Android Learning note Advanced 15 shader rendering

The shader class provided by Android is primarily rendered images and some geometry.

Shader has several direct subclasses:

Bitmapshader: Mainly used to render images

LinearGradient: Used for linear rendering

Radialgradient: Used for ring rendering

Sweepgradient: Scan Gradient---Scan gradients around a central point like the radar scan in a movie, for gradient rendering.

Composeshader: Combined rendering, which can be combined with several other subclasses.

1 Bitmapshader

The renderer shades a bitmap as a texture. Bitmaps can be duplicated or set mode.

Public Bitmapshader(Bitmap bitmap,shader.tilemode tilex,shader.tilemode Tiley)

Call this method to produce a renderer (Shader) that draws a bitmap.

Bitmap bitmaps used within the renderer

Tilex the tiling mode for x to draw the bitmap in. X-Directional tile pattern on the bitmap

Tiley the tiling mode for Y-draw the bitmap in. Y-Direction tile pattern on the bitmap

Tilemode: (a total of three kinds)

CLAMP: If the renderer exceeds the original boundary range, the range edge staining is copied.

REPEAT: Landscape and portrait Repeat renderer picture, tiled.

MIRROR: Horizontal and vertical duplicate renderer picture, this is not the same as the repeat repetition, he is tiled in a mirrored manner.

2 lineargradient

[Java]View PlainCopy

1. Public lineargradient (float x0, float y0, float x1, float y1, int[] colors, float[] Positio NS, Shader.tilemode tile)

X0: Gradient Initial point coordinate x position

Y0: Gradient initial point coordinate y position

X1: Gradient End coordinate x position

Y1: Gradient end coordinate y position

Colors: array of gradient colors

Positions: This is also an array used to specify the relative position of the color array if NULL is evenly distributed along the slope line

Tile: Tiling mode

[Java]View PlainCopy

1. Public lineargradient (float x0, float y0, float x1, float y1, int color0, int Color1, Shader.ti Lemode tile)

X0: Gradient Initial point coordinate x position

Y0: Gradient initial point coordinate y position

X1: Gradient End coordinate x position

Y1: Gradient end coordinate y position

Color0: Gradient Start color

Color1: Gradient End Color

Tile: Tiling mode

LinearGradient is a linear gradient with the following usage:

Gradient is based on the shader class, so we use the Setshader method of paint to set this gradient, the code is as follows:

Paint p=new paint ();
LinearGradient lg=new Lineargradien (0,0,100,100,color.red,color.blue,shader.tilemode.mirror);

Gradient is based on the shader class, so we use the Setshader method of paint to set this gradient, the code is as follows:

P.setshader (LG);
Canvas.drawcicle (0,0,200,P); Parameter 3 is the radius of the circle, and the type is float type.

Android Learning note Advanced 15 shader rendering