API	Description
OH_Drawing_Brush* OH_Drawing_BrushCreate(void)	Creates a brush object.
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.
void OH_Drawing_BrushSetColor(OH_Drawing_Brush* brush, uint32_t color)	Sets the color for a brush. The color is used by the brush to fill in a shape and is represented by a 32-bit (ARGB) variable.
void OH_Drawing_BrushSetAntiAlias(OH_Drawing_Brush* brush, bool antiAlias)	Sets the anti-aliasing property for a brush. If set to true, the brush applies semi-transparent blurring to the edge pixels of a shape when drawing, making the shape edges smoother.
void OH_Drawing_CanvasDetachBrush(OH_Drawing_Canvas* canvas)	Removes the brush from the canvas. After the execution, the canvas does not use the previously set brush and is restored to the default fill effect.
void OH_Drawing_BrushDestroy(OH_Drawing_Brush* brush)	Destroys a brush object and reclaims the memory occupied by it.

[h2]How to Develop

Call OH_Drawing_BrushCreate() to create a brush object.

// Create a brush object.
OH_Drawing_Brush* brush = OH_Drawing_BrushCreate();

(Optional) Use the brush to set the basic drawing effect. You can select one or more of the following effects:
- You can call OH_Drawing_BrushSetColor() to set the fill color.
```
// Set the fill color to red.
uint32_t color = 0xffff0000;
OH_Drawing_BrushSetColor(brush, color);
```
  color is a 32-bit (ARGB) variable, for example, 0xffff0000.
- You can call OH_Drawing_BrushSetAntiAlias() to enable the anti-aliasing effect to smooth the edges of the graphics.
```
// Enable the anti-aliasing effect.
OH_Drawing_BrushSetAntiAlias(brush, true);
```
Call OH_Drawing_CanvasAttachBrush() to set a brush for the canvas. This API takes two parameters: (1) Canvas object, which must be created or obtained. For details, see Obtaining a Canvas and Displaying Drawing Results (C/C++); (2) brush object to be set. The canvas uses the brush style and color to fill the shape.
```
// Set the brush of the canvas.
OH_Drawing_CanvasAttachBrush(canvas, brush);
```
Draw primitives as required. For details, see Drawing Primitives.
If no fill effect is required, you can use OH_Drawing_CanvasDetachBrush() to remove the brush. The input parameter is the Canvas object.
```
// Remove the brush from the canvas.
OH_Drawing_CanvasDetachBrush(canvas);
```
When the brush is no longer needed, destroy the brush object using OH_Drawing_BrushDestroy().
```
// Destroy objects.
OH_Drawing_BrushDestroy(brush);
```

Stroke Effect

You can set the basic stroke color using a pen and use the pen to implement more complex drawing effects, such as the blend mode, path effect, shader effect, and filter effect. For details, see Complex Drawing Effects.

[h2]Available APIs

The following table lists the common APIs for setting drawing effects with a pen. For details about the usage and parameters, see drawing_pen and drawing_canvas.

API	Description
OH_Drawing_Pen* OH_Drawing_PenCreate(void)	Creates a pen object.
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.
void OH_Drawing_PenSetColor(OH_Drawing_Pen* pen, uint32_t color)	Sets the color for a pen. The color is used by the pen to outline a shape.
void OH_Drawing_PenSetWidth(OH_Drawing_Pen* pen, float width)	Sets the width for a pen. The value 0 is treated as an unusually thin width. During drawing, the width of 0 is always drawn as 1 pixel wide, regardless of any scaling applied to the canvas. Negative values are also regarded as the value 0 during the drawing process.
void OH_Drawing_PenSetAntiAlias(OH_Drawing_Pen* pen, bool antiAlias)	Enables or disables anti-aliasing for a pen. Anti-aliasing makes the pixels around the shape edges semi-transparent.
void OH_Drawing_PenSetCap(OH_Drawing_Pen* pen, OH_Drawing_PenLineCapStyle capStyle)	Sets the line cap style for a pen.
void OH_Drawing_PenSetJoin(OH_Drawing_Pen* pen, OH_Drawing_PenLineJoinStyle joinStyle)	Sets the line join style for a pen.
void OH_Drawing_CanvasDetachPen(OH_Drawing_Canvas* canvas)	Removes the pen from the canvas. After this operation, the canvas no longer draws the outline of the graphics shape and restores the default stroke effect.
void OH_Drawing_PenDestroy(OH_Drawing_Pen* pen)	Destroys a pen object and reclaims the memory occupied by the object.

[h2]How to Develop

Call OH_Drawing_PenCreate() to create a pen object.

// Create a pen object.
OH_Drawing_Pen* pen = OH_Drawing_PenCreate();

Use the pen to set specific stroke effects (you can choose one or more of the following effects).

You can call OH_Drawing_PenSetColor() to set the pen color, which is used to outline a shape.
```
// Set the pen color to red.
uint32_t color = 0xffff0000;
OH_Drawing_PenSetColor(pen, color);
```
color is a 32-bit (ARGB) variable, for example, 0xffff0000.
You can call OH_Drawing_PenSetWidth() to set the pen width.
```
// Set the pen width to 50 pixels.
float width = 50.0;
OH_Drawing_PenSetWidth(pen, width);
```
width indicates the pixel value of the pen width.
You can call OH_Drawing_PenSetAntiAlias() to set anti-aliasing for the pen to make the drawing edge smoother.
```
// Set anti-aliasing for the pen.
OH_Drawing_PenSetAntiAlias(pen, true);
```

You can call OH_Drawing_PenSetCap() to set the pen cap style.

// Set the pen cap style.
OH_Drawing_PenSetCap(pen, LINE_ROUND_CAP);

The options of OH_Drawing_PenLineCapStyle are as follows.

Line Cap Style	Description	Effect
LINE_FLAT_CAP	No cap style. Both ends of the line segment are cut off squarely.
LINE_SQUARE_CAP	Square cap style. Both ends have a square, the width of which is the same as the line segment, and the height is half of the line segment width.
LINE_ROUND_CAP	Round cap style. Both ends have a semicircle centered, the diameter of which is the same as the width of the line segment.

You can call OH_Drawing_PenSetJoin() to set the pen join style.

// Set the pen join style.
OH_Drawing_PenSetJoin(pen, LINE_BEVEL_JOIN);

The options of OH_Drawing_PenLineJoinStyle are as follows.

Join Style	Description	Effect
LINE_MITER_JOIN	The line join style is a sharp corner.
LINE_ROUND_JOIN	The line join style is a round corner.
LINE_BEVEL_JOIN	The line join style is a flat corner.

Call OH_Drawing_CanvasAttachPen() to attach the pen to the canvas. This API accepts two parameters: one is the canvas object. Ensure that you have created or obtained the canvas. For details, see Obtaining a Canvas and Displaying Drawing Results (C/C++). The other parameter is the pen object to set. The canvas will use the configured pen style and color to draw graphics outlines.
```
// Attach the pen to the canvas.
OH_Drawing_CanvasAttachPen(canvas, pen);
```
Draw primitives as required. For details, see Drawing Primitives.
If no stroke effect is required, you can use OH_Drawing_CanvasDetachPen() to remove the pen. The input parameter is the Canvas object. Ensure that the canvas has been created or obtained. For details, see Obtaining a Canvas and Displaying Drawing Results (C/C++).
```
// Remove the pen from the canvas.
OH_Drawing_CanvasDetachPen(canvas);
```
When the pen is no longer needed for stroke, destroy the pen object using OH_Drawing_PenDestroy().
```
// Destroy objects.
OH_Drawing_PenDestroy(pen);
```

Sample Code

Drawing (C/C++)

目录

Basic Drawing Effects (C/C++)

Overview

Fill Effect

[h2]Available APIs

[h2]How to Develop

Stroke Effect

[h2]Available APIs

[h2]How to Develop

Sample Code