The WebGLRenderingContext.getShaderPrecisionFormat() method of the WebGL API returns a new WebGLShaderPrecisionFormat object describing the range and precision for the specified shader numeric format.
Syntax
WebGLShaderPrecisionFormat gl.getShaderPrecisionFormat(shaderType, precisionType);
Parameters
shaderType- Either a
FRAGMENT_SHADERor aVERTEXT_SHADER. precisionType- A precision type value. Either
LOW_FLOAT,MEDIUM_FLOAT,HIGH_FLOAT,LOW_INT,MEDIUM_INT, orHIGH_INT.
Return value
A WebGLShaderPrecisionFormat object or null, if an error occurs.
Exceptions
gl.INVALID_ENUMif the shader or precision types aren't recognized.gl.INVALID_OPERATIONif the shader compiler isn't supported.
Examples
The following code gets the precision format of a VERTEX_SHADER with a MEDIUM_FLOAT precision type.
var canvas = document.getElementById("canvas");
var gl = canvas.getContext("webgl");
gl.getShaderPrecisionFormat(gl.VERTEX_SHADER, gl.MEDIUM_FLOAT);
// WebGLShaderPrecisionFormat { rangeMin: 127, rangeMax: 127, precision: 23 }
Specifications
| Specification | Status | Comment |
|---|---|---|
| WebGL 1.0 The definition of 'getShaderPrecisionFormat' in that specification. |
Recommendation | Initial definition. |
| OpenGL ES 2.0 The definition of 'glGetShaderPrecisionFormat' in that specification. |
Standard | Man page of the (similar) OpenGL API. |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | 9 | 11.0 (11.0) | 11 | 12 | 5.1 |
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | ? | 25 | (Yes) | ? | 12 | 8.1 |