# HG changeset patch
# User Sam <sam@basx.dev>
# Date 1695990607 -25200
# Node ID 3eccdbf32c53ecbdc232b364159aefff70bbcbc3
# Parent  97e913c0e7fee0918f62663542a5b6db15b35202
add: support inverse matrix and normalized mouse position

diff -r 97e913c0e7fe -r 3eccdbf32c53 src/semicongine/core/matrix.nim
--- a/src/semicongine/core/matrix.nim	Sun Sep 24 23:15:08 2023 +0700
+++ b/src/semicongine/core/matrix.nim	Fri Sep 29 19:30:07 2023 +0700
@@ -404,6 +404,27 @@
     0'f32,                         0'f32,                         0'f32,                         1'f32,
   ])
 
+func asMat3(m: Mat4): auto =
+  Mat3(data: [
+    m[0, 0], m[0, 1], m[0, 2],
+    m[1, 0], m[1, 1], m[1, 2],
+    m[2, 0], m[2, 1], m[2, 2],
+  ])
+
+
+func inversed*(m: Mat4): Mat4 =
+  var m3 = m.asMat3.transposed
+  m3[0, 0] = 1'f32 / m3[0, 0]
+  m3[1, 1] = 1'f32 / m3[1, 1]
+  m3[2, 2] = 1'f32 / m3[2, 2]
+  let col3 = -(m3 * m.col(3).xyz)
+  return Mat4(data: [
+        m3[0, 0],     m3[0, 1],     m3[0, 2], col3.x,
+        m3[1, 0],     m3[1, 1],     m3[1, 2], col3.y,
+        m3[2, 0],     m3[2, 1],     m3[2, 2], col3.z,
+               0,            0,            0,      1,
+  ])
+
 
 # call e.g. TMat32[int]().randomized() to get a random matrix
 template makeRandomInit(mattype: typedesc) =
@@ -444,10 +465,10 @@
 func orthoWindowAspect*(windowAspect: float32): Mat4 =
   if windowAspect > 1:
     let space = 2 * (windowAspect - 1) / 2
-    ortho(-1, 1, -1 - space, 1 + space, -1, 1)
+    ortho(-1, 1, -1 - space, 1 + space, 0, 1)
   else:
     let space = 2 * (1 / windowAspect - 1) / 2
-    ortho(-1 - space, 1 + space, -1, 1, -1, 1)
+    ortho(-1 - space, 1 + space, -1, 1, 0, 1)
 
 func position*(mat: Mat4): Vec3f =
   mat.col(3).toVec3
diff -r 97e913c0e7fe -r 3eccdbf32c53 src/semicongine/engine.nim
--- a/src/semicongine/engine.nim	Sun Sep 24 23:15:08 2023 +0700
+++ b/src/semicongine/engine.nim	Fri Sep 29 19:30:07 2023 +0700
@@ -194,6 +194,9 @@
 func mouseWasPressed*(engine: Engine, button: MouseButton): auto = button in engine.input.mouseWasPressed
 func mouseWasReleased*(engine: Engine, button: MouseButton): auto = button in engine.input.mouseWasReleased
 func mousePosition*(engine: Engine): auto = engine.input.mousePosition
+func mousePositionNormalized*(engine: Engine): Vec2f =
+  result.x = (engine.input.mousePosition.x / float32(engine.window.size[0])) * 2.0 - 1.0
+  result.y = (engine.input.mousePosition.y / float32(engine.window.size[1])) * 2.0 - 1.0
 func mouseMove*(engine: Engine): auto = engine.input.mouseMove
 func mouseWheel*(engine: Engine): auto = engine.input.mouseWheel
 func eventsProcessed*(engine: Engine): auto = engine.input.eventsProcessed