2015-08-10 17:59:18 -07:00

540 lines
14 KiB
Lua

-- double 4x4, 1-based, column major
-- local matrix = {}
local current_folder = (...):gsub('%.[^%.]+$', '') .. "."
local constants = require(current_folder .. "constants")
local vec2 = require(current_folder .. "vec2")
local vec3 = require(current_folder .. "vec3")
local quat = require(current_folder .. "quat")
local mat4 = {}
mat4.__index = mat4
setmetatable(mat4, mat4)
-- from https://github.com/davidm/lua-matrix/blob/master/lua/matrix.lua
-- Multiply two matrices; m1 columns must be equal to m2 rows
-- e.g. #m1[1] == #m2
local function matrix_mult_nxn(m1, m2)
local mtx = {}
for i = 1, #m1 do
mtx[i] = {}
for j = 1, #m2[1] do
local num = m1[i][1] * m2[1][j]
for n = 2, #m1[1] do
num = num + m1[i][n] * m2[n][j]
end
mtx[i][j] = num
end
end
return mtx
end
function mat4.from_direction(direction, up)
local forward = direction:normalize()
local side = forward:cross(up):normalize()
local new_up = side:cross(forward):normalize()
local view = mat4()
view[1] = side.x
view[5] = side.y
view[9] = side.z
view[2] = new_up.x
view[6] = new_up.y
view[10] = new_up.z
view[3] = forward.x
view[7] = forward.y
view[11] = forward.z
view[16] = 1
return view
end
function mat4:to_quat()
local m = self:transpose():to_vec4s()
local w = math.sqrt(1 + m[1][1] + m[2][2] + m[3][3]) / 2
local scale = w * 4
-- return quat(
-- m[2][3] - m[3][2] / scale,
-- m[3][1] - m[1][3] / scale,
-- m[1][2] - m[2][1] / scale,
-- w
-- ):normalize()
return quat(
m[3][2] - m[2][3] / scale,
m[1][3] - m[3][1] / scale,
m[2][1] - m[1][2] / scale,
w
):normalize()
end
function mat4:__call(v)
local m = {
1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1
}
if type(v) == "table" and #v == 16 then
for i=1,16 do
m[i] = tonumber(v[i])
end
elseif type(v) == "table" and #v == 9 then
m[1], m[2], m[3] = v[1], v[2], v[3]
m[5], m[6], m[7] = v[4], v[5], v[6]
m[9], m[10], m[11] = v[7], v[8], v[9]
m[16] = 1
elseif type(v) == "table" and type(v[1]) == "table" then
local idx = 1
for i=1, 4 do
for j=1, 4 do
m[idx] = v[i][j]
idx = idx + 1
end
end
end
-- Look in mat4 for metamethods
setmetatable(m, mat4)
return m
end
function mat4:__eq(b)
local abs = math.abs
for i=1, 16 do
if abs(self[i] - b[i]) > constants.FLT_EPSILON then
return false
end
end
return true
end
function mat4:__tostring()
local str = "[ "
for i, v in ipairs(self) do
str = str .. string.format("%2.5f", v)
if i < #self then
str = str .. ", "
end
end
str = str .. " ]"
return str
end
function mat4:ortho(left, right, top, bottom, near, far)
local out = mat4()
out[1] = 2 / (right - left)
out[6] = 2 / (top - bottom)
out[11] = -2 / (far - near)
out[13] = -((right + left) / (right - left))
out[14] = -((top + bottom) / (top - bottom))
out[15] = -((far + near) / (far - near))
out[16] = 1
return out
end
-- Adapted from the Oculus SDK.
function mat4:hmd_perspective(tanHalfFov, zNear, zFar, flipZ, farAtInfinity)
-- CPML is right-handed and intended for GL, so these don't need to be arguments.
local rightHanded = true
local isOpenGL = true
local function CreateNDCScaleAndOffsetFromFov(tanHalfFov)
x_scale = 2 / (tanHalfFov.LeftTan + tanHalfFov.RightTan)
x_offset = (tanHalfFov.LeftTan - tanHalfFov.RightTan) * x_scale * 0.5
y_scale = 2 / (tanHalfFov.UpTan + tanHalfFov.DownTan )
y_offset = (tanHalfFov.UpTan - tanHalfFov.DownTan ) * y_scale * 0.5
local result = {
Scale = vec2(x_scale, y_scale),
Offset = vec2(x_offset, y_offset)
}
-- Hey - why is that Y.Offset negated?
-- It's because a projection matrix transforms from world coords with Y=up,
-- whereas this is from NDC which is Y=down.
return result
end
if not flipZ and farAtInfinity then
print("Error: Cannot push Far Clip to Infinity when Z-order is not flipped")
farAtInfinity = false
end
-- A projection matrix is very like a scaling from NDC, so we can start with that.
local scaleAndOffset = CreateNDCScaleAndOffsetFromFov(tanHalfFov)
local handednessScale = rightHanded and -1.0 or 1.0
local projection = mat4()
-- Produces X result, mapping clip edges to [-w,+w]
projection[1] = scaleAndOffset.Scale.x
projection[2] = 0
projection[3] = handednessScale * scaleAndOffset.Offset.x
projection[4] = 0
-- Produces Y result, mapping clip edges to [-w,+w]
-- Hey - why is that YOffset negated?
-- It's because a projection matrix transforms from world coords with Y=up,
-- whereas this is derived from an NDC scaling, which is Y=down.
projection[5] = 0
projection[6] = scaleAndOffset.Scale.y
projection[7] = handednessScale * -scaleAndOffset.Offset.y
projection[8] = 0
-- Produces Z-buffer result - app needs to fill this in with whatever Z range it wants.
-- We'll just use some defaults for now.
projection[9] = 0
projection[10] = 0
if farAtInfinity then
if isOpenGL then
-- It's not clear this makes sense for OpenGL - you don't get the same precision benefits you do in D3D.
projection[11] = -handednessScale
projection[12] = 2.0 * zNear
else
projection[11] = 0
projection[12] = zNear
end
else
if isOpenGL then
-- Clip range is [-w,+w], so 0 is at the middle of the range.
projection[11] = -handednessScale * (flipZ and -1.0 or 1.0) * (zNear + zFar) / (zNear - zFar)
projection[12] = 2.0 * ((flipZ and -zFar or zFar) * zNear) / (zNear - zFar)
else
-- Clip range is [0,+w], so 0 is at the start of the range.
projection[11] = -handednessScale * (flipZ and -zNear or zFar) / (zNear - zFar)
projection[12] = ((flipZ and -zFar or zFar) * zNear) / (zNear - zFar)
end
end
-- Produces W result (= Z in)
projection[13] = 0
projection[14] = 0
projection[15] = handednessScale
projection[16] = 0
return projection:transpose()
end
function mat4:perspective(fovy, aspect, near, far)
assert(aspect ~= 0)
assert(near ~= far)
local t = math.tan(math.rad(fovy) / 2)
local result = {
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0,
0, 0, 0, 0
}
result[1] = 1 / (t * aspect)
result[6] = 1 / t
result[11] = -(far + near) / (far - near)
result[12] = -1
result[15] = -(2 * far * near) / (far - near)
result[16] = 1
return mat4(result)
end
function mat4:translate(t)
local m = {
1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
t.x, t.y, t.z, 1
}
return mat4(m) * mat4(self)
end
function mat4:scale(s)
local m = {
s.x, 0, 0, 0,
0, s.y, 0, 0,
0, 0, s.z, 0,
0, 0, 0, 1
}
return mat4(m) * mat4(self)
end
local function len(v)
return math.sqrt(v[1] * v[1] + v[2] * v[2] + v[3] * v[3])
end
function mat4:rotate(angle, axis)
if type(angle) == "table" then
angle, axis = angle:to_axis_angle()
end
local l = len(axis)
if l == 0 then
return self
end
local x, y, z = axis[1] / l, axis[2] / l, axis[3] / l
local c = math.cos(angle)
local s = math.sin(angle)
local m = {
x*x*(1-c)+c, y*x*(1-c)+z*s, x*z*(1-c)-y*s, 0,
x*y*(1-c)-z*s, y*y*(1-c)+c, y*z*(1-c)+x*s, 0,
x*z*(1-c)+y*s, y*z*(1-c)-x*s, z*z*(1-c)+c, 0,
0, 0, 0, 1,
}
return mat4(m) * mat4(self)
end
-- Set mat4 to identity mat4. Tested OK
function mat4:identity()
local out = mat4()
for i=1, 16, 5 do
out[i] = 1
end
return out
end
function mat4:clone()
return mat4(self)
end
-- Inverse of matrix. Tested OK
function mat4:invert()
local out = mat4()
out[1] = self[6] * self[11] * self[16] -
self[6] * self[12] * self[15] -
self[10] * self[7] * self[16] +
self[10] * self[8] * self[15] +
self[14] * self[7] * self[12] -
self[14] * self[8] * self[11]
out[5] = -self[5] * self[11] * self[16] +
self[5] * self[12] * self[15] +
self[9] * self[7] * self[16] -
self[9] * self[8] * self[15] -
self[13] * self[7] * self[12] +
self[13] * self[8] * self[11]
out[9] = self[5] * self[10] * self[16] -
self[5] * self[12] * self[14] -
self[9] * self[6] * self[16] +
self[9] * self[8] * self[14] +
self[13] * self[6] * self[12] -
self[13] * self[8] * self[10]
out[13] = -self[5] * self[10] * self[15] +
self[5] * self[11] * self[14] +
self[9] * self[6] * self[15] -
self[9] * self[7] * self[14] -
self[13] * self[6] * self[11] +
self[13] * self[7] * self[10]
out[2] = -self[2] * self[11] * self[16] +
self[2] * self[12] * self[15] +
self[10] * self[3] * self[16] -
self[10] * self[4] * self[15] -
self[14] * self[3] * self[12] +
self[14] * self[4] * self[11]
out[6] = self[1] * self[11] * self[16] -
self[1] * self[12] * self[15] -
self[9] * self[3] * self[16] +
self[9] * self[4] * self[15] +
self[13] * self[3] * self[12] -
self[13] * self[4] * self[11]
out[10] = -self[1] * self[10] * self[16] +
self[1] * self[12] * self[14] +
self[9] * self[2] * self[16] -
self[9] * self[4] * self[14] -
self[13] * self[2] * self[12] +
self[13] * self[4] * self[10]
out[14] = self[1] * self[10] * self[15] -
self[1] * self[11] * self[14] -
self[9] * self[2] * self[15] +
self[9] * self[3] * self[14] +
self[13] * self[2] * self[11] -
self[13] * self[3] * self[10]
out[3] = self[2] * self[7] * self[16] -
self[2] * self[8] * self[15] -
self[6] * self[3] * self[16] +
self[6] * self[4] * self[15] +
self[14] * self[3] * self[8] -
self[14] * self[4] * self[7]
out[7] = -self[1] * self[7] * self[16] +
self[1] * self[8] * self[15] +
self[5] * self[3] * self[16] -
self[5] * self[4] * self[15] -
self[13] * self[3] * self[8] +
self[13] * self[4] * self[7]
out[11] = self[1] * self[6] * self[16] -
self[1] * self[8] * self[14] -
self[5] * self[2] * self[16] +
self[5] * self[4] * self[14] +
self[13] * self[2] * self[8] -
self[13] * self[4] * self[6]
out[15] = -self[1] * self[6] * self[15] +
self[1] * self[7] * self[14] +
self[5] * self[2] * self[15] -
self[5] * self[3] * self[14] -
self[13] * self[2] * self[7] +
self[13] * self[3] * self[6]
out[4] = -self[2] * self[7] * self[12] +
self[2] * self[8] * self[11] +
self[6] * self[3] * self[12] -
self[6] * self[4] * self[11] -
self[10] * self[3] * self[8] +
self[10] * self[4] * self[7]
out[8] = self[1] * self[7] * self[12] -
self[1] * self[8] * self[11] -
self[5] * self[3] * self[12] +
self[5] * self[4] * self[11] +
self[9] * self[3] * self[8] -
self[9] * self[4] * self[7]
out[12] = -self[1] * self[6] * self[12] +
self[1] * self[8] * self[10] +
self[5] * self[2] * self[12] -
self[5] * self[4] * self[10] -
self[9] * self[2] * self[8] +
self[9] * self[4] * self[6]
out[16] = self[1] * self[6] * self[11] -
self[1] * self[7] * self[10] -
self[5] * self[2] * self[11] +
self[5] * self[3] * self[10] +
self[9] * self[2] * self[7] -
self[9] * self[3] * self[6]
local det = self[1] * out[1] + self[2] * out[5] + self[3] * out[9] + self[4] * out[13]
if det == 0 then return self end
det = 1.0 / det
for i = 1, 16 do
out[i] = out[i] * det
end
return out
end
-- https://github.com/g-truc/glm/blob/master/glm/gtc/matrix_transform.inl#L317
-- Note: GLM calls the view matrix "model"
function mat4.project(obj, view, projection, viewport)
local position = { obj.x, obj.y, obj.z, 1 }
position = view:transpose() * position
position = projection:transpose() * position
position[1] = position[1] / position[4] * 0.5 + 0.5
position[2] = position[2] / position[4] * 0.5 + 0.5
position[3] = position[3] / position[4] * 0.5 + 0.5
position[4] = position[4] / position[4] * 0.5 + 0.5
position[1] = position[1] * viewport[3] + viewport[1]
position[2] = position[2] * viewport[4] + viewport[2]
return vec3(position[1], position[2], position[3])
end
-- https://github.com/g-truc/glm/blob/master/glm/gtc/matrix_transform.inl#L338
-- Note: GLM calls the view matrix "model"
function mat4.unproject(win, view, projection, viewport)
local inverse = (view * projection):invert()
local position = { win.x, win.y, win.z, 1 }
position[1] = (position[1] - viewport[1]) / viewport[3]
position[2] = (position[2] - viewport[2]) / viewport[4]
position[1] = position[1] * 2 - 1
position[2] = position[2] * 2 - 1
position[3] = position[3] * 2 - 1
position[4] = position[4] * 2 - 1
position = inverse * position
position[1] = position[1] / position[4]
position[2] = position[2] / position[4]
position[3] = position[3] / position[4]
position[4] = position[4] / position[4]
return vec3(position[1], position[2], position[3])
end
function mat4:look_at(eye, center, up)
local forward = (center - eye):normalize()
local side = forward:cross(up):normalize()
local new_up = side:cross(forward):normalize()
local view = mat4()
view[1] = side.x
view[5] = side.y
view[9] = side.z
view[2] = new_up.x
view[6] = new_up.y
view[10] = new_up.z
view[3] = -forward.x
view[7] = -forward.y
view[11] = -forward.z
view[16] = 1
local out = mat4():translate(-eye - forward) * view
return out * self
end
function mat4:transpose()
local m = {
self[1], self[5], self[9], self[13],
self[2], self[6], self[10], self[14],
self[3], self[7], self[11], self[15],
self[4], self[8], self[12], self[16]
}
return mat4(m)
end
function mat4:__unm()
return self:invert()
end
-- Multiply mat4 by a mat4. Tested OK
function mat4:__mul(m)
if #m == 4 then
local tmp = matrix_mult_nxn(self:transpose():to_vec4s(), { {m[1]}, {m[2]}, {m[3]}, {m[4]} })
local v = {}
for i=1, 4 do
v[i] = tmp[i][1]
end
return v
end
local out = mat4()
for i=0, 12, 4 do
for j=1, 4 do
out[i+j] = m[j] * self[i+1] + m[j+4] * self[i+2] + m[j+8] * self[i+3] + m[j+12] * self[i+4]
end
end
return out
end
function mat4:to_vec4s()
return {
{ self[1], self[2], self[3], self[4] },
{ self[5], self[6], self[7], self[8] },
{ self[9], self[10], self[11], self[12] },
{ self[13], self[14], self[15], self[16] }
}
end
return mat4