Implemented game#valid_move.

lib/display.c

@@ -66,8 +66,6 @@ void erase_stack(struct stack *stack) {
   box(empty_stack, 0, 0);
   wrefresh(empty_stack);
   delwin(empty_stack);
-
-  return;
 }
 
 void draw_empty_stacks() {
@@ -198,7 +196,16 @@ void draw_card(struct card *card) {
 }
 
 void draw_stack(struct stack *stack) {
-  if (!empty(stack)) {
+  erase_stack(stack);
+  if (empty(stack)) {
+    WINDOW *empty_stack = newwin(FRAME_HEIGHT,
+                                 FRAME_WIDTH,
+                                 stack->card->frame->start_y,
+                                 stack->card->frame->start_x);
+    box(empty_stack, 0, 0);
+    wrefresh(empty_stack);
+    delwin(empty_stack);
+  } else {
     if (maneuvre_stack(stack)) {
       struct stack *reversed_stack = reverse(stack);
 

lib/game.c

@@ -8,23 +8,82 @@
 #include "util.h"
 #include "game.h"
 
+bool stock_stack(struct stack *stack) {
+  return(stack && stack->card && stack->card->frame &&
+         (stack->card->frame->start_y == STOCK_STARTING_Y) &&
+         (stack->card->frame->start_x == STOCK_STARTING_X));
+}
+
+bool waste_pile_stack(struct stack *stack) {
+  return(stack && stack->card && stack->card->frame &&
+         (stack->card->frame->start_y == WASTE_PILE_STARTING_Y) &&
+         (stack->card->frame->start_x == WASTE_PILE_STARTING_X));
+}
+
+bool foundation_stack(struct stack *stack) {
+  return(stack && stack->card && stack->card->frame &&
+         stack->card->frame->start_y == FOUNDATION_STARTING_Y &&
+         (stack->card->frame->start_x == FOUNDATION_0_STARTING_X ||
+          stack->card->frame->start_x == FOUNDATION_1_STARTING_X ||
+          stack->card->frame->start_x == FOUNDATION_2_STARTING_X ||
+          stack->card->frame->start_x == FOUNDATION_3_STARTING_X));
+}
+
 bool maneuvre_stack(struct stack *stack) {
-  return(stack->card->frame->start_y >= MANEUVRE_STACKS_STARTING_Y);
+  return(stack && stack->card && stack->card->frame &&
+         stack->card->frame->start_y >= MANEUVRE_STACKS_STARTING_Y &&
+         (stack->card->frame->start_x == MANEUVRE_0_STARTING_X ||
+          stack->card->frame->start_x == MANEUVRE_1_STARTING_X ||
+          stack->card->frame->start_x == MANEUVRE_2_STARTING_X ||
+          stack->card->frame->start_x == MANEUVRE_3_STARTING_X ||
+          stack->card->frame->start_x == MANEUVRE_4_STARTING_X ||
+          stack->card->frame->start_x == MANEUVRE_5_STARTING_X ||
+          stack->card->frame->start_x == MANEUVRE_6_STARTING_X));
+}
+
+bool valid_move(struct stack *origin, struct stack *destination) {
+  if (stock_stack(origin)) {
+    if (waste_pile_stack(destination)) {
+      return(true);
+    } else {
+      return(false);
+    }
+  } else if (waste_pile_stack(origin)) {
+    if (foundation_stack(destination) || maneuvre_stack(destination)) {
+      return(true);
+    } else {
+      return(false);
+    }
+  } else if (foundation_stack(origin)) {
+    if ((foundation_stack(destination) && origin != destination) || maneuvre_stack(destination)) {
+      return(true);
+    } else {
+      return(false);
+    }
+  } else if (maneuvre_stack(origin)) {
+    if ((maneuvre_stack(destination) && origin != destination) || foundation_stack(destination)) {
+      return(true);
+    } else {
+      return(false);
+    }
+  } else {
+    return(false);
+  }
 }
 
 void move_card(struct stack **origin, struct stack **destination) {
-  struct stack *stack = NULL;
+  struct stack *stack;
 
-  (*origin)->card->frame->start_x = (*destination)->card->frame->start_x;
-  (*origin)->card->frame->start_y = (*destination)->card->frame->start_y;
+  if (!empty(*origin)) {
+    (*origin)->card->frame->start_x = (*destination)->card->frame->start_x;
+    (*origin)->card->frame->start_y = (*destination)->card->frame->start_y;
+  }
   if (!empty(*destination) && maneuvre_stack(*destination)) {
     (*origin)->card->frame->start_y++;
   }
   if ((stack = pop(origin))) {
     push(destination, stack->card);
   }
-
-  return;
 }
 
 static void set_stacks_initial_coordinates(struct deck *deck) {

lib/game.h

@@ -34,6 +34,8 @@ extern const char *program_name;
 struct deck *deck;
 struct cursor *cursor;
 
+bool valid_move(struct stack *, struct stack *);
+bool maneuvre_stack(struct stack *);
 void move_card(struct stack **, struct stack **);
 void greet_player();
 void initialize_game();

lib/keyboard.c

@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include "card.h"
 #include "game.h"
 #include "display.h"
@@ -90,19 +91,19 @@ static void handle_card_movement(struct cursor *cursor) {
       move_cursor(cursor, RIGHT);
       break;
     case KEY_SPACEBAR:
-      if (!cursor_on_invalid_spot(cursor) &&
-          !cursor_on_stock(cursor) &&
-          !cursor_on_stack(cursor, origin)) {
-        destination = cursor_stack(cursor);
+      destination = cursor_stack(cursor);
+      if (valid_move(origin, destination)) {
         move_card(&origin, &destination);
         draw_stack(origin);
         draw_stack(destination);
       }
       return;
+    case 'q':
+    case 'Q':
+      end_curses();
+      exit(0);
     }
   }
-
-  return;
 }
 
 void handle_keyboard_event(int key) {
@@ -131,6 +132,4 @@ void handle_keyboard_event(int key) {
     }
     break;
   }
-
-  return;
 }