WebGL2RenderingContext: copyBufferSubData() method
The WebGL2RenderingContext.copyBufferSubData()
method of
the WebGL 2 API copies part of the data of a
buffer to another buffer.
Syntax
js
copyBufferSubData(readTarget, writeTarget, readOffset, writeOffset, size)
Parameters
readTarget writeTarget
-
A
GLenum
specifying the binding point (target) from whose data store should be read or written. Possible values:-
gl.ARRAY_BUFFER
: Buffer containing vertex attributes, such as vertex coordinates, texture coordinate data, or vertex color data. gl.ELEMENT_ARRAY_BUFFER
: Buffer used for element indices.-
gl.COPY_READ_BUFFER
: Buffer for copying from one buffer object to another (provided specifically for copy operations). -
gl.COPY_WRITE_BUFFER
: Buffer for copying from one buffer object to another (provided specifically for copy operations). -
gl.TRANSFORM_FEEDBACK_BUFFER
: Buffer for transform feedback operations. gl.UNIFORM_BUFFER
: Buffer used for storing uniform blocks.gl.PIXEL_PACK_BUFFER
: Buffer used for pixel transfer operations.gl.PIXEL_UNPACK_BUFFER
: Buffer used for pixel transfer operations.
-
readOffset writeOffset
-
A
GLintptr
specifying the byte offset from which to start reading from or writing to the buffer. size
-
A
GLsizei
in bytes specifying the size of the data to be copied fromreadTarget
towriteTarget
.
Return value
None (undefined
).
Examples
js
const srcBuffer = gl.createBuffer();
const dstBuffer = gl.createBuffer();
const data = new Float32Array(vertices);
const length = vertices.length * 4;
gl.bindBuffer(gl.ARRAY_BUFFER, srcBuffer);
gl.bufferData(gl.ARRAY_BUFFER, data, gl.STATIC_DRAW);
gl.bindBuffer(gl.COPY_READ_BUFFER, srcBuffer);
gl.bindBuffer(gl.ARRAY_BUFFER, dstBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(length), gl.STATIC_DRAW);
gl.copyBufferSubData(gl.COPY_READ_BUFFER, gl.ARRAY_BUFFER, 0, 0, length);
Specifications
Specification |
---|
WebGL 2.0 Specification # 3.7.3 |
Browser compatibility
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