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, 10 insertions, 6 deletions

diff --git a/src/math/quat.h b/src/math/quat.h
index 763253b..271070a 100644
--- a/src/math/quat.h
+++ b/src/math/quat.h
@@ -14,18 +14,22 @@ struct Quaternion {
         return {1.f, 0.f, 0.f, 0.f};
     }
 
-    static constexpr Quaternion euler_zyx(float a, float b, float c) {
-        float ca = std::cos(a / 2.f), sa = std::sin(a / 2.f),
-              cb = std::cos(b / 2.f), sb = std::sin(b / 2.f),
-              cc = std::cos(c / 2.f), sc = std::sin(c / 2.f);
+    static constexpr Quaternion euler_zxy(float rx, float ry, float rz) {
+        float ca = std::cos(rx / 2.f), sa = std::sin(rx / 2.f),
+              cb = std::cos(ry / 2.f), sb = std::sin(ry / 2.f),
+              cc = std::cos(rz / 2.f), sc = std::sin(rz / 2.f);
         return {
-            ca * cb * cc - sa * sb * sc,
+            ca * cb * cc + sa * sb * sc,
             sa * cb * cc + ca * sb * sc,
             ca * sb * cc - sa * cb * sc,
-            ca * cb * sc + sa * sb * cc,
+            ca * cb * sc - sa * sb * cc,
         };
     }
 
+    static constexpr Quaternion rot_y(float a) {
+        return {std::cos(a / 2.f), 0.f, std::sin(a / 2.f), 0.f};
+    }
+
     float w, x, y, z;
 
     constexpr Quaternion() {}