WebGLRenderingContext.activeTexture

The WebGLRenderingContext.activeTexture() method of the WebGL API specifies which texture unit to make active.

Syntax

void gl.activeTexture(texture);

Parameters

texture

The texture unit to make active. The value is a gl.TEXTUREI where I is within the range from 0 to gl.MAX_COMBINED_TEXTURE_IMAGE_UNITS - 1.

Return value

None.

Exceptions

If texture is not one of gl.TEXTUREI, where I is within the range from 0 to gl.MAX_COMBINED_TEXTURE_IMAGE_UNITS - 1, a gl.INVALID_ENUM error is thrown.

Examples

The following call selects gl.TEXTURE1 as the current texture. Subsequent calls that modify the texture state will affect this texture.

gl.activeTexture(gl.TEXTURE1);

The number of texture units is implementation dependent, you can get this number with the help of the MAX_COMBINED_TEXTURE_IMAGE_UNITS constant. It is, per specification, at least 8.

gl.getParameter(gl.MAX_COMBINED_TEXTURE_IMAGE_UNITS);

To get the active texture, query the ACTIVE_TEXTURE constant.

gl.activeTexture(gl.TEXTURE0);
gl.getParameter(gl.ACTIVE_TEXTURE);
// returns "33984" (0x84C0, gl.TEXTURE0 enum value)

Specifications

Browser compatibility

See also

• WebGLRenderingContext.getParameter()