WebGLRenderingContext.polygonOffset()

The WebGLRenderingContext.polygonOffset() method of the WebGL API specifies the scale factors and units to calculate depth values.

The offset is added before the depth test is performed and before the value is written into the depth buffer.

语法

void gl.polygonOffset(factor, units);

参数

factor
A GLfloat (en-US) which sets the scale factor for the variable depth offset for each polygon. 默认值为 0.
units
GLfloat (en-US) which sets the multiplier by which an implementation-specific value is multiplied with to create a constant depth offset. 默认值为 0.

返回值

None.

例子

The polygon offset fill is disabled by default. To enable or disable polygon offset fill, use the enable() and disable() methods with the argument gl.POLYGON_OFFSET_FILL.

gl.enable(gl.POLYGON_OFFSET_FILL);
gl.polygonOffset(2, 3);

想要查看当前多边形偏移的 factor 或 units, 查询 POLYGON_OFFSET_FACTOR 和POLYGON_OFFSET_UNITS 的内容即可.

gl.getParameter(gl.POLYGON_OFFSET_FACTOR); // 2
gl.getParameter(gl.POLYGON_OFFSET_UNITS);  // 3

说明

Specification Status Comment
WebGL 1.0
polygonOffset
Recommendation Initial definition.
OpenGL ES 2.0
glPolygonOffset
Standard Man page of the OpenGL API.

Browser compatibility

BCD tables only load in the browser

See also