diff options
Diffstat (limited to 'Spear/Math/MatrixUtils.hs')
-rw-r--r-- | Spear/Math/MatrixUtils.hs | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/Spear/Math/MatrixUtils.hs b/Spear/Math/MatrixUtils.hs index 88ad3b1..e6e498f 100644 --- a/Spear/Math/MatrixUtils.hs +++ b/Spear/Math/MatrixUtils.hs | |||
@@ -7,8 +7,11 @@ where | |||
7 | 7 | ||
8 | import Spear.Math.Matrix3 as M3 | 8 | import Spear.Math.Matrix3 as M3 |
9 | import Spear.Math.Matrix4 as M4 | 9 | import Spear.Math.Matrix4 as M4 |
10 | import Spear.Math.Vector2 as V2 | ||
11 | import Spear.Math.Vector3 as V3 | ||
10 | 12 | ||
11 | 13 | ||
14 | -- | Compute the normal matrix of the given matrix. | ||
12 | fastNormalMatrix :: Matrix4 -> Matrix3 | 15 | fastNormalMatrix :: Matrix4 -> Matrix3 |
13 | fastNormalMatrix m = | 16 | fastNormalMatrix m = |
14 | let m' = M4.transpose . M4.inverseTransform $ m | 17 | let m' = M4.transpose . M4.inverseTransform $ m |
@@ -16,3 +19,44 @@ fastNormalMatrix m = | |||
16 | (M4.m00 m') (M4.m10 m') (M4.m20 m') | 19 | (M4.m00 m') (M4.m10 m') (M4.m20 m') |
17 | (M4.m01 m') (M4.m11 m') (M4.m21 m') | 20 | (M4.m01 m') (M4.m11 m') (M4.m21 m') |
18 | (M4.m02 m') (M4.m12 m') (M4.m22 m') | 21 | (M4.m02 m') (M4.m12 m') (M4.m22 m') |
22 | |||
23 | |||
24 | -- | Compute the inverse transform of the given transformation matrix. | ||
25 | -- | ||
26 | -- This function maps an object's transform in 2D to the object's inverse in 3D. | ||
27 | -- | ||
28 | -- The XY plane in 2D translates to the X(-Z) plane in 3D. | ||
29 | -- | ||
30 | -- Use this in games such as RPGs and RTSs. | ||
31 | rpgInverse :: Float -- ^ Height above the ground. | ||
32 | -> Matrix3 -> Matrix4 | ||
33 | rpgInverse h mat = | ||
34 | let r = let r' = M3.right mat in vec3 (V2.x r') (V2.y r') 0 | ||
35 | u = V3.unity | ||
36 | f = let f' = M3.forward mat in vec3 (V2.x f') 0 (-V2.y f') | ||
37 | t = let t' = M3.position mat in -(vec3 (V2.x t') 0 (-V2.y t')) | ||
38 | in mat4 | ||
39 | (V3.x r) (V3.y r) (V3.z r) (t `V3.dot` r) | ||
40 | (V3.x u) (V3.y u) (V3.z u) (t `V3.dot` u) | ||
41 | (V3.x f) (V3.y f) (V3.z f) (t `V3.dot` f) | ||
42 | 0 0 0 1 | ||
43 | |||
44 | |||
45 | -- | Compute the inverse transform of the given transformation matrix. | ||
46 | -- | ||
47 | -- This function maps an object's transform in 2D to the object's inverse in 3D. | ||
48 | -- | ||
49 | -- The XY plane in 2D translates to the XY plane in 3D. | ||
50 | -- | ||
51 | -- Use this in games like platformers and space invaders style games. | ||
52 | pltInverse :: Matrix3 -> Matrix4 | ||
53 | pltInverse mat = | ||
54 | let r = let r' = M3.right mat in vec3 (V2.x r') (V2.y r') 0 | ||
55 | u = let u' = M3.up mat in vec3 (V2.x u') (V2.y u') 0 | ||
56 | f = V3.unitz | ||
57 | t = let t' = M3.position mat in vec3 (V2.x t') (V2.y t') 0 | ||
58 | in mat4 | ||
59 | (V3.x r) (V3.y r) (V3.z r) (t `V3.dot` r) | ||
60 | (V3.x u) (V3.y u) (V3.z u) (t `V3.dot` u) | ||
61 | (V3.x f) (V3.y f) (V3.z f) (t `V3.dot` f) | ||
62 | 0 0 0 1 | ||