is then returned to the user.
VIDEO_IOCTL_FINDMODE	Find a matching mode. ioctl(..., tVideo_IOCtl_Mode *info) Returns: 1 if a mode was found, 0 otherwise Using avaliable modes matching the bpp and flags fields set the id field to the mode id of the mode with the closest width and height.
VIDEO_IOCTL_MODEINFO	Get mode info. ioctl(..., tVideo_IOCtl_Mode *info) Returns: 1 if the mode exists, 0 otherwise Set info's fields to the mode specified by the id field.
VIDEO_IOCTL_SETBUFFORMAT	Switches between Text, Framebuffer and 3D modes. ioctl(..., int *NewFormat) Parameters: NewFormat  Pointer to the new format code (see eTplVideo_BufFormats) Returns: Original format Enabes and disables the video text mode, changing the behavior of writes to the device file.
VIDEO_IOCTL_SETCURSOR	Sets the cursor position. ioctl(..., tVideo_IOCtl_Pos *pos) Returns: Boolean success Set the text mode cursor position (if it is supported) If the pos is set to (-1,-1) the cursor is hidden, otherwise pos MUST be within the current screen size (as given by the current mode's tVideo_IOCtl_Mode.width and tVideo_IOCtl_Mode.height fields).
VIDEO_IOCTL_REQLFB	Request access to Framebuffer. ioctl(..., tVAddr MapTo) Returns: Boolean Success Requests the driver to allow the user direct access to the framebuffer by mapping it to the supplied address. If the driver does not allow this boolean FALSE (0) is returned, else if the call succeeds (and the framebuffer ends up mapped) boolean TRUE (1) is returned.

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Function Documentation

Uint64 DrvUtil_Video_2DStream	(	void *	Ent,
		void *	Buffer,
		int	Length,
		tDrvUtil_Video_2DHandlers *	Handlers,
		int	SizeofHandlers
	)

Handle a 2D operation stream for a driver.

Parameters:

	Ent	Value to pass to handlers
	Buffer	Stream buffer
	Length	Length of stream
	Handlers	Handlers to use for the stream
	SizeofHandlers	Size of tDrvUtil_Video_2DHandlers according to the driver. Used as version control and error avoidence.

Uint32 VT_Colour12to24

(

Uint16

Col12

)

Converts a colour from 12bpp to 32bpp.

Parameters:

Col12

12-bpp input colour

Returns:

Expanded 32-bpp (24-bit colour) version of Col12

void VT_Font_Render	(	Uint32	Codepoint,
		void *	Buffer,
		int	Pitch,
		Uint32	BGC,
		Uint32	FGC
	)

Driver helper that renders a character to a buffer.

Parameters:

	Codepoint	Unicode character to render
	Buffer	Buffer to render to (32-bpp)
	Pitch	Number of DWords per line
	BGC	32-bit Background Colour
	FGC	32-bit Foreground Colour

This function is provided to help video drivers to support a simple text mode by keeping the character rendering abstracted from the driver, easing the driver development and reducing code duplication.