Move the ship about

game.c

@@ -24,6 +24,7 @@ void handle_input(Game *g) {
 
 void run_frame(Game *g) {
   handle_input(g);
+  move_player(g->player);
 }
 
 void draw_frame(Game *g) {

player.c

@@ -7,13 +7,15 @@
 //    Starship Futuretime is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 //
 //    You should have received a copy of the GNU General Public License along with Starship Futuretime. If not, see <https://www.gnu.org/licenses/>. 
+#include <stdio.h>
 #include <raylib.h>
 
 #include "player.h"
 
 void initialize_player(Player *p) {
-
   p->position = (Vector2) { 400, 300 };
+  p->velocity = (Vector2) { 0, 0 };
+  p->acceleration = (Vector2) { 0, 0 };
   p->pitch = PITCH_NEUTRAL;
   p->roll = ROLL_NEUTRAL;
 }
@@ -41,3 +43,27 @@ void draw_player(Player *p) {
 
   DrawTriangle(nose, left_wing, right_wing, DARKGRAY);
 }
+
+void move_player(Player *p) {
+  switch (p->roll) {
+  case ROLL_LEFT: p->acceleration.x = -ACCEL_X; break;
+  case ROLL_NEUTRAL: p->acceleration.x = 0; break;
+  case ROLL_RIGHT: p->acceleration.x = ACCEL_X; break;
+  }
+
+  switch (p->pitch) {
+  case PITCH_DESCENDING: p->acceleration.y = 4; break;
+  case PITCH_NEUTRAL: p->acceleration.y = 0; break;
+  case PITCH_ASCENDING: p->acceleration.y = -4; break;
+  }
+
+  p->velocity.x += p->acceleration.x;
+  p->velocity.x = CLAMP(p->velocity.x, MAX_VEL_X);
+  p->velocity.x *= DAMPING_X;
+  
+  p->velocity.y += p->acceleration.y;
+  p->velocity.y = CLAMP(p->velocity.y, MAX_VEL_Y);
+
+  p->position.x += p->velocity.x;
+  p->position.y += p->velocity.y;
+}

player.h

@@ -10,6 +10,15 @@
 #ifndef PLAYER_H
 #define PLAYER_H
 
+#define ACCEL_X 0.7
+#define MAX_VEL_X 5
+#define DAMPING_X 0.85
+#define MAX_VEL_Y 2
+
+#define MAX(a, b) ((a > b) ? a : b)
+#define MIN(a, b) ((a < b) ? a : b)
+#define CLAMP(a, b) (MIN(MAX(a, -b), b))
+
 typedef enum PlayerPitch {
   PITCH_DESCENDING,
   PITCH_NEUTRAL,
@@ -24,11 +33,15 @@ typedef enum PlayerRoll {
 
 typedef struct Player {
   Vector2 position;
+  Vector2 velocity;
+  Vector2 acceleration;
   PlayerPitch pitch;
   PlayerRoll roll;
 } Player;
 
+void initialize_player(Player *p);
 void handle_player_input(Player *p);
 void draw_player(Player *p);
+void move_player(Player *p);
 
 #endif