Add target draw and collision

include/header.h

@@ -88,6 +88,11 @@ struct squishy_square
     Vector2 right_vertices[BEZIER_POINTS+1];
 };
 
+struct target_obj
+{
+    double radius;
+    struct kinematic_obj kinematic;
+};
 // Object functions, kinematics.c
 struct kinematic_obj init_kinematic_obj(int width, int height);
 void move(struct kinematic_obj *obj, Vector2 acceleration);
@@ -101,6 +106,7 @@ double mag(Vector2 vec);
 int sign(double val);
 Vector2 dir(Vector2 vec);
 void approach(double *val, double target, float f);
+Vector2 center(Rectangle rect);
 
 // Linked list, linked_list.c
 void create_list(void);
@@ -123,7 +129,7 @@ struct player_obj init_player_obj();
 void player_input_check(struct player_obj *player);
 
 //Target stuff, target.c
-struct kinematic_obj init_target();
+struct target_obj init_target();
 
 //Debug stuff, debug.c
 void state_string(char *str, enum PLAYER_STATE state);

main.c

@@ -24,6 +24,7 @@
 
 #include "header.h"
 struct kinematic_obj_node *kinematic_HEAD = NULL;
+struct kinematic_obj_node *target_HEAD = NULL;
 int PLAYER_ACCEL = 1500;
 int JUMP_ACCEL = 15000;
 int JUMP_SPD = 350;
@@ -60,8 +61,6 @@ int main()
     struct kinematic_obj tile6 = init_kinematic_obj(50, 300);
     struct kinematic_obj tile7 = init_kinematic_obj(50, 300);
 
-    struct kinematic_obj target = init_target(50, 300);
-
     set_position(&player.kinematic, 400, 100);
     set_position(&tile, -50, 380);
     set_position(&tile2, 100, 280);
@@ -81,6 +80,11 @@ int main()
     add_node(&tile6, &kinematic_HEAD);
     add_node(&tile7, &kinematic_HEAD);
     add_node(&player.kinematic, &kinematic_HEAD);
+
+
+    struct target_obj target = init_target(50, 300);
+    set_position(&target.kinematic, 150, 380);
+    add_node(&target.kinematic, &target_HEAD);
     
     SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
     //--------------------------------------------------------------------------------------
@@ -110,6 +114,11 @@ int main()
                     DrawRectangleLinesEx(current->obj->rect, 1, BLACK);
                     current = current->next;
                 }
+                current = target_HEAD;
+                while(current){
+                    DrawCircle(current->obj->pos.x, current->obj->pos.y, current->obj->ori_width, BLACK);
+                    current = current->next;
+                }
                 DrawFPS(0,0);
                 state_string(current_state, player.state);
                 DrawText(current_state, 250, 0, 12, BLACK);
@@ -127,6 +136,7 @@ int main()
     // De-Initialization
     //--------------------------------------------------------------------------------------
     free_list(&kinematic_HEAD);
+    free_list(&target_HEAD);
     free_afterimages(&player);
     CloseWindow();        // Close window and OpenGL context
     //--------------------------------------------------------------------------------------

obj/kinematics.c

@@ -103,13 +103,6 @@ bool place_meeting(struct kinematic_obj *obj, Vector2 dir){
     return false;
 }
 
-Vector2 center(Rectangle rect){
-    return (Vector2){
-        .x = rect.x + rect.width/2, 
-        .y = rect.y + rect.height/2
-    };
-}
-
 void adjust_hitbox(struct kinematic_obj *obj){
     approach(&obj->dim_reduction[0], obj->set_dim_reduction[0], 0.2);
     approach(&obj->dim_reduction[1], obj->set_dim_reduction[1], 0.2);

obj/player.c

@@ -34,6 +34,8 @@ const unsigned int afterimage_frames = 10;
 static enum PLAYER_STATE state_buffer = IDLE;
 unsigned int PLAYER_SIZE = 30;
 
+extern struct kinematic_obj_node *target_HEAD;
+
 // The player FSM
 void player_input_check(struct player_obj *player){
     Vector2 accel = (Vector2){

obj/target.c

@@ -1,5 +1,47 @@
 #include "header.h"
+#include <raymath.h>
+#include <math.h>
+// Target is circular, thus a kinematic obj has w=h
+struct target_obj init_target(){
+    return (struct target_obj){
+        .radius = 12,
+        .kinematic = init_kinematic_obj(12, 12)
+    };
+}
 
-struct kinematic_obj init_target(){
-    return init_kinematic_obj(25, 25);
+bool collide_target(struct kinematic_obj *obj, struct target_obj *target){
+    /* The method is based off SAT
+    */
+    Vector2 obj_center = center(obj->rect);
+    Vector2 target_center = center(target->kinematic.rect);
+
+    float dist = Vector2Distance(obj_center, target_center);
+
+    if (dist < target->radius)
+        return true;
+
+    double max_dim = fmax(obj->rect.width, obj->rect.height);
+    if (dist > max_dim + target->radius)
+        return false;
+
+    Vector2 n = Vector2Subtract(target_center, obj_center);
+    n = Vector2Normalize(n);
+
+    Vector2 pos_check = obj->pos;
+    double obj_proj1 = Vector2DotProduct(pos_check, n);
+    pos_check.x += obj->rect.width;
+    double obj_proj2 = Vector2DotProduct(pos_check, n);
+    pos_check.y += obj->rect.height;
+    double obj_proj3 = Vector2DotProduct(pos_check, n);
+    pos_check.x -= obj->rect.width;
+    double obj_proj4 = Vector2DotProduct(pos_check, n);
+
+    double min_proj = fmin(fmin(fmin(obj_proj1, obj_proj2), obj_proj3), obj_proj4);
+    double max_proj = fmax(fmax(fmax(obj_proj1, obj_proj2), obj_proj3), obj_proj4);
+   
+    double target_proj = Vector2DotProduct(target_center, n);
+
+    if (!(max_proj < target_proj - target->radius) && !(min_proj > target_proj + target->radius))
+        return true;
+    return false;
 }

utilities/math.c

@@ -7,4 +7,11 @@ int sign(double val){
 
 void approach(double *val, double target, float f){
     *val += (target - *val) * f;
+}
+
+Vector2 center(Rectangle rect){
+    return (Vector2){
+        .x = rect.x + rect.width/2, 
+        .y = rect.y + rect.height/2
+    };
 }