WEBGL_draw_buffers.drawBuffersWEBGL() - Web APIs 编辑

The WEBGL_draw_buffers.drawBuffersWEBGL() method is part of the WebGL API and allows you to define the draw buffers to which all fragment colors are written.

This method is part of the WEBGL_draw_buffers extension.

Note: When using WebGL2, this method is available as gl.drawBuffers() by default and the constants are named gl.COLOR_ATTACHMENT1 etc. without the "WEBGL" suffix.

Syntax

void gl.getExtension('WEBGL_draw_buffers').drawBuffersWEBGL(buffers);

Parameters

buffers

An Array of GLenum constants defining drawing buffers. Possible values:

• gl.NONE: The fragment shader is not written to any color buffer.
• gl.BACK: The fragment shader is written to the back color buffer.
• ext.COLOR_ATTACHMENT0_WEBGL The fragment shader is written the nth color attachment of the framebuffer.
• ext.COLOR_ATTACHMENT1_WEBGL
• ext.COLOR_ATTACHMENT2_WEBGL
• ext.COLOR_ATTACHMENT3_WEBGL
• ext.COLOR_ATTACHMENT4_WEBGL
• ext.COLOR_ATTACHMENT5_WEBGL
• ext.COLOR_ATTACHMENT6_WEBGL
• ext.COLOR_ATTACHMENT7_WEBGL
• ext.COLOR_ATTACHMENT8_WEBGL
• ext.COLOR_ATTACHMENT9_WEBGL
• ext.COLOR_ATTACHMENT10_WEBGL
• ext.COLOR_ATTACHMENT11_WEBGL
• ext.COLOR_ATTACHMENT12_WEBGL
• ext.COLOR_ATTACHMENT13_WEBGL
• ext.COLOR_ATTACHMENT14_WEBGL
• ext.COLOR_ATTACHMENT15_WEBGL

Return value

None.

Examples

See WEBGL_draw_buffers for more context with this example code.

ext.drawBuffersWEBGL([
  ext.COLOR_ATTACHMENT0_WEBGL, // gl_FragData[0]
  ext.COLOR_ATTACHMENT1_WEBGL, // gl_FragData[1]
  ext.COLOR_ATTACHMENT2_WEBGL, // gl_FragData[2]
  ext.COLOR_ATTACHMENT3_WEBGL  // gl_FragData[3]
]);

Specifications

Browser compatibility

BCD tables only load in the browser

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

See also

• WEBGL_draw_buffers
• WebGLRenderingContext.getExtension()
• WebGLRenderingContext.framebufferRenderbuffer(),
• WebGLRenderingContext.framebufferTexture2D(),
• WebGLRenderingContext.getFramebufferAttachmentParameter() 
• WebGLRenderingContext.getParameter()
• WebGL deferred shading - Mozilla Hacks blog