fix writing canvas past bounds

src/canvas.c

@@ -4,6 +4,7 @@
  * TODO: assert get/set positions are within canvas sizes?
  */
 #include "canvas.h"
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -81,7 +82,11 @@ void canvas_schari(Canvas *canvas, int i, char c) {
 /* Get the character at position (x, y)
  *
  */
-char canvas_gcharyx(Canvas *canvas, int y, int x) { return canvas->rows[y][x]; }
+char canvas_gcharyx(Canvas *canvas, int y, int x) {
+  assert(x <= canvas->num_cols);
+  assert(y <= canvas->num_rows);
+  return canvas->rows[y][x];
+}
 
 /* Get the character at index i
  *

src/cursor.c

@@ -23,7 +23,11 @@ void cursor_move_up(Cursor *cursor, View *view) {
 }
 
 void cursor_move_down(Cursor *cursor, View *view) {
-  if (cursor->y == view_max_y) {
+  if (cursor->y + 1 >= view->canvas->num_rows - view->y) {
+    cursor->y = view->canvas->num_rows - view->y - 1;
+    return;
+  }
+  if (cursor->y + 1 >= view_max_y) {
     view_move_down(view);
     return;
   }
@@ -39,7 +43,11 @@ void cursor_move_left(Cursor *cursor, View *view) {
 }
 
 void cursor_move_right(Cursor *cursor, View *view) {
-  if (cursor->x == view_max_x) {
+  if (cursor->x >= view->canvas->num_cols - view->x - 1) {
+    cursor->x = view->canvas->num_cols - view->x - 1;
+    return;
+  }
+  if (cursor->x + 1 >= view_max_x) {
     view_move_right(view);
     return;
   }

src/fe_modes.c

@@ -16,6 +16,7 @@ int (*mode_functions[])(State *, WINDOW *, WINDOW *) = {
     mode_picker,
     mode_insert,
     mode_pan,
+    mode_free_line,
 };
 
 //////////////////////////////
@@ -38,6 +39,50 @@ Mode_ID return_to_canvas(int input_ch) {  // State?
   return LAST;
 }
 
+////////////////////////////
+// SPECIFC MODE FUNCTIONS //
+////////////////////////////
+
+/* free_line_arrows_to_char
+ *
+ * Takes the current and previous arrow directions, and returns the
+ * appropriate character, including diagonals.
+ *
+ * NOTE: Assumes that the input character is an arrow key
+ *
+ * Reference table:
+ *       ^ v > <  (current)
+ *
+ *   ^   | | / \
+ *   v   | | \ /
+ *   >   \ / - -
+ *   <   / \ - -
+ * (last)
+ */
+int free_line_arrows_to_char(int last_arrow, int current_arrow) {
+  char horizontal = '-';
+  char vertical = '|';
+  char diag_up = '/';
+  char diag_down = '\\';
+
+  if ((last_arrow == KEY_UP || current_arrow == KEY_DOWN) &&
+      (last_arrow == KEY_DOWN || current_arrow == KEY_UP)) {
+    // arrows are vertically parallel (top left quarter of truth table)
+    return vertical;
+  } else if ((last_arrow == KEY_LEFT || current_arrow == KEY_RIGHT) &&
+             (last_arrow == KEY_RIGHT || current_arrow == KEY_LEFT)) {
+    // arrows are horizontally parallel (bottom right quarter of truth table)
+    return horizontal;
+  } else if ((last_arrow == KEY_UP && current_arrow == KEY_RIGHT) ||
+             (last_arrow == KEY_DOWN && current_arrow == KEY_LEFT) ||
+             (last_arrow == KEY_LEFT && current_arrow == KEY_DOWN) ||
+             (last_arrow == KEY_RIGHT && current_arrow == KEY_UP)) {
+    return diag_up;
+  } else {
+    return diag_down;
+  }
+}
+
 ////////////////////
 // MODE FUNCTIONS //
 ////////////////////
@@ -114,7 +159,6 @@ int mode_pan(State *state, WINDOW *canvas_win, WINDOW *status_win) {
     state->current_mode = MODE_PICKER;
     return 0;
   }
-
   if ((state->ch_in == KEY_LEFT) || (state->ch_in == KEY_RIGHT) ||
       (state->ch_in == KEY_UP) || (state->ch_in == KEY_DOWN)) {
     view_pan_ch(state->ch_in, state->view);
@@ -123,6 +167,42 @@ int mode_pan(State *state, WINDOW *canvas_win, WINDOW *status_win) {
   return 0;
 }
 
-////////////////////////////
-// SPECIFC MODE FUNCTIONS //
-////////////////////////////
+/* mode_free_line
+ *
+ * Move with arrows and insert character with keyboard.
+ */
+int mode_free_line(State *state, WINDOW *canvas_win, WINDOW *status_win) {
+  // handle mode changing
+  if (state->ch_in == KEY_TAB) {
+    // Clean up code
+    state->last_canvas_mode = MODE_INSERT;
+
+    state->current_mode = MODE_PICKER;
+    return 0;
+  }
+
+  // free line behavior
+  if ((state->ch_in == KEY_LEFT) || (state->ch_in == KEY_RIGHT) ||
+      (state->ch_in == KEY_UP) || (state->ch_in == KEY_DOWN)) {
+    int current_arrow = state->ch_in;
+    int last_arrow = state->last_arrow_direction;
+
+    front_setcharcursor(free_line_arrows_to_char(last_arrow, current_arrow));
+
+    state->last_cursor->x = state->cursor->x;
+    state->last_cursor->y = state->cursor->y;
+
+    cursor_key_to_move(current_arrow, state->cursor, state->view);
+
+    state->last_arrow_direction = state->ch_in;
+  } else if (state->ch_in == KEY_BACKSPACE) {
+    cursor_key_to_move(cursor_opposite_dir(state->last_arrow_direction),
+                       state->cursor, state->view);
+    front_setcharcursor(' ');
+  }
+
+  wmove(canvas_win, cursor_y_to_canvas(state->cursor),
+        cursor_x_to_canvas(state->cursor));
+
+  return 0;
+}

src/fe_modes.h

@@ -7,6 +7,7 @@
 int mode_picker(State *state, WINDOW *canvas_win, WINDOW *status_win);
 int mode_insert(State *state, WINDOW *canvas_win, WINDOW *status_win);
 int mode_pan(State *state, WINDOW *canvas_win, WINDOW *status_win);
+int mode_free_line(State *state, WINDOW *canvas_win, WINDOW *status_win);
 
 extern int (*mode_functions[])(State *, WINDOW *, WINDOW *);
 

src/frontend.c

@@ -7,11 +7,24 @@
 #include "frontend.h"
 #include "mode_id.h"
 #include "state.h"
+#include "util.h"
+
+#include <stdio.h>
+#include <unistd.h>
 
 WINDOW *canvas_win, *status_win;
 Cursor *cursor;
 View *view;
 
+#ifdef DEBUG
+#define LOG_TO_FILE
+#endif
+
+#ifdef LOG_TO_FILE
+char *logfile_path = "out.txt";
+FILE *logfile = NULL;
+#endif
+
 /* Layout
  * ___________________________________________
  * | 0 -- X, COLS                           | canvas window
@@ -30,6 +43,19 @@ View *view;
  */
 
 int main(int argc, char *argv[]) {
+#ifdef LOG_TO_FILE
+  logfile = fopen(logfile_path, "a");
+  if (logfile == NULL) {
+    perror("logfile fopen:");
+    exit(1);
+  }
+  if (-1 == dup2(fileno(logfile), fileno(stderr))) {
+    perror("stderr dup2:");
+    exit(1);
+  }
+#endif
+  logd("Starting frontend\n");
+
   /* initialize your non-curses data structures here */
 
   (void)signal(SIGINT, finish); /* arrange interrupts to terminate */
@@ -41,7 +67,7 @@ int main(int argc, char *argv[]) {
   (void)noecho();       /* don't print on getch() */
   curs_set(2);
 
-  define_key("\r", KEY_ENTER); // Bind the <Enter> key properly
+  define_key("\r", KEY_ENTER);  // Bind the <Enter> key properly
 
   if (has_colors()) {
     setup_colors();
@@ -51,6 +77,7 @@ int main(int argc, char *argv[]) {
   status_win = create_status_win();
 
   cursor = cursor_new();
+  Cursor *last_cursor = cursor_new();
   Canvas *canvas = canvas_new_blank(1000, 1000);
 
   view = view_new_startpos(canvas, 300, 300);
@@ -59,22 +86,28 @@ int main(int argc, char *argv[]) {
   keypad(canvas_win, TRUE);
   keypad(status_win, TRUE);
 
+  // update the screen size first. This clears the status window on any changes
+  // (including the first time it's run), so refreshing after updating the
+  // status will clear it otherwise
+  update_screen_size();
+
   char test_msg[] = "Test mode";
   print_status(test_msg, status_win);
 
-  // Move cursor to starting location and redraw
-  wmove(canvas_win, cursor_y_to_canvas(cursor), cursor_x_to_canvas(cursor));
-  wrefresh(status_win);
-  wrefresh(canvas_win);  // Refresh Canvas last so it gets the cursor
+  // Move cursor to starting location and redraw canvases
+  refresh_screen();
 
   //// Main loop
   State new_state = {
       .ch_in = 0,
       .cursor = cursor,
       .current_mode = MODE_INSERT,
+      // .current_mode = MODE_FREE_LINE,
+
       .last_arrow_direction = KEY_RIGHT,
       .last_canvas_mode = MODE_INSERT,
       .view = view,
+      .last_cursor = last_cursor,
   };
   State *state = &new_state;
 
@@ -83,8 +116,6 @@ int main(int argc, char *argv[]) {
 
     mode_functions[state->current_mode](state, canvas_win, status_win);
 
-    update_screen_size(canvas_win, status_win, cursor);
-
     refresh_screen();
   }
 
@@ -115,12 +146,34 @@ void front_setcharcursor(char ch) {
 }
 
 void redraw_canvas_win() {
-  for (int x = 0; x < view_max_x; x++) {
-    for (int y = 0; y < view_max_y; y++) {
+  // find max ranges to draw canvas
+  int max_x = view_max_x;
+  int max_y = view_max_y;
+
+  if (max_x >= view->canvas->num_cols - view->x)
+    (max_x = view->canvas->num_cols - view->x);
+  if (max_y >= view->canvas->num_rows - view->y)
+    (max_y = view->canvas->num_rows - view->y);
+
+  // draw canvas onto window
+  for (int x = 0; x < max_x; x++) {
+    for (int y = 0; y < max_y; y++) {
       mvwaddch(canvas_win, y + 1, x + 1,
                canvas_gcharyx(view->canvas, y + view->y, x + view->x));
     }
   }
+
+  // draw fill in rest of window
+  for (int x = max_x; x < view_max_x; x++) {
+    for (int y = 0; y < view_max_y; y++) {
+      mvwaddch(canvas_win, y + 1, x + 1, 'X');
+    }
+  }
+  for (int y = max_y; y < view_max_y; y++) {
+    for (int x = 0; x < view_max_x; x++) {
+      mvwaddch(canvas_win, y + 1, x + 1, 'X');
+    }
+  }
 }
 
 void refresh_screen() {
@@ -218,6 +271,10 @@ void finish(int sig) {
   endwin();
 
   /* do your non-curses wrapup here */
-
+#ifdef LOG_TO_FILE
+  if (logfile != NULL) {
+    fclose(logfile);
+  }
+#endif
   exit(0);
 }

src/frontend.h

@@ -7,6 +7,7 @@
 
 #define KEY_TAB '\t'
 #define KEY_SHIFT_TAB KEY_BTAB
+// TODO: Understand delete/backspace on mac
 
 void finish(int sig);
 void setup_colors();

src/mode_id.h

@@ -9,6 +9,7 @@ typedef enum {
   MODE_PICKER,
   MODE_INSERT,
   MODE_PAN,
+  MODE_FREE_LINE,
 
   // ^ add your mode above
   LAST,  // used to get number of elements

src/state.h

@@ -19,6 +19,7 @@ typedef struct {
   Mode_ID last_canvas_mode;
   int last_arrow_direction;
   View *view;
+  Cursor *last_cursor;
 } State;
 
 #endif

src/util.h

@@ -0,0 +1,17 @@
+#ifndef util_h
+#define util_h
+
+#include <stdio.h>
+
+// printf to stderr
+#define eprintf(...) fprintf(stderr, __VA_ARGS__)
+
+#ifdef DEBUG
+// log to stderr if DEBUG is defined
+#define logd(...) eprintf(__VA_ARGS__)
+#else
+// do nothing
+#define logd(...)
+#endif
+
+#endif

src/view.c

@@ -23,7 +23,7 @@ void view_move_up(View *view) {
 }
 
 void view_move_down(View *view) {
-  if (view->y - view_max_y == view->canvas->num_rows) {
+  if (view->y + view_max_y > view->canvas->num_rows) {
     return;
   }
   view->y++;
@@ -37,7 +37,7 @@ void view_move_left(View *view) {
 }
 
 void view_move_right(View *view) {
-  if (view->x + view_max_x == view->canvas->num_cols) {
+  if (view->x + view_max_x > view->canvas->num_cols) {
     return;
   }
   view->x++;

src/view.h

@@ -6,8 +6,8 @@
 #include "canvas.h"
 
 #define STATUS_HEIGHT 2  // not including borders
-#define view_max_x (COLS - 3)
-#define view_max_y (LINES - 4 - STATUS_HEIGHT)
+#define view_max_x (COLS - 2)
+#define view_max_y (LINES - 3 - STATUS_HEIGHT)
 
 typedef struct {
   int x, y;