Add new procedures for package math: atan2, asin, acos, atan, sin_bit, ldexp

This commit is contained in:
gingerBill
2019-12-28 18:12:27 +00:00
parent 9ba2926e7e
commit 6a7ccd8c0a
2 changed files with 240 additions and 23 deletions

View File

@@ -64,6 +64,10 @@ length :: proc(v: $T/[$N]$E) -> E {
return math.sqrt(dot(v, v));
}
length2 :: proc(v: $T/[$N]$E) -> E {
return dot(v, v);
}
identity :: proc($T: typeid/[$N][N]$E) -> (m: T) {
for i in 0..<N do m[i][i] = E(1);
@@ -176,17 +180,51 @@ Matrix4x2 :: distinct [4][2]Float;
Matrix4x3 :: distinct [4][3]Float;
Matrix4x4 :: distinct [4][4]Float;
Matrix1 :: Matrix1x1;
Matrix2 :: Matrix2x2;
Matrix3 :: Matrix3x3;
Matrix4 :: Matrix4x4;
Quaternion :: distinct (size_of(Float) == size_of(f32) ? quaternion128 : quaternion256);
MATRIX1_IDENTITY :: Matrix1{{1}};
MATRIX2_IDENTITY :: Matrix2{{1, 0}, {0, 1}};
MATRIX3_IDENTITY :: Matrix3{{1, 0, 0}, {0, 1, 0}, {0, 0, 1}};
MATRIX4_IDENTITY :: Matrix4{{1, 0, 0, 0}, {0, 1, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1}};
translate_matrix4 :: proc(v: Vector3) -> Matrix4 {
QUATERNION_IDENTITY :: Quaternion(1);
VECTOR3_X_AXIS :: Vector3{1, 0, 0};
VECTOR3_Y_AXIS :: Vector3{0, 1, 0};
VECTOR3_Z_AXIS :: Vector3{0, 0, 1};
vector3_orthogonal :: proc(v: Vector3) -> Vector3 {
x := abs(v.x);
y := abs(v.y);
z := abs(v.z);
other: Vector3 = x < y ? (x < z ? {1, 0, 0} : {0, 0, 1}) : (y < z ? {0, 1, 0} : {0, 0, 1});
return normalize(cross3(v, other));
}
vector3_reflect :: proc(i, n: Vector3) -> Vector3 {
b := n * 2 * dot(n, i);
return i - b;
}
vector3_refract :: proc(i, n: Vector3, eta: Float) -> Vector3 {
dv := dot(n, i);
k := 1 - eta*eta - (1 - dv*dv);
a := i * eta;
b := n * eta*dv*math.sqrt(k);
return (a - b) * Float(int(k >= 0));
}
translate_matrix4 :: matrix4_translate;
matrix4_translate :: proc(v: Vector3) -> Matrix4 {
m := identity(Matrix4);
m[3][0] = v[0];
m[3][1] = v[1];
@@ -195,7 +233,8 @@ translate_matrix4 :: proc(v: Vector3) -> Matrix4 {
}
rotate_matrix4 :: proc(v: Vector3, angle_radians: Float) -> Matrix4 {
rotate_matrix4 :: matrix4_rotate;
matrix4_rotate :: proc(v: Vector3, angle_radians: Float) -> Matrix4 {
c := math.cos(angle_radians);
s := math.sin(angle_radians);
@@ -222,7 +261,8 @@ rotate_matrix4 :: proc(v: Vector3, angle_radians: Float) -> Matrix4 {
return rot;
}
scale_matrix4 :: proc(m: Matrix4, v: Vector3) -> Matrix4 {
scale_matrix4 :: matrix4_scale;
matrix4_scale :: proc(m: Matrix4, v: Vector3) -> Matrix4 {
mm := m;
mm[0][0] *= v[0];
mm[1][1] *= v[1];
@@ -230,8 +270,8 @@ scale_matrix4 :: proc(m: Matrix4, v: Vector3) -> Matrix4 {
return mm;
}
look_at :: proc(eye, centre, up: Vector3) -> Matrix4 {
look_at :: matrix4_look_at;
matrix4_look_at :: proc(eye, centre, up: Vector3) -> Matrix4 {
f := normalize(centre - eye);
s := normalize(cross(f, up));
u := cross(s, f);
@@ -244,7 +284,8 @@ look_at :: proc(eye, centre, up: Vector3) -> Matrix4 {
}
perspective :: proc(fovy, aspect, near, far: Float) -> (m: Matrix4) {
perspective :: matrix4_perspective;
matrix4_perspective :: proc(fovy, aspect, near, far: Float) -> (m: Matrix4) {
tan_half_fovy := math.tan(0.5 * fovy);
m[0][0] = 1 / (aspect*tan_half_fovy);
m[1][1] = 1 / (tan_half_fovy);
@@ -255,7 +296,7 @@ perspective :: proc(fovy, aspect, near, far: Float) -> (m: Matrix4) {
}
ortho3d :: proc(left, right, bottom, top, near, far: Float) -> (m: Matrix4) {
matrix_ortho3d :: proc(left, right, bottom, top, near, far: Float) -> (m: Matrix4) {
m[0][0] = +2 / (right - left);
m[1][1] = +2 / (top - bottom);
m[2][2] = -2 / (far - near);
@@ -267,23 +308,41 @@ ortho3d :: proc(left, right, bottom, top, near, far: Float) -> (m: Matrix4) {
}
axis_angle :: proc(axis: Vector3, angle_radians: Float) -> Quaternion {
axis_angle :: quaternion_angle_axis;
angle_axis :: quaternion_angle_axis;
quaternion_angle_axis :: proc(angle_radians: Float, axis: Vector3) -> Quaternion {
t := angle_radians*0.5;
w := math.cos(t);
v := normalize(axis) * math.sin(t);
return quaternion(w, v.x, v.y, v.z);
}
angle_axis :: proc(angle_radians: Float, axis: Vector3) -> Quaternion {
t := angle_radians*0.5;
w := math.cos(t);
v := normalize(axis) * math.sin(t);
return quaternion(w, v.x, v.y, v.z);
}
euler_angles :: proc(pitch, yaw, roll: Float) -> Quaternion {
p := axis_angle({1, 0, 0}, pitch);
y := axis_angle({0, 1, 0}, yaw);
r := axis_angle({0, 0, 1}, roll);
euler_angles :: quaternion_from_euler_angles;
quaternion_from_euler_angles :: proc(pitch, yaw, roll: Float) -> Quaternion {
p := quaternion_angle_axis(pitch, {1, 0, 0});
y := quaternion_angle_axis(yaw, {0, 1, 0});
r := quaternion_angle_axis(roll, {0, 0, 1});
return (y * p) * r;
}
euler_angles_from_quaternion :: proc(q: Quaternion) -> (roll, pitch, yaw: Float) {
// roll (x-axis rotation)
sinr_cosp: Float = 2 * (real(q)*imag(q) + jmag(q)*kmag(q));
cosr_cosp: Float = 1 - 2 * (imag(q)*imag(q) + jmag(q)*jmag(q));
roll = Float(math.atan2(sinr_cosp, cosr_cosp));
// pitch (y-axis rotation)
sinp: Float = 2 * (real(q)*kmag(q) - kmag(q)*imag(q));
if abs(sinp) >= 1 {
pitch = Float(math.copy_sign(math.TAU * 0.25, sinp));
} else {
pitch = Float(math.asin(sinp));
}
// yaw (z-axis rotation)
siny_cosp: Float = 2 * (real(q)*kmag(q) + imag(q)*jmag(q));
cosy_cosp: Float = 1 - 2 * (jmag(q)*jmag(q) + kmag(q)*kmag(q));
yaw = Float(math.atan2(siny_cosp, cosy_cosp));
return;
}

View File

@@ -71,6 +71,12 @@ foreign _ {
exp_f32 :: proc(x: f32) -> f32 ---;
@(link_name="llvm.exp.f64")
exp_f64 :: proc(x: f64) -> f64 ---;
@(link_name="llvm.ldexp.f32")
ldexp_f32 :: proc(val: f32, exp: i32) -> f32 ---;
@(link_name="llvm.ldexp.f64")
ldexp_f64 :: proc(val: f64, exp: i32) -> f64 ---;
}
sqrt :: proc{sqrt_f32, sqrt_f64};
@@ -81,6 +87,8 @@ fmuladd :: proc{fmuladd_f32, fmuladd_f64};
ln :: proc{ln_f32, ln_f64};
exp :: proc{exp_f32, exp_f64};
ldexp :: proc{ldexp_f32, ldexp_f64};
log_f32 :: proc(x, base: f32) -> f32 { return ln(x) / ln(base); }
log_f64 :: proc(x, base: f64) -> f64 { return ln(x) / ln(base); }
log :: proc{log_f32, log_f64};
@@ -108,6 +116,14 @@ sign_f32 :: proc(x: f32) -> f32 { return f32(int(0 < x) - int(x < 0)); }
sign_f64 :: proc(x: f64) -> f64 { return f64(int(0 < x) - int(x < 0)); }
sign :: proc{sign_f32, sign_f64};
sign_bit_f32 :: proc(x: f32) -> bool {
return (transmute(u32)x) & (1<<31) != 0;
}
sign_bit_f64 :: proc(x: f64) -> bool {
return (transmute(u64)x) & (1<<63) != 0;
}
sign_bit :: proc{sign_bit_f32, sign_bit_f64};
copy_sign_f32 :: proc(x, y: f32) -> f32 {
ix := transmute(u32)x;
iy := transmute(u32)y;
@@ -511,8 +527,31 @@ is_nan_f32 :: proc(x: f32) -> bool { return classify(x) == .NaN; }
is_nan_f64 :: proc(x: f64) -> bool { return classify(x) == .NaN; }
is_nan :: proc{is_nan_f32, is_nan_f64};
is_inf_f32 :: proc(x: f32) -> bool { return classify(abs(x)) == .Inf; }
is_inf_f64 :: proc(x: f64) -> bool { return classify(abs(x)) == .Inf; }
// is_inf reports whether f is an infinity, according to sign.
// If sign > 0, is_inf reports whether f is positive infinity.
// If sign < 0, is_inf reports whether f is negative infinity.
// If sign == 0, is_inf reports whether f is either infinity.
is_inf_f32 :: proc(x: f32, sign: int = 0) -> bool {
class := classify(abs(x));
switch {
case sign > 0:
return class == .Inf;
case sign < 0:
return class == .Neg_Inf;
}
return class == .Inf || class == .Neg_Inf;
}
is_inf_f64 :: proc(x: f64, sign: int = 0) -> bool {
class := classify(abs(x));
switch {
case sign > 0:
return class == .Inf;
case sign < 0:
return class == .Neg_Inf;
}
return class == .Inf || class == .Neg_Inf;
}
is_inf :: proc{is_inf_f32, is_inf_f64};
@@ -572,6 +611,125 @@ cumsum :: proc(dst, src: $T/[]$E) -> T
}
atan2_f32 :: proc(y, x: f32) -> f32 {
// TODO(bill): Better atan2_f32
return f32(atan2_f64(f64(y), f64(x)));
}
atan2_f64 :: proc(y, x: f64) -> f64 {
// TODO(bill): Faster atan2_f64 if possible
// The original C code:
// Stephen L. Moshier
// moshier@na-net.ornl.gov
NAN :: 0h7fff_ffff_ffff_ffff;
INF :: 0h7FF0_0000_0000_0000;
PI :: 0h4009_21fb_5444_2d18;
atan :: proc(x: f64) -> f64 {
if x == 0 {
return x;
}
if x > 0 {
return s_atan(x);
}
return -s_atan(-x);
}
// s_atan reduces its argument (known to be positive) to the range [0, 0.66] and calls x_atan.
s_atan :: proc(x: f64) -> f64 {
MORE_BITS :: 6.123233995736765886130e-17; // pi/2 = PIO2 + MORE_BITS
TAN3PI08 :: 2.41421356237309504880; // tan(3*pi/8)
if x <= 0.66 {
return x_atan(x);
}
if x > TAN3PI08 {
return PI/2 - x_atan(1/x) + MORE_BITS;
}
return PI/4 + x_atan((x-1)/(x+1)) + 0.5*MORE_BITS;
}
// x_atan evaluates a series valid in the range [0, 0.66].
x_atan :: proc(x: f64) -> f64 {
P0 :: -8.750608600031904122785e-01;
P1 :: -1.615753718733365076637e+01;
P2 :: -7.500855792314704667340e+01;
P3 :: -1.228866684490136173410e+02;
P4 :: -6.485021904942025371773e+01;
Q0 :: +2.485846490142306297962e+01;
Q1 :: +1.650270098316988542046e+02;
Q2 :: +4.328810604912902668951e+02;
Q3 :: +4.853903996359136964868e+02;
Q4 :: +1.945506571482613964425e+02;
z := x * x;
z = z * ((((P0*z+P1)*z+P2)*z+P3)*z + P4) / (((((z+Q0)*z+Q1)*z+Q2)*z+Q3)*z + Q4);
z = x*z + x;
return z;
}
switch {
case is_nan(y) || is_nan(x):
return NAN;
case y == 0:
if x >= 0 && !sign_bit(x) {
return copy_sign(0.0, y);
}
return copy_sign(PI, y);
case x == 0:
return copy_sign(PI*0.5, y);
case is_inf(x, 0):
if is_inf(x, 1) {
if is_inf(y, 0) {
return copy_sign(PI*0.25, y);
}
return copy_sign(0, y);
}
if is_inf(y, 0) {
return copy_sign(PI*0.75, y);
}
return copy_sign(PI, y);
case is_inf(y, 0):
return copy_sign(PI*0.5, y);
}
q := atan(y / x);
if x < 0 {
if q <= 0 {
return q + PI;
}
return q - PI;
}
return q;
}
atan2 :: proc{atan2_f32, atan2_f64};
atan_f32 :: proc(x: f32) -> f32 {
return atan2_f32(1.0, x);
}
atan :: proc{atan_f32};
asin_f32 :: proc(x: f32) -> f32 {
return atan2_f32(x, sqrt_f32(1 - x*x));
}
asin_f64 :: proc(x: f64) -> f64 {
return atan2_f64(x, sqrt_f64(1 - x*x));
}
asin :: proc{asin_f32};
acos_f32 :: proc(x: f32) -> f32 {
return atan2_f32(sqrt_f32(1 - x), sqrt_f32(1 + x));
}
acos_f64 :: proc(x: f64) -> f64 {
return atan2_f64(sqrt_f64(1 - x), sqrt_f64(1 + x));
}
acos :: proc{acos_f32};
F32_DIG :: 6;
F32_EPSILON :: 1.192092896e-07;
F32_GUARD :: 0;