ray: split object render from object description

This moves the per-object _prepared state into ray_render_object_$type
structs with all the rendering-related object methods switched to
operate on the new render structs.

Since the current rendering code just makes all these assumptions
about light objects being point lights, I've just dropped all the
stuff associated with rendering light objects for now.  I think it
will be refactored a bit later on when the rendering code stops
hard-coding the point light stuff.

These changes open up the possibility of constifying the scene and
constituent objects, now that rendering doesn't shove the prepared
state into the embedded _prepared object substructs.

1 files changed, 61 insertions, 0 deletions

diff --git a/src/modules/ray/ray_render_object_plane.h b/src/modules/ray/ray_render_object_plane.h
new file mode 100644
index 0000000..e5c6fa7
--- /dev/null
+++ b/src/modules/ray/ray_render_object_plane.h
@@ -0,0 +1,61 @@
+#ifndef _RAY_RENDER_OBJECT_PLANE_H
+#define _RAY_RENDER_OBJECT_PLANE_H
+
+#include "ray_3f.h"
+#include "ray_camera.h"
+#include "ray_object_plane.h"
+#include "ray_object_type.h"
+#include "ray_ray.h"
+#include "ray_surface.h"
+
+
+typedef struct ray_render_object_plane_t {
+	ray_object_plane_t	object;
+	float			primary_dot_plus;
+} ray_render_object_plane_t;
+
+
+static ray_render_object_plane_t ray_render_object_plane_prepare(ray_object_plane_t *plane, ray_camera_t *camera)
+{
+	ray_render_object_plane_t	prepared = { .object = *plane };
+
+	prepared.primary_dot_plus = ray_3f_dot(&plane->normal, &camera->position) + plane->distance;
+
+	return prepared;
+}
+
+
+static inline int ray_render_object_plane_intersects_ray(ray_render_object_plane_t *plane, unsigned depth, ray_ray_t *ray, float *res_distance)
+{
+	float	d = ray_3f_dot(&plane->object.normal, &ray->direction);
+
+	if (d < 0.0f) {
+		float	distance = plane->primary_dot_plus;
+
+		if (depth)
+			distance = (ray_3f_dot(&plane->object.normal, &ray->origin) + plane->object.distance);
+
+		distance /= -d;
+		if (distance > 0.0f) {
+			*res_distance = distance;
+
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+
+static inline ray_3f_t ray_render_object_plane_normal(ray_render_object_plane_t *plane, ray_3f_t *point)
+{
+	return plane->object.normal;
+}
+
+
+static inline ray_surface_t ray_render_object_plane_surface(ray_render_object_plane_t *plane, ray_3f_t *point)
+{
+	return plane->object.surface;
+}
+
+#endif