"The zero start of Android game programming" 13. Game Development Basics (Paint brush)

1.Paint brushes

A panit (brush) is a drawing amount helper class that contains attribute information such as text and bitmap amount styles, colors, and so on. The common methods for Paint are as follows:

Setantialias (Boolean AA)

Function: Sets whether the brush is non-aliased

Parameters: True for no aliasing, false for aliasing, false for default.

Setalpha (int a)

Function: Sets the transparency of the brush

Parameters: Transparent values

SetTextAlign (Paint.align Align)

Function: Sets the anchor point of the drawing text

Parameters: Constants in the Paint.align class

Measuretext (String text)

Function: Gets the width of the text content

Parameters: Text content

SetStyle (Style style)

Action: Set Brush style

Parameters: Style Instances

SetColor (int color)

Action: Set Brush color

Parameters: Color values

Setstrokewidth (float width)

Effect: Set Brush amount Thickness

Parameters: Brush Thickness values

Settextsize (float textSize)

Function: Sets the size of the text font when the brush draws text

Parameters: Dimension values

Setargb (int a,int r,int g,int b)

Function: Sets the ARGB component of the brush

First parameter: Brush transparency component

Second parameter: Red component of brush

Third parameter: Brush green component

Fourth parameter: Blue component of brush

2.Paint Brush Instances

As follows:

Step: New Project "Panitproject", the game frame for the Mysurfaceview game framework, the specific steps refer to "11. Game Development Basics (Surfaceview game frame, View and Surfaceview differences)".

The main drawing Method Mydraw () is modified as follows:

  Public voidMydraw () {Try{Canvas=Sfh.lockcanvas (); if(canvas!=NULL) {canvas.drawcolor (color.white); //--Set brush non-aliasingPaint Paint1 =NewPaint (); Canvas.drawcircle (40,30,20, Paint1); Paint1.setantialias (true); Canvas.drawcircle (100,30,20, Paint1); //--Set the transparency of the brushCanvas.drawtext ("No transparency", 100, 70,NewPaint ()); Paint Paint2=NewPaint (); Paint2.setalpha (0x77); Canvas.drawtext ("Semi-transparent", 20, 70,NewPaint ()); //--set anchor points for drawing textCanvas.drawtext ("Anchor Point", 20, 90,NewPaint ()); Paint Paint3=NewPaint (); //setting is drawn as the center point of the textpaint3.settextalign (Paint.Align.CENTER); Canvas.drawtext ("Anchor Point", 20,105, Paint3); //--Get the length of the textPaint paint4 =NewPaint (); floatLen = Paint4.measuretext ("Text width:"); Canvas.drawtext ("Text length:" +len,20,130,NewPaint ()); //--Set brush styleCanvas.drawrect (NewRect (20,140,40,160),NewPaint ()); Paint paint5=NewPaint (); //set Brush is not populatedPaint5.setstyle (Paint.Style.STROKE); Canvas.drawrect (NewRect (60,140,80,160), PAINT5); //--Set brush colorPaint paint6 =NewPaint ();                Paint6.setcolor (Color.Blue); Canvas.drawtext ("Blue", 30,180, PAINT6); //--Set the thickness of the brushCanvas.drawline (20,200,70,200,NewPaint ()); Paint paint7=NewPaint (); Paint7.setstrokewidth (7); Canvas.drawline (20,220,70,220, paint7); //--Set the font weight of the brush drawing textPaint paint8 =NewPaint (); Paint8.settextsize (20); Canvas.drawtext ("Text Size", 20,260, paint8); //--Set the ARGB component of the brushPaint paint9 =NewPaint (); Paint9.setargb (0x77,0xff,0x00,0x00); Canvas.drawtext ("Red translucent", 20,290, PAINT9); }        }        Catch(Exception ex) {}finally {            if(canvas!=NULL) {sfh.unlockcanvasandpost (canvas); }        }    }

The Paint brush class provides an anti-aliasing function, in fact the canvas canvas also provides the amount of plot antialiasing functions, as follows:

Canvas.setdrawfilter (Drawfilter filter);

Function: Set drawing antialiasing for the canvas

Parameters: Drawing Filter Instance

Instantiate an object of the Drawfilter class, as shown in the following code:

New Paintflagsdrawfilter (0,paint.anti_alias_flag| Paint.filter_bitmap_flag);

"The zero start of Android game programming" 13. Game Development Basics (Paint brush)