udi_gfx.h

Valid values

Ranges

Must include at least 1

The primary state of the connector or engine.  An enabled state indicates it is functioning and generating live output.  A disabled state is one where it is not contributing to any output but is otherwise functional.  Finally the reset state is where the driver is free to deallocate all resources corresponding to this component and trash any state not referenced by other components.

A disabled or reset engine forwards all data from the previous stage unmodified.  The disabled state indicates that the component might be returned to its enabled state within short notice.

A disabled connector will not send pixel data, but can perform other initialisation communication such as DDC.  A reset connector will not respond in any fashion and can not be used for other purposes.  Hardware is expected to be powered down in such state.

Users should expect significant delays when moving components in and out of the reset state.  Moving engines between the enabled and disabled state should take effect within one frame, such transition should take effect on a frame boundary when supported.

Valid values

Any valid engine ID, provided no dependency cycles are created, or -1

Ranges

Any non-empty set of valid values.  Often hardwired.

Points to the engine that is processed before this unit.  In the case of a connector, it points to the last engine in a pipeline, and each engine points to the next engine in the sequence.  A value of -1 indicates a source that only yields black pixels.  Implementations must not allow cyclic structures.  Changing this value may reallocate resources, and engines that are no longer referenced may lose their data (but not their state) when it is not part of any pipeline.  If preservation is required, the ENABLE state should be used instead.  Valid ranges includes one or more from the list of engines and -1 combined.  In most cases, this property can not be modified.

Valid values

Any non-zero positive number.

Ranges

Contains at least one valid value.  Often only multiples of UNIT_WIDTH or a power of two are allowed.  May be hardwired.

Contains the amount of pixels in the horizontal direction.  For connectors, this is the amount of data pixels rendered horizontally.  For engines, this is the width in pixels of the image.  Pixels requested from an engine outside the range (0..width-1) are defined according to the UDI_GFX_PROP_CLIP property.  In some cases, hardware may support only fixed combinations of width and height.  In such cases, changing the width will also change the height to a corresponding valid number.  Valid ranges include any values strictly above zero.  For connectors, expect large continuous ranges, large ranges with a certain modulus, a limited number of fixed values, or a constant value.

Valid values

Any non-zero positive number.

Ranges

Contains at least one valid value.  Often only multiples of UNIT_HEIGHT or a power of two are allowed.  May be hardwired.

Contains the amount of pixels in the vertical direction.  Functions similar to the width property, but changing it will not alter the width property, and it’s range at any time contains the valid range for the currently selected width.

The first property index of the driver’s custom range.  These are not assigned directly assigned by the UDI specification, but may be specified in the operator tree.

Valid values

Ranges

Hardwired zero for connectors.  Any non-empty subset for engines, usually hardwired.

For engines, contains the behaviour for pixels requested outside the width and height of the engine.  Can be either 0 (pass from next stage), 1 (the coordinates are wrapped modulus the height and width), 2 (the coordinates overflow onto the next scanline horizontally, and wrap vertically), 3 (the coordinates overflow onto the next column vertically, and wrap horizontally).  Valid ranges contain one or more of these options.  For overlays and sprites, a value 0 is common.  For framebuffers, 2 is the most common value.  For connectors, this property is always 0 since they do not store pixel data

Valid values

Any non-zero positive value

Ranges

Any non-empty set of valid values.  May be hardwired to 1 for framebuffers, or a range of small values for hardware scaling, or any larger hardwired number or set for tiling engines.

Tiles are used to indicate that the hardware groups sets of pixels and have each group share certain properties, i.e. color or tile index, or share the same chroma subsample with only a different intensity.  If the engine has no such grouping, or shares all properties over the entire contents, the value of this property should be 1.  Some tile examples include rescaling, where a tile width of 2 indicates a pixel doubling in X direction, or in text mode where a tile width of 8 or 9 corresponds with the width of common bitmap fonts

Valid values

Any non-zero positive value

Ranges

Any non-empty set of valid values.  May be hardwired to 1 for framebuffers, or a range of small values for hardware scaling, or any larger hardwired number or set for tiling engines.

See UDI_GFX_PROP_UNIT_WIDTH, but for the Y direction.  Common values are 1-2 for framebuffers (doublescanning on or off), identical to the tile width, or mostly independent.

Valid values

Any, signed value.

Ranges

Any non-empty set.  Typical values are hardwired zero, continuous between -WIDTH and WIDTH, -WIDTH to zero inclusive, or all possible values

The horizontal offset where drawing starts.  A positive value means the top-left corner moves towards the right end of the screen, a negative value moves the origin off the screen on the left side.  Clipped areas moved off the screen do not reappear on the opposite side.

With clipping enabled, this field combined with UDI_GFX_PROP_WIDTH determines the area where the image should be drawn, which is the horizontal range from UDI_GFX_PROP_TRANSLATEX to UDI_GFX_PROP_WIDTH + UDI_GFX_PROP_TRANSLATEX - 1

Valid values

Any signed value.

Ranges

Any non-empty set.  Typical values are hardwired zero, continuous between -WIDTH and WIDTH, or all possible values

See UDI_GFX_PROP_TRANSLATEX but for the Y direction.

Value

Zero, or any constant from UDI_GFX_STOCK_FORMAT

Ranges

Any non-empty set of valid values.

This field indicates the storage format is one from a limited set of typical configurations.  If the field is zero, the engine is not knowingly configured as a common framebuffer.  If nonzero, the operator chain and any dependent settings are defined to be functionally equivalent to that of a typical framebuffer device.

The value zero does not imply that the device does not actually follow a set convention.  This saves drivers from writing elaborate checking code to determine the condition in question.

Writing this field potentially modifies other property fields within the same engine to establish the requested configuration.  Manually writing such properties after changing this setting may in turn revert this property to the zero state, even if there was no modification or the behaviour is still as previously advertised by this property.

Valid values

Any non-zero positive number

Ranges

Most likely constant.  Can be any set of valid values.

The current value is the number of entries in the operator tree that can be requested for this engine using <udi_gfx_get_engine_operator_req> and <udi_gfx_get_engine_operator_ack>

the ops number used for the graphics driver

the ops number used for the graphics application