| /* Copyright (c) 2015, Brandon Jones, Colin MacKenzie IV. |
| |
| Permission is hereby granted, free of charge, to any person obtaining a copy |
| of this software and associated documentation files (the "Software"), to deal |
| in the Software without restriction, including without limitation the rights |
| to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| copies of the Software, and to permit persons to whom the Software is |
| furnished to do so, subject to the following conditions: |
| |
| The above copyright notice and this permission notice shall be included in |
| all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| THE SOFTWARE. */ |
| |
| var glMatrix = require("./common.js"); |
| |
| /** |
| * @class 2 Dimensional Vector |
| * @name vec2 |
| */ |
| var vec2 = {}; |
| |
| /** |
| * Creates a new, empty vec2 |
| * |
| * @returns {vec2} a new 2D vector |
| */ |
| vec2.create = function() { |
| var out = new glMatrix.ARRAY_TYPE(2); |
| out[0] = 0; |
| out[1] = 0; |
| return out; |
| }; |
| |
| /** |
| * Creates a new vec2 initialized with values from an existing vector |
| * |
| * @param {vec2} a vector to clone |
| * @returns {vec2} a new 2D vector |
| */ |
| vec2.clone = function(a) { |
| var out = new glMatrix.ARRAY_TYPE(2); |
| out[0] = a[0]; |
| out[1] = a[1]; |
| return out; |
| }; |
| |
| /** |
| * Creates a new vec2 initialized with the given values |
| * |
| * @param {Number} x X component |
| * @param {Number} y Y component |
| * @returns {vec2} a new 2D vector |
| */ |
| vec2.fromValues = function(x, y) { |
| var out = new glMatrix.ARRAY_TYPE(2); |
| out[0] = x; |
| out[1] = y; |
| return out; |
| }; |
| |
| /** |
| * Copy the values from one vec2 to another |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the source vector |
| * @returns {vec2} out |
| */ |
| vec2.copy = function(out, a) { |
| out[0] = a[0]; |
| out[1] = a[1]; |
| return out; |
| }; |
| |
| /** |
| * Set the components of a vec2 to the given values |
| * |
| * @param {vec2} out the receiving vector |
| * @param {Number} x X component |
| * @param {Number} y Y component |
| * @returns {vec2} out |
| */ |
| vec2.set = function(out, x, y) { |
| out[0] = x; |
| out[1] = y; |
| return out; |
| }; |
| |
| /** |
| * Adds two vec2's |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {vec2} out |
| */ |
| vec2.add = function(out, a, b) { |
| out[0] = a[0] + b[0]; |
| out[1] = a[1] + b[1]; |
| return out; |
| }; |
| |
| /** |
| * Subtracts vector b from vector a |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {vec2} out |
| */ |
| vec2.subtract = function(out, a, b) { |
| out[0] = a[0] - b[0]; |
| out[1] = a[1] - b[1]; |
| return out; |
| }; |
| |
| /** |
| * Alias for {@link vec2.subtract} |
| * @function |
| */ |
| vec2.sub = vec2.subtract; |
| |
| /** |
| * Multiplies two vec2's |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {vec2} out |
| */ |
| vec2.multiply = function(out, a, b) { |
| out[0] = a[0] * b[0]; |
| out[1] = a[1] * b[1]; |
| return out; |
| }; |
| |
| /** |
| * Alias for {@link vec2.multiply} |
| * @function |
| */ |
| vec2.mul = vec2.multiply; |
| |
| /** |
| * Divides two vec2's |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {vec2} out |
| */ |
| vec2.divide = function(out, a, b) { |
| out[0] = a[0] / b[0]; |
| out[1] = a[1] / b[1]; |
| return out; |
| }; |
| |
| /** |
| * Alias for {@link vec2.divide} |
| * @function |
| */ |
| vec2.div = vec2.divide; |
| |
| /** |
| * Returns the minimum of two vec2's |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {vec2} out |
| */ |
| vec2.min = function(out, a, b) { |
| out[0] = Math.min(a[0], b[0]); |
| out[1] = Math.min(a[1], b[1]); |
| return out; |
| }; |
| |
| /** |
| * Returns the maximum of two vec2's |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {vec2} out |
| */ |
| vec2.max = function(out, a, b) { |
| out[0] = Math.max(a[0], b[0]); |
| out[1] = Math.max(a[1], b[1]); |
| return out; |
| }; |
| |
| /** |
| * Scales a vec2 by a scalar number |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the vector to scale |
| * @param {Number} b amount to scale the vector by |
| * @returns {vec2} out |
| */ |
| vec2.scale = function(out, a, b) { |
| out[0] = a[0] * b; |
| out[1] = a[1] * b; |
| return out; |
| }; |
| |
| /** |
| * Adds two vec2's after scaling the second operand by a scalar value |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @param {Number} scale the amount to scale b by before adding |
| * @returns {vec2} out |
| */ |
| vec2.scaleAndAdd = function(out, a, b, scale) { |
| out[0] = a[0] + (b[0] * scale); |
| out[1] = a[1] + (b[1] * scale); |
| return out; |
| }; |
| |
| /** |
| * Calculates the euclidian distance between two vec2's |
| * |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {Number} distance between a and b |
| */ |
| vec2.distance = function(a, b) { |
| var x = b[0] - a[0], |
| y = b[1] - a[1]; |
| return Math.sqrt(x*x + y*y); |
| }; |
| |
| /** |
| * Alias for {@link vec2.distance} |
| * @function |
| */ |
| vec2.dist = vec2.distance; |
| |
| /** |
| * Calculates the squared euclidian distance between two vec2's |
| * |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {Number} squared distance between a and b |
| */ |
| vec2.squaredDistance = function(a, b) { |
| var x = b[0] - a[0], |
| y = b[1] - a[1]; |
| return x*x + y*y; |
| }; |
| |
| /** |
| * Alias for {@link vec2.squaredDistance} |
| * @function |
| */ |
| vec2.sqrDist = vec2.squaredDistance; |
| |
| /** |
| * Calculates the length of a vec2 |
| * |
| * @param {vec2} a vector to calculate length of |
| * @returns {Number} length of a |
| */ |
| vec2.length = function (a) { |
| var x = a[0], |
| y = a[1]; |
| return Math.sqrt(x*x + y*y); |
| }; |
| |
| /** |
| * Alias for {@link vec2.length} |
| * @function |
| */ |
| vec2.len = vec2.length; |
| |
| /** |
| * Calculates the squared length of a vec2 |
| * |
| * @param {vec2} a vector to calculate squared length of |
| * @returns {Number} squared length of a |
| */ |
| vec2.squaredLength = function (a) { |
| var x = a[0], |
| y = a[1]; |
| return x*x + y*y; |
| }; |
| |
| /** |
| * Alias for {@link vec2.squaredLength} |
| * @function |
| */ |
| vec2.sqrLen = vec2.squaredLength; |
| |
| /** |
| * Negates the components of a vec2 |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a vector to negate |
| * @returns {vec2} out |
| */ |
| vec2.negate = function(out, a) { |
| out[0] = -a[0]; |
| out[1] = -a[1]; |
| return out; |
| }; |
| |
| /** |
| * Returns the inverse of the components of a vec2 |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a vector to invert |
| * @returns {vec2} out |
| */ |
| vec2.inverse = function(out, a) { |
| out[0] = 1.0 / a[0]; |
| out[1] = 1.0 / a[1]; |
| return out; |
| }; |
| |
| /** |
| * Normalize a vec2 |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a vector to normalize |
| * @returns {vec2} out |
| */ |
| vec2.normalize = function(out, a) { |
| var x = a[0], |
| y = a[1]; |
| var len = x*x + y*y; |
| if (len > 0) { |
| //TODO: evaluate use of glm_invsqrt here? |
| len = 1 / Math.sqrt(len); |
| out[0] = a[0] * len; |
| out[1] = a[1] * len; |
| } |
| return out; |
| }; |
| |
| /** |
| * Calculates the dot product of two vec2's |
| * |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {Number} dot product of a and b |
| */ |
| vec2.dot = function (a, b) { |
| return a[0] * b[0] + a[1] * b[1]; |
| }; |
| |
| /** |
| * Computes the cross product of two vec2's |
| * Note that the cross product must by definition produce a 3D vector |
| * |
| * @param {vec3} out the receiving vector |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @returns {vec3} out |
| */ |
| vec2.cross = function(out, a, b) { |
| var z = a[0] * b[1] - a[1] * b[0]; |
| out[0] = out[1] = 0; |
| out[2] = z; |
| return out; |
| }; |
| |
| /** |
| * Performs a linear interpolation between two vec2's |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the first operand |
| * @param {vec2} b the second operand |
| * @param {Number} t interpolation amount between the two inputs |
| * @returns {vec2} out |
| */ |
| vec2.lerp = function (out, a, b, t) { |
| var ax = a[0], |
| ay = a[1]; |
| out[0] = ax + t * (b[0] - ax); |
| out[1] = ay + t * (b[1] - ay); |
| return out; |
| }; |
| |
| /** |
| * Generates a random vector with the given scale |
| * |
| * @param {vec2} out the receiving vector |
| * @param {Number} [scale] Length of the resulting vector. If ommitted, a unit vector will be returned |
| * @returns {vec2} out |
| */ |
| vec2.random = function (out, scale) { |
| scale = scale || 1.0; |
| var r = glMatrix.RANDOM() * 2.0 * Math.PI; |
| out[0] = Math.cos(r) * scale; |
| out[1] = Math.sin(r) * scale; |
| return out; |
| }; |
| |
| /** |
| * Transforms the vec2 with a mat2 |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the vector to transform |
| * @param {mat2} m matrix to transform with |
| * @returns {vec2} out |
| */ |
| vec2.transformMat2 = function(out, a, m) { |
| var x = a[0], |
| y = a[1]; |
| out[0] = m[0] * x + m[2] * y; |
| out[1] = m[1] * x + m[3] * y; |
| return out; |
| }; |
| |
| /** |
| * Transforms the vec2 with a mat2d |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the vector to transform |
| * @param {mat2d} m matrix to transform with |
| * @returns {vec2} out |
| */ |
| vec2.transformMat2d = function(out, a, m) { |
| var x = a[0], |
| y = a[1]; |
| out[0] = m[0] * x + m[2] * y + m[4]; |
| out[1] = m[1] * x + m[3] * y + m[5]; |
| return out; |
| }; |
| |
| /** |
| * Transforms the vec2 with a mat3 |
| * 3rd vector component is implicitly '1' |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the vector to transform |
| * @param {mat3} m matrix to transform with |
| * @returns {vec2} out |
| */ |
| vec2.transformMat3 = function(out, a, m) { |
| var x = a[0], |
| y = a[1]; |
| out[0] = m[0] * x + m[3] * y + m[6]; |
| out[1] = m[1] * x + m[4] * y + m[7]; |
| return out; |
| }; |
| |
| /** |
| * Transforms the vec2 with a mat4 |
| * 3rd vector component is implicitly '0' |
| * 4th vector component is implicitly '1' |
| * |
| * @param {vec2} out the receiving vector |
| * @param {vec2} a the vector to transform |
| * @param {mat4} m matrix to transform with |
| * @returns {vec2} out |
| */ |
| vec2.transformMat4 = function(out, a, m) { |
| var x = a[0], |
| y = a[1]; |
| out[0] = m[0] * x + m[4] * y + m[12]; |
| out[1] = m[1] * x + m[5] * y + m[13]; |
| return out; |
| }; |
| |
| /** |
| * Perform some operation over an array of vec2s. |
| * |
| * @param {Array} a the array of vectors to iterate over |
| * @param {Number} stride Number of elements between the start of each vec2. If 0 assumes tightly packed |
| * @param {Number} offset Number of elements to skip at the beginning of the array |
| * @param {Number} count Number of vec2s to iterate over. If 0 iterates over entire array |
| * @param {Function} fn Function to call for each vector in the array |
| * @param {Object} [arg] additional argument to pass to fn |
| * @returns {Array} a |
| * @function |
| */ |
| vec2.forEach = (function() { |
| var vec = vec2.create(); |
| |
| return function(a, stride, offset, count, fn, arg) { |
| var i, l; |
| if(!stride) { |
| stride = 2; |
| } |
| |
| if(!offset) { |
| offset = 0; |
| } |
| |
| if(count) { |
| l = Math.min((count * stride) + offset, a.length); |
| } else { |
| l = a.length; |
| } |
| |
| for(i = offset; i < l; i += stride) { |
| vec[0] = a[i]; vec[1] = a[i+1]; |
| fn(vec, vec, arg); |
| a[i] = vec[0]; a[i+1] = vec[1]; |
| } |
| |
| return a; |
| }; |
| })(); |
| |
| /** |
| * Returns a string representation of a vector |
| * |
| * @param {vec2} vec vector to represent as a string |
| * @returns {String} string representation of the vector |
| */ |
| vec2.str = function (a) { |
| return 'vec2(' + a[0] + ', ' + a[1] + ')'; |
| }; |
| |
| module.exports = vec2; |