Add thruster block and thruster thrust

gamestate.c

@@ -217,7 +217,8 @@ float grid_angular_velocity(struct Grid *grid)
 V2 box_pos(struct Box *box)
 {
     struct Grid *g = (struct Grid *)cpBodyGetUserData(cpShapeGetBody(box->shape));
-    return V2add(grid_pos(g), cp_to_v2(cpShapeGetCenterOfGravity(box->shape)));
+    V2 local_pos = cp_to_v2(cpShapeGetCenterOfGravity(box->shape));
+    return V2add(grid_pos(g), V2rotate(local_pos, grid_rotation(g)));
 }
 float box_rotation(struct Box *box)
 {
@@ -319,6 +320,10 @@ void ser_grid(char **out, struct Grid *g)
         if (exists)
         {
             ser_V2(out, cp_to_v2(cpShapeGetCenterOfGravity(g->boxes[i].shape)));
+
+            ser_int(out, g->boxes[i].type); // @Robust separate enum serialization that checks for out of bounds enum
+            ser_int(out, g->boxes[i].rotation);
+            ser_float(out, g->boxes[i].thrust);
             ser_float(out, g->boxes[i].damage);
         }
     }
@@ -353,6 +358,10 @@ void des_grid(char **in, struct Grid *g, struct GameState *gs)
             V2 pos = {0};
             des_V2(in, &pos);
             box_new(&g->boxes[i], gs, g, pos);
+
+            des_int(in, (int *)&g->boxes[i].type);
+            des_int(in, (int *)&g->boxes[i].rotation);
+            des_float(in, &g->boxes[i].thrust);
             des_float(in, &g->boxes[i].damage);
         }
     }
@@ -529,6 +538,22 @@ static float hash11(float p)
     return fract(p);
 }
 
+V2 thruster_direction(struct Box *box)
+{
+    assert(box->type == BoxThruster);
+    V2 to_return = (V2){.x = 1.0f, .y = 0.0f};
+
+    to_return = V2rotate(to_return, rotangle(box->rotation));
+    to_return = V2rotate(to_return, box_rotation(box));
+
+    return to_return;
+}
+
+V2 thruster_force(struct Box *box)
+{
+    return V2scale(thruster_direction(box), -box->thrust * THRUSTER_FORCE);
+}
+
 uint64_t tick(struct GameState *gs)
 {
     return (uint64_t)floor(gs->time / ((double)TIMESTEP));
@@ -618,6 +643,11 @@ void process(struct GameState *gs, float dt)
 
         // process movement
         {
+            // no cheating by making movement bigger than length 1
+            if (V2length(p->movement) != 0.0f)
+            {
+                p->movement = V2scale(V2normalize(p->movement), clamp(V2length(p->movement), 0.0f, 1.0f));
+            }
             if (p->currently_inhabiting_index == -1)
             {
                 // @Robust make sure movement vector is normalized so player can't cheat
@@ -628,10 +658,32 @@ void process(struct GameState *gs, float dt)
             {
                 struct Grid *g = &gs->grids[p->currently_inhabiting_index];
                 V2 target_new_pos = V2lerp(p->pos, grid_com(g), dt * 20.0f);
-                p->vel = V2scale(V2sub(target_new_pos, p->pos), 1.0f / dt);
-                cpBodyApplyForceAtWorldPoint(g->body, v2_to_cp(V2scale(p->movement, 5.0f)), v2_to_cp(grid_com(g)));
+                p->vel = V2scale(V2sub(target_new_pos, p->pos), 1.0f / dt); // set vel correctly so newly built grids have the correct velocity copied from it
+
+                // set thruster forces from movement
+                float thruster_spice_consumption = 0.0f;
+                {
+                    V2 target_direction = {0};
+                    if (V2length(p->movement) > 0.0f)
+                    {
+                        target_direction = V2normalize(p->movement);
+                    }
+                    for (int ii = 0; ii < MAX_BOXES_PER_GRID; ii++)
+                    {
+                        SKIPNULL(g->boxes[ii].shape);
+                        if (g->boxes[ii].type != BoxThruster)
+                            continue;
+
+                        float wanted_thrust = -V2dot(target_direction, thruster_direction(&g->boxes[ii]));
+                        wanted_thrust = clamp01(wanted_thrust);
+                        thruster_spice_consumption += wanted_thrust;
+                        g->boxes[ii].thrust = wanted_thrust;
+                    }
+                }
+
+                // cpBodyApplyForceAtWorldPoint(g->body, v2_to_cp(V2scale(p->movement, 5.0f)), v2_to_cp(grid_com(g)));
                 // bigger the ship, the more efficient the spice usage
-                p->spice_taken_away += dt * 0.15f / (cpBodyGetMass(g->body) * 2.0f) * V2length(p->movement);
+                p->spice_taken_away += dt * thruster_spice_consumption * THRUSTER_SPICE_PER_SECOND;
             }
             p->pos = V2add(p->pos, V2scale(p->vel, dt));
         }
@@ -702,5 +754,19 @@ void process(struct GameState *gs, float dt)
         p->spice_taken_away = clamp01(p->spice_taken_away);
     }
 
+    // add thrust from thruster blocks
+    for (int i = 0; i < MAX_GRIDS; i++)
+    {
+        SKIPNULL(gs->grids[i].body);
+        for (int ii = 0; ii < MAX_BOXES_PER_GRID; ii++)
+        {
+            SKIPNULL(gs->grids[i].boxes[ii].shape);
+            if (gs->grids[i].boxes[ii].type == BoxThruster)
+            {
+                cpBodyApplyForceAtWorldPoint(gs->grids[i].body, v2_to_cp(thruster_force(&gs->grids[i].boxes[ii])), v2_to_cp(box_pos(&gs->grids[i].boxes[ii])));
+            }
+        }
+    }
+
     cpSpaceStep(gs->space, dt);
 }

main.c

@@ -39,8 +39,39 @@ static ENetHost *client;
 static ENetPeer *peer;
 static float zoom_target = 300.0f;
 static float zoom = 300.0f;
-static sg_image image_box;
+static sg_image image_hullpiece;
+static sg_image image_thruster;
 
+static sg_image load_image(const char *path)
+{
+    sg_image to_return = sg_alloc_image();
+
+    int x = 0;
+    int y = 0;
+    int comp = 0;
+    const int desired_channels = 4;
+    stbi_set_flip_vertically_on_load(true);
+    stbi_uc *image_data = stbi_load(path, &x, &y, &comp, desired_channels);
+    if (!image_data)
+    {
+        fprintf(stderr, "Failed to load image: %s\n", stbi_failure_reason());
+        exit(-1);
+    }
+    sg_init_image(to_return, &(sg_image_desc){
+                                 .width = x,
+                                 .height = y,
+                                 .pixel_format = SG_PIXELFORMAT_RGBA8,
+                                 .min_filter = SG_FILTER_NEAREST,
+                                 .mag_filter = SG_FILTER_NEAREST,
+                                 .data.subimage[0][0] = {
+                                     .ptr = image_data,
+                                     .size = (size_t)(x * y * desired_channels),
+                                 }});
+
+    stbi_image_free(image_data);
+
+    return to_return;
+}
 static void init(void)
 {
     // @BeforeShip make all fprintf into logging to file, warning dialog grids on failure instead of exit(-1), replace the macros in sokol with this as well, like assert
@@ -65,30 +96,8 @@ static void init(void)
 
     // image loading
     {
-        image_box = sg_alloc_image();
-
-        int x = 0;
-        int y = 0;
-        int comp = 0;
-        const int desired_channels = 4;
-        stbi_uc *image_data = stbi_load("loaded/box.png", &x, &y, &comp, desired_channels);
-        if (!image_data)
-        {
-            fprintf(stderr, "Failed to load image: %s\n", stbi_failure_reason());
-            exit(-1);
-        }
-        sg_init_image(image_box, &(sg_image_desc){
-                                     .width = x,
-                                     .height = y,
-                                     .pixel_format = SG_PIXELFORMAT_RGBA8,
-                                     .min_filter = SG_FILTER_NEAREST,
-                                     .mag_filter = SG_FILTER_NEAREST,
-                                     .data.subimage[0][0] = {
-                                         .ptr = image_data,
-                                         .size = (size_t)(x * y * desired_channels),
-                                     }});
-
-        stbi_image_free(image_data);
+        image_hullpiece = load_image("loaded/hullpiece.png");
+        image_thruster = load_image("loaded/thruster.png");
     }
 
     // socket initialization
@@ -139,20 +148,26 @@ static void init(void)
     }
 }
 
-static void drawbox(V2 gridpos, float rot, V2 bpos, float damage, bool offset_from_grid)
+static void drawbox(V2 boxpos, float rot, float damage, enum BoxType type, enum Rotation rotation)
 {
     float halfbox = BOX_SIZE / 2.0f;
     sgp_push_transform();
-    if (offset_from_grid)
-    {
-        sgp_rotate_at(rot, gridpos.x, gridpos.y);
-    }
-    else
+    sgp_rotate_at(rot, boxpos.x, boxpos.y);
+    
+    switch(type)
     {
-        sgp_rotate_at(rot, bpos.x, bpos.y);
+        case BoxHullpiece:
+            sgp_set_image(0, image_hullpiece);
+            break;
+        case BoxThruster:
+            sgp_set_image(0, image_thruster);
+            break;
+        default:
+            Log("Unknown image for box type of type %d\n", type);
+            break;
     }
-    sgp_set_image(0, image_box);
-    sgp_draw_textured_rect(bpos.x - halfbox, bpos.y -halfbox, BOX_SIZE, BOX_SIZE);
+    sgp_rotate_at( rotangle(rotation),boxpos.x,boxpos.y);
+    sgp_draw_textured_rect(boxpos.x - halfbox, boxpos.y - halfbox, BOX_SIZE, BOX_SIZE);
     sgp_reset_image(0);
 
     /*sgp_draw_line(bpos.x - halfbox, bpos.y - halfbox, bpos.x - halfbox, bpos.y + halfbox); // left
@@ -165,7 +180,7 @@ static void drawbox(V2 gridpos, float rot, V2 bpos, float damage, bool offset_fr
     if (damage > 0.0f)
     {
         sgp_set_color(0.5f, 0.1f, 0.1f, damage);
-        sgp_draw_filled_rect(bpos.x - halfbox, bpos.y - halfbox, BOX_SIZE, BOX_SIZE);
+        sgp_draw_filled_rect(boxpos.x - halfbox, boxpos.y - halfbox, BOX_SIZE, BOX_SIZE);
     }
 
     sgp_pop_transform();
@@ -438,7 +453,6 @@ static void frame(void)
 
         float halfbox = BOX_SIZE / 2.0f;
 
-        
         // mouse
         if (mouse_frozen)
         {
@@ -449,7 +463,7 @@ static void frame(void)
         // building preview
         {
             sgp_set_color(0.5f, 0.5f, 0.5f, (sin(time * 9.0f) + 1.0) / 3.0f + 0.2);
-            drawbox(build_preview.grid_pos, build_preview.grid_rotation, build_preview.pos, 0.0f, false);
+            drawbox(build_preview.pos, build_preview.grid_rotation, 0.0f, BoxHullpiece, Right);
         }
 
         // grids
@@ -463,7 +477,14 @@ static void frame(void)
                     SKIPNULL(g->boxes[ii].shape);
                     struct Box *b = &g->boxes[ii];
                     sgp_set_color(0.5f, 0.5f, 0.5f, 1.0f);
-                    drawbox(grid_pos(g), grid_rotation(g), box_pos(b), b->damage, true);
+                    // debug draw force vectors for thrusters
+                    if (false){
+                        if(b->type == BoxThruster) {
+                            dbg_rect(box_pos(b));
+                            dbg_line(box_pos(b), V2add(box_pos(b), V2scale(thruster_force(b), -1.0f)));
+                        }
+                    }
+                    drawbox(box_pos(b), grid_rotation(g), b->damage, b->type, b->rotation);
                 }
                 sgp_set_color(1.0f, 0.0f, 0.0f, 1.0f);
                 V2 vel = grid_vel(&gs.grids[i]);
@@ -499,7 +520,6 @@ static void frame(void)
             // sgp_draw_line(grid_pos(p->grid).x, grid_pos(p->grid).y, to.x, to.y);
         }
 
-
         // gold target
         set_color(GOLD);
         sgp_draw_filled_rect(gs.goldpos.x, gs.goldpos.y, 0.1f, 0.1f);

server.c

@@ -22,6 +22,11 @@ void server(void *data)
         box_new(&gs.grids[0].boxes[1], &gs, &gs.grids[0], (V2){0, BOX_SIZE});
         box_new(&gs.grids[0].boxes[2], &gs, &gs.grids[0], (V2){0, BOX_SIZE*2.0});
         box_new(&gs.grids[0].boxes[3], &gs, &gs.grids[0], (V2){BOX_SIZE, BOX_SIZE*2.0});
+        gs.grids[0].boxes[3].type = BoxThruster;
+        gs.grids[0].boxes[3].rotation = Right;
+        box_new(&gs.grids[0].boxes[4], &gs, &gs.grids[0], (V2){0, BOX_SIZE*3.0});
+        gs.grids[0].boxes[4].type = BoxThruster;
+        gs.grids[0].boxes[4].rotation = Up;
 
         grid_new(&gs.grids[1], &gs, (V2){.x = -BOX_SIZE*1.5, .y = 0.0});
         box_new(&gs.grids[1].boxes[0], &gs, &gs.grids[1], (V2){0});

types.h

@@ -8,6 +8,9 @@
 #define BUILD_BOX_SNAP_DIST_TO_SHIP 0.2f
 #define MAX_BOXES_PER_GRID 32
 #define BOX_MASS 1.0f
+#define THRUSTER_FORCE 2.0f
+#define THRUSTER_SPICE_PER_SECOND 0.1f
+
 #define TIMESTEP (1.0f / 60.0f) // not required to simulate at this, but this defines what tick the game is on
 #define TIME_BETWEEN_INPUT_PACKETS (1.0f / 20.0f)
 #define SERVER_PORT 2551
@@ -19,6 +22,7 @@
 // @Robust remove this include somehow, needed for sqrt and cos
 #include <math.h>
 #include <stdint.h> // tick is unsigned integer
+#include <stdio.h> // logging on errors for functions
 
 // including headers from headers bad
 #ifndef SOKOL_GP_INCLUDED
@@ -80,7 +84,9 @@ struct GameState
         float goldness;         // how much the player is a winner
 
         // input
-        V2 movement;
+        // @Cleanup make this a frameinput struct instead of copying over all the fields like this
+
+        V2 movement; // can be at maximum length 1.0
         bool inhabit;
 
         // if grid_index != -1, this is in local coordinates to the grid
@@ -98,12 +104,54 @@ struct GameState
 
         struct Box
         {
+            enum BoxType
+            {
+                BoxHullpiece,
+                BoxThruster,
+            } type;
+            enum Rotation
+            {
+                Right,
+                Down,
+                Left,
+                Up,
+            } rotation;
+            
+            // thruster
+            float thrust; // must be between 0 and 1
+
             cpShape *shape;
             float damage;
         } boxes[MAX_BOXES_PER_GRID]; // @Robust this needs to be dynamically allocated, huge disparity in how many blocks a body can have...
     } grids[MAX_GRIDS];
 };
 
+#define PI 3.14159f
+
+// returns in radians
+static float rotangle(enum Rotation rot)
+{
+    switch(rot)
+    {
+        case Right:
+            return 0.0f;
+            break;
+        case Down:
+            return -PI/2.0f;
+            break;
+        case Left:
+            return -PI;
+            break;
+        case Up:
+            return -3.0f * PI/2.0f;
+            break;
+        default:
+            Log("Unknown rotation %d\n", rot);
+            return -0.0f;
+            break;
+    }
+}
+
 struct ServerToClient
 {
     struct GameState *cur_gs;
@@ -154,6 +202,10 @@ void box_new(struct Box *to_modify, struct GameState *gs, struct Grid *grid, V2
 V2 box_pos(struct Box *box);
 float box_rotation(struct Box *box);
 
+// thruster
+V2 thruster_direction(struct Box *box);
+V2 thruster_force(struct Box *box);
+
 // debug draw
 void dbg_drawall();
 void dbg_line(V2 from, V2 to);
@@ -166,7 +218,6 @@ void dbg_rect(V2 center);
 
 // all the math is static so that it can be defined in each compilation unit its included in
 
-#define PI 3.14159f
 
 static V2 V2add(V2 a, V2 b)
 {
@@ -244,9 +295,9 @@ static inline float clamp01(float f)
 
 static inline float clamp(float f, float minimum, float maximum)
 {
-    if(f < minimum)
+    if (f < minimum)
         return minimum;
-    if(f > maximum)
+    if (f > maximum)
         return maximum;
     return f;
 }