WebGLRenderingContext.vertexAttrib[1234]f[v]()

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WebGLRenderingContext.vertexAttrib[1234]f[v]() methods of the WebGL API specify constant values for generic vertex attributes.

句法

void gl.vertexAttrib1f(index, v0);
void gl.vertexAttrib2f(index, v0, v1);
void gl.vertexAttrib3f(index, v0, v1, v2);
void gl.vertexAttrib4f(index, v0, v1, v2, v3);
void gl.vertexAttrib1fv(index, value);
void gl.vertexAttrib2fv(index, value);
void gl.vertexAttrib3fv(index, value);
void gl.vertexAttrib4fv(index, value);

参数

index: GLuint specifying the position of the vertex attribute to be modified.
v0, v1, v2, v3: A floating point Number for the vertex attribute value.
value

返回值

None.

描述

While vertex attributes are usually used to specify values which are different for each vertex (using vertexAttribPointer ), it can be useful to specify a constant value. For example, if you have a shader which has a color vertex attribute, but you want to draw everything in a single color, you can use vertexAttrib to achieve that without creating a buffer filled with only one value or having to create a separate shader which uses a uniform for the color.

This value will be used if a bound array buffer has not been enabled with enableVertexAttribArray .

Attributes may be matrices, in which case columns of the matrix must be loaded into successive vertex attribute slots.

The values set with vertexAttribPointer are context-global, i.e. they aren't part of the shader state (like generix vertex attribute indexes to shader variable bindings) and aren't part of the vertex array object state (like enabled vertex attribute arrays). The only way to change the values is by calling this function again.

范例

const a_foobar = gl.getAttribLocation(shaderProgram, 'foobar');
//either set each component individually:
gl.vertexAttrib3f(a_foobar, 10.0, 5.0, 2.0);
//or provide a Float32Array:
const floatArray = new Float32Array([10.0, 5.0, 2.0]);
gl.vertexAttrib3fv(a_foobar, floatArray);

// we want to load the following 3x3 matrix into attribute named "matrix3x3"
// 0 1 2
// 3 4 5
// 6 7 8
const matrix3x3Location = gl.getAttribLocation(shaderProgram, 'matrix3x3');
gl.vertexAttrib3f(matrix3x3Location,     0, 3, 6);
gl.vertexAttrib3f(matrix3x3Location + 1, 1, 4, 7);
gl.vertexAttrib3f(matrix3x3Location + 2, 2, 5, 8);

规范

规范	状态	注释
WebGL 1.0 The definition of 'vertexAttrib' in that specification.	推荐	初始定义。
OpenGL ES 2.0 The definition of 'glVertexAttrib' in that specification.	标准	Man page of the OpenGL API.

浏览器兼容性

更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`vertexAttrib1f`	Chrome 9	Edge 12	Firefox 4	IE 11	Opera 12	Safari 5.1	WebView Android Yes	Chrome Android 25	Firefox Android Yes	Opera Android 12	Safari iOS 8	Samsung Internet Android 1.5

图例

完整支持

另请参阅

WebGLRenderingContext.getVertexAttrib()

元数据

最后修改： 2019 年 3 月 23 日

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句法

参数

返回值

描述

范例

规范

浏览器兼容性

图例

另请参阅

相关话题