drawing_canvas.h

Overview

This file declares the functions related to the canvas in the drawing module.
By default, the canvas has a black brush with anti-aliasing enabled and without any other style. This brush takes effect only when no brush or pen is proactively set in the canvas.

Sample: NDKAPIDrawing (API Version 20)

File to include: <native_drawing/drawing_canvas.h>

Library: libnative_drawing.so

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Related module: Drawing

Summary

Enums

Name	typedef Keyword	Description
OH_Drawing_SrcRectConstraint	OH_Drawing_SrcRectConstraint	Defines an enum for the constraint types of the source rectangle.
OH_Drawing_PointMode	OH_Drawing_PointMode	Defines an enum for the modes of drawing multiple points. The modes include discrete points, line segments, and open polygons.
OH_Drawing_CanvasClipOp	OH_Drawing_CanvasClipOp	Defines an enum for the canvas clipping modes.
OH_Drawing_CanvasShadowFlags	OH_Drawing_CanvasShadowFlags	Defines an enum for the shadow flags.
OH_Drawing_VertexMode	OH_Drawing_VertexMode	Defines an enum for the modes of interpreting the geometry of a given vertex.

Functions

Name	Description
OH_Drawing_Canvas* OH_Drawing_CanvasCreate(void)	Creates an OH_Drawing_Canvas object.
OH_Drawing_Canvas* OH_Drawing_CanvasCreateWithPixelMap(OH_Drawing_PixelMap* pixelMap)	Binds a pixel map to a canvas so that the content drawn on the canvas is output to the pixel map. (This process is called CPU rendering.) A canvas bound to a pixel map is a non-recording canvas. You should unbind the pixel map object by calling OH_Drawing_PixelMapDissolve after the canvas object is destroyed.
void OH_Drawing_CanvasDestroy(OH_Drawing_Canvas* canvas)	Destroys an OH_Drawing_Canvas object and reclaims the memory occupied by the object.
void OH_Drawing_CanvasBind(OH_Drawing_Canvas* canvas, OH_Drawing_Bitmap* bitmap)	Binds a bitmap to a canvas so that the content drawn on the canvas is output to the bitmap. (This process is called CPU rendering.) A canvas bound to a bitmap is a non-recording canvas. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or bitmap is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasAttachPen(OH_Drawing_Canvas* canvas, const OH_Drawing_Pen* pen)	Attaches a pen to a canvas so that the canvas can use the style and color of the pen to outline a shape. If the pen effect changes after this function is called, you must call the function again to use the new effect in the subsequent drawing. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or pen is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDetachPen(OH_Drawing_Canvas* canvas)	Detaches the pen from a canvas so that the canvas can no longer use the style and color of the pen to outline a shape. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasAttachBrush(OH_Drawing_Canvas* canvas, const OH_Drawing_Brush* brush)	Attaches a brush to a canvas so that the canvas can use the style and color of the brush to fill in a shape. If the brush effect changes after this function is called, you must call the function again to use the new effect in the subsequent drawing. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or brush is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDetachBrush(OH_Drawing_Canvas* canvas)	Detaches the brush from a canvas so that the canvas can no longer use the previously set brush to fill in a shape. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasSave(OH_Drawing_Canvas* canvas)	Saves the current canvas status (canvas matrix) to the top of the stack. This function works with OH_Drawing_CanvasRestore. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasSaveLayer(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect, const OH_Drawing_Brush* brush)	Saves the matrix and cropping region, and allocates a bitmap for subsequent drawing. If you call OH_Drawing_CanvasRestore, changes made to the matrix and clipping region are discarded, and the bitmap is drawn. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasRestore(OH_Drawing_Canvas* canvas)	Restores the canvas status (canvas matrix) saved on the top of the stack. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
uint32_t OH_Drawing_CanvasGetSaveCount(OH_Drawing_Canvas* canvas)	Obtains the number of canvas statuses (canvas matrices) saved in the stack. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasRestoreToCount(OH_Drawing_Canvas* canvas, uint32_t saveCount)	Restores to a given number of canvas statuses (canvas matrices). This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawLine(OH_Drawing_Canvas* canvas, float x1, float y1, float x2, float y2)	Draws a line segment. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawPath(OH_Drawing_Canvas* canvas, const OH_Drawing_Path* path)	Draws a path. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or path is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawPixelMapNine(OH_Drawing_Canvas* canvas, OH_Drawing_PixelMap* pixelMap,const OH_Drawing_Rect* center, const OH_Drawing_Rect* dst, OH_Drawing_FilterMode mode)	Splits a pixel map into nine sections using two horizontal and two vertical lines: four edge sections, four corner sections, and a central section. If the four corner sections are smaller than the target rectangle, they will be drawn in the target rectangle without scaling. Otherwise, they will be scaled to fit the target rectangle. Any remaining space will be filled by stretching or compressing the other five sections to cover the entire target rectangle.
void OH_Drawing_CanvasDrawPixelMapRect(OH_Drawing_Canvas* canvas, OH_Drawing_PixelMap* pixelMap,const OH_Drawing_Rect* src, const OH_Drawing_Rect* dst, const OH_Drawing_SamplingOptions* samplingOptions)	Draws a portion of a pixel map onto a specified area of the canvas. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If one of canvas, pixelMap, or dst is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawBackground(OH_Drawing_Canvas* canvas, const OH_Drawing_Brush* brush)	Draws a background filled with a brush. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or brush is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawRegion(OH_Drawing_Canvas* canvas, const OH_Drawing_Region* region)	Draws a region. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or region is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawPoint(OH_Drawing_Canvas* canvas, const OH_Drawing_Point2D* point)	Draws a point.
void OH_Drawing_CanvasDrawPoints(OH_Drawing_Canvas* canvas, OH_Drawing_PointMode mode,uint32_t count, const OH_Drawing_Point2D* point2D)	Draws multiple points. You can draw a single point, a line segment, or an open polygon. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or point2D is NULL, or count is 0, OH_DRAWING_ERROR_INVALID_PARAMETER is returned. If mode is not within the enumerated range, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.
void OH_Drawing_CanvasDrawBitmap(OH_Drawing_Canvas* canvas, const OH_Drawing_Bitmap* bitmap, float left, float top)	Draws a bitmap. A bitmap, also referred to as a dot matrix image, a pixel map image, or a grid image, includes single points called pixels (image elements). This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or bitmap is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawBitmapRect(OH_Drawing_Canvas* canvas, const OH_Drawing_Bitmap* bitmap,const OH_Drawing_Rect* src, const OH_Drawing_Rect* dst, const OH_Drawing_SamplingOptions* samplingOptions)	Draws a portion of a bitmap onto a specified area of the canvas. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If one of canvas, bitmap, or dst is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawRect(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect)	Draws a rectangle. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or OH_Drawing_Rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawCircle(OH_Drawing_Canvas* canvas, const OH_Drawing_Point* point, float radius)	Draws a circle. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or point is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned. If radius is less than or equal to 0, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawColor(OH_Drawing_Canvas* canvas, uint32_t color,OH_Drawing_BlendMode blendMode)	Fills the entire canvas with the specified color and blend mode.
void OH_Drawing_CanvasDrawOval(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect)	Draws an oval. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawArc(OH_Drawing_Canvas* canvas,const OH_Drawing_Rect* rect, float startAngle, float sweepAngle)	Draws an arc. If the absolute value of the sweep angle exceeds 360 degrees, an ellipse is drawn. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawArcWithCenter(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect,float startAngle, float sweepAngle, bool useCenter)	Draws an arc. It enables you to define the starting angle, sweep angle, and whether the arc's endpoints should connect to its center.
void OH_Drawing_CanvasDrawRoundRect(OH_Drawing_Canvas* canvas, const OH_Drawing_RoundRect* roundRect)	Draws a rounded rectangle. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or roundRect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawNestedRoundRect(OH_Drawing_Canvas* canvas, const OH_Drawing_RoundRect* outer,const OH_Drawing_RoundRect* inner)	Draws two nested rounded rectangles. The outer rectangle boundary must contain the inner rectangle boundary. Otherwise, there is no drawing effect.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawSingleCharacter(OH_Drawing_Canvas* canvas, const char* str,const OH_Drawing_Font* font, float x, float y)	Draws a single character. If the typeface of the current font does not support the character to draw, the system typeface is used to draw the character.
void OH_Drawing_CanvasDrawTextBlob(OH_Drawing_Canvas* canvas, const OH_Drawing_TextBlob* textBlob, float x, float y)	Draws a text blob. If the typeface used to construct OH_Drawing_TextBlob does not support a character, that character will not be drawn. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or textBlob is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasClipRect(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect,OH_Drawing_CanvasClipOp clipOp, bool doAntiAlias)	Clips a rectangle. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned. If clipOp is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.
void OH_Drawing_CanvasClipRoundRect(OH_Drawing_Canvas* canvas, const OH_Drawing_RoundRect* roundRect,OH_Drawing_CanvasClipOp clipOp, bool doAntiAlias)	Clips a rounded rectangle. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or roundRect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned. If clipOp is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.
void OH_Drawing_CanvasClipPath(OH_Drawing_Canvas* canvas, const OH_Drawing_Path* path,OH_Drawing_CanvasClipOp clipOp, bool doAntiAlias)	Clips a path. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or path is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned. If clipOp is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.
OH_Drawing_ErrorCode OH_Drawing_CanvasClipRegion(OH_Drawing_Canvas* canvas, const OH_Drawing_Region* region,OH_Drawing_CanvasClipOp clipOp)	Clips a rectangle.
void OH_Drawing_CanvasRotate(OH_Drawing_Canvas* canvas, float degrees, float px, float py)	Rotates a canvas by a given angle. A positive value indicates a clockwise rotation, and a negative value indicates a counterclockwise rotation. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasTranslate(OH_Drawing_Canvas* canvas, float dx, float dy)	Translates a canvas by a given distance. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasScale(OH_Drawing_Canvas* canvas, float sx, float sy)	Scales a canvas. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasSkew(OH_Drawing_Canvas* canvas, float sx, float sy)	Skews a canvas. This function premultiplies the current canvas matrix by a skew transformation matrix and applies the resulting matrix to the canvas. The skew transformation matrix is as follows: |1 sx 0| |sy 1 0| |0 0 1|. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
int32_t OH_Drawing_CanvasGetWidth(OH_Drawing_Canvas* canvas)	Obtains the canvas width. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
int32_t OH_Drawing_CanvasGetHeight(OH_Drawing_Canvas* canvas)	Obtains the canvas height. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasGetLocalClipBounds(OH_Drawing_Canvas* canvas, OH_Drawing_Rect* rect)	Obtains the bounds of the cropping region of the canvas. This function cannot be used for a canvas of the recording type. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasGetTotalMatrix(OH_Drawing_Canvas* canvas, OH_Drawing_Matrix* matrix)	Obtains the 3x3 matrix of a canvas. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or matrix is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasConcatMatrix(OH_Drawing_Canvas* canvas, OH_Drawing_Matrix* matrix)	Preconcats the existing matrix of the canvas with the passed-in matrix. The drawing operation triggered before this API is called is not affected. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or matrix is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawShadow(OH_Drawing_Canvas* canvas, OH_Drawing_Path* path, OH_Drawing_Point3D planeParams,OH_Drawing_Point3D devLightPos, float lightRadius, uint32_t ambientColor, uint32_t spotColor,OH_Drawing_CanvasShadowFlags flag)	Draws a spot shadow and uses a given path to outline the ambient shadow. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or path is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned. If flag is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.
void OH_Drawing_CanvasClear(OH_Drawing_Canvas* canvas, uint32_t color)	Clears a canvas by using a given color. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasSetMatrix(OH_Drawing_Canvas* canvas, OH_Drawing_Matrix* matrix)	Sets the matrix status for a canvas. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or matrix is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasResetMatrix(OH_Drawing_Canvas* canvas)	Resets the matrix of this canvas to an identity matrix. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawImageRectWithSrc(OH_Drawing_Canvas* canvas, const OH_Drawing_Image* image,const OH_Drawing_Rect* src, const OH_Drawing_Rect* dst, const OH_Drawing_SamplingOptions* samplingOptions,OH_Drawing_SrcRectConstraint srcRectConstraint)	Draws a portion of an image onto a specified area of the canvas. The area selected by the source rectangle is scaled and translated to the destination rectangle. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If one of canvas, image, src, or dst is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawImageRect(OH_Drawing_Canvas* canvas, OH_Drawing_Image* image,OH_Drawing_Rect* rect, OH_Drawing_SamplingOptions* samplingOptions)	Draws an image onto a specified area of the canvas. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If one of canvas, image, or dst is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
void OH_Drawing_CanvasDrawVertices(OH_Drawing_Canvas* canvas, OH_Drawing_VertexMode vertexMmode,int32_t vertexCount, const OH_Drawing_Point2D* positions, const OH_Drawing_Point2D* texs,const uint32_t* colors, int32_t indexCount, const uint16_t* indices, OH_Drawing_BlendMode mode)	Draws a triangular grid described by a vertex array. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or positions is NULL, vertexCount is less than 3, or indexCount is less than 3 but not 0, OH_DRAWING_ERROR_INVALID_PARAMETER is returned. If either vertexMmode or mode is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.
bool OH_Drawing_CanvasReadPixels(OH_Drawing_Canvas* canvas, OH_Drawing_Image_Info* imageInfo,void* dstPixels, uint32_t dstRowBytes, int32_t srcX, int32_t srcY)	Copies pixel data from a canvas to a specified address. This function cannot be used for a canvas of the recording type. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If one of canvas, imageInfo, or dstPixels is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
bool OH_Drawing_CanvasReadPixelsToBitmap(OH_Drawing_Canvas* canvas,OH_Drawing_Bitmap* bitmap, int32_t srcX, int32_t srcY)	Copies pixel data from a canvas to an image. This function cannot be used for a canvas of the recording type. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or bitmap is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
OH_Drawing_ErrorCode OH_Drawing_CanvasIsClipEmpty(OH_Drawing_Canvas* canvas, bool* isClipEmpty)	Checks whether the region that can be drawn is empty after clipping.
OH_Drawing_ErrorCode OH_Drawing_CanvasGetImageInfo(OH_Drawing_Canvas* canvas, OH_Drawing_Image_Info* imageInfo)	Obtains the image information of a canvas.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawRecordCmd(OH_Drawing_Canvas* canvas, OH_Drawing_RecordCmd* recordCmd)	Draws an OH_Drawing_RecordCmd object.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawRecordCmdNesting(OH_Drawing_Canvas* canvas, OH_Drawing_RecordCmd* recordCmd)	Draws an OH_Drawing_RecordCmd object. This API supports nesting. Specifically, it can use the canvas object generated by OH_Drawing_RecordCmdUtilsBeginRecording as the input parameter. However, multi-layer nesting is not recommended because it affects performance.
OH_Drawing_ErrorCode OH_Drawing_CanvasQuickRejectPath(OH_Drawing_Canvas* canvas, const OH_Drawing_Path* path,bool* quickReject)	Checks whether the path is not intersecting with the canvas area. The canvas area includes its boundaries.
OH_Drawing_ErrorCode OH_Drawing_CanvasQuickRejectRect(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect,bool* quickReject)	Checks whether the rectangle is not intersecting with the canvas area. The canvas area includes its boundaries.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawPixelMapRectConstraint(OH_Drawing_Canvas* canvas,OH_Drawing_PixelMap* pixelMap, const OH_Drawing_Rect* src, const OH_Drawing_Rect* dst,const OH_Drawing_SamplingOptions* samplingOptions, OH_Drawing_SrcRectConstraint constraint)	Draws a portion of a pixel map onto a specified area of the canvas.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawSingleCharacterWithFeatures(OH_Drawing_Canvas* canvas, const char* str,const OH_Drawing_Font* font, float x, float y, OH_Drawing_FontFeatures* fontFeatures)	Draws a single character with font features. If the typeface of the current font does not support the character to draw, the system typeface is used to draw the character.
OH_Drawing_ErrorCode OH_Drawing_CanvasDrawPixelMapMesh(OH_Drawing_Canvas* cCanvas, OH_Drawing_PixelMap* pixelMap, uint32_t meshWidth, uint32_t meshHeight, const float* vertices, uint32_t verticesSize, uint32_t vertOffset, const uint32_t* colors, uint32_t colorsSize, uint32_t colorOffset)	Draws a PixelMap based on a mesh, where mesh vertices are evenly distributed across the PixelMap. (This API works with brushes but not pens.)

Enum Description

OH_Drawing_SrcRectConstraint

enum OH_Drawing_SrcRectConstraint

Description

Enumerates the constraint types of the source rectangle.

Since: 12

Value	Description
STRICT_SRC_RECT_CONSTRAINT	The source rectangle must be completely contained in the image.
FAST_SRC_RECT_CONSTRAINT	The source rectangle can be partly outside the image.

OH_Drawing_PointMode

enum OH_Drawing_PointMode

Description

Enumerates the modes of drawing multiple points. The modes include discrete points, line segments, and open polygons.

Since: 12

Value	Description
POINT_MODE_POINTS	Draws each point separately.
POINT_MODE_LINES	Draws every two points as a line segment.
POINT_MODE_POLYGON	Draws an array of points as an open polygon.

OH_Drawing_CanvasClipOp

enum OH_Drawing_CanvasClipOp

Description

Enumerates the canvas clipping modes.

Since: 11

Value	Description
DIFFERENCE	Clips a specified area. That is, the difference set is obtained.
INTERSECT	Retains a specified area. That is, the intersection is obtained.

OH_Drawing_CanvasShadowFlags

enum OH_Drawing_CanvasShadowFlags

Description

Enumerates the shadow flags.

Since: 12

Value	Description
SHADOW_FLAGS_NONE	There is no shadow flag.
SHADOW_FLAGS_TRANSPARENT_OCCLUDER	The occluding object is transparent.
SHADOW_FLAGS_GEOMETRIC_ONLY	No analysis on the shadows is required.
SHADOW_FLAGS_ALL	All the preceding shadow flags are used.

OH_Drawing_VertexMode

enum OH_Drawing_VertexMode

Description

Enumerates the modes of interpreting the geometry of a given vertex.

Since: 12

Value	Description
VERTEX_MODE_TRIANGLES	Draws a triangle list. Specifically, a list of isolated triangles are drawn using every three vertices. If the number of vertices is not a multiple of 3, the extra vertices will be ignored.
VERTEX_MODE_TRIANGLES_STRIP	Draws a triangle strip. Specifically, the first triangle is drawn between the first 3 vertices, and all subsequent triangles use the previous 2 vertices plus the next additional vertex.
VERTEX_MODE_TRIANGLE_FAN	Draws a triangle fan. A triangle fan is similar to a triangle strip, except that all the triangles share one vertex (the first vertex).

Function Description

OH_Drawing_CanvasDrawSingleCharacterWithFeatures()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawSingleCharacterWithFeatures(OH_Drawing_Canvas* canvas, const char* str, const OH_Drawing_Font* font, float x, float y, OH_Drawing_FontFeatures* fontFeatures)

Description

Draws a single character with font features. If the typeface of the current font does not support the character to draw, the system typeface is used to draw the character.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 20

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const char* str	Pointer to the single character to draw. A string can be passed in, but only the first character in the string is parsed and drawn in UTF-8 encoding.
const OH_Drawing_Font* font	Pointer to the OH_Drawing_Font object.
float x	X coordinate of the left point of the character baseline.
float y	Y coordinate of the left point of the character baseline.
OH_Drawing_FontFeatures* fontFeatures	Pointer to the OH_Drawing_FontFeatures object. If no font feature is set, the preset font feature in the TrueType fonts (TTF) file is used.

Returns

Type	Description
OH_Drawing_ErrorCode	Execution result. OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if at least one of the parameters canvas, str, font, or fontFeatures is NULL, or the length of str is 0.

OH_Drawing_CanvasDrawPixelMapRectConstraint()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawPixelMapRectConstraint(OH_Drawing_Canvas* canvas,OH_Drawing_PixelMap* pixelMap, const OH_Drawing_Rect* src, const OH_Drawing_Rect* dst, const OH_Drawing_SamplingOptions* samplingOptions, OH_Drawing_SrcRectConstraint constraint)

Description

Draws a portion of a pixel map onto a specified area of the canvas.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 20

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_PixelMap* pixelMap	Pointer to the OH_Drawing_PixelMap object.
const OH_Drawing_Rect* src	Pointer to a rectangle on the pixel map. If NULL is passed in, it refers to the entire pixel map.
const OH_Drawing_Rect* dst	Pointer to a rectangle on the canvas.
const OH_Drawing_SamplingOptions* samplingOptions	Pointer to the OH_Drawing_SamplingOptions object. A null pointer means that the default sampling options are used.
OH_Drawing_SrcRectConstraint constraint	Constraint type. For details about the available options, see OH_Drawing_SrcRectConstraint.

Returns

Type	Description
OH_Drawing_ErrorCode	Execution result. OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if canvas, pixelMap, or dst is NULL.

OH_Drawing_CanvasDrawRecordCmdNesting()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawRecordCmdNesting(OH_Drawing_Canvas* canvas, OH_Drawing_RecordCmd* recordCmd)

Description

Draws an OH_Drawing_RecordCmd object. This API supports nesting.

Specifically, it can use the canvas object generated by OH_Drawing_RecordCmdUtilsBeginRecording as the input parameter. However, multi-layer nesting is not recommended because it affects performance.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 19

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object. Only the canvas of the recording type is supported.
OH_Drawing_RecordCmd* recordCmd	Pointer to the OH_Drawing_RecordCmd object.

Returns

Type	Description
OH_Drawing_ErrorCode	Operation code. OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if either canvas or recordCmd is NULL.

OH_Drawing_CanvasCreate()

OH_Drawing_Canvas* OH_Drawing_CanvasCreate(void)

Description

Creates an OH_Drawing_Canvas object.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Returns

Type	Description
OH_Drawing_Canvas*	Returns the pointer to the OH_Drawing_Canvas object created.

OH_Drawing_CanvasCreateWithPixelMap()

OH_Drawing_Canvas* OH_Drawing_CanvasCreateWithPixelMap(OH_Drawing_PixelMap* pixelMap)

Description

Binds a pixel map to a canvas so that the content drawn on the canvas is output to the pixel map. (This process is called CPU rendering.) A canvas bound to a pixel map is a non-recording canvas.
You should unbind the pixel map object by calling OH_Drawing_PixelMapDissolve after the canvas object is destroyed.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 20

Parameters

Name	Description
OH_Drawing_PixelMap* pixelMap	Pointer to the OH_Drawing_PixelMap object.

Returns

Type	Description
OH_Drawing_Canvas*	Pointer to the created canvas object OH_Drawing_Canvas. If the returned object is NULL, the creation fails due to insufficient memory or an empty pixel map object.

OH_Drawing_CanvasDestroy()

void OH_Drawing_CanvasDestroy(OH_Drawing_Canvas* canvas)

Description

Destroys an OH_Drawing_Canvas object and reclaims the memory occupied by the object.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.

OH_Drawing_CanvasBind()

void OH_Drawing_CanvasBind(OH_Drawing_Canvas* canvas, OH_Drawing_Bitmap* bitmap)

Description

Binds a bitmap to a canvas so that the content drawn on the canvas is output to the bitmap. (This process is called CPU rendering.) A canvas bound to a bitmap is a non-recording canvas.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or bitmap is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
OH_Drawing_Bitmap* bitmap	Pointer to an OH_Drawing_Bitmap object.

OH_Drawing_CanvasAttachPen()

void OH_Drawing_CanvasAttachPen(OH_Drawing_Canvas* canvas, const OH_Drawing_Pen* pen)

Description

Attaches a pen to a canvas so that the canvas can use the style and color of the pen to outline a shape. If the pen effect changes after this function is called, you must call the function again to use the new effect in the subsequent drawing.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or pen is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Pen* pen	Pointer to an OH_Drawing_Pen object.

OH_Drawing_CanvasDetachPen()

void OH_Drawing_CanvasDetachPen(OH_Drawing_Canvas* canvas)

Description

Detaches the pen from a canvas so that the canvas can no longer use the style and color of the pen to outline a shape.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.

OH_Drawing_CanvasAttachBrush()

void OH_Drawing_CanvasAttachBrush(OH_Drawing_Canvas* canvas, const OH_Drawing_Brush* brush)

Description

Attaches a brush to a canvas so that the canvas can use the style and color of the brush to fill in a shape. If the brush effect changes after this function is called, you must call the function again to use the new effect in the subsequent drawing.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or brush is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Brush* brush	Pointer to an OH_Drawing_Brush object.

OH_Drawing_CanvasDetachBrush()

void OH_Drawing_CanvasDetachBrush(OH_Drawing_Canvas* canvas)

Description

Detaches the brush from a canvas so that the canvas can no longer use the previously set brush to fill in a shape.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.

OH_Drawing_CanvasSave()

void OH_Drawing_CanvasSave(OH_Drawing_Canvas* canvas)

Description

Saves the current canvas status (canvas matrix) to the top of the stack. This function works with OH_Drawing_CanvasRestore.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.

OH_Drawing_CanvasSaveLayer()

void OH_Drawing_CanvasSaveLayer(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect, const OH_Drawing_Brush* brush)

Description

Saves the matrix and cropping region, and allocates a bitmap for subsequent drawing. If you call OH_Drawing_CanvasRestore, changes made to the matrix and clipping region are discarded, and the bitmap is drawn.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const OH_Drawing_Rect* rect	Pointer to the OH_Drawing_Rect object, which is used to limit the layer size. A null pointer means no limit.
const OH_Drawing_Brush* brush	Pointer to an OH_Drawing_Brush object. The alpha value, filter effect, and blend mode of the brush are applied when the bitmap is drawn. If NULL is passed in, no effect is applied.

OH_Drawing_CanvasRestore()

void OH_Drawing_CanvasRestore(OH_Drawing_Canvas* canvas)

Description

Restores the canvas status (canvas matrix) saved on the top of the stack.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.

OH_Drawing_CanvasGetSaveCount()

uint32_t OH_Drawing_CanvasGetSaveCount(OH_Drawing_Canvas* canvas)

Description

Obtains the number of canvas statuses (canvas matrices) saved in the stack.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.

Returns

Type	Description
uint32_t	Returns a 32-bit value that describes the number of canvas statuses (canvas matrices). The initial number is 1.

OH_Drawing_CanvasRestoreToCount()

void OH_Drawing_CanvasRestoreToCount(OH_Drawing_Canvas* canvas, uint32_t saveCount)

Description

Restores to a given number of canvas statuses (canvas matrices).
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
uint32_t saveCount	Number of canvas statuses (canvas matrices). If the value is less than or equal to 1, the canvas is restored to the initial state. If the value is greater than the number of canvas statuses that have been saved, no operation is performed.

OH_Drawing_CanvasDrawLine()

void OH_Drawing_CanvasDrawLine(OH_Drawing_Canvas* canvas, float x1, float y1, float x2, float y2)

Description

Draws a line segment.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
float x1	X coordinate of the start point of the line segment.
float y1	Y coordinate of the start point of the line segment.
float x2	X coordinate of the end point of the line segment.
float y2	Y coordinate of the end point of the line segment.

OH_Drawing_CanvasDrawPath()

void OH_Drawing_CanvasDrawPath(OH_Drawing_Canvas* canvas, const OH_Drawing_Path* path)

Description

Draws a path.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or path is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Path* path	Pointer to an OH_Drawing_Path object.

OH_Drawing_CanvasDrawPixelMapNine()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawPixelMapNine(OH_Drawing_Canvas* canvas, OH_Drawing_PixelMap* pixelMap,const OH_Drawing_Rect* center, const OH_Drawing_Rect* dst, OH_Drawing_FilterMode mode)

Description

Splits a pixel map into nine sections using two horizontal and two vertical lines: four edge sections, four corner sections, and a central section.
If the four corner sections are smaller than the target rectangle, they will be drawn in the target rectangle without scaling. Otherwise, they will be scaled to fit the target rectangle.
Any remaining space will be filled by stretching or compressing the other five sections to cover the entire target rectangle.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 18

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_PixelMap* pixelMap	Pointer to the OH_Drawing_PixelMap object.
const OH_Drawing_Rect* center	Pointer to the OH_Drawing_Rect object, which indicates the central rectangle splitting the pixel map. It divides the image into nine sections by extending its four edges.
const OH_Drawing_Rect* dst	Pointer to the OH_Drawing_Rect object, which indicates the target region on the canvas.
OH_Drawing_FilterMode mode	Enumeration of filter modes.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if canvas, pixelMap, or dst is NULL.

OH_Drawing_CanvasDrawPixelMapRect()

void OH_Drawing_CanvasDrawPixelMapRect(OH_Drawing_Canvas* canvas, OH_Drawing_PixelMap* pixelMap,const OH_Drawing_Rect* src, const OH_Drawing_Rect* dst, const OH_Drawing_SamplingOptions* samplingOptions)

Description

Draws a portion of a pixel map onto a specified area of the canvas.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If one of canvas, pixelMap, or dst is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_PixelMap* pixelMap	Pointer to the OH_Drawing_PixelMap object.
const OH_Drawing_Rect* src	Pointer to a rectangle on the pixel map. If NULL is passed in, it refers to the entire pixel map.
const OH_Drawing_Rect* dst	Pointer to a rectangle on the canvas.
const OH_Drawing_SamplingOptions* samplingOptions	Pointer to the OH_Drawing_SamplingOptions object. A null pointer means that the default sampling options are used.

OH_Drawing_CanvasDrawBackground()

void OH_Drawing_CanvasDrawBackground(OH_Drawing_Canvas* canvas, const OH_Drawing_Brush* brush)

Description

Draws a background filled with a brush.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or brush is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Brush* brush	Pointer to an OH_Drawing_Brush object.

OH_Drawing_CanvasDrawRegion()

void OH_Drawing_CanvasDrawRegion(OH_Drawing_Canvas* canvas, const OH_Drawing_Region* region)

Description

Draws a region.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or region is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Region* region	Pointer to an OH_Drawing_Region object.

OH_Drawing_CanvasDrawPoint()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawPoint(OH_Drawing_Canvas* canvas, const OH_Drawing_Point2D* point)

Description

Draws a point.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const OH_Drawing_Point2D* point	Pointer to the OH_Drawing_Point2D object.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if either canvas or point is NULL.

OH_Drawing_CanvasDrawPoints()

void OH_Drawing_CanvasDrawPoints(OH_Drawing_Canvas* canvas, OH_Drawing_PointMode mode,uint32_t count, const OH_Drawing_Point2D* point2D)

Description

Draws multiple points. You can draw a single point, a line segment, or an open polygon.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or point2D is NULL, or count is 0, OH_DRAWING_ERROR_INVALID_PARAMETER is returned. If mode is not within the enumerated range, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
OH_Drawing_PointMode mode	Mode for drawing multiple points. For details, see OH_Drawing_PointMode.
uint32_t count	Number of vertices, that is, the number of vertices in the vertex array.
const OH_Drawing_Point2D* point2D	Pointer to an array holding the vertices.

OH_Drawing_CanvasDrawBitmap()

void OH_Drawing_CanvasDrawBitmap(OH_Drawing_Canvas* canvas, const OH_Drawing_Bitmap* bitmap, float left, float top)

Description

Draws a bitmap. A bitmap, also referred to as a dot matrix image, a pixel map image, or a grid image, includes single points called pixels (image elements).
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or bitmap is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Bitmap* bitmap	Pointer to an OH_Drawing_Bitmap object.
float left	X coordinate of the upper left corner of the bitmap.
float top	Y coordinate of the upper left corner of the bitmap.

OH_Drawing_CanvasDrawBitmapRect()

void OH_Drawing_CanvasDrawBitmapRect(OH_Drawing_Canvas* canvas, const OH_Drawing_Bitmap* bitmap,const OH_Drawing_Rect* src, const OH_Drawing_Rect* dst, const OH_Drawing_SamplingOptions* samplingOptions)

Description

Draws a portion of a bitmap onto a specified area of the canvas.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If one of canvas, bitmap, or dst is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const OH_Drawing_Bitmap* bitmap	Pointer to the OH_Drawing_Bitmap object.
const OH_Drawing_Rect* src	Pointer to a rectangle on the bitmap. If NULL is passed in, it refers to the entire bitmap.
const OH_Drawing_Rect* dst	Pointer to a rectangle on the canvas.
const OH_Drawing_SamplingOptions* samplingOptions	Pointer to the OH_Drawing_SamplingOptions object. A null pointer means that the default sampling options are used.

OH_Drawing_CanvasDrawRect()

void OH_Drawing_CanvasDrawRect(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect)

Description

Draws a rectangle.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or OH_Drawing_Rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Rect* rect	Pointer to an OH_Drawing_Rect object.

OH_Drawing_CanvasDrawCircle()

void OH_Drawing_CanvasDrawCircle(OH_Drawing_Canvas* canvas, const OH_Drawing_Point* point, float radius)

Description

Draws a circle. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or point is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
If radius is less than or equal to 0, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Point* point	Pointer to an OH_Drawing_Point object, which indicates the center of the circle.
float radius	Radius of the circle. The value is invalid if it is less than or equal to 0.

OH_Drawing_CanvasDrawColor()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawColor(OH_Drawing_Canvas* canvas, uint32_t color,OH_Drawing_BlendMode blendMode)

Description

Fills the entire canvas with the specified color and blend mode.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
uint32_t color	Color, represented by a 32-bit (ARGB) variable.
OH_Drawing_BlendMode blendMode	Blend mode.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if canvas is NULL. OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE if blendMode is not set to one of the enumerated values.

OH_Drawing_CanvasDrawOval()

void OH_Drawing_CanvasDrawOval(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect)

Description

Draws an oval. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Rect* rect	Pointer to an OH_Drawing_Rect object.

OH_Drawing_CanvasDrawArc()

void OH_Drawing_CanvasDrawArc(OH_Drawing_Canvas* canvas,const OH_Drawing_Rect* rect, float startAngle, float sweepAngle)

Description

Draws an arc. If the absolute value of the sweep angle exceeds 360 degrees, an ellipse is drawn.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Rect* rect	Pointer to an OH_Drawing_Rect object.
float startAngle	Start angle. When the degree is 0, the start point is located at the right end of the oval. A positive number indicates that the start point is placed clockwise, and a negative number indicates that the start point is placed counterclockwise.
float sweepAngle	Angle to sweep, in degrees. A positive number indicates a clockwise sweep, and a negative value indicates a counterclockwise swipe. The valid range is from -360 degrees to 360 degrees. If the absolute value of the sweep angle exceeds 360 degrees, an ellipse is drawn.

OH_Drawing_CanvasDrawArcWithCenter()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawArcWithCenter(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect,float startAngle, float sweepAngle, bool useCenter)

Description

Draws an arc. It enables you to define the start angle, sweep angle, and whether the arc's endpoints should connect to its center.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 18

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const OH_Drawing_Rect* rect	Pointer to the OH_Drawing_Rect object.
float startAngle	Start angle, in degrees. The value is a floating point number. When the degree is 0, the start point is located at the right end of the oval. A positive number indicates that the start point is placed clockwise, and a negative number indicates that the start point is placed counterclockwise.
float sweepAngle	Angle to sweep, in degrees. The value is a floating point number. A positive number indicates a clockwise sweep, and a negative value indicates a counterclockwise swipe. The swipe angle can exceed 360 degrees, and a complete ellipse is drawn.
bool useCenter	Whether the start point and end point of the arc are connected to its center. The value true means that they are connected to the center; the value false means the opposite.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if either canvas or rect is NULL.

OH_Drawing_CanvasDrawRoundRect()

void OH_Drawing_CanvasDrawRoundRect(OH_Drawing_Canvas* canvas, const OH_Drawing_RoundRect* roundRect)

Description

Draws a rounded rectangle. This API may return an error code. For details, call OH_Drawing_ErrorCodeGet. If either canvas or roundRect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_RoundRect* roundRect	Pointer to an OH_Drawing_RoundRect object.

OH_Drawing_CanvasDrawNestedRoundRect()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawNestedRoundRect(OH_Drawing_Canvas* canvas, const OH_Drawing_RoundRect* outer,const OH_Drawing_RoundRect* inner)

Description

Draws two nested rounded rectangles. The outer rectangle boundary must contain the inner rectangle boundary. Otherwise, there is no drawing effect.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 18

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const OH_Drawing_RoundRect* outer	Pointer to the OH_Drawing_RoundRect object, indicating the outer rounded rectangle.
const OH_Drawing_RoundRect* inner	Pointer to the OH_Drawing_RoundRect object, indicating the inner rounded rectangle.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if canvas, outer, or inner is NULL.

OH_Drawing_CanvasDrawSingleCharacter()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawSingleCharacter(OH_Drawing_Canvas* canvas, const char* str,const OH_Drawing_Font* font, float x, float y)

Description

Draws a single character. If the typeface of the current font does not support the character to draw, the system typeface is used to draw the character.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const char* str	Pointer to the single character to draw. A string can be passed in, but only the first character in the string is parsed and drawn in UTF-8 encoding.
const OH_Drawing_Font* font	Pointer to the OH_Drawing_Font object.
float x	X coordinate of the left point of the character baseline.
float y	Y coordinate of the left point of the character baseline.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if at least one of the parameters canvas, str, or font is NULL, or the length of str is 0.

OH_Drawing_CanvasDrawTextBlob()

void OH_Drawing_CanvasDrawTextBlob(OH_Drawing_Canvas* canvas, const OH_Drawing_TextBlob* textBlob, float x, float y)

Description

Draws a text blob. If the typeface used to construct OH_Drawing_TextBlob does not support a character, that character will not be drawn.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or textBlob is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_TextBlob* textBlob	Pointer to an OH_Drawing_TextBlob object.
float x	X coordinate of the left point of the text baseline.
float y	Y coordinate of the left point of the text baseline.

OH_Drawing_CanvasClipRect()

void OH_Drawing_CanvasClipRect(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect,OH_Drawing_CanvasClipOp clipOp, bool doAntiAlias)

Description

Clips a rectangle.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
If clipOp is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Rect* rect	Pointer to an OH_Drawing_Rect object.
OH_Drawing_CanvasClipOp clipOp	Clip mode. For details about the available options, see OH_Drawing_CanvasClipOp.
bool doAntiAlias	Whether to enable anti-aliasing. The value true means to enable anti-aliasing, and false means the opposite.

OH_Drawing_CanvasClipRoundRect()

void OH_Drawing_CanvasClipRoundRect(OH_Drawing_Canvas* canvas, const OH_Drawing_RoundRect* roundRect,OH_Drawing_CanvasClipOp clipOp, bool doAntiAlias)

Description

Clips a rounded rectangle.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or roundRect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
If clipOp is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_RoundRect* roundRect	Pointer to an OH_Drawing_RoundRect object.
OH_Drawing_CanvasClipOp clipOp	Clip mode. For details about the available options, see OH_Drawing_CanvasClipOp.
bool doAntiAlias	Whether to perform anti-aliasing. The value true means to perform anti-aliasing, and false means the opposite.

OH_Drawing_CanvasClipPath()

void OH_Drawing_CanvasClipPath(OH_Drawing_Canvas* canvas, const OH_Drawing_Path* path,OH_Drawing_CanvasClipOp clipOp, bool doAntiAlias)

Description

Clips a path.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or path is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
If clipOp is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
const OH_Drawing_Path* path	Pointer to an OH_Drawing_Path object.
OH_Drawing_CanvasClipOp clipOp	Clip mode. For details about the available options, see OH_Drawing_CanvasClipOp.
bool doAntiAlias	Whether to enable anti-aliasing. The value true means to enable anti-aliasing, and false means the opposite.

OH_Drawing_CanvasClipRegion()

OH_Drawing_ErrorCode OH_Drawing_CanvasClipRegion(OH_Drawing_Canvas* canvas, const OH_Drawing_Region* region,OH_Drawing_CanvasClipOp clipOp)

Description

Clips a rectangle.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const OH_Drawing_Region* region	Pointer to the OH_Drawing_Region object.
OH_Drawing_CanvasClipOp clipOp	Clip mode. For details about the available options, see OH_Drawing_CanvasClipOp.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if either canvas or region is NULL. OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE if clipOp is not set to one of the enumerated values.

OH_Drawing_CanvasRotate()

void OH_Drawing_CanvasRotate(OH_Drawing_Canvas* canvas, float degrees, float px, float py)

Description

Rotates a canvas by a given angle. A positive value indicates a clockwise rotation, and a negative value indicates a counterclockwise rotation.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
float degrees	Rotation angle.
float px	X coordinate of the rotation point.
float py	Y coordinate of the rotation point.

OH_Drawing_CanvasTranslate()

void OH_Drawing_CanvasTranslate(OH_Drawing_Canvas* canvas, float dx, float dy)

Description

Translates a canvas by a given distance.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
float dx	Distance to translate on the X axis.
float dy	Distance to translate on the Y axis.

OH_Drawing_CanvasScale()

void OH_Drawing_CanvasScale(OH_Drawing_Canvas* canvas, float sx, float sy)

Description

Scales a canvas.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 11

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
float sx	Scale ratio on the X axis.
float sy	Scale ratio on the Y axis.

OH_Drawing_CanvasSkew()

void OH_Drawing_CanvasSkew(OH_Drawing_Canvas* canvas, float sx, float sy)

Description

Skews a canvas. This function premultiplies the current canvas matrix by a skew transformation matrix and applies the resulting matrix to the canvas. The skew transformation matrix is as follows:
|1 sx 0|
|sy 1 0|
|0 0 1|
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
float sx	Amount of tilt on the X axis. A positive number tilts the drawing rightwards along the positive direction of the Y axis, and a negative number tilts the drawing leftwards along the positive direction of the Y axis.
float sy	Amount of tilt on the Y axis. A positive number tilts the drawing downwards along the positive direction of the X axis, and a negative number tilts the drawing upwards along the positive direction of the X axis.

OH_Drawing_CanvasGetWidth()

int32_t OH_Drawing_CanvasGetWidth(OH_Drawing_Canvas* canvas)

Description

Obtains the canvas width.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.

Returns

Type	Description
int32_t	Returns the canvas width, in px.

OH_Drawing_CanvasGetHeight()

int32_t OH_Drawing_CanvasGetHeight(OH_Drawing_Canvas* canvas)

Description

Obtains the canvas height.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.

Returns

Type	Description
int32_t	Returns the canvas height, in pixels.

OH_Drawing_CanvasGetLocalClipBounds()

void OH_Drawing_CanvasGetLocalClipBounds(OH_Drawing_Canvas* canvas, OH_Drawing_Rect* rect)

Description

Obtains the bounds of the cropping region of the canvas. This function cannot be used for a canvas of the recording type.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or rect is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_Rect* rect	Pointer to the OH_Drawing_Rect object. You can call OH_Drawing_RectCreate to create a rectangle object.

OH_Drawing_CanvasGetTotalMatrix()

void OH_Drawing_CanvasGetTotalMatrix(OH_Drawing_Canvas* canvas, OH_Drawing_Matrix* matrix)

Description

Obtains the 3x3 matrix of a canvas.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or matrix is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_Matrix* matrix	Pointer to the OH_Drawing_Matrix object. You can call OH_Drawing_MatrixCreate to create a matrix object.

OH_Drawing_CanvasConcatMatrix()

void OH_Drawing_CanvasConcatMatrix(OH_Drawing_Canvas* canvas, OH_Drawing_Matrix* matrix)

Description

Preconcats the existing matrix of the canvas with the passed-in matrix. The drawing operation triggered before this API is called is not affected.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or matrix is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_Matrix* matrix	Pointer to the OH_Drawing_Matrix object.

OH_Drawing_CanvasDrawShadow()

void OH_Drawing_CanvasDrawShadow(OH_Drawing_Canvas* canvas, OH_Drawing_Path* path, OH_Drawing_Point3D planeParams,OH_Drawing_Point3D devLightPos, float lightRadius, uint32_t ambientColor, uint32_t spotColor,OH_Drawing_CanvasShadowFlags flag)

Description

Draws a spot shadow and uses a given path to outline the ambient shadow.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or path is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
If flag is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_Path* path	Pointer to the OH_Drawing_Path object, which is used to generate shadows.
OH_Drawing_Point3D planeParams	Z-axis offset of an occluder relative to the canvas, based on its x and y coordinates.
OH_Drawing_Point3D devLightPos	Position of the light relative to the canvas.
float lightRadius	Radius of the light source. The value must be greater than or equal to 0.
uint32_t ambientColor	Ambient shadow color, which is represented by a 32-bit (ARGB) variable.
uint32_t spotColor	Point shadow color, which is represented by a 32-bit (ARGB) variable.
OH_Drawing_CanvasShadowFlags flag	Enumeration of shadow flags.

OH_Drawing_CanvasClear()

void OH_Drawing_CanvasClear(OH_Drawing_Canvas* canvas, uint32_t color)

Description

Clears a canvas by using a given color.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 8

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
uint32_t color	Color, which is a 32-bit (ARGB) variable.

OH_Drawing_CanvasSetMatrix()

void OH_Drawing_CanvasSetMatrix(OH_Drawing_Canvas* canvas, OH_Drawing_Matrix* matrix)

Description

Sets the matrix status for a canvas.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or matrix is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_Matrix* matrix	Pointer to the OH_Drawing_Matrix object. You can call OH_Drawing_MatrixCreate to create a matrix object.

OH_Drawing_CanvasResetMatrix()

void OH_Drawing_CanvasResetMatrix(OH_Drawing_Canvas* canvas)

Description

Resets the matrix of this canvas to an identity matrix.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If canvas is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.

OH_Drawing_CanvasDrawImageRectWithSrc()

void OH_Drawing_CanvasDrawImageRectWithSrc(OH_Drawing_Canvas* canvas, const OH_Drawing_Image* image,const OH_Drawing_Rect* src, const OH_Drawing_Rect* dst, const OH_Drawing_SamplingOptions* samplingOptions,OH_Drawing_SrcRectConstraint srcRectConstraint)

Description

Draws a portion of an image onto a specified area of the canvas. The area selected by the source rectangle is scaled and translated to the destination rectangle.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If one of canvas, image, src, or dst is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const OH_Drawing_Image* image	Pointer to the OH_Drawing_Image object.
const OH_Drawing_Rect* src	Pointer to the OH_Drawing_Rect object.
const OH_Drawing_Rect* dst	Pointer to the OH_Drawing_Rect object.
const OH_Drawing_SamplingOptions* samplingOptions	Pointer to the OH_Drawing_SamplingOptions object. A null pointer means that the default sampling options are used.
OH_Drawing_SrcRectConstraint srcRectConstraint	Constraint type. For details about the available options, see OH_Drawing_SrcRectConstraint.

OH_Drawing_CanvasDrawImageRect()

void OH_Drawing_CanvasDrawImageRect(OH_Drawing_Canvas* canvas, OH_Drawing_Image* image,OH_Drawing_Rect* rect, OH_Drawing_SamplingOptions* samplingOptions)

Description

Draws an image onto a specified area of the canvas.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If one of canvas, image, or dst is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_Image* image	Pointer to the OH_Drawing_Image object.
OH_Drawing_Rect* rect	Pointer to the OH_Drawing_Rect object.
OH_Drawing_SamplingOptions* samplingOptions	Pointer to the OH_Drawing_SamplingOptions object. A null pointer means that the default sampling options are used.

OH_Drawing_CanvasDrawVertices()

void OH_Drawing_CanvasDrawVertices(OH_Drawing_Canvas* canvas, OH_Drawing_VertexMode vertexMmode,int32_t vertexCount, const OH_Drawing_Point2D* positions, const OH_Drawing_Point2D* texs,const uint32_t* colors, int32_t indexCount, const uint16_t* indices, OH_Drawing_BlendMode mode)

Description

Draws a triangular grid described by a vertex array.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or positions is NULL, vertexCount is less than 3, or indexCount is less than 3 but not 0, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.
If either vertexMmode or mode is not set to one of the enumerated values, OH_DRAWING_ERROR_PARAMETER_OUT_OF_RANGE is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to an OH_Drawing_Canvas object.
OH_Drawing_VertexMode vertexMmode	Mode for drawing vertices. For details about the available options, see OH_Drawing_VertexMode.
int32_t vertexCount	Number of elements in the vertex array. The value must be greater than or equal to 3.
const OH_Drawing_Point2D* positions	Pointer to the array that holds the position of every vertex. The array cannot be null and its length must be equal to the value of vertexCount.
const OH_Drawing_Point2D* texs	Pointer to the array that holds the texture space coordinate corresponding to each vertex. The array can be null. If the array is not null, its length must be equal to the value of vertexCount.
const uint32_t* colors	Pointer to the array that holds the color corresponding to each vertex. It is used for interpolation in a triangle. The array can be null. If the array is not null, its length must be equal to the value of vertexCount.
int32_t indexCount	Number of indices. The value can be 0 or a value greater than or equal to 3.
const uint16_t* indices	Pointer to the array that holds the index of each vertex. The array can be null. If the array is not null, its length must be equal to the value of indexCount.
OH_Drawing_BlendMode mode	Enumeration of blend modes. For details about the available options, see OH_Drawing_BlendMode.

OH_Drawing_CanvasReadPixels()

bool OH_Drawing_CanvasReadPixels(OH_Drawing_Canvas* canvas, OH_Drawing_Image_Info* imageInfo,void* dstPixels, uint32_t dstRowBytes, int32_t srcX, int32_t srcY)

Description

Copies pixel data from a canvas to a specified address. This function cannot be used for a canvas of the recording type.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If one of canvas, imageInfo, or dstPixels is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_Image_Info* imageInfo	Pointer to the OH_Drawing_Image_Info object.
void* dstPixels	Pointer to the start address for storing the pixel data.
uint32_t dstRowBytes	Number of bytes in each row of pixels. The value is invalid if it is less than or equal to 0.
int32_t srcX	X offset of the pixels on the canvas, in px.
int32_t srcY	Y offset of the pixels on the canvas, in px.

Returns

Type	Description
bool	Returns true if the pixel data is copied to the start address of the storage; returns false otherwise.

OH_Drawing_CanvasReadPixelsToBitmap()

bool OH_Drawing_CanvasReadPixelsToBitmap(OH_Drawing_Canvas* canvas,OH_Drawing_Bitmap* bitmap, int32_t srcX, int32_t srcY)

Description

Copies pixel data from a canvas to an image. This function cannot be used for a canvas of the recording type.
This API may return an error code. For details, call OH_Drawing_ErrorCodeGet.
If either canvas or bitmap is NULL, OH_DRAWING_ERROR_INVALID_PARAMETER is returned.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_Bitmap* bitmap	Pointer to the OH_Drawing_Bitmap object.
int32_t srcX	X offset of the pixels on the canvas, in px.
int32_t srcY	Y offset of the pixels on the canvas, in px.

Returns

Type	Description
bool	Returns true if the pixel data is copied to the image; returns false otherwise.

OH_Drawing_CanvasIsClipEmpty()

OH_Drawing_ErrorCode OH_Drawing_CanvasIsClipEmpty(OH_Drawing_Canvas* canvas, bool* isClipEmpty)

Description

Checks whether the region that can be drawn is empty after clipping.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
bool* isClipEmpty	Pointer to the variable that specifies whether the region is empty. The value true means that the region is empty, and false means the opposite.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if either canvas or isClipEmpty is NULL.

OH_Drawing_CanvasGetImageInfo()

OH_Drawing_ErrorCode OH_Drawing_CanvasGetImageInfo(OH_Drawing_Canvas* canvas, OH_Drawing_Image_Info* imageInfo)

Description

Obtains the image information of a canvas.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 12

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_Image_Info* imageInfo	Pointer to the OH_Drawing_Image_Info object.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if either canvas or imageInfo is NULL.

OH_Drawing_CanvasDrawRecordCmd()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawRecordCmd(OH_Drawing_Canvas* canvas, OH_Drawing_RecordCmd* recordCmd)

Description

Draws an OH_Drawing_RecordCmd object.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 13

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object. Only the canvas of the recording type is supported.
OH_Drawing_RecordCmd* recordCmd	Pointer to the OH_Drawing_RecordCmd object.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if either canvas or recordCmd is NULL.

OH_Drawing_CanvasQuickRejectPath()

OH_Drawing_ErrorCode OH_Drawing_CanvasQuickRejectPath(OH_Drawing_Canvas* canvas, const OH_Drawing_Path* path,bool* quickReject)

Description

Checks whether the path is not intersecting with the canvas area. The canvas area includes its boundaries.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 18

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const OH_Drawing_Path* path	Pointer to the OH_Drawing_Path object.
bool* quickReject	Pointer to the check result. The value true means that the path is not intersecting with the canvas area, and false means the opposite.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if canvas, path, or quickReject is NULL.

OH_Drawing_CanvasQuickRejectRect()

OH_Drawing_ErrorCode OH_Drawing_CanvasQuickRejectRect(OH_Drawing_Canvas* canvas, const OH_Drawing_Rect* rect,bool* quickReject)

Description

Checks whether the rectangle is not intersecting with the canvas area. The canvas area includes its boundaries.

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 18

Parameters

Name	Description
OH_Drawing_Canvas* canvas	Pointer to the OH_Drawing_Canvas object.
const OH_Drawing_Rect* rect	Pointer to the OH_Drawing_Rect object.
bool* quickReject	Pointer to the check result. The value true means that the rectangle is not intersecting with the canvas area, and false means the opposite.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INVALID_PARAMETER if canvas, rect, or quickReject is NULL.

OH_Drawing_CanvasDrawPixelMapMesh()

OH_Drawing_ErrorCode OH_Drawing_CanvasDrawPixelMapMesh(OH_Drawing_Canvas* cCanvas, OH_Drawing_PixelMap* pixelMap, uint32_t meshWidth, uint32_t meshHeight, const float* vertices, uint32_t verticesSize, uint32_t vertOffset, const uint32_t* colors, uint32_t colorsSize, uint32_t colorOffset)

Description

Draws a PixelMap based on a mesh, where mesh vertices are evenly distributed across the PixelMap. (This API works with brushes but not pens.)

System capability: SystemCapability.Graphic.Graphic2D.NativeDrawing

Since: 23

Parameters

Name	Description
OH_Drawing_Canvas* cCanvas	Pointer to the OH_Drawing_Canvas object.
OH_Drawing_PixelMap* pixelMap	Pointer to the OH_Drawing_PixelMap object.
uint32_t meshWidth	Number of columns in the mesh. The value is an integer greater than 0.
uint32_t meshHeight	Number of rows in the mesh. The value is an integer greater than 0.
const float* vertices	Pointer to the mesh vertex array.
uint32_t verticesSize	Size of the mesh vertex array. The value must be ((meshWidth + 1) * (meshHeight + 1) + vertoffset) * 2.
uint32_t vertOffset	Number of vertices to skip before drawing. The value is an integer greater than or equal to 0.
const uint32_t* colors	Pointer to the mesh color array, which can be null.
uint32_t colorsSize	Size of the mesh color array. If the array exists, the size must be (meshWidth + 1) * (meshHeight + 1) + colorOffset.
uint32_t colorOffset	Number of colors to skip before drawing. The value is an integer greater than or equal to 0.

Returns

Type	Description
OH_Drawing_ErrorCode	Returns one of the following result codes: OH_DRAWING_SUCCESS if the operation is successful. OH_DRAWING_ERROR_INCORRECT_PARAMETER if any of the parameters, such as cCanvas, pixelMap, and vertices, is empty or the input parameter does not meet the value rule.

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