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