securityos/node_modules/regl/lib/util/pool.js

102 lines
2.0 KiB
JavaScript

var loop = require('./loop')
var GL_BYTE = 5120
var GL_UNSIGNED_BYTE = 5121
var GL_SHORT = 5122
var GL_UNSIGNED_SHORT = 5123
var GL_INT = 5124
var GL_UNSIGNED_INT = 5125
var GL_FLOAT = 5126
function nextPow16 (v) {
for (var i = 16; i <= (1 << 28); i *= 16) {
if (v <= i) {
return i
}
}
return 0
}
function log2 (v) {
var r, shift
r = (v > 0xFFFF) << 4
v >>>= r
shift = (v > 0xFF) << 3
v >>>= shift; r |= shift
shift = (v > 0xF) << 2
v >>>= shift; r |= shift
shift = (v > 0x3) << 1
v >>>= shift; r |= shift
return r | (v >> 1)
}
function createPool () {
var bufferPool = loop(8, function () {
return []
})
function alloc (n) {
var sz = nextPow16(n)
var bin = bufferPool[log2(sz) >> 2]
if (bin.length > 0) {
return bin.pop()
}
return new ArrayBuffer(sz)
}
function free (buf) {
bufferPool[log2(buf.byteLength) >> 2].push(buf)
}
function allocType (type, n) {
var result = null
switch (type) {
case GL_BYTE:
result = new Int8Array(alloc(n), 0, n)
break
case GL_UNSIGNED_BYTE:
result = new Uint8Array(alloc(n), 0, n)
break
case GL_SHORT:
result = new Int16Array(alloc(2 * n), 0, n)
break
case GL_UNSIGNED_SHORT:
result = new Uint16Array(alloc(2 * n), 0, n)
break
case GL_INT:
result = new Int32Array(alloc(4 * n), 0, n)
break
case GL_UNSIGNED_INT:
result = new Uint32Array(alloc(4 * n), 0, n)
break
case GL_FLOAT:
result = new Float32Array(alloc(4 * n), 0, n)
break
default:
return null
}
if (result.length !== n) {
return result.subarray(0, n)
}
return result
}
function freeType (array) {
free(array.buffer)
}
return {
alloc: alloc,
free: free,
allocType: allocType,
freeType: freeType
}
}
var pool = createPool()
// zero pool for initial zero data
pool.zero = createPool()
module.exports = pool