From 4cb11b87b09d0b9e61dacbd8eac871a468d7be07 Mon Sep 17 00:00:00 2001
From: treeform <starplant@gmail.com>
Date: Sun, 28 Feb 2021 11:02:59 -0800
Subject: [PATCH] Make sure every type has a hash.

---
 src/vmath.nim  | 71 +++++++++++++++++++++++++-------------------------
 tests/test.nim | 18 +++++++++++++
 2 files changed, 54 insertions(+), 35 deletions(-)

diff --git a/src/vmath.nim b/src/vmath.nim
index 2350322..7f16ef8 100644
--- a/src/vmath.nim
+++ b/src/vmath.nim
@@ -674,6 +674,19 @@ proc `pos=`*(a: var Mat3, b: Vec2) {.inline.} =
   a[2, 0] = b.x
   a[2, 1] = b.y
 
+proc hash*(a: Mat3): Hash {.inline.} =
+  hash((
+    a[0],
+    a[1],
+    a[2],
+    a[3],
+    a[4],
+    a[5],
+    a[6],
+    a[7],
+    a[8]
+  ))
+
 type Mat4* = array[16, float32] ## 4x4 Matrix - OpenGL row order
 
 proc `[]`*(a: Mat4, i, j: int): float32 = a[i * 4 + j]
@@ -914,41 +927,6 @@ proc dist*(a, b: Mat4): float32 {.inline.} =
     z = a[14] - b[14]
   sqrt(x * x + y * y + z * z)
 
-#[
-proc translate*(a: Mat4, v: Vec3): Mat4 =
-  var
-    a00 = a[0]
-    a01 = a[1]
-    a02 = a[2]
-    a03 = a[3]
-    a10 = a[4]
-    a11 = a[5]
-    a12 = a[6]
-    a13 = a[7]
-    a20 = a[8]
-    a21 = a[9]
-    a22 = a[10]
-    a23 = a[11]
-
-  result[0] = a00
-  result[1] = a01
-  result[2] = a02
-  result[3] = a03
-  result[4] = a10
-  result[5] = a11
-  result[6] = a12
-  result[7] = a13
-  result[8] = a20
-  result[9] = a21
-  result[10] = a22
-  result[11] = a23
-
-  result[12] = a00*v.x + a10*v.y + a20*v.z + a[12]
-  result[13] = a01*v.x + a11*v.y + a21*v.z + a[13]
-  result[14] = a02*v.x + a12*v.y + a22*v.z + a[14]
-  result[15] = a03*v.x + a13*v.y + a23*v.z + a[15]
-]#
-
 proc translate*(v: Vec3): Mat4 =
   result[0] = 1
   result[5] = 1
@@ -1167,6 +1145,26 @@ proc mat4Rotation*(m: Mat3): Mat4 =
   result[2, 1] = m[2, 1]
   result[2, 2] = m[2, 2]
 
+proc hash*(a: Mat4): Hash {.inline.} =
+  hash((
+    a[0],
+    a[1],
+    a[2],
+    a[3],
+    a[4],
+    a[5],
+    a[6],
+    a[7],
+    a[8],
+    a[9],
+    a[10],
+    a[11],
+    a[12],
+    a[13],
+    a[14],
+    a[15],
+  ))
+
 proc `$`*(a: Mat4): string =
   &"""[{a[0]:.5f}, {a[1]:.5f}, {a[2]:.5f}, {a[3]:.5f},
 {a[4]:.5f}, {a[5]:.5f}, {a[6]:.5f}, {a[7]:.5f},
@@ -1467,6 +1465,9 @@ proc nlerp*(a: Quat, b: Quat, v: float32): Quat =
   else:
     (a * (1.0 - v) + b * v).normalize()
 
+proc hash*(a: Quat): Hash {.inline.} =
+  hash((a.x, a.y, a.z, a.w))
+
 proc `$`*(a: Quat): string =
   &"q({a.x:.8f}, {a.y:.8f}, {a.z:.8f}, {a.w:.8f})"
 
diff --git a/tests/test.nim b/tests/test.nim
index d42d3c5..9dc2465 100644
--- a/tests/test.nim
+++ b/tests/test.nim
@@ -284,3 +284,21 @@ block:
   doAssert a3.mat4 * vec3(77.64571380615234, 0, 1) ~= vec3(50.0, 50.0, 1.0)
   doAssert a3 * vec2(77.64571380615234, 0) ~= vec2(50.0, 50.0)
   doAssert a3 * vec3(77.64571380615234, 0, 1.0) ~= vec3(50.0, 50.0, 1.0)
+
+block:
+  # hashing
+  doAssert hash(vec2(PI, E)) == 1311648097060332001
+  doAssert hash(vec3(PI, E, TAU)) == 5625953707464987239
+  doAssert hash(vec4(PI, E, TAU, sqrt(2.0))) == -6538384897102876123
+  doAssert hash(quat(1, 0, 0, sqrt(2.0))) == 1497919211694084820
+  doAssert hash( mat3(
+    300.0000, 360.0000, 420.0000,
+    660.0000, 810.0000, 960.0000,
+    1020.0000, 1260.0000, 1500.0000
+  )) == -4194936143766837151
+  doAssert hash(mat4(
+    1.00000, 0.00000, 0.00000, 0.00000,
+    0.00000, 1.00000, 0.00000, 0.00000,
+    0.00000, 0.00000, 1.00000, 0.00000,
+    7.00000, 8.00000, 9.00000, 1.00000
+  )) == 7507518476139335223