Fix SHIP_FLYING attribute applied too generously; close #96

src/wipeout/camera.c

@@ -42,7 +42,7 @@ void camera_update(camera_t *camera, ship_t *ship, droid_t *droid) {
 void camera_update_race_external(camera_t *camera, ship_t *ship, droid_t *droid) {
 	vec3_t pos = vec3_sub(ship->position, vec3_mulf(ship->dir_forward, 1024));
 	pos.y -= 200;
-	camera->section = track_nearest_section(pos, camera->section, NULL);
+	camera->section = track_nearest_section(pos, vec3(1,1,1), camera->section, NULL);
 	section_t *next = camera->section->next;
 
 	vec3_t target = vec3_project_to_ray(pos, next->center, camera->section->center);
@@ -78,7 +78,7 @@ void camera_update_race_intro(camera_t *camera, ship_t *ship, droid_t *droid) {
 		camera->has_initial_section = true;
 	}
 	else {
-		camera->section = track_nearest_section(pos, camera->section, NULL);
+		camera->section = track_nearest_section(pos, vec3(1,1,1), camera->section, NULL);
 	}
 
 	camera->position = pos;

src/wipeout/ship.c

@@ -467,8 +467,15 @@ void ship_update(ship_t *self) {
 	self->dir_up.z = (sy * sz) + (cy * sx * cz);
 
 	self->prev_section = self->section;
+
+	// To find the nearest section to the ship, the original source de-emphasizes
+	// the .y component when calculating the distance to each section by a 
+	// >> 2 shift. I.e. it tries to find the section that is more closely to the
+	// horizontal x,z plane (directly underneath the ship), instead of finding 
+	// the section with the "real" closest distance. Hence the bias of 
+	// vec3(1, 0.25, 1) here.
 	float distance;
-	self->section = track_nearest_section(self->position, self->section, &distance);
+	self->section = track_nearest_section(self->position, vec3(1, 0.25, 1), self->section, &distance);
 	if (distance > 3700) {
 		flags_add(self->flags, SHIP_FLYING);
 	}

src/wipeout/track.c

@@ -323,7 +323,7 @@ track_face_t *track_section_get_base_face(section_t *section) {
 	return face;
 }
 
-section_t *track_nearest_section(vec3_t pos, section_t *section, float *distance) {
+section_t *track_nearest_section(vec3_t pos, vec3_t bias, section_t *section, float *distance) {
 	// Start search several sections before current section
 
 	for (int i = 0; i < TRACK_SEARCH_LOOK_BACK; i++) {
@@ -340,7 +340,10 @@ section_t *track_nearest_section(vec3_t pos, section_t *section, float *distance
 			junction = section->junction;
 		}
 
-		float d = vec3_len(vec3_sub(pos, section->center));
+		// Some callers of this function want to de-emphazise the .y component
+		// of the difference, hence the multiplication with the bias vector.
+		// For the real, exact difference bias should be vec3(1,1,1)
+		float d = vec3_len(vec3_mul(vec3_sub(pos, section->center), bias));
 		if (d < shortest_distance) {
 			shortest_distance = d;
 			nearest_section = section;
@@ -352,7 +355,7 @@ section_t *track_nearest_section(vec3_t pos, section_t *section, float *distance
 	if (junction) {
 		section = junction;
 		for (int i = 0; i < TRACK_SEARCH_LOOK_AHEAD; i++) {
-			float d = vec3_len(vec3_sub(pos, section->center));
+			float d = vec3_len(vec3_mul(vec3_sub(pos, section->center), bias));
 			if (d < shortest_distance) {
 				shortest_distance = d;
 				nearest_section = section;

src/wipeout/track.h

@@ -86,7 +86,7 @@ void track_load_sections(char *file);
 bool track_collect_pickups(track_face_t *face);
 void track_face_set_color(track_face_t *face, rgba_t color);
 track_face_t *track_section_get_base_face(section_t *section);
-section_t *track_nearest_section(vec3_t pos, section_t *section, float *distance);
+section_t *track_nearest_section(vec3_t pos, vec3_t bias, section_t *section, float *distance);
 
 struct camera_t;
 void track_draw(struct camera_t *camera);

src/wipeout/weapon.c

@@ -195,7 +195,7 @@ void weapons_update(void) {
 			}
 
 			// Track collision
-			weapon->section = track_nearest_section(weapon->position, weapon->section, NULL);
+			weapon->section = track_nearest_section(weapon->position, vec3(1,1,1), weapon->section, NULL);
 			if (weapon_collides_with_track(weapon)) {
 				for (int p = 0; p < 32; p++) {
 					vec3_t velocity = vec3(rand_float(-512, 512), rand_float(-512, 512), rand_float(-512, 512));