Instance Method


Copies a block of pixels into a section of texture slice 0.



func replace(region: MTLRegion, mipmapLevel level: Int, withBytes pixelBytes: UnsafeRawPointer, bytesPerRow: Int)



The location of a block of pixels in the texture slice. The region must be within the dimensions of the slice.


A zero-based value that specifies which mipmap level is the destination. If the texture doesn't have mipmaps, use 0.


A pointer to the bytes in memory to copy.


For an ordinary or packed pixel format, the stride, in bytes, between rows of source data. For a compressed pixel format, the stride is the number of bytes from the beginning of one row of blocks to the beginning of the next.

Specify a nonzero value when you copy pixels to texture types other than MTLTextureType.type1D or MTLTextureType.type1DArray. Specify a value greater than or equal to the width of one row (the size of one pixel, in bytes, multiplied by the pixel width of one row) and less than or equal to 32767 multiplied by the size of one pixel. For an ordinary or packed pixel format, use a multiple of size of one pixel. For a compressed pixel format, use a multiple of the compressed block size. If you specify a nonzero value that is smaller than the width of the texture or is not a multiple of the size of the pixel format or compressed block size, an error occurs.

When you copy pixels to a MTLTextureType.type1D or MTLTextureType.type1DArray texture, use 0.


This method immediately copies the pixel data into the texture. It does not synchronize against any GPU accesses to this texture. For example, if a command buffer includes read or write operations on a given texture, you must ensure that these operations complete before calling the replace(region:mipmapLevel:withBytes:bytesPerRow:) method on the given texture. You can use the addCompletedHandler(_:) method, waitUntilCompleted() method, or custom semaphores to signal that a command buffer has completed execution.

If the texture image has a compressed pixel format, then only block-aligned regions can be written. If the size of a dimension of region is not a multiple of the block size, then bytesPerRow in system memory must include the full edge block, and the size of that dimension less than or equal to the texture dimensions.

This method is supported if you're copying to an entire texture with a PowerVR Texture Compression (PVRTC) pixel format; in which case, bytesPerRow and bytesPerImage must both be set to 0. This method isn't supported for copying to a subregion of a texture that has a PVRTC pixel format.

For all other pixel formats, compressed or uncompressed, set the bytesPerRow and bytesPerImage to 0 if they are not applicable.

Don't use this method for textures with a private storage mode. To copy data to a private texture, copy that data to a texture that has a non-private storage mode and then use a MTLBlitCommandEncoder to copy the data to the private texture.

See Also

Copying Data into a Texture Image