ray: don't assume x_alpha is 0 at begin or y_step

Currently fragments always start at the left edge of the frame, but
when switching to a tiling fragmenter this is no longer true and
causes visible errors.

2 files changed, 2 insertions, 2 deletions

diff --git a/src/modules/ray/ray_camera.c b/src/modules/ray/ray_camera.c
index 8a06aa3..e7792f2 100644
--- a/src/modules/ray/ray_camera.c
+++ b/src/modules/ray/ray_camera.c
@@ -81,5 +81,5 @@ void ray_camera_frame_begin(ray_camera_t *camera, fb_fragment_t *fragment, ray_r
 	frame->cur_e = ray_3f_lerp(&frame->ne, &frame->se, frame->y_alpha);
 
 	ray->origin = camera->position;
-	ray->direction = ray_3f_normalize(&frame->cur_w);
+	ray->direction = ray_3f_nlerp(&frame->cur_w, &frame->cur_e, frame->x_alpha);
 }
diff --git a/src/modules/ray/ray_camera.h b/src/modules/ray/ray_camera.h
index b0c874a..191d614 100644
--- a/src/modules/ray/ray_camera.h
+++ b/src/modules/ray/ray_camera.h
@@ -69,7 +69,7 @@ static inline int ray_camera_frame_y_step(ray_camera_frame_t *frame)
 	frame->y_alpha += frame->y_delta;
 	frame->cur_w = ray_3f_lerp(&frame->nw, &frame->sw, frame->y_alpha);
 	frame->cur_e = ray_3f_lerp(&frame->ne, &frame->se, frame->y_alpha);
-	frame->ray->direction = ray_3f_normalize(&frame->cur_w);
+	frame->ray->direction = ray_3f_nlerp(&frame->cur_w, &frame->cur_e, frame->x_alpha);
 
 	return 1;
 }