various improvements

- cleaned up the computation of the camera's matrix
- changed VertexData to being a struct which transmit data between the "vertex shader" and the "fragment shader"
- started working on keyboard and mouse controls
- added fov (field of view)
- changed quaternion to euler angles conversion, from zyx to zxy
- fixed computations of z coordinates in triangle rendering
- improved naming in the triangle rasterizer

1 files changed, 15 insertions, 0 deletions

diff --git a/src/math/tform.h b/src/math/tform.h
index 2d61494..2a654b8 100644
--- a/src/math/tform.h
+++ b/src/math/tform.h
@@ -1,6 +1,7 @@
 #ifndef MATH_TFORM_H
 #define MATH_TFORM_H
 
+#include <array>
 #include "math/vector.h"
 #include "math/mat4.h"
 #include "math/quat.h"
@@ -28,6 +29,20 @@ class Transform {
                 0.f,                                                     0.f,                                                     0.f,                                                     1.f,
             };
         }
+
+        constexpr Matrix4 to_inverse_mat4() const & {
+            std::array<float, 3 * 3> m{{
+                (2.f * (rot.w * rot.w + rot.x * rot.x) - 1.f) / scale.x, (2.f * (rot.x * rot.y + rot.w * rot.z)      ) / scale.x, (2.f * (rot.x * rot.z - rot.w * rot.y)      ) / scale.x,
+                (2.f * (rot.x * rot.y - rot.w * rot.z)      ) / scale.y, (2.f * (rot.w * rot.w + rot.y * rot.y) - 1.f) / scale.y, (2.f * (rot.y * rot.z + rot.w * rot.x)      ) / scale.y,
+                (2.f * (rot.x * rot.z + rot.w * rot.y)      ) / scale.z, (2.f * (rot.y * rot.z - rot.w * rot.x)      ) / scale.z, (2.f * (rot.w * rot.w + rot.z * rot.z) - 1.f) / scale.z,
+            }};
+            return {
+                m[0], m[1], m[2], - (m[0] * loc.x + m[1] * loc.y + m[2] * loc.z),
+                m[3], m[4], m[5], - (m[3] * loc.x + m[4] * loc.y + m[5] * loc.z),
+                m[6], m[7], m[8], - (m[6] * loc.x + m[7] * loc.y + m[8] * loc.z),
+                0.f,            0.f,            0.f,            1.0f,
+            };
+        }
 };
 
 }