extent_buffer_cache.js

/**
 * Lazy-create Int16Array objects for any buffer size
 * @param {number} extent buffer extent: by default 4096.
 * @returns {Int16Array} extent buffer
 */
module.exports.getDebugBuffer = function getDebugBuffer(gl, extent) {
    if (!debugBuffers[extent]) {
        var debugBuffer = gl.createBuffer();
        debugBuffer.itemSize = 2;
        debugBuffer.itemCount = 5;
        gl.bindBuffer(gl.ARRAY_BUFFER, this.debugBuffer);
        gl.bufferData(gl.ARRAY_BUFFER, new Int16Array([
            0, 0, extent - 1, 0, extent - 1, extent - 1, 0, extent - 1, 0, 0]));
        debugBuffers[extent] = debugBuffer;
    }
    return debugBuffers[extent];
};