Buffer API documentation

Version: beta

FUNCTION
buffer.create()	creates a new buffer
buffer.get_stream()	gets a stream from a buffer
buffer.copy_stream()	copies data from one stream to another
buffer.copy_buffer()	copies one buffer to another
buffer.get_bytes()	gets data from a stream

CONSTANT
buffer.VALUE_TYPE_UINT8	uint8
buffer.VALUE_TYPE_UINT16	uint16
buffer.VALUE_TYPE_UINT32	uint32
buffer.VALUE_TYPE_UINT64	uint64
buffer.VALUE_TYPE_INT8	int8
buffer.VALUE_TYPE_INT16	int16
buffer.VALUE_TYPE_INT32	int32
buffer.VALUE_TYPE_INT64	int64
buffer.VALUE_TYPE_FLOAT32	float32

Functions

buffer.create()

buffer.create(element_count,declaration)

Create a new data buffer containing a specified set of streams. A data buffer can contain one or more streams with typed data. This is useful for managing compound data, for instance a vertex buffer could contain separate streams for vertex position, color, normal etc.

PARAMETERS

`element_count`	The number of elements the buffer should hold
`declaration`	A table where each entry (table) describes a stream hash \| string `name`: The name of the stream constant `type`: The data type of the stream number `count`: The number of values each element should hold

RETURNS

buffer the new buffer

EXAMPLES

How to create and initialize a buffer

function init(self)
  local size = 128
  self.image = buffer.create( size * size, { {name=hash("rgb"), type=buffer.VALUE_TYPE_UINT8, count=3 } })
  self.imagestream = buffer.get_stream(self.image, hash("rgb"))

  for y=0,self.height-1 do
     for x=0,self.width-1 do
         local index = y * self.width * 3 + x * 3 + 1
         self.imagestream[index + 0] = self.r
         self.imagestream[index + 1] = self.g
         self.imagestream[index + 2] = self.b
     end
  end

buffer.get_stream()

buffer.get_stream(buffer,stream_name)

Get a specified stream from a buffer.

PARAMETERS

`buffer`	the buffer to get the stream from
`stream_name`	the stream name

RETURNS

stream the data stream

buffer.copy_stream()

buffer.copy_stream(dst,dstoffset,src,srcoffset,count)

Copy a specified amount of data from one stream to another. The value type and size must match between source and destination streams. The source and destination streams can be the same.

PARAMETERS

`dst`	the destination stream
`dstoffset`	the offset to start copying data to (measured in value type)
`src`	the source data stream
`srcoffset`	the offset to start copying data from (measured in value type)
`count`	the number of values to copy (measured in value type)

EXAMPLES

How to update a texture of a sprite:

-- copy entire stream
local srcstream = buffer.get_stream(srcbuffer, hash("xyz"))
local dststream = buffer.get_stream(dstbuffer, hash("xyz"))
buffer.copy_stream(dststream, 0, srcstream, 0, #srcstream)

buffer.copy_buffer()

buffer.copy_buffer(dst,dstoffset,src,srcoffset,count)

Copy all data streams from one buffer to another, element wise. Each of the source streams must have a matching stream in the destination buffer. The streams must match in both type and size. The source and destination buffer can be the same.

PARAMETERS

`dst`	the destination buffer
`dstoffset`	the offset to start copying data to
`src`	the source data buffer
`srcoffset`	the offset to start copying data from
`count`	the number of elements to copy

EXAMPLES

How to copy elements (e.g. vertices) from one buffer to another

-- copy entire buffer
buffer.copy_buffer(dstbuffer, 0, srcbuffer, 0, #srcbuffer)

-- copy last 10 elements to the front of another buffer
buffer.copy_buffer(dstbuffer, 0, srcbuffer, #srcbuffer - 10, 10)

buffer.get_bytes()

buffer.get_bytes(buffer,stream_name)

Get a copy of all the bytes from a specified stream as a Lua string.

PARAMETERS

`buffer`	the source buffer
`stream_name`	the name of the stream

RETURNS

data the buffer data as a Lua string

Buffer API documentation

Functions

Constants