Buffer API documentation

Version: beta

Functions for manipulating buffers and streams

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

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

Functions

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`	buffer the destination buffer
`dstoffset`	number the offset to start copying data to
`src`	buffer the source data buffer
`srcoffset`	number the offset to start copying data from
`count`	number 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.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`	bufferstream the destination stream
`dstoffset`	number the offset to start copying data to (measured in value type)
`src`	bufferstream the source data stream
`srcoffset`	number the offset to start copying data from (measured in value type)
`count`	number 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.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

number The number of elements the buffer should hold

declaration

table 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

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_bytes()

buffer.get_bytes(buffer,stream_name)

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

PARAMETERS

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

RETURNS

data

string the buffer data as a Lua string

buffer.get_stream()

buffer.get_stream(buffer,stream_name)

Get a specified stream from a buffer.

PARAMETERS

`buffer`	buffer the buffer to get the stream from
`stream_name`	hash \| string the stream name

RETURNS

stream

bufferstream the data stream

Buffer API documentation

Functions

Constants