test camera math comment

Author: btipling

src/foundations/math/matrix.zig

@@ -91,6 +91,12 @@ test perspectiveProjection {
     const clip_space_left: vector.vec4 = .{ 1, 0, 0, 1 };
     const perspective_transformed_left = vector.normalize(transformVector(p, clip_space_left));
 
+    try std.testing.expect(float.equal(plane_extracted_left[0], perspective_transformed_left[0], 0.000001));
+    try std.testing.expect(float.equal(plane_extracted_left[1], perspective_transformed_left[1], 0.000001));
+    try std.testing.expect(float.equal(plane_extracted_left[2], perspective_transformed_left[2], 0.000001));
+    try std.testing.expect(float.equal(plane_extracted_left[3], perspective_transformed_left[3], 0.000001));
+
+    // This doesn't really test the perspective function, it's testing camera math using perspective values.
     var cam = identity();
     cam = transformMatrix(cam, translate(10, -3, 9));
     cam = transformMatrix(cam, rotationX(std.math.pi * 0.2));
@@ -105,8 +111,10 @@ test perspectiveProjection {
     const f_camera = vector.mul(1.0 / @sqrt(g * g + s * s), camera_space_left);
     const f_world = transformVector(transpose(inverse(cam)), f_camera);
 
-    try std.testing.expect(float.equal(plane_extracted_left[0], perspective_transformed_left[0], 0.000001));
     try std.testing.expect(float.equal(left_plane.parameterized[0], f_world[0], 0.000001));
+    try std.testing.expect(float.equal(left_plane.parameterized[1], f_world[1], 0.000001));
+    try std.testing.expect(float.equal(left_plane.parameterized[2], f_world[2], 0.000001));
+    try std.testing.expect(float.equal(left_plane.parameterized[3], f_world[3], 0.000001));
 }
 
 pub inline fn perspectiveProjectionCamera(perspective_plane_distance_g: f32, aspect_ratio_s: f32, near: f32, far: f32) matrix {