# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1401136452 -10800
# Node ID 09028848f276d4a94a31f916f7a14a36bd454848
# Parent  e9da2916bc79e54e6aaab529b6bc70a1235b1cb6
- implemented Box object intersection
- implemented interactive camera manipulation

diff -r e9da2916bc79 -r 09028848f276 liberebus/src/erebus.cc
--- a/liberebus/src/erebus.cc	Mon May 26 05:41:28 2014 +0300
+++ b/liberebus/src/erebus.cc	Mon May 26 23:34:12 2014 +0300
@@ -210,13 +210,13 @@
 	ctx->scn->add_object(sph);
 	ctx->scn->add_node(sph_node);
 
-	sph = new Sphere;
-	sph->mtl.set_attrib("diffuse", Color(0.3, 0.4, 1.0));
-	sph_node = new SceneNode(sph);
-	sph_node->set_position(Vector3(0, -251.0, 0));
-	sph_node->set_scaling(Vector3(250.0, 250.0, 250.0));
-	ctx->scn->add_object(sph);
-	ctx->scn->add_node(sph_node);
+	Box *box = new Box;
+	box->mtl.set_attrib("diffuse", Color(0.9, 0.8, 0.75));
+	SceneNode *box_node = new SceneNode(box);
+	box_node->set_position(Vector3(0, -1.25, 0));
+	box_node->set_scaling(Vector3(5, 0.5, 5));
+	ctx->scn->add_object(box);
+	ctx->scn->add_node(box_node);
 
 	Sphere *lt = new Sphere;
 	lt->mtl.set_attrib("emissive", Color(10, 10, 10));
@@ -304,11 +304,38 @@
 
 bool erb_input_mouse_motion(struct erebus *ctx, int x, int y)
 {
-	if(!ctx) return false;
+	bool res = false;
+
+	if(!ctx) return res;
+
+	int dx = x - ctx->mouse_pos[0];
+	int dy = y - ctx->mouse_pos[1];
+
+	if(dx || dy) {
+		TargetCamera *cam = (TargetCamera*)ctx->scn->get_active_camera();
+		if(cam && ctx->bnstate[0]) {
+			Vector3 cpos = cam->get_position();
+			float mag = cpos.length();
+
+			float theta = atan2(cpos.z / mag, cpos.x / mag) + DEG_TO_RAD(dx * 0.5);
+			float phi = acos(cpos.y / mag) + DEG_TO_RAD(dy * 0.5);
+
+			if(phi < 0) phi = 0;
+			if(phi > M_PI) phi = M_PI;
+
+			cpos.x = cos(theta) * sin(phi) * mag;
+			cpos.y = cos(phi) * mag;
+			cpos.z = sin(theta) * sin(phi) * mag;
+			cam->set_position(cpos);
+
+			erb_begin_frame(ctx, 0);
+			res = true;
+		}
+	}
 
 	ctx->mouse_pos[0] = x;
 	ctx->mouse_pos[1] = y;
-	return false;
+	return res;
 }
 
 bool erb_input_6dof_button(struct erebus *ctx, int bn, bool pressed)
diff -r e9da2916bc79 -r 09028848f276 liberebus/src/geomobj.cc
--- a/liberebus/src/geomobj.cc	Mon May 26 05:41:28 2014 +0300
+++ b/liberebus/src/geomobj.cc	Mon May 26 23:34:12 2014 +0300
@@ -102,7 +102,71 @@
 
 bool Box::intersect(const Ray &ray, RayHit *hit) const
 {
+	Vector3 param[2] = {Vector3{-0.5, -0.5, -0.5}, Vector3{0.5, 0.5, 0.5}};
+	Vector3 inv_dir{1.0f / ray.dir.x, 1.0f / ray.dir.y, 1.0f / ray.dir.z};
+	int sign[3] = {inv_dir.x < 0, inv_dir.y < 0, inv_dir.z < 0};
+
+	float tmin = (param[sign[0]].x - ray.origin.x) * inv_dir.x;
+	float tmax = (param[1 - sign[0]].x - ray.origin.x) * inv_dir.x;
+	float tymin = (param[sign[1]].y - ray.origin.y) * inv_dir.y;
+	float tymax = (param[1 - sign[1]].y - ray.origin.y) * inv_dir.y;
+
+	if(tmin > tymax || tymin > tmax) {
+		return false;
+	}
+	if(tymin > tmin) {
+		tmin = tymin;
+	}
+	if(tymax < tmax) {
+		tmax = tymax;
+	}
+
+	float tzmin = (param[sign[2]].z - ray.origin.z) * inv_dir.z;
+	float tzmax = (param[1 - sign[2]].z - ray.origin.z) * inv_dir.z;
+
+	if(tmin > tzmax || tzmin > tmax) {
+		return false;
+	}
+	if(tzmin > tmin) {
+		tmin = tzmin;
+	}
+	if(tzmax < tmax) {
+		tmax = tzmax;
+	}
+
+	float t = tmin < 1e-4 ? tmax : tmin;
+	if(t >= 1e-4) {
+		if(hit) {
+			hit->obj = this;
+			hit->dist = t;
+		}
+		return true;
+	}
 	return false;
+
+}
+
+#define BOX_EXT		0.499999
+Vector3 Box::calc_normal(const RayHit &hit) const
+{
+	Vector3 pt = hit.local_ray.origin + hit.local_ray.dir * hit.dist;
+	if(pt.x > BOX_EXT) return Vector3(1, 0, 0);
+	if(pt.x < -BOX_EXT) return Vector3(-1, 0, 0);
+	if(pt.y > BOX_EXT) return Vector3(0, 1, 0);
+	if(pt.y < -BOX_EXT) return Vector3(0, -1, 0);
+	if(pt.z > BOX_EXT) return Vector3(0, 0, 1);
+	if(pt.z < -BOX_EXT) return Vector3(0, 0, -1);
+	return Vector3(0, 0, 0);	// shouldn't happen unless numerical precision is fucked
+}
+
+Vector3 Box::calc_tangent(const RayHit &hit) const
+{
+	return Vector3(1, 0, 0);	// TODO
+}
+
+Vector2 Box::calc_texcoords(const RayHit &hit) const
+{
+	return Vector2(0, 0);	// TODO
 }
 
 // --- class Triangle ---
diff -r e9da2916bc79 -r 09028848f276 liberebus/src/geomobj.h
--- a/liberebus/src/geomobj.h	Mon May 26 05:41:28 2014 +0300
+++ b/liberebus/src/geomobj.h	Mon May 26 23:34:12 2014 +0300
@@ -34,6 +34,10 @@
 class Box : public GeomObject {
 public:
 	bool intersect(const Ray &ray, RayHit *hit = 0) const override;
+
+	Vector3 calc_normal(const RayHit &hit) const override;
+	Vector3 calc_tangent(const RayHit &hit) const override;
+	Vector2 calc_texcoords(const RayHit &hit) const override;
 };
 
 class Triangle : public GeomObject {
diff -r e9da2916bc79 -r 09028848f276 liberebus/src/rt.cc
--- a/liberebus/src/rt.cc	Mon May 26 05:41:28 2014 +0300
+++ b/liberebus/src/rt.cc	Mon May 26 23:34:12 2014 +0300
@@ -30,6 +30,7 @@
 	const Ray &ray = hit.world_ray;
 
 	Vector3 norm = hit.calc_normal();
+	//return norm * 0.5 + Vector3(0.5, 0.5, 0.5);
 	Vector2 texcoords = hit.calc_texcoords();
 
 	Color color = mtl->get_attrib_color("diffuse", texcoords.x, texcoords.y);