Display.md - Openharmony v1.0 / docs / api / api-SmartVision-Devices - 最全华为鸿蒙分布式操作系统技术资料库，手册，指南

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Display.md

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# Display
## **Overview**
Defines driver functions of the display module.
The driver functions provided for the GUI include the layer, hardware acceleration, memory, and callback functions.
**Since:**
1.0
**Version:**
1.0
## **Summary**
## Files

File Name	Description
display_gfx.h	Declares the driver functions for implementing hardware acceleration.
display_gralloc.h	Declares the driver functions for memory.
display_layer.h	Declares the driver functions for implementing layer operations.
display_type.h	Declares the types used by the display driver functions.

## Data Structures

Data Structure Name	Description
GfxFuncs	Defines pointers to the hardware acceleration driver functions.
GrallocFuncs	Defines pointers to the memory driver functions.
LayerFuncs	Defines pointers to the layer driver functions.
DisplayInfo	Defines display information.
LayerInfo	Defines layer information.
LayerAlpha	Defines alpha operations on a layer.
BufferHandle	Defines the buffer handle type. The virtual address of a handle maps to its physical address.
GrallocBuffer	Defines the memory buffer, including the buffer handle, memory type, memory size, and virtual memory address.
BufferData	Defines buffer data of a layer, including the virtual and physical memory addresses.
LayerBuffer	Defines the buffer, which is used to store layer data.
IRect	Defines the coordinates of the upper left corner of a rectangle as well as its width and height to describe a rectangular area for an image.
ISurface	Stores surface information for hardware acceleration, such as draw image, and bit blit.
ILine	Describes a line to help draw lines in hardware acceleration.
ICircle	Describes a circle to help draw circles in hardware acceleration.
Rectangle	Describes a rectangle to help draw rectangles in hardware acceleration.
GfxOpt	Defines hardware acceleration options.

## Enumerations

Enumeration Name	Description
DispErrCode { DISPLAY_SUCCESS = 0, DISPLAY_FAILURE = -1, DISPLAY_FD_ERR = -2, DISPLAY_PARAM_ERR = -3, DISPLAY_NULL_PTR = -4, DISPLAY_NOT_SUPPORT = -5, DISPLAY_NOMEM = -6, DISPLAY_SYS_BUSY = -7, DISPLAY_NOT_PERM = -8 }	Enumerates return values of the functions.
LayerType { LAYER_TYPE_GRAPHIC, LAYER_TYPE_OVERLAY, LAYER_TYPE_SDIEBAND, LAYER_TYPE_BUTT }	Enumerates layer types.
PixelFormat { PIXEL_FMT_RGB_565, PIXEL_FMT_RGBA_5658, PIXEL_FMT_RGBX_4444, PIXEL_FMT_RGBA_4444, PIXEL_FMT_RGB_444, PIXEL_FMT_RGBX_5551, PIXEL_FMT_RGBA_5551, PIXEL_FMT_RGB_555, PIXEL_FMT_RGBX_8888, PIXEL_FMT_RGBA_8888, PIXEL_FMT_RGB_888, PIXEL_FMT_BGR_565, PIXEL_FMT_BGRX_4444, PIXEL_FMT_BGRA_4444, PIXEL_FMT_BGRX_5551, PIXEL_FMT_BGRA_5551, PIXEL_FMT_BGRX_8888, PIXEL_FMT_BGRA_8888, PIXEL_FMT_YUV_422_I, PIXEL_FMT_YCBCR_422_SP, PIXEL_FMT_YCRCB_422_SP, PIXEL_FMT_YCBCR_420_SP, PIXEL_FMT_YCRCB_420_SP, PIXEL_FMT_YCBCR_422_P, PIXEL_FMT_YCRCB_422_P, PIXEL_FMT_YCBCR_420_P, PIXEL_FMT_YCRCB_420_P, PIXEL_FMT_YUYV_422_PKG, PIXEL_FMT_UYVY_422_PKG, PIXEL_FMT_YVYU_422_PKG, PIXEL_FMT_VYUY_422_PKG, PIXEL_FMT_BUTT }	Enumerates pixel formats.
TransformType { ROTATE_NONE = 0, ROTATE_90, ROTATE_180, ROTATE_270, ROTATE_BUTT }	Enumerates transform types of images.
MemType { NORMAL_MEM = 0, CACHE_MEM, SHM_MEM }	Enumerates memory types.
BlendType { BLEND_NONE = 0, BLEND_CLEAR, BLEND_SRC, BLEND_SRCOVER, BLEND_DSTOVER, BLEND_SRCIN, BLEND_DSTIN, BLEND_SRCOUT, BLEND_DSTOUT, BLEND_SRCATOP, BLEND_DSTATOP, BLEND_ADD, BLEND_XOR, BLEND_DST, BLEND_AKS, BLEND_AKD, BLEND_BUTT }	Enumerates image blending types.
RopType { ROP_BLACK = 0, ROP_NOTMERGEPEN, ROP_MASKNOTPEN, ROP_NOTCOPYPEN, ROP_MASKPENNOT, ROP_NOT, ROP_XORPEN, ROP_NOTMASKPEN, ROP_MASKPEN, ROP_NOTXORPEN, ROP_NOP, ROP_MERGENOTPEN, ROP_COPYPE, ROP_MERGEPENNOT, ROP_MERGEPEN, ROP_WHITE, ROP_BUTT }	Enumerates ROP types supported by hardware acceleration.
ColorKey { CKEY_NONE = 0, CKEY_SRC, CKEY_DST, CKEY_BUTT }	Enumerates color key types supported by hardware acceleration.
MirrorType { MIRROR_NONE = 0, MIRROR_LR, MIRROR_TB, MIRROR_BUTT }	Enumerates mirror types supported by hardware acceleration.
Connection { INVALID = 0, CONNECTED, DISCONNECTED }	Enumerates connection types of hot plugging.

## Functions

Function Name	Description
GfxInitialize (GfxFuncs **funcs)	int32_t Initializes the hardware acceleration module to obtain the pointer to functions for hardware acceleration operations.
GfxUninitialize (GfxFuncs *funcs)	int32_t Deinitializes the hardware acceleration module to release the memory allocated to the pointer to functions for hardware acceleration operations.
GrallocInitialize (GrallocFuncs **funcs)	int32_t Initializes the memory module to obtain the pointer to functions for memory operations.
GrallocUninitialize (GrallocFuncs *funcs)	int32_t Deinitializes the memory module to release the memory allocated to the pointer to functions for memory operations.
LayerInitialize (LayerFuncs **funcs)	int32_t Initializes the layer to apply for resources used by the layer and obtain the pointer to functions for layer operations.
LayerUninitialize (LayerFuncs *funcs)	int32_t Deinitializes the layer module to release the memory allocated to the pointer to functions for layer operations.

## **Details**
## **Enumeration Type Documentation**
## BlendType
```
enum [BlendType](Display.md#gaab1839ed4aab1030dfda801a51e68817)
```
**Description:**
Enumerates image blending types.
The system combines images based on a specified blending type during hardware acceleration.

Enumerator	Description
BLEND_NONE	No blending
BLEND_CLEAR	CLEAR blending
BLEND_SRC	SRC blending
BLEND_SRCOVER	SRC_OVER blending
BLEND_DSTOVER	DST_OVER blending
BLEND_SRCIN	SRC_IN blending
BLEND_DSTIN	DST_IN blending
BLEND_SRCOUT	SRC_OUT blending
BLEND_DSTOUT	DST_OUT blending
BLEND_SRCATOP	SRC_ATOP blending
BLEND_DSTATOP	DST_ATOP blending
BLEND_ADD	ADD blending
BLEND_XOR	XOR blending
BLEND_DST	DST blending
BLEND_AKS	AKS blending
BLEND_AKD	AKD blending
BLEND_BUTT	Null operation

## ColorKey
```
enum [ColorKey](Display.md#ga4fe6fb05c7ba0048b1739d88f4d4878e)
```
**Description:**
Enumerates color key types supported by hardware acceleration.

Enumerator	Description
CKEY_NONE	No color key
CKEY_SRC	Source color key
CKEY_DST	Destination color key
CKEY_BUTT	Null operation

## Connection
```
enum [Connection](Display.md#gab0845c0c8d309ee865c78b095b00e671)
```
**Description:**
Enumerates connection types of hot plugging.

Enumerator	Description
INVALID	Invalid connection
CONNECTED	Connected
DISCONNECTED	Disconnected

Enumerator

Description

INVALID

Invalid connection

CONNECTED

Connected

DISCONNECTED

Disconnected

## DispErrCode
```
enum [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0)
```
**Description:**
Enumerates return values of the functions.

Enumerator	Description
DISPLAY_SUCCESS	Success
DISPLAY_FAILURE	Failure
DISPLAY_FD_ERR	File handle (FD) error
DISPLAY_PARAM_ERR	Parameter error
DISPLAY_NULL_PTR	Null pointer
DISPLAY_NOT_SUPPORT	Unsupported feature
DISPLAY_NOMEM	Insufficient memory
DISPLAY_SYS_BUSY	System busy
DISPLAY_NOT_PERM	Forbidden operation

## LayerType
```
enum [LayerType](Display.md#ga56943a0946e5f15e5e58054b8e7a04a4)
```
**Description:**
Enumerates layer types.

Enumerator	Description
LAYER_TYPE_GRAPHIC	Graphic layer
LAYER_TYPE_OVERLAY	Overlay layer
LAYER_TYPE_SDIEBAND	Sideband layer
LAYER_TYPE_BUTT	Empty layer

## MemType
```
enum [MemType](Display.md#gabd31f838aefffa46191d0d7dc36a96b2)
```
**Description:**
Enumerates memory types.
Memory is allocated based on the type specified by the GUI.

Enumerator	Description
NORMAL_MEM	Memory without cache
CACHE_MEM	Memory with cache
SHM_MEM	Shared memory

Enumerator

Description

NORMAL_MEM

Memory without cache

CACHE_MEM

Memory with cache

SHM_MEM

Shared memory

## MirrorType
```
enum [MirrorType](Display.md#ga08d32376574b541d162d8534adb78fd0)
```
**Description:**
Enumerates mirror types supported by hardware acceleration.

Enumerator	Description
MIRROR_NONE	No mirror
MIRROR_LR	Left and right mirrors
MIRROR_TB	Top and bottom mirrors
MIRROR_BUTT	Null operation

## PixelFormat
```
enum [PixelFormat](Codec.md#ga60883d4958a60b91661e97027a85072a)
```
**Description:**
Enumerates pixel formats.

Enumerator	Description
PIXEL_FMT_RGB_565	RGB565 format
PIXEL_FMT_RGBA_5658	RGBA5658 format
PIXEL_FMT_RGBX_4444	RGBX4444 format
PIXEL_FMT_RGBA_4444	RGBA4444 format
PIXEL_FMT_RGB_444	RGB444 format
PIXEL_FMT_RGBX_5551	RGBX5551 format
PIXEL_FMT_RGBA_5551	RGBA5551 format
PIXEL_FMT_RGB_555	RGB555 format
PIXEL_FMT_RGBX_8888	RGBX8888 format
PIXEL_FMT_RGBA_8888	RGBA8888 format
PIXEL_FMT_RGB_888	RGB888 format
PIXEL_FMT_BGR_565	BGR565 format
PIXEL_FMT_BGRX_4444	BGRX4444 format
PIXEL_FMT_BGRA_4444	BGRA4444 format
PIXEL_FMT_BGRX_5551	BGRX5551 format
PIXEL_FMT_BGRA_5551	BGRA5551 format
PIXEL_FMT_BGRX_8888	BGRX8888 format
PIXEL_FMT_BGRA_8888	BGRA8888 format
PIXEL_FMT_YUV_422_I	YUV422 interleaved format
PIXEL_FMT_YCBCR_422_SP	YCBCR422 semi-planar format
PIXEL_FMT_YCRCB_422_SP	YCRCB422 semi-planar format
PIXEL_FMT_YCBCR_420_SP	YCBCR420 semi-planar format
PIXEL_FMT_YCRCB_420_SP	YCRCB420 semi-planar format
PIXEL_FMT_YCBCR_422_P	YCBCR422 planar format
PIXEL_FMT_YCRCB_422_P	YCRCB422 planar format
PIXEL_FMT_YCBCR_420_P	YCBCR420 planar format
PIXEL_FMT_YCRCB_420_P	YCRCB420 planar format
PIXEL_FMT_YUYV_422_PKG	YUYV422 packed format
PIXEL_FMT_UYVY_422_PKG	UYVY422 packed format
PIXEL_FMT_YVYU_422_PKG	YVYU422 packed format
PIXEL_FMT_VYUY_422_PKG	VYUY422 packed format
PIXEL_FMT_BUTT	Invalid pixel format

## RopType
```
enum [RopType](Display.md#ga24265f7618fbdba53d3da4806d3097c4)
```
**Description:**
Enumerates ROP types supported by hardware acceleration.
ROP performs bitwise Boolean operations \(including bitwise AND and bitwise OR\) on the RGB color and alpha values of the foreground bitmap with those of the background bitmap, and then outputs the result.

Enumerator	Description
ROP_BLACK	Blackness
ROP_NOTMERGEPEN	~(S2+S1)
ROP_MASKNOTPEN	~S2&S1
ROP_NOTCOPYPEN	~S2
ROP_MASKPENNOT	S2&~S1
ROP_NOT	~S1
ROP_XORPEN	S2^S1
ROP_NOTMASKPEN	~(S2&S1)
ROP_MASKPEN	S2&S1
ROP_NOTXORPEN	~(S2^S1)
ROP_NOP	S1
ROP_MERGENOTPEN	~S2+S1
ROP_COPYPE	S2
ROP_MERGEPENNOT	S2+~S1
ROP_MERGEPEN	S2+S1
ROP_WHITE	Whiteness
ROP_BUTT	Invalid ROP type

## TransformType
```
enum [TransformType](Display.md#gaa65f3b21a9a92ff022e435a7304126d2)
```
**Description:**
Enumerates transform types of images.

Enumerator	Description
ROTATE_NONE	No rotation
ROTATE_90	Rotation by 90 degrees
ROTATE_180	Rotation by 180 degrees
ROTATE_270	Rotation by 270 degrees
ROTATE_BUTT	Invalid operation

## **Function Documentation**
## GfxInitialize\(\)
```
int32_t GfxInitialize ([GfxFuncs](zh-cn_topic_0000001054598159.md) ** funcs)
```
**Description:**
Initializes the hardware acceleration module to obtain the pointer to functions for hardware acceleration operations.
**Parameters:**

Name	Description
funcs	Indicates the double pointer to functions for hardware acceleration operations. Memory is allocated automatically when you initiate the hardware acceleration module, so you can simply use the pointer to gain access to the functions.

**Returns:**
Returns **0** if the operation is successful; returns an error code defined in [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0) otherwise.
**See also:**
[GfxUninitialize](Display.md#ga32595139adb26cfaacf709661b29b347)
## GfxUninitialize\(\)
```
int32_t GfxUninitialize ([GfxFuncs](zh-cn_topic_0000001054598159.md) * funcs)
```
**Description:**
Deinitializes the hardware acceleration module to release the memory allocated to the pointer to functions for hardware acceleration operations.
**Parameters:**

Name	Description
funcs	Indicates the pointer to functions for hardware acceleration operations.

**Returns:**
Returns **0** if the operation is successful; returns an error code defined in [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0) otherwise.
**See also:**
[GfxInitialize](Display.md#ga251580eb0614b601ef2c901c722a59d3)
## GrallocInitialize\(\)
```
int32_t GrallocInitialize ([GrallocFuncs](zh-cn_topic_0000001054918153.md) ** funcs)
```
**Description:**
Initializes the memory module to obtain the pointer to functions for memory operations.
**Parameters:**

Name	Description
funcs	Indicates the double pointer to functions for memory operations. Memory is allocated automatically when you initiate the memory module initialization, so you can simply use the pointer to gain access to the functions.

**Returns:**
Returns **0** if the operation is successful; returns an error code defined in [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0) otherwise.
## GrallocUninitialize\(\)
```
int32_t GrallocUninitialize ([GrallocFuncs](zh-cn_topic_0000001054918153.md) * funcs)
```
**Description:**
Deinitializes the memory module to release the memory allocated to the pointer to functions for memory operations.
**Parameters:**

Name	Description
funcs	Indicates the pointer to functions for memory operations.

**Returns:**
Returns **0** if the operation is successful; returns an error code defined in [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0) otherwise.
## LayerInitialize\(\)
```
int32_t LayerInitialize ([LayerFuncs](zh-cn_topic_0000001055678100.md) ** funcs)
```
**Description:**
Initializes the layer to apply for resources used by the layer and obtain the pointer to functions for layer operations.
**Parameters:**

Name	Description
funcs	Indicates the double pointer to functions for layer operations. Memory is allocated automatically when you initiate the layer module, so you can simply use the pointer to gain access to the functions.

**Returns:**
Returns **0** if the operation is successful; returns an error code defined in [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0) otherwise.
**See also:**
[LayerUninitialize](Display.md#ga4e32b1a65cf243a9ac015b632a4eea0b)
## LayerUninitialize\(\)
```
int32_t LayerUninitialize ([LayerFuncs](zh-cn_topic_0000001055678100.md) * funcs)
```
**Description:**
Deinitializes the layer module to release the memory allocated to the pointer to functions for layer operations.
**Parameters:**

Name	Description
funcs	Indicates the pointer to functions for layer operations.

**Returns:**
Returns **0** if the operation is successful; returns an error code defined in [DispErrCode](Display.md#ga12a925dadef7573cd74d63d06824f9b0) otherwise.
**See also:**
[LayerInitialize](Display.md#ga061e587306a5d0367ff228d64434c05d)