Make hand in local space sometimes again

- needed because world pos is incorrect wrt lag

gamestate.c

@@ -229,6 +229,12 @@ void grid_create(GameState* gs, Entity* e)
 	create_body(gs, e);
 }
 
+void entity_set_rotation(Entity* e, float rot)
+{
+	assert(e->body != NULL);
+	cpBodySetAngle(e->body, rot);
+}	
+
 void entity_set_pos(Entity* e, V2 pos)
 {
 	assert(e->is_grid);
@@ -676,7 +682,7 @@ void ser_entityid(SerState* ser, EntityID* id)
 	SER_VAR(&id->index);
 }
 
-void ser_inputframe(SerState* ser, struct InputFrame* i)
+void ser_inputframe(SerState* ser, InputFrame* i)
 {
 	SER_VAR(&i->tick);
 	SER_VAR(&i->movement);
@@ -684,11 +690,11 @@ void ser_inputframe(SerState* ser, struct InputFrame* i)
 	SER_VAR(&i->seat_action);
 	ser_entityid(ser, &i->seat_to_inhabit);
 	SER_VAR(&i->hand_pos);
+	ser_entityid(ser, &i->grid_hand_pos_local_to);
 
 	SER_VAR(&i->dobuild);
 	SER_VAR(&i->build_type);
 	SER_VAR(&i->build_rotation);
-	ser_entityid(ser, &i->grid_to_build_on);
 }
 
 void ser_player(SerState* ser, Player* p)
@@ -962,6 +968,18 @@ uint64_t tick(GameState* gs)
 	return (uint64_t)floor(gs->time / ((double)TIMESTEP));
 }
 
+V2 get_world_hand_pos(GameState* gs, InputFrame* input, Entity* player)
+{
+	Entity* potential_grid = get_entity(gs, input->grid_hand_pos_local_to);
+	if (potential_grid != NULL)
+	{
+		return grid_local_to_world(potential_grid, input->hand_pos);
+	}
+	else {
+		return input->hand_pos;
+	}
+}
+
 void process(GameState* gs, float dt)
 {
 	assert(gs->space != NULL);
@@ -993,6 +1011,7 @@ void process(GameState* gs, float dt)
 		}
 
 #if 1
+		V2 world_hand_pos = get_world_hand_pos(gs, &player->input, p);
 		if (player->input.seat_action)
 		{
 			player->input.seat_action = false; // "handle" the input
@@ -1000,7 +1019,7 @@ void process(GameState* gs, float dt)
 			if (the_seat == NULL) // not piloting any seat
 			{
 				cpPointQueryInfo query_info = { 0 };
-				cpShape* result = cpSpacePointQueryNearest(gs->space, v2_to_cp(player->input.hand_pos), 0.1f, cpShapeFilterNew(CP_NO_GROUP, CP_ALL_CATEGORIES, BOXES), &query_info);
+				cpShape* result = cpSpacePointQueryNearest(gs->space, v2_to_cp(world_hand_pos), 0.1f, cpShapeFilterNew(CP_NO_GROUP, CP_ALL_CATEGORIES, BOXES), &query_info);
 				if (result != NULL)
 				{
 					Entity* potential_seat = cp_shape_entity(result);
@@ -1013,7 +1032,8 @@ void process(GameState* gs, float dt)
 				}
 				else
 				{
-					Log("No ship above player at point %f %f\n", player->input.hand_pos.x, player->input.hand_pos.y);
+
+					Log("No ship above player at point %f %f\n", world_hand_pos.x, world_hand_pos.y);
 				}
 			}
 			else
@@ -1075,10 +1095,10 @@ void process(GameState* gs, float dt)
 			player->input.dobuild = false; // handle the input. if didn't do this, after destruction of hovered box, would try to build on its grid with grid_index...
 
 			cpPointQueryInfo info = { 0 };
-			V2 world_build = player->input.hand_pos;
+			V2 world_build = world_hand_pos;
 
 			// @Robust sanitize this input so player can't build on any grid in the world
-			Entity* target_grid = get_entity(gs, player->input.grid_to_build_on);
+			Entity* target_grid = get_entity(gs, player->input.grid_hand_pos_local_to);
 			cpShape* nearest = cpSpacePointQueryNearest(gs->space, v2_to_cp(world_build), 0.01f, cpShapeFilterNew(CP_NO_GROUP, CP_ALL_CATEGORIES, BOXES), &info);
 			if (nearest != NULL)
 			{

main.c

@@ -420,7 +420,7 @@ frame(void)
 		V2 grid_pos;
 		float grid_rotation;
 	} build_preview = { 0 };
-	V2 hand_pos = { 0 };
+	V2 hand_pos = { 0 }; // in local space of grid when hovering over a grid
 	bool hand_at_arms_length = false;
 	{
 		// interpolate zoom
@@ -439,6 +439,7 @@ frame(void)
 
 		// calculate build preview stuff
 		EntityID grid_to_build_on = (EntityID){ 0 };
+		V2 possibly_local_hand_pos = (V2){ 0 };
 		if (myentity() != NULL) {
 			hand_pos = V2sub(world_mouse_pos, entity_pos(myentity()));
 			float hand_len = V2length(hand_pos);
@@ -452,6 +453,7 @@ frame(void)
 			hand_pos = V2scale(V2normalize(hand_pos), hand_len);
 			hand_pos = V2add(hand_pos, entity_pos(myentity()));
 
+			possibly_local_hand_pos = hand_pos;
 			Entity* placing_grid = closest_to_point_in_radius(&gs, hand_pos, BUILD_BOX_SNAP_DIST_TO_SHIP);
 			if (placing_grid == NULL) {
 				build_preview = (struct BuildPreviewInfo){
@@ -462,6 +464,7 @@ frame(void)
 			else {
 				grid_to_build_on = get_id(&gs, placing_grid);
 				hand_pos = grid_snapped_box_pos(placing_grid, hand_pos);
+				possibly_local_hand_pos = grid_world_to_local(placing_grid, hand_pos);
 				build_preview = (struct BuildPreviewInfo){ .grid_pos = entity_pos(placing_grid),
 					.grid_rotation = entity_rotation(placing_grid),
 				};
@@ -474,7 +477,7 @@ frame(void)
 			// every frame
 
 			static size_t last_frame_id = 0;
-			struct InputFrame cur_input_frame = { 0 };
+			InputFrame cur_input_frame = { 0 };
 			cur_input_frame.id = last_frame_id;
 			V2 input = (V2){
 				.x = (float)keydown[SAPP_KEYCODE_D] - (float)keydown[SAPP_KEYCODE_A],
@@ -484,15 +487,16 @@ frame(void)
 				input = V2normalize(input);
 			cur_input_frame.movement = input;
 			cur_input_frame.seat_action = keypressed[SAPP_KEYCODE_G].pressed;
-			cur_input_frame.hand_pos = hand_pos;
+			cur_input_frame.grid_hand_pos_local_to = grid_to_build_on;
+			cur_input_frame.hand_pos = possibly_local_hand_pos;
+
 			if (mouse_pressed && cur_editing_boxtype != -1) {
 				cur_input_frame.dobuild = mouse_pressed;
 				cur_input_frame.build_type = cur_editing_boxtype;
 				cur_input_frame.build_rotation = cur_editing_rotation;
-				cur_input_frame.grid_to_build_on = grid_to_build_on;
 			}
 
-			struct InputFrame latest = client_to_server.inputs[0];
+			InputFrame latest = client_to_server.inputs[0];
 			// @Robust split this into separate lines and be very careful about testing for inequality
 
 			bool input_differs = false;
@@ -505,12 +509,12 @@ frame(void)
 			input_differs = input_differs || cur_input_frame.dobuild != latest.dobuild;
 			input_differs = input_differs || cur_input_frame.build_type != latest.build_type;
 			input_differs = input_differs || cur_input_frame.build_rotation != latest.build_rotation;
-			input_differs = input_differs || !entityids_same(cur_input_frame.grid_to_build_on, latest.grid_to_build_on);
+			input_differs = input_differs || !entityids_same(cur_input_frame.grid_hand_pos_local_to, latest.grid_hand_pos_local_to);
 
 			if (input_differs) {
-				struct InputFrame last_frame = client_to_server.inputs[0];
+				InputFrame last_frame = client_to_server.inputs[0];
 				for (int i = 0; i < INPUT_BUFFER - 1; i++) {
-					struct InputFrame last_last_frame = last_frame;
+					InputFrame last_last_frame = last_frame;
 					last_frame = client_to_server.inputs[i + 1];
 					client_to_server.inputs[i + 1] = last_last_frame;
 				}
@@ -518,7 +522,6 @@ frame(void)
 				client_to_server.inputs[0] = cur_input_frame;
 				last_frame_id += 1;
 			}
-			dbg_rect(client_to_server.inputs[0].hand_pos);
 
 			static double last_input_sent_time = 0.0;
 			if (fabs(last_input_sent_time - time) > TIME_BETWEEN_INPUT_PACKETS) {
@@ -545,7 +548,8 @@ frame(void)
 		sgp_set_blend_mode(SGP_BLENDMODE_BLEND);
 
 		// Draw background color
-		sgp_set_color(0.1f, 0.1f, 0.1f, 1.0f);
+		set_color(colhexcode(0x020509));
+		// sgp_set_color(0.1f, 0.1f, 0.1f, 1.0f);
 		sgp_clear();
 
 		// sokol drawing library draw in world space

server.c

@@ -1,3 +1,4 @@
+#include <chipmunk.h> // initializing bodies
 #include "types.h"
 #include "sokol_time.h"
 #include <enet/enet.h>
@@ -5,6 +6,7 @@
 #include <inttypes.h> // int64 printing
 #include <stdlib.h>
 
+
 // started in a thread from host
 void server(void* data)
 {
@@ -26,7 +28,24 @@ void server(void* data)
 		entity_set_pos(grid, (V2) { -BOX_SIZE * 2, 0.0f });
 		Entity* box = new_entity(&gs);
 		box_create(&gs, box, grid, (V2) { 0 });
+	}
 
+	// rotation test
+	if (false)
+	{
+		Entity* grid = new_entity(&gs);
+		grid_create(&gs, grid);
+		entity_set_pos(grid, (V2) { -BOX_SIZE * 2, 0.0f });
+		entity_set_rotation(grid, PI / 1.7f);
+		cpBodySetVelocity(grid->body, cpv(-0.1, 0.0));
+		cpBodySetAngularVelocity(grid->body, 1.0f);
+		
+#define BOX_AT(pos) { Entity* box = new_entity(&gs); box_create(&gs, box, grid, pos); }
+		BOX_AT(((V2) { 0 }));
+		BOX_AT(((V2) { BOX_SIZE, 0 }));
+		BOX_AT(((V2) { 2.0*BOX_SIZE, 0 }));
+		BOX_AT(((V2) { 2.0*BOX_SIZE, BOX_SIZE }));
+		BOX_AT(((V2) { 0.0*BOX_SIZE, -BOX_SIZE }));
 	}
 
 	if (enet_initialize() != 0)
@@ -133,7 +152,7 @@ void server(void* data)
 									continue;
 								if (received.inputs[i].id <= latest_id)
 									continue; // don't reprocess inputs already processed
-								struct InputFrame cur_input = received.inputs[i];
+								InputFrame cur_input = received.inputs[i];
 								gs.players[player_slot].input.movement = cur_input.movement;
 								gs.players[player_slot].input.hand_pos = cur_input.hand_pos;
 
@@ -143,10 +162,11 @@ void server(void* data)
 								if (cur_input.seat_action)
 								{
 									gs.players[player_slot].input.seat_action = cur_input.seat_action;
+									gs.players[player_slot].input.grid_hand_pos_local_to = cur_input.grid_hand_pos_local_to;
 								}
 								if (cur_input.dobuild)
 								{
-									gs.players[player_slot].input.grid_to_build_on = cur_input.grid_to_build_on;
+									gs.players[player_slot].input.grid_hand_pos_local_to = cur_input.grid_hand_pos_local_to;
 									gs.players[player_slot].input.dobuild = cur_input.dobuild;
 									gs.players[player_slot].input.build_type = cur_input.build_type;
 									gs.players[player_slot].input.build_rotation = cur_input.build_rotation;

types.h

@@ -98,7 +98,7 @@ static bool entityids_same(EntityID a, EntityID b)
 
 // when updated, must update serialization, AND comparison
 // function in main.c
-struct InputFrame
+typedef struct
 {
 	uint64_t tick;
 	size_t id; // each input has unique, incrementing, I.D, so server doesn't double process inputs. Inputs to server should be ordered from 0-max like biggest id-smallest. This is done so if packet loss server still processes input
@@ -106,13 +106,13 @@ struct InputFrame
 
 	bool seat_action;
 	EntityID seat_to_inhabit;
-	V2 hand_pos; // world coords, world star!
+	V2 hand_pos;
+	EntityID grid_hand_pos_local_to; // when not null, hand_pos is local to this grid. this prevents bug where 
 
 	bool dobuild;
 	enum BoxType build_type;
 	enum CompassRotation build_rotation;
-	EntityID grid_to_build_on;
-};
+} InputFrame;
 
 typedef struct Entity
 {
@@ -158,7 +158,7 @@ typedef struct Player
 {
 	bool connected;
 	EntityID entity;
-	struct InputFrame input;
+	InputFrame input;
 } Player;
 // gotta update the serialization functions when this changes
 typedef struct GameState
@@ -215,7 +215,7 @@ typedef struct ServerToClient
 
 struct ClientToServer
 {
-	struct InputFrame inputs[INPUT_BUFFER];
+	InputFrame inputs[INPUT_BUFFER];
 };
 
 // server
@@ -235,6 +235,7 @@ Entity* get_entity(struct GameState* gs, EntityID id);
 Entity* new_entity(struct GameState* gs);
 EntityID get_id(struct GameState* gs, Entity* e);
 V2 entity_pos(Entity* e);
+void entity_set_rotation(Entity* e, float rot);
 void entity_set_pos(Entity* e, V2 pos);
 float entity_rotation(Entity* e);
 #define BOX_CHAIN_ITER(gs, cur, starting_box) for (Entity *cur = get_entity(gs, starting_box); cur != NULL; cur = get_entity(gs, cur->next_box))
@@ -409,6 +410,15 @@ static Color colhex(int r, int g, int b)
 	};
 }
 
+static Color colhexcode(int hexcode)
+{
+	// 0x020509;
+	int r = (hexcode >> 16) & 0xFF;
+	int g = (hexcode >> 8) & 0xFF;
+	int b = (hexcode >> 0) & 0xFF;
+	return colhex(r, g, b);
+}
+
 static Color Collerp(Color a, Color b, float factor)
 {
 	Color to_return = { 0 };