Android Shader color and Image Rendering

Android Shader color and Image Rendering

 

Shader

Shader is a base class that indicates the horizontal span of colors during painting.

Its subclass is embedded in the Paint and called the paint. setShader (shader ).

For objects other than Bitmap, the color is obtained from the shader when the Paint is used for painting.

 

Shader. TileMode rendering Mode

 

public enum TileMode {     CLAMP   (0),    REPEAT  (1),    MIRROR  (2);    TileMode(int nativeInt) {        this.nativeInt = nativeInt;    }    final int nativeInt;}

CLAMP: if it exceeds the bounds (bounds ),

 

 

REPEAT: REPEAT bitmap

MIRROR: REPEAT bitmap. If it is different from REPEAT, it is an image REPEAT, that is, a reverse REPEAT.

 

Shader subclass:

BitmapShader (android. graphics) Image Rendering
ComposeShader (android. graphics) combined Rendering
LinearGradient (android. graphics) linear Rendering
RadialGradient (android. graphics) ring Rendering
SweepGradient (android. graphics) scan Rendering

 

BitmapShader

New BitmapShader (bitmap, Shader. TileMode. REPEAT, Shader. TileMode. MIRROR); rendering images in a certain rendering Mode

 

ComposeShader

New ComposeShader (shaderA, shaderB, PorterDuff. Mode. DST); combines the two rendering effects and combines them with PorterDuff. Mode.

 

LinearGradient

New LinearGradient (0, 0, bitmap. getWidth (), bitmap. getHeight (), 0x470000ff, 0xefffff00, Shader. TileMode. CLAMP );

Linear changes between two colors in a certain rendering mode within a certain area

New LinearGradient (0, 0, bitmap. getWidth (), bitmap. getHeight (), new int [] {0xffabc777, 0x2300ff00, 0x470000ff, 0xefffff00}, new float [] {0.1f, 0.3f, 0.5f, 1.0f}, Shader. tileMode. CLAMP );

In a certain area, linear changes are made between a set of colors in a certain rendering mode. The position of the changes is determined by the float array. The length of the int array and float array must be the same.

 

RadialGradient

Perform ring rendering with vertices (x, y) and radius r.

New RadialGradient (w/2, h/2, Math. min (w, h)/2, 0xddff00f0, 0xffabc777, Shader. TileMode. REPEAT );

New RadialGradient (w/2, h/2, Math. min (w, h)/2, new int [] {0xddff0000, 0x2300ff00, 0x470000ff, 0xffabc777}, new float [] {0.1f, 0.3f, 0.5f, 1.0f}, Shader. tileMode. CLAMP );

 

SweepGradient

Scan and rendering with points (x, y)

New SweepGradient (w/2, h/2, 0xddff00f0, 0xffabc777 );

New SweepGradient (w, h, new int [] {0xffff0000, 0xff00ff00, 0xff0000ff, 0xffabc777, signature}, new float [] {0.2f, 0.4f, 0.6f, 0.75f, 1f });

 

PorterDuff. Mode

 

Canvas. drawBitmap (mDstB, 0, 0, paint); // draw the target paint. setXfermode (SModes[I]); // use modecanvas. drawBitmap (mSrcB, 0, 0, paint); // draw the source paint. setXfermode (null); // clear the mode